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Zhu X, He S, Zhang R, Kang L, Lei X, Dong W. Protective Effect and Mechanism of Autophagy in Endothelial Cell Injury Induced by Hyperoxia. Am J Perinatol 2024; 41:e2365-e2375. [PMID: 37516120 DOI: 10.1055/s-0043-1771258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/31/2023]
Abstract
OBJECTIVE Bronchopulmonary dysplasia is a chronic lung disease in premature infants with alveolar simplification and pulmonary vascular development disorder as the main pathological feature and hyperoxia as the main etiology. Autophagy is a highly conserved cytological behavior of self-degrading cellular components and is accompanied by oxidative stress. Studies have reported that autophagy is regulated by FOXO1 posttranslational modification. However, whether autophagy can be involved in the regulation of endothelial cell injury induced by hyperoxia and its mechanism are still unclear. STUDY DESIGN We have activated and inhibited autophagy in human umbilical vein endothelial cells under hyperoxia and verified the role of autophagy in endothelial cell-related functions from both positive and negative aspects. RESULTS Our research showed that the expression level of autophagy-related proteins decreased, accompanied by decreased cell migration ability and tube formation ability and increased cell reactive oxygen species level and cell permeability under hyperoxia conditions. Using an autophagy agonist alleviated hyperoxia-induced changes and played a protective role. However, inhibition of autophagy aggravated the cell damage induced by hyperoxia. Moreover, the decrease in autophagy proteins was accompanied by the upregulation of FOXO1 phosphorylation and acetylation. CONCLUSION We concluded that autophagy was a protective mechanism against endothelial cell injury caused by hyperoxia. Autophagy might participate in this process by coregulating posttranslational modifications of FOXO1. KEY POINTS · Hyperoxia induces vascular endothelial cell injury.. · Autophagy may has a protective role under hyperoxia conditions.. · FOXO1 posttranslational modification may be involved in the regulation of autophagy..
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Affiliation(s)
- Xiaodan Zhu
- Division of Neonatology, Department of Pediatrics, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Department of Perinatology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Sichuan Clinical Research Center for Birth Defects, Luzhou, China
| | - Shasha He
- Division of Neonatology, Department of Pediatrics, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Department of Perinatology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Sichuan Clinical Research Center for Birth Defects, Luzhou, China
| | - Rong Zhang
- Division of Neonatology, Department of Pediatrics, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Department of Perinatology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Sichuan Clinical Research Center for Birth Defects, Luzhou, China
| | - Lan Kang
- Division of Neonatology, Department of Pediatrics, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Department of Perinatology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Sichuan Clinical Research Center for Birth Defects, Luzhou, China
| | - Xiaoping Lei
- Division of Neonatology, Department of Pediatrics, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Department of Perinatology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Sichuan Clinical Research Center for Birth Defects, Luzhou, China
| | - Wenbin Dong
- Division of Neonatology, Department of Pediatrics, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Department of Perinatology, The Affiliated Hospital of Southwest Medical University, Luzhou, China
- Sichuan Clinical Research Center for Birth Defects, Luzhou, China
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2
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Biswas B, Gangwar G, Nain V, Gupta I, Thakur A, Puria R. Rapamycin and Torin2 inhibit Candida auris TOR: Insights through growth profiling, docking, and MD simulations. J Biomol Struct Dyn 2023; 41:8445-8461. [PMID: 36264093 DOI: 10.1080/07391102.2022.2134927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 10/03/2022] [Indexed: 10/24/2022]
Abstract
The fungus Candida auris is a pathogen of utmost concern due to its rapid emergence across the globe, acquired antifungal drug tolerance, thermotolerance, and ability to survive in hospital settings and preserved foods. Recent incidences of comorbidity of corona patients with its infection in hospital settings highlighted the importance of understanding the pathobiology and drug tolerance of this fungus on priority. The Target of rapamycin (TOR) is a central regulator of growth across eukaryotes with an illustrated role in fungal pathology. The role of the TOR signalling pathway in the growth of C. auris is yet to be described. In-silico, analysis revealed the presence of highly conserved Tor kinase, components of TORC, and key downstream components in C. auris. Rapamycin and Torin2, the specific inhibitors of Tor reduce the growth of C. auris. An inhibition of Tor leads to cell cycle arrest at the G1 phase with a defect in cytokinesis. Interestingly, with an insignificant difference in growth at 30 and 37 °C, a sharp decline in growth is seen with Torin2 at 37 °C. The heterogeneous response emphasizes the importance of physiology-based differential cellular response at different temperatures. In addition, the inhibition of Tor suppresses the biofilm formation. In silico studies through docking and simulations showed rapamycin and torin2 as specific inhibitors of C. auris Tor kinase (CauTor kinase) and hence can be exploited for a thorough understanding of the TOR signalling pathway in pathobiology and drug tolerance of C. auris. HIGHLIGHTSConservation of TOR signalling pathway in Candida aurisRapamycin and torin2 are specific inhibitors of Cau TorUnderstanding of the role of TOR signalling pathway through the use of inhibitors rapamycin and torin2.Heterogenous response of C. auris to torin2 at different physiological conditions.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Biswambhar Biswas
- Regional Centre for Biotechnology, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad, Haryana, India
| | - Garima Gangwar
- School of Biotechnology, Gautam Buddha University, Greater Noida, Uttar Pradesh, India
| | - Vikrant Nain
- School of Biotechnology, Gautam Buddha University, Greater Noida, Uttar Pradesh, India
| | - Ishaan Gupta
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Delhi, India
| | - Anil Thakur
- Regional Centre for Biotechnology, 3rd Milestone Gurgaon-Faridabad Expressway, Faridabad, Haryana, India
| | - Rekha Puria
- School of Biotechnology, Gautam Buddha University, Greater Noida, Uttar Pradesh, India
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3
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Nicastro R, Brohée L, Alba J, Nüchel J, Figlia G, Kipschull S, Gollwitzer P, Romero-Pozuelo J, Fernandes SA, Lamprakis A, Vanni S, Teleman AA, De Virgilio C, Demetriades C. Malonyl-CoA is a conserved endogenous ATP-competitive mTORC1 inhibitor. Nat Cell Biol 2023; 25:1303-1318. [PMID: 37563253 PMCID: PMC10495264 DOI: 10.1038/s41556-023-01198-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 06/29/2023] [Indexed: 08/12/2023]
Abstract
Cell growth is regulated by the mammalian/mechanistic target of rapamycin complex 1 (mTORC1), which functions both as a nutrient sensor and a master controller of virtually all biosynthetic pathways. This ensures that cells are metabolically active only when conditions are optimal for growth. Notably, although mTORC1 is known to regulate fatty acid biosynthesis, how and whether the cellular lipid biosynthetic capacity signals back to fine-tune mTORC1 activity remains poorly understood. Here we show that mTORC1 senses the capacity of a cell to synthesise fatty acids by detecting the levels of malonyl-CoA, an intermediate of this biosynthetic pathway. We find that, in both yeast and mammalian cells, this regulation is direct, with malonyl-CoA binding to the mTOR catalytic pocket and acting as a specific ATP-competitive inhibitor. When fatty acid synthase (FASN) is downregulated/inhibited, elevated malonyl-CoA levels are channelled to proximal mTOR molecules that form direct protein-protein interactions with acetyl-CoA carboxylase 1 (ACC1) and FASN. Our findings represent a conserved and unique homeostatic mechanism whereby impaired fatty acid biogenesis leads to reduced mTORC1 activity to coordinately link this metabolic pathway to the overall cellular biosynthetic output. Moreover, they reveal the existence of a physiological metabolite that directly inhibits the activity of a signalling kinase in mammalian cells by competing with ATP for binding.
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Affiliation(s)
- Raffaele Nicastro
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Laura Brohée
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Josephine Alba
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Julian Nüchel
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Gianluca Figlia
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
| | | | - Peter Gollwitzer
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Jesus Romero-Pozuelo
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg University, Heidelberg, Germany
- Unidad de Investigación Biomedica, Universidad Alfonso X El Sabio (UAX), Madrid, Spain
| | | | - Andreas Lamprakis
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Fribourg, Switzerland.
| | - Aurelio A Teleman
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Heidelberg University, Heidelberg, Germany.
| | | | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), Cologne, Germany.
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany.
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4
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Kaufmann P, Wiberg RAW, Papachristos K, Scofield DG, Tellgren-Roth C, Immonen E. Y-Linked Copy Number Polymorphism of Target of Rapamycin Is Associated with Sexual Size Dimorphism in Seed Beetles. Mol Biol Evol 2023; 40:msad167. [PMID: 37479678 PMCID: PMC10414808 DOI: 10.1093/molbev/msad167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 07/03/2023] [Accepted: 07/11/2023] [Indexed: 07/23/2023] Open
Abstract
The Y chromosome is theorized to facilitate evolution of sexual dimorphism by accumulating sexually antagonistic loci, but empirical support is scarce. Due to the lack of recombination, Y chromosomes are prone to degenerative processes, which poses a constraint on their adaptive potential. Yet, in the seed beetle, Callosobruchus maculatus segregating Y linked variation affects male body size and thereby sexual size dimorphism (SSD). Here, we assemble C. maculatus sex chromosome sequences and identify molecular differences associated with Y-linked SSD variation. The assembled Y chromosome is largely euchromatic and contains over 400 genes, many of which are ampliconic with a mixed autosomal and X chromosome ancestry. Functional annotation suggests that the Y chromosome plays important roles in males beyond primary reproductive functions. Crucially, we find that, besides an autosomal copy of the gene target of rapamycin (TOR), males carry an additional TOR copy on the Y chromosome. TOR is a conserved regulator of growth across taxa, and our results suggest that a Y-linked TOR provides a male specific opportunity to alter body size. A comparison of Y haplotypes associated with male size difference uncovers a copy number variation for TOR, where the haplotype associated with decreased male size, and thereby increased sexual dimorphism, has two additional TOR copies. This suggests that sexual conflict over growth has been mitigated by autosome to Y translocation of TOR followed by gene duplications. Our results reveal that despite of suppressed recombination, the Y chromosome can harbor adaptive potential as a male-limited supergene.
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Affiliation(s)
- Philipp Kaufmann
- Department of Ecology and Genetics (Evolutionary Biology program), Uppsala University, Uppsala, Sweden
| | - R Axel W Wiberg
- Department of Ecology and Genetics (Evolutionary Biology program), Uppsala University, Uppsala, Sweden
- Ecology Division, Department of Zoology, Stockholm University, Stockholm, Sweden
| | | | - Douglas G Scofield
- Uppsala Multidisciplinary Center for Advanced Computational Science, Uppsala University, Uppsala, Sweden
| | - Christian Tellgren-Roth
- National Genomics Infrastructure, Uppsala Genome Center, SciLifeLab, BioMedical Centre, Uppsala University, Uppsala, Sweden
| | - Elina Immonen
- Department of Ecology and Genetics (Evolutionary Biology program), Uppsala University, Uppsala, Sweden
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5
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Kuczyńska M, Gabig-Cimińska M, Moskot M. Molecular treatment trajectories within psoriatic T lymphocytes: a mini review. Front Immunol 2023; 14:1170273. [PMID: 37251381 PMCID: PMC10213638 DOI: 10.3389/fimmu.2023.1170273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/28/2023] [Indexed: 05/31/2023] Open
Abstract
Multiple biological processes in mammalian cells are implicated in psoriasis (Ps) development and progression, as well as in the pathogenic mechanisms associated with this chronic immune-mediated inflammatory disease (IMID). These refer to molecular cascades contributing to the pathological topical and systemic reactions in Ps, where local skin-resident cells derived from peripheral blood and skin-infiltrating cells originating from the circulatory system, in particular T lymphocytes (T cells), are key actors. The interplay between molecular components of T cell signalling transduction and their involvement in cellular cascades (i.e. throughout Ca2+/CaN/NFAT, MAPK/JNK, PI3K/Akt/mTOR, JAK/STAT pathways) has been of concern in the last few years; this is still less characterised than expected, even though some evidence has accumulated to date identifying them as potential objects in the management of Ps. Innovative therapeutic strategies for the use of compounds such as synthetic Small Molecule Drugs (SMDs) and their various combinations proved to be promising tools for the treatment of Ps via incomplete blocking, also known as modulation of disease-associated molecular tracks. Despite recent drug development having mainly centred on biological therapies for Ps, yet displaying serious limitations, SMDs acting on specific pathway factor isoforms or single effectors within T cell, could represent a valid innovation in real-world treatment patterns in patients with Ps. Of note, due to the intricate crosstalk between intracellular pathways, the use of selective agents targeting proper tracks is, in our opinion, a challenge for modern science regarding the prevention of disease at its onset and also in the prediction of patient response to Ps treatment.
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Affiliation(s)
| | | | - Marta Moskot
- *Correspondence: Magdalena Gabig-Cimińska, ; Marta Moskot,
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6
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Fujita A, Kato M, Sugano H, Iimura Y, Suzuki H, Tohyama J, Fukuda M, Ito Y, Baba S, Okanishi T, Enoki H, Fujimoto A, Yamamoto A, Kawamura K, Kato S, Honda R, Ono T, Shiraishi H, Egawa K, Shirai K, Yamamoto S, Hayakawa I, Kawawaki H, Saida K, Tsuchida N, Uchiyama Y, Hamanaka K, Miyatake S, Mizuguchi T, Nakashima M, Saitsu H, Miyake N, Kakita A, Matsumoto N. An integrated genetic analysis of epileptogenic brain malformed lesions. Acta Neuropathol Commun 2023; 11:33. [PMID: 36864519 PMCID: PMC9983246 DOI: 10.1186/s40478-023-01532-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 02/17/2023] [Indexed: 03/04/2023] Open
Abstract
Focal cortical dysplasia is the most common malformation during cortical development, sometimes excised by epilepsy surgery and often caused by somatic variants of the mTOR pathway genes. In this study, we performed a genetic analysis of epileptogenic brain malformed lesions from 64 patients with focal cortical dysplasia, hemimegalencephy, brain tumors, or hippocampal sclerosis. Targeted sequencing, whole-exome sequencing, and single nucleotide polymorphism microarray detected four germline and 35 somatic variants, comprising three copy number variants and 36 single nucleotide variants and indels in 37 patients. One of the somatic variants in focal cortical dysplasia type IIB was an in-frame deletion in MTOR, in which only gain-of-function missense variants have been reported. In focal cortical dysplasia type I, somatic variants of MAP2K1 and PTPN11 involved in the RAS/MAPK pathway were detected. The in-frame deletions of MTOR and MAP2K1 in this study resulted in the activation of the mTOR pathway in transiently transfected cells. In addition, the PTPN11 missense variant tended to elongate activation of the mTOR or RAS/MAPK pathway, depending on culture conditions. We demonstrate that epileptogenic brain malformed lesions except for focal cortical dysplasia type II arose from somatic variants of diverse genes but were eventually linked to the mTOR pathway.
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Affiliation(s)
- Atsushi Fujita
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Mitsuhiro Kato
- Department of Pediatrics, Showa University School of Medicine, Tokyo, 142-8666, Japan
| | - Hidenori Sugano
- Department of Neurosurgery, Epilepsy Center, Juntendo University, Tokyo, 113-8421, Japan
| | - Yasushi Iimura
- Department of Neurosurgery, Epilepsy Center, Juntendo University, Tokyo, 113-8421, Japan
| | - Hiroharu Suzuki
- Department of Neurosurgery, Epilepsy Center, Juntendo University, Tokyo, 113-8421, Japan
| | - Jun Tohyama
- Department of Child Neurology, National Hospital Organization Nishiniigata Chuo Hospital, Niigata, 950-2085, Japan
| | - Masafumi Fukuda
- Department of Functional Neurosurgery, Epilepsy Center, National Hospital Organization Nishiniigata Chuo Hospital, Niigata, 950-2085, Japan
| | - Yosuke Ito
- Department of Functional Neurosurgery, Epilepsy Center, National Hospital Organization Nishiniigata Chuo Hospital, Niigata, 950-2085, Japan
| | - Shimpei Baba
- Department of Child Neurology, Comprehensive Epilepsy Center, Seirei Hamamatsu General Hospital, Hamamatsu, 430-8558, Japan
| | - Tohru Okanishi
- Division of Child Neurology, Department of Brain and Neurosciences, Faculty of Medicine, Tottori University, Yonago, 683-8503, Japan
| | - Hideo Enoki
- Department of Pediatrics, Kawasaki Medical School, Kurashiki, 701-0192, Japan
| | - Ayataka Fujimoto
- Comprehensive Epilepsy Center, Seirei Hamamatsu General Hospital, Hamamatsu, 430-8558, Japan
| | - Akiyo Yamamoto
- Department of Pediatrics, Sapporo Medical University School of Medicine, Sapporo, 060-8543, Japan
| | - Kentaro Kawamura
- Department of Pediatrics, Sapporo Medical University School of Medicine, Sapporo, 060-8543, Japan
| | - Shinsuke Kato
- Department of Pediatrics, Sapporo Medical University School of Medicine, Sapporo, 060-8543, Japan
| | - Ryoko Honda
- Department of Pediatrics, National Hospital Organization Nagasaki Medical Center, Omura, 856-8562, Japan
| | - Tomonori Ono
- Epilepsy Center, National Hospital Organization Nagasaki Medical Center, Omura, 856-8562, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan
| | - Kentaro Shirai
- Department of Pediatrics, Tsuchiura Kyodo General Hospital, Tsuchiura, 300-0028, Japan
| | - Shinji Yamamoto
- Department of Neurosurgery, Tsuchiura Kyodo General Hospital, Tsuchiura, 300-0028, Japan
| | - Itaru Hayakawa
- Division of Neurology, National Center for Child Health and Development, Tokyo, 157-8535, Japan
| | - Hisashi Kawawaki
- Department of Pediatric Neurology, Children's Medical Center, Osaka City General Hospital, Osaka, 534-0021, Japan
| | - Ken Saida
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Naomi Tsuchida
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.,Department of Rare Disease Genomics, Yokohama City University Hospital, Yokohama, 236-0004, Japan
| | - Yuri Uchiyama
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.,Department of Rare Disease Genomics, Yokohama City University Hospital, Yokohama, 236-0004, Japan
| | - Kohei Hamanaka
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Satoko Miyatake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.,Department of Clinical Genetics, Yokohama City University Hospital, Yokohama, 236-0004, Japan
| | - Takeshi Mizuguchi
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan
| | - Mitsuko Nakashima
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.,Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan
| | - Hirotomo Saitsu
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.,Department of Biochemistry, Hamamatsu University School of Medicine, Hamamatsu, 431-3192, Japan
| | - Noriko Miyake
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.,Department of Human Genetics, Research Institute, National Center for Global Health and Medicine, Tokyo, 162-8655, Japan
| | - Akiyoshi Kakita
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Naomichi Matsumoto
- Department of Human Genetics, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.
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7
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Chen MY, Hsu CH, Setiawan SA, Tzeng DTW, Ma HP, Ong JR, Chu YC, Hsieh MS, Wu ATH, Tzeng YM, Yeh CT. Ovatodiolide and antrocin synergistically inhibit the stemness and metastatic potential of hepatocellular carcinoma via impairing ribosome biogenesis and modulating ERK/Akt-mTOR signaling axis. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 108:154478. [PMID: 36265255 DOI: 10.1016/j.phymed.2022.154478] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 08/28/2022] [Accepted: 09/25/2022] [Indexed: 06/16/2023]
Abstract
Activation of mitogen-activated protein kinase (MAPK) and PI3K signaling confers resistance against sorafenib, a mainstay treatment for advanced hepatocellular carcinoma (HCC). Antrocin and ovatodiolide constitute as the most potent secondary metabolites isolated from Antrodia camphorata and Anisomeles indica, respectively. Both natural compounds have recently gained a lot of attention due to their putative inhibition of MAPK and PI3K signaling in various solid cancers. However, whether their combination is effective in HCC remains unknown. Here, we investigated their effect, alone or in various combinations, on MAPK and PI3K signaling pathways in HCC cells. An array of in vitro study were used to investigate anticancer and stemness effects to treat HCC, such as cytotoxicity, drug combination index, migration, invasion, colony formation, and tumor sphere formation. Drug effect in vivo was evaluated using mouse xenograft models. In this study, antrocin and ovatodiolide synergistically inhibited the SNU387, Hep3B, Mahlavu, and Huh7 cell lines. Sequential combination treatment of Huh7 and Mahlavu with ovatodiolide followed by antrocin resulted stronger cytotoxic effect than did treatment with antrocin followed by ovatodiolide, their simultaneous administration, antrocin alone, or ovatodiolide alone. In the Huh7 and Mahlavu cell lines, ovatodiolide→antrocin significantly suppressed colony formation and proliferation as well as markedly downregulated ERK1/2, Akt, and mTOR expression. Inhibition of ERK1/2 and Akt/mTOR signaling by ovatodiolide→antrocin suppressed ribosomal biogenesis, autophagy, and cancer stem cell-like phenotypes and promoted apoptosis in Huh7 and Mahlavu cells. The sorafenib-resistant clone of Huh7 was effectively inhibited by synergistic combination of both compound in vitro. Eventually, the ovatodiolide→antrocin combination synergistically suppressed the growth of HCC xenografts. Taken together, our findings suggested that ovatodiolide→antrocin combination may represent potential therapeutic approach for patients with advanced HCC.
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Affiliation(s)
- Ming-Yao Chen
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei City 110, Taiwan; Division of Gastroenterology and Hepatology, Department of Internal Medicine, Taipei Medical University-Shuang Ho Hospital, New Taipei City 235, Taiwan
| | - Chia-Hung Hsu
- Department of Emergency Medicine, Taipei Medical University-Shuang Ho Hospital, New Taipei City 235, Taiwan; Graduate Institute of Injury Prevention and Control, College of Public Health, Taipei Medical University, Taipei City 110, Taiwan; Department of Emergency Medicine, School of Medicine, Taipei Medical University, Taipei City 110, Taiwan
| | - Syahru Agung Setiawan
- International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei City 110, Taiwan; Department of Medical Research & Education, Taipei Medical University - Shuang-Ho Hospital, New Taipei City 235, Taiwan
| | - David T W Tzeng
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong SAR, 999077, China; Lifebit, Mindspace Shoreditch, London, England, EC2A 2AP, UK
| | - Hon-Ping Ma
- Department of Emergency Medicine, Taipei Medical University-Shuang Ho Hospital, New Taipei City 235, Taiwan; Graduate Institute of Injury Prevention and Control, College of Public Health, Taipei Medical University, Taipei City 110, Taiwan; Department of Emergency Medicine, School of Medicine, Taipei Medical University, Taipei City 110, Taiwan
| | - Jiann Ruey Ong
- Department of Emergency Medicine, Taipei Medical University-Shuang Ho Hospital, New Taipei City 235, Taiwan; Graduate Institute of Injury Prevention and Control, College of Public Health, Taipei Medical University, Taipei City 110, Taiwan; Department of Emergency Medicine, School of Medicine, Taipei Medical University, Taipei City 110, Taiwan
| | - Yi Cheng Chu
- Department of Medicine, St. George's University School of Medicine, St. George, Grenada
| | - Ming-Shou Hsieh
- Department of Medical Research & Education, Taipei Medical University - Shuang-Ho Hospital, New Taipei City 235, Taiwan
| | - Alexander T H Wu
- Department of Medical Research & Education, Taipei Medical University - Shuang-Ho Hospital, New Taipei City 235, Taiwan
| | - Yew-Min Tzeng
- Department of Applied Science, National Taitung University, Taitung 95092, Taiwan.
| | - Chi-Tai Yeh
- Department of Medical Research & Education, Taipei Medical University - Shuang-Ho Hospital, New Taipei City 235, Taiwan; Continuing Education Program of Food Biotechnology Applications, College of Science and Engineering, National Taitung University, Taitung 95092, Taiwan.
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8
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Identification of a HTT-specific binding motif in DNAJB1 essential for suppression and disaggregation of HTT. Nat Commun 2022; 13:4692. [PMID: 35948542 PMCID: PMC9365803 DOI: 10.1038/s41467-022-32370-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 07/26/2022] [Indexed: 11/10/2022] Open
Abstract
Huntington’s disease is a neurodegenerative disease caused by an expanded polyQ stretch within Huntingtin (HTT) that renders the protein aggregation-prone, ultimately resulting in the formation of amyloid fibrils. A trimeric chaperone complex composed of Hsc70, DNAJB1 and Apg2 can suppress and reverse the aggregation of HTTExon1Q48. DNAJB1 is the rate-limiting chaperone and we have here identified and characterized the binding interface between DNAJB1 and HTTExon1Q48. DNAJB1 exhibits a HTT binding motif (HBM) in the hinge region between C-terminal domains (CTD) I and II and binds to the polyQ-adjacent proline rich domain (PRD) of soluble as well as aggregated HTT. The PRD of HTT represents an additional binding site for chaperones. Mutation of the highly conserved H244 of the HBM of DNAJB1 completely abrogates the suppression and disaggregation of HTT fibrils by the trimeric chaperone complex. Notably, this mutation does not affect the binding and remodeling of any other protein substrate, suggesting that the HBM of DNAJB1 is a specific interaction site for HTT. Overexpression of wt DNAJB1, but not of DNAJB1H244A can prevent the accumulation of HTTExon1Q97 aggregates in HEK293 cells, thus validating the biological significance of the HBM within DNAJB1. Ayala Mariscal et al have identified and characterized the interface of pathogenic Huntingtin and the molecular chaperone DNAJB1. Histidine-244 of the C-terminal domain of DNAJB1 is a key residues for binding to the poly-proline region of HTT. This binding site is specific for the interaction with Huntingtin.
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Negi A, Kieffer C, Voisin‐Chiret AS. Azobenzene Photoswitches in Proteolysis Targeting Chimeras: Photochemical Control Strategies and Therapeutic Benefits. ChemistrySelect 2022. [DOI: 10.1002/slct.202200981] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Arvind Negi
- Department of Bioproduct and Biosystems Aalto University Espoo 02150 Finland
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10
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Chakraborty S, Mukherjee S, Biswas P, Ghosh A, Siddhanta A. FRB domain of human TOR protein induces compromised proliferation and mitochondrial dysfunction in Labrus donovani promastigotes. Parasitol Int 2022; 89:102591. [PMID: 35472440 DOI: 10.1016/j.parint.2022.102591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/14/2022] [Accepted: 04/19/2022] [Indexed: 11/26/2022]
Abstract
Visceral leishmaniasis (VL) or Kala-azar, the second-largest parasitic killer worldwide, is caused by Leishmania donovani. The drugs to treat VL are toxic and expensive. Moreover, their indiscriminate use gave rise to resistant strains. The high rate of parasite proliferation within the host macrophage cells causes pathogenesis. In the proliferative pathway, FRB domain of TOR protein is ubiquitously essential. Although orthologues of mTOR protein are reported in trypanosomatids and Leishmania but therein depth molecular characterization is yet to be done. Considerable protein sequence homology exists between the TOR of kinetoplastidas and mammals. Interestingly, exogenous human FRB domain was shown to block G1 to S transition in mammalian cancer cells. Thus, we hypothesized that expression of human FRB domain would inhibit the proliferation of Labrus donovani. Indeed, promastigotes stably expressing wild type human FRB domain show 4.7 and 1.5 folds less intra- and extra-cellular proliferations than that of untransfected controls. They also manifested 2.65 times lower rate of glucose stimulated oxygen consumption. The activities of all respiratory complexes were compromised in the hFRB expressing promastigotes. In these cells, depolarized mitochondria were 2-fold more than control cells. However, promastigotes expressing its mutant version (Trp2027-Phe) has shown similar characteristics like untransfected cells. Thus, this study reveals greater insights on the conserved role of TOR in the regulation of the respiratory complexes in L. donovani. The slow growing variant of FRB expressing promastigotes will have great potential to be exploited as a prophylactic agent against leishmaniasis.
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Affiliation(s)
- Sudipta Chakraborty
- Department of Biochemistry, University of Calcutta, India; Department of Microbiology, Bidhannagar College, Kolkata, India
| | | | - Priyam Biswas
- Department of Biochemistry, University of Calcutta, India
| | - Alok Ghosh
- Department of Biochemistry, University of Calcutta, India
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11
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Chang H, Lee C, Chang C, Jan F. FKBP-type peptidyl-prolyl cis-trans isomerase interacts with the movement protein of tomato leaf curl New Delhi virus and impacts viral replication in Nicotiana benthamiana. MOLECULAR PLANT PATHOLOGY 2022; 23:561-575. [PMID: 34984809 PMCID: PMC8916215 DOI: 10.1111/mpp.13181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 11/29/2021] [Accepted: 12/15/2021] [Indexed: 06/14/2023]
Abstract
Begomoviruses belonging to the family Geminiviridae are plant-infecting DNA viruses. Begomoviral movement protein (MP) has been reported to be required for virus movement, host range determination, and symptom development. In the present study, the FK506-binding protein (FKBP)-type peptidyl-prolyl cis-trans isomerase (NbFKPPIase) of Nicotiana benthamiana was identified by a yeast two-hybrid screening system using the MP of tomato leaf curl New Delhi virus (ToLCNDV) oriental melon (OM) isolate (MPOM ) as bait. Transient silencing of the gene encoding NbFKPPIase increased replication of three test begomoviruses, and transient overexpression decreased viral replication, indicating that NbFKPPIase plays a role in defence against begomoviruses. However, infection of N. benthamiana by ToLCNDV-OM or overexpression of the gene encoding MPOM drastically reduced the expression of the gene encoding NbFKPPIase. Fluorescence resonance energy transfer analysis revealed that MPOM interacted with NbFKPPIase in the periphery of cells. Expression of the gene encoding NbFKPPIase was induced by salicylic acid but not by methyl jasmonate or ethylene. Moreover, the expression of the gene encoding NbFKPPIase was down-regulated in response to 6-benzylaminopurine and up-regulated in response to gibberellin or indole-3-acetic acid, suggesting a role of NbFKPPIase in plant development. Transcriptome analysis and comparison of N. benthamiana transient silencing and overexpression of the gene encoding MPOM led to the identification of several differentially expressed genes whose functions are probably associated with cell cycle regulation. Our results indicate that begomoviruses could suppress NbFKPPIase-mediated defence and biological functions by transcriptional inhibition and physical interaction between MP and NbFKPPIase to facilitate infection.
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Affiliation(s)
- Ho‐Hsiung Chang
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
| | - Chia‐Hwa Lee
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
- Ph.D. Program in Microbial GenomicsNational Chung Hsing University and Academia SinicaTaichung and TaipeiTaiwan
| | - Chung‐Jan Chang
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
- Department of Plant PathologyUniversity of GeorgiaGriffinGeorgiaUSA
| | - Fuh‐Jyh Jan
- Department of Plant PathologyNational Chung Hsing UniversityTaichungTaiwan
- Ph.D. Program in Microbial GenomicsNational Chung Hsing University and Academia SinicaTaichung and TaipeiTaiwan
- Advanced Plant Biotechnology CenterNational Chung Hsing UniversityTaichungTaiwan
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12
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Agrawal A, Raval A, Velhal S, Patel V, Patravale V. Nanoparticles eluting stents for coronary intervention: Formulation, characterization and in vitro evaluation. Can J Physiol Pharmacol 2021; 100:220-233. [PMID: 34570985 DOI: 10.1139/cjpp-2021-0245] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Coronary artery disease (CAD) is currently a leading cause of death worldwide. In the history of percutaneous coronary intervention for the treatment of CAD, a drug-eluting stent (DES) is recognized as a revolutionary technology that has the unique ability to significantly reduce restenosis and provide both mechanical and biological solutions simultaneously to the target lesion. The aim of the research work was to design and fabricate DES coated with a nanoparticulate drug formulation. Sirolimus, an inhibitor of the smooth muscle cell (SMC) proliferation and migration, was encapsulated in polymeric nanoparticles. The nanoparticle formulation was characterized for various physicochemical parameters. Cell viability and cell uptake studies were performed using human coronary artery smooth muscle cells (HCASMCs). The developed nanoparticle formulation showed enhanced efficacy compared to plain drug solution and exhibited time-dependent uptake into the HCASMCs. The developed nanoparticle formulation was coated on the FlexinniumTM ultra-thin cobalt-chromium alloy coronary stent platform. The nanoparticle coated stents were characterized for morphology and residual solvent analysis. In-vitro drug release was also evaluated. Ex-vivo arterial permeation was carried out to evaluate the nanoparticle uptake from the surface of the stents. The characterization studies together corroborated that the developed nanoparticle coated stent can be a promising replacement of the current drug-eluting stents.
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Affiliation(s)
- Ankit Agrawal
- Institute of Chemical Technology, 80493, Department of Pharmaceutical Sciences, Mumbai, Mumbai, Maharashtra, India, 400019;
| | - Ankur Raval
- Sahajanand Medical Technologies Pvt Ltd, 78648, Surat, Gujarat, India;
| | - Shilpa Velhal
- National Institute for Research in Reproductive Health, 29528, Mumbai, Maharashtra, India;
| | - Vainav Patel
- National Institute for Research in Reproductive Health, 29528, Mumbai, Maharashtra, India;
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Moustafa-Kamal M, Kucharski TJ, El-Assaad W, Abbas YM, Gandin V, Nagar B, Pelletier J, Topisirovic I, Teodoro JG. The mTORC1/S6K/PDCD4/eIF4A Axis Determines Outcome of Mitotic Arrest. Cell Rep 2021; 33:108230. [PMID: 33027666 DOI: 10.1016/j.celrep.2020.108230] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/29/2020] [Accepted: 09/14/2020] [Indexed: 12/26/2022] Open
Abstract
mTOR is a serine/threonine kinase and a master regulator of cell growth and proliferation. Raptor, a scaffolding protein that recruits substrates to mTOR complex 1 (mTORC1), is known to be phosphorylated during mitosis, but the significance of this phosphorylation remains largely unknown. Here we show that raptor expression and mTORC1 activity are dramatically reduced in cells arrested in mitosis. Expression of a non-phosphorylatable raptor mutant reactivates mTORC1 and significantly reduces cytotoxicity of the mitotic poison Taxol. This effect is mediated via degradation of PDCD4, a tumor suppressor protein that inhibits eIF4A activity and is negatively regulated by the mTORC1/S6K pathway. Moreover, pharmacological inhibition of eIF4A is able to enhance the effects of Taxol and restore sensitivity in Taxol-resistant cancer cells. These findings indicate that the mTORC1/S6K/PDCD4/eIF4A axis has a pivotal role in the death versus slippage decision during mitotic arrest and may be exploited clinically to treat tumors resistant to anti-mitotic agents.
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Affiliation(s)
- Mohamed Moustafa-Kamal
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Thomas J Kucharski
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Wissal El-Assaad
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada
| | - Yazan M Abbas
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Valentina Gandin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Bhushan Nagar
- Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Jerry Pelletier
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada
| | - Ivan Topisirovic
- Department of Biochemistry, McGill University, Montréal, QC, Canada; Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, and Department of Oncology, McGill University, Montréal, QC, Canada.
| | - Jose G Teodoro
- Goodman Cancer Research Center, McGill University, Montréal, QC, Canada; Department of Biochemistry, McGill University, Montréal, QC, Canada.
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14
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Ganner A, Gehrke C, Klein M, Thegtmeier L, Matulenski T, Wingendorf L, Wang L, Pilz F, Greidl L, Meid L, Kotsis F, Walz G, Frew IJ, Neumann-Haefelin E. VHL suppresses RAPTOR and inhibits mTORC1 signaling in clear cell renal cell carcinoma. Sci Rep 2021; 11:14827. [PMID: 34290272 PMCID: PMC8295262 DOI: 10.1038/s41598-021-94132-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/25/2021] [Indexed: 01/08/2023] Open
Abstract
Inactivation of the tumor suppressor von Hippel-Lindau (VHL) gene is a key event in hereditary and sporadic clear cell renal cell carcinomas (ccRCC). The mechanistic target of rapamycin (mTOR) signaling pathway is a fundamental regulator of cell growth and proliferation, and hyperactivation of mTOR signaling is a common finding in VHL-dependent ccRCC. Deregulation of mTOR signaling correlates with tumor progression and poor outcome in patients with ccRCC. Here, we report that the regulatory-associated protein of mTOR (RAPTOR) is strikingly repressed by VHL. VHL interacts with RAPTOR and increases RAPTOR degradation by ubiquitination, thereby inhibiting mTORC1 signaling. Consistent with hyperactivation of mTORC1 signaling in VHL-deficient ccRCC, we observed that loss of vhl-1 function in C. elegans increased mTORC1 activity, supporting an evolutionary conserved mechanism. Our work reveals important new mechanistic insight into deregulation of mTORC1 signaling in ccRCC and links VHL directly to the control of RAPTOR/mTORC1. This may represent a novel mechanism whereby loss of VHL affects organ integrity and tumor behavior.
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Affiliation(s)
- Athina Ganner
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Christina Gehrke
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Marinella Klein
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lena Thegtmeier
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tanja Matulenski
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Laura Wingendorf
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lu Wang
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Felicitas Pilz
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lars Greidl
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lisa Meid
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Fruzsina Kotsis
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Gerd Walz
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Ian J Frew
- Department of Internal Medicine I, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Elke Neumann-Haefelin
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
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Kamynina M, Tskhovrebova S, Fares J, Timashev P, Laevskaya A, Ulasov I. Oncolytic Virus-Induced Autophagy in Glioblastoma. Cancers (Basel) 2021; 13:cancers13143482. [PMID: 34298694 PMCID: PMC8304501 DOI: 10.3390/cancers13143482] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 07/07/2021] [Indexed: 01/20/2023] Open
Abstract
Simple Summary Glioblastoma (GBM) is the most common and aggressive brain tumor with an incidence rate of nearly 3.19/100,000. Current therapeutic options fall short in improving the survival of patients with GBM. Various genetic and microenvironmental factors contribute to GBM progression and resistance to therapy. The development of gene therapies using self-replicating oncolytic viruses can advance GBM treatment. Due to GBM heterogeneity, oncolytic viruses have been genetically modified to improve the antiglioma effect in vitro and in vivo. Oncolytic viruses can activate autophagy signaling in GBM upon tumoral infection. Autophagy can be cytoprotective, whereby the GBM cells catabolize damaged organelles to accommodate to virus-induced stress, or cytotoxic, whereby it leads to the destruction of GBM cells. Understanding the molecular mechanisms that control oncolytic virus-induced autophagic signaling in GBM can fuel further development of novel and more effective genetic vectors. Abstract Autophagy is a catabolic process that allows cells to scavenge damaged organelles and produces energy to maintain cellular homeostasis. It is also an effective defense method for cells, which allows them to identify an internalized pathogen and destroy it through the fusion of the autophagosome and lysosomes. Recent reports have demonstrated that various chemotherapeutic agents and viral gene therapeutic vehicles provide therapeutic advantages for patients with glioblastoma as monotherapy or in combination with standards of care. Despite nonstop efforts to develop effective antiglioma therapeutics, tumor-induced autophagy in some studies manifests tumor resistance and glioma progression. Here, we explore the functional link between autophagy regulation mediated by oncolytic viruses and discuss how intracellular interactions control autophagic signaling in glioblastoma. Autophagy induced by oncolytic viruses plays a dual role in cell death and survival. On the one hand, autophagy stimulation has mostly led to an increase in cytotoxicity mediated by the oncolytic virus, but, on the other hand, autophagy is also activated as a cell defense mechanism against intracellular pathogens and modulates antiviral activity through the induction of ER stress and unfolded protein response (UPR) signaling. Despite the fact that the moment of switch between autophagic prosurvival and prodeath modes remains to be known, in the context of oncolytic virotherapy, cytotoxic autophagy is a crucial mechanism of cancer cell death.
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Affiliation(s)
- Margarita Kamynina
- Group of Experimental Biotherapy and Diagnostic, Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (M.K.); (S.T.); (A.L.)
| | - Salome Tskhovrebova
- Group of Experimental Biotherapy and Diagnostic, Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (M.K.); (S.T.); (A.L.)
| | - Jawad Fares
- Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
| | - Peter Timashev
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia;
- Department of Polymers and Composites, N. N. Semenov Institute of Chemical Physics, 119991 Moscow, Russia
- Chemistry Department, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Anastasia Laevskaya
- Group of Experimental Biotherapy and Diagnostic, Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (M.K.); (S.T.); (A.L.)
| | - Ilya Ulasov
- Group of Experimental Biotherapy and Diagnostic, Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, 119991 Moscow, Russia; (M.K.); (S.T.); (A.L.)
- Correspondence:
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16
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Park HR, Kim TM, Lee Y, Kim S, Park S, Ju YS, Kim M, Keam B, Jeon YK, Kim DW, Heo DS. Acquired Resistance to Third-Generation EGFR Tyrosine Kinase Inhibitors in Patients With De Novo EGFR T790M-Mutant NSCLC. J Thorac Oncol 2021; 16:1859-1871. [PMID: 34242789 DOI: 10.1016/j.jtho.2021.06.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/19/2021] [Accepted: 06/07/2021] [Indexed: 10/20/2022]
Abstract
INTRODUCTION EGFRT790M mostly exists subclonally and is acquired as the most common mechanism of resistance to EGFR tyrosine kinase inhibitors (TKIs). Nevertheless, because de novo EGFRT790M-mutant NSCLC is rare, little is known on acquired resistance mechanisms to third-generation EGFR TKIs. METHODS Acquired resistance mechanisms were analyzed using tumor and plasma samples before and after third-generation EGFR TKI treatment in four patients with de novo EGFRT790M-mutant NSCLC. Genetic alterations were analyzed by whole-exome sequencing, targeted sequencing, fluorescence in situ hybridization, and droplet digital PCR. MTORL1433S, confirmed for oncogenicity using the Ba/F3 system, was reproduced in H1975 cell lines using CRISPR/Cas9-RNP. RESULTS Of seven patients with NSCLC with de novo EGFRT790M/L858R mutation, four (LC1-4) who received third-generation EGFR TKIs acquired resistance after achieving a partial response (median = 27 mo, range: 17-48 mo). Novel MTORL1433S and EGFRC797S/L798I mutations in cis, MET amplification, and EGFRC797S mutation were identified as acquired resistance mechanisms to third-generation EGFR TKIs. The MTORL1433S mutation was oncogenic in Ba/F3 models and revealed resistance to osimertinib through AKT signaling activation in NCI-H1975 cells harboring the MTORL1433S mutation edited by CRISPR/Cas9 (half-maximal inhibitory concentration, 800 ± 67 nM). Osimertinib in combination with mTOR inhibitors abrogated acquired resistance to osimertinib. CONCLUSIONS Activation of bypass pathways and the EGFRC797S or EGFRC797S/L798I mutation were identified as acquired resistance mechanisms to third-generation EGFR TKIs in patients with NSCLC with de novo EGFRT790M mutation. In addition, MTORL1433S- and EGFRL858R/T790M-mutant NSCLC cells were sensitive to osimertinib plus mTOR inhibitors.
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Affiliation(s)
- Ha-Ram Park
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea
| | - Tae Min Kim
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
| | - Yusoo Lee
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea
| | - Soyeon Kim
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea; Biomedical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Seongyeol Park
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Young Seok Ju
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Miso Kim
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Bhumsuk Keam
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Yoon Kyung Jeon
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea; Department of Pathology, Seoul National University Hospital, Seoul, Republic of Korea
| | - Dong-Wan Kim
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Dae Seog Heo
- Seoul National University Cancer Research Institute, Seoul, Republic of Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea
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Nüchel J, Tauber M, Nolte JL, Mörgelin M, Türk C, Eckes B, Demetriades C, Plomann M. An mTORC1-GRASP55 signaling axis controls unconventional secretion to reshape the extracellular proteome upon stress. Mol Cell 2021; 81:3275-3293.e12. [PMID: 34245671 PMCID: PMC8382303 DOI: 10.1016/j.molcel.2021.06.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 04/21/2021] [Accepted: 06/14/2021] [Indexed: 01/13/2023]
Abstract
Cells communicate with their environment via surface proteins and secreted factors. Unconventional protein secretion (UPS) is an evolutionarily conserved process, via which distinct cargo proteins are secreted upon stress. Most UPS types depend upon the Golgi-associated GRASP55 protein. However, its regulation and biological role remain poorly understood. Here, we show that the mechanistic target of rapamycin complex 1 (mTORC1) directly phosphorylates GRASP55 to maintain its Golgi localization, thus revealing a physiological role for mTORC1 at this organelle. Stimuli that inhibit mTORC1 cause GRASP55 dephosphorylation and relocalization to UPS compartments. Through multiple, unbiased, proteomic analyses, we identify numerous cargoes that follow this unconventional secretory route to reshape the cellular secretome and surfactome. Using MMP2 secretion as a proxy for UPS, we provide important insights on its regulation and physiological role. Collectively, our findings reveal the mTORC1-GRASP55 signaling hub as the integration point in stress signaling upstream of UPS and as a key coordinator of the cellular adaptation to stress. mTORC1 phosphorylates GRASP55 directly at the Golgi in non-stressed cells mTORC1 inactivation by stress leads to GRASP55 dephosphorylation and relocalization GRASP55 relocalization to autophagosomes and MVBs drives UPS of selected cargo mTORC1-GRASP55 link cellular stress to changes in the extracellular proteome via UPS
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Affiliation(s)
- Julian Nüchel
- Max Planck Institute for Biology of Ageing (MPI-AGE), 50931 Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Biochemistry, 50931 Cologne, Germany
| | - Marina Tauber
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Biochemistry, 50931 Cologne, Germany
| | - Janica L Nolte
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
| | | | - Clara Türk
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany
| | - Beate Eckes
- University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Translational Matrix Biology, 50931 Cologne, Germany
| | - Constantinos Demetriades
- Max Planck Institute for Biology of Ageing (MPI-AGE), 50931 Cologne, Germany; University of Cologne, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), 50931 Cologne, Germany.
| | - Markus Plomann
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Biochemistry, 50931 Cologne, Germany.
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18
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Xiao B, Zuo D, Hirukawa A, Cardiff RD, Lamb R, Sonenberg N, Muller WJ. Rheb1-Independent Activation of mTORC1 in Mammary Tumors Occurs through Activating Mutations in mTOR. Cell Rep 2021; 31:107571. [PMID: 32348753 DOI: 10.1016/j.celrep.2020.107571] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 12/06/2019] [Accepted: 04/02/2020] [Indexed: 11/25/2022] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a master modulator of cellular growth, and its aberrant regulation is recurrently documented within breast cancer. While the small GTPase Rheb1 is the canonical activator of mTORC1, Rheb1-independent mechanisms of mTORC1 activation have also been reported but have not been fully understood. Employing multiple transgenic mouse models of breast cancer, we report that ablation of Rheb1 significantly impedes mammary tumorigenesis. In the absence of Rheb1, a block in tumor initiation can be overcome by multiple independent mutations in Mtor to allow Rheb1-independent reactivation of mTORC1. We further demonstrate that the mTOR kinase is indispensable for tumor initiation as the genetic ablation of mTOR abolishes mammary tumorigenesis. Collectively, our findings demonstrate that mTORC1 activation is indispensable for mammary tumor initiation and that tumors acquire alternative mechanisms of mTORC1 activation.
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Affiliation(s)
- Bin Xiao
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Dongmei Zuo
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Alison Hirukawa
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - Robert D Cardiff
- Center for Comparative Medicine, University of California, Davis, Davis, CA 95616, USA
| | | | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Faculty of Medicine, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada
| | - William J Muller
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada; Faculty of Medicine, McGill University, Montreal, QC H3A 1A3, Canada; Rosalind & Morris Goodman Cancer Centre, McGill University, Montreal, QC H3A 1A3, Canada.
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19
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Zhang H, Yi JK, Huang H, Park S, Park S, Kwon W, Kim E, Jang S, Kim SY, Choi SK, Kim SH, Liu K, Dong Z, Ryoo ZY, Kim MO. Rhein Suppresses Colorectal Cancer Cell Growth by Inhibiting the mTOR Pathway In Vitro and In Vivo. Cancers (Basel) 2021; 13:cancers13092176. [PMID: 33946531 PMCID: PMC8125196 DOI: 10.3390/cancers13092176] [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] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/16/2021] [Accepted: 04/27/2021] [Indexed: 01/05/2023] Open
Abstract
Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. Rhein has demonstrated therapeutic effects in various cancer models. However, its effects and underlying mechanisms of action in CRC remain poorly understood. We investigated the potential anticancer activity and underlying mechanisms of rhein in CRC in vitro and in vivo. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of rhein on CRC cells. Wound-healing and Transwell assays were conducted to assess cell migration and invasion capacity. Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. A tissue microarray was used to detect mTOR expression in CRC patient tissues. Gene overexpression and knockdown were done to analyze the function of mTOR in CRC. The anticancer effect of rhein in vivo was assessed in a CRC xenograft mouse model. The results show that rhein significantly inhibited CRC cell growth by inducing S-phase cell cycle arrest and apoptosis. Rhein inhibited CRC cell migration and invasion through the epithelial-mesenchymal transition (EMT) process. mTOR was highly expressed in CRC cancer tissues and cells. Overexpression of mTOR promoted cell growth, migration, and invasion, whereas mTOR knockdown diminished these phenomena in CRC cells in vitro. In addition, rhein directly targeted mTOR and inhibited the mTOR signaling pathway in CRC cells. Rhein promoted mTOR degradation through the ubiquitin-proteasome pathway. Intraperitoneal administration of rhein inhibited HCT116 xenograft tumor growth through the mTOR pathway. In conclusion, rhein exerts anticancer activity in vitro and in vivo by targeting mTOR and inhibiting the mTOR signaling pathway in CRC. Our results indicate that rhein is a potent anticancer agent that may be useful for the prevention and treatment of CRC.
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Affiliation(s)
- Haibo Zhang
- Department of Animal Science and Biotechnology, ITRD, Kyungpook National University, Sangju 37224, Korea; (H.Z.); (H.H.); (E.K.)
| | - Jun-Koo Yi
- Gyeongbuk Livestock Research Institute, Yeongju 36052, Korea;
| | - Hai Huang
- Department of Animal Science and Biotechnology, ITRD, Kyungpook National University, Sangju 37224, Korea; (H.Z.); (H.H.); (E.K.)
| | - Song Park
- Core Protein Resources Center, DGIST, Daegu 41566, Korea; (S.P.); (S.-K.C.)
- Department of Brain and Cognitive Science, DGIST, Daegu 41566, Korea
| | - Sijun Park
- School of Life Sciences, BK21 FOUR KNU Creative Bioresearch, Kyungpook National University, Daegu 41566, Korea; (S.P.); (S.J.); (S.-Y.K.)
| | - Wookbong Kwon
- Division of Biotechnology, DGIST, Daegu 41566, Korea;
| | - Eungyung Kim
- Department of Animal Science and Biotechnology, ITRD, Kyungpook National University, Sangju 37224, Korea; (H.Z.); (H.H.); (E.K.)
| | - Soyoung Jang
- School of Life Sciences, BK21 FOUR KNU Creative Bioresearch, Kyungpook National University, Daegu 41566, Korea; (S.P.); (S.J.); (S.-Y.K.)
| | - Si-Yong Kim
- School of Life Sciences, BK21 FOUR KNU Creative Bioresearch, Kyungpook National University, Daegu 41566, Korea; (S.P.); (S.J.); (S.-Y.K.)
| | - Seong-Kyoon Choi
- Core Protein Resources Center, DGIST, Daegu 41566, Korea; (S.P.); (S.-K.C.)
- Division of Biotechnology, DGIST, Daegu 41566, Korea;
| | - Sung-Hyun Kim
- Department of Bio-Medical Analysis, Korea Polytechnic College, Chungnam 34134, Korea;
| | - Kangdong Liu
- China-US (Henan) Hormel Cancer Institute, Zhengzhou 450008, China; (K.L.); (Z.D.)
| | - Zigang Dong
- China-US (Henan) Hormel Cancer Institute, Zhengzhou 450008, China; (K.L.); (Z.D.)
| | - Zae Young Ryoo
- School of Life Sciences, BK21 FOUR KNU Creative Bioresearch, Kyungpook National University, Daegu 41566, Korea; (S.P.); (S.J.); (S.-Y.K.)
- Correspondence: (Z.Y.R.); (M.O.K.); Tel.: +82-53-950-7361 (Z.Y.R.); +82-54-530-1234 (M.O.K.)
| | - Myoung Ok Kim
- Department of Animal Science and Biotechnology, ITRD, Kyungpook National University, Sangju 37224, Korea; (H.Z.); (H.H.); (E.K.)
- Correspondence: (Z.Y.R.); (M.O.K.); Tel.: +82-53-950-7361 (Z.Y.R.); +82-54-530-1234 (M.O.K.)
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20
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Sirt4 Modulates Oxidative Metabolism and Sensitivity to Rapamycin Through Species-Dependent Phenotypes in Drosophila mtDNA Haplotypes. G3-GENES GENOMES GENETICS 2020; 10:1599-1612. [PMID: 32152006 PMCID: PMC7202034 DOI: 10.1534/g3.120.401174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The endosymbiotic theory proposes that eukaryotes evolved from the symbiotic relationship between anaerobic (host) and aerobic prokaryotes. Through iterative genetic transfers, the mitochondrial and nuclear genomes coevolved, establishing the mitochondria as the hub of oxidative metabolism. To study this coevolution, we disrupt mitochondrial-nuclear epistatic interactions by using strains that have mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) from evolutionarily divergent species. We undertake a multifaceted approach generating introgressed Drosophila strains containing D. simulans mtDNA and D. melanogaster nDNA with Sirtuin 4 (Sirt4)-knockouts. Sirt4 is a nuclear-encoded enzyme that functions, exclusively within the mitochondria, as a master regulator of oxidative metabolism. We exposed flies to the drug rapamycin in order to eliminate TOR signaling, thereby compromising the cytoplasmic crosstalk between the mitochondria and nucleus. Our results indicate that D. simulans and D. melanogaster mtDNA haplotypes display opposite Sirt4-mediated phenotypes in the regulation of whole-fly oxygen consumption. Moreover, our data reflect that the deletion of Sirt4 rescued the metabolic response to rapamycin among the introgressed strains. We propose that Sirt4 is a suitable candidate for studying the properties of mitochondrial-nuclear epistasis in modulating mitochondrial metabolism.
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21
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Sheik Amamuddy O, Veldman W, Manyumwa C, Khairallah A, Agajanian S, Oluyemi O, Verkhivker GM, Tastan Bishop Ö. Integrated Computational Approaches and Tools forAllosteric Drug Discovery. Int J Mol Sci 2020; 21:E847. [PMID: 32013012 PMCID: PMC7036869 DOI: 10.3390/ijms21030847] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/20/2020] [Accepted: 01/21/2020] [Indexed: 12/16/2022] Open
Abstract
Understanding molecular mechanisms underlying the complexity of allosteric regulationin proteins has attracted considerable attention in drug discovery due to the benefits and versatilityof allosteric modulators in providing desirable selectivity against protein targets while minimizingtoxicity and other side effects. The proliferation of novel computational approaches for predictingligand-protein interactions and binding using dynamic and network-centric perspectives has ledto new insights into allosteric mechanisms and facilitated computer-based discovery of allostericdrugs. Although no absolute method of experimental and in silico allosteric drug/site discoveryexists, current methods are still being improved. As such, the critical analysis and integration ofestablished approaches into robust, reproducible, and customizable computational pipelines withexperimental feedback could make allosteric drug discovery more efficient and reliable. In this article,we review computational approaches for allosteric drug discovery and discuss how these tools can beutilized to develop consensus workflows for in silico identification of allosteric sites and modulatorswith some applications to pathogen resistance and precision medicine. The emerging realization thatallosteric modulators can exploit distinct regulatory mechanisms and can provide access to targetedmodulation of protein activities could open opportunities for probing biological processes and insilico design of drug combinations with improved therapeutic indices and a broad range of activities.
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Affiliation(s)
- Olivier Sheik Amamuddy
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa; (O.S.A.); (W.V.); (C.M.); (A.K.)
| | - Wayde Veldman
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa; (O.S.A.); (W.V.); (C.M.); (A.K.)
| | - Colleen Manyumwa
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa; (O.S.A.); (W.V.); (C.M.); (A.K.)
| | - Afrah Khairallah
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa; (O.S.A.); (W.V.); (C.M.); (A.K.)
| | - Steve Agajanian
- Graduate Program in Computational and Data Sciences, Keck Center for Science and Engineering, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA 92866, USA; (S.A.); (O.O.)
| | - Odeyemi Oluyemi
- Graduate Program in Computational and Data Sciences, Keck Center for Science and Engineering, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA 92866, USA; (S.A.); (O.O.)
| | - Gennady M. Verkhivker
- Graduate Program in Computational and Data Sciences, Keck Center for Science and Engineering, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA 92866, USA; (S.A.); (O.O.)
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA 92618, USA
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa; (O.S.A.); (W.V.); (C.M.); (A.K.)
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22
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Ruan C, Ouyang X, Liu H, Li S, Jin J, Tang W, Xia Y, Su B. Sin1-mediated mTOR signaling in cell growth, metabolism and immune response. Natl Sci Rev 2019; 6:1149-1162. [PMID: 34691993 PMCID: PMC8291397 DOI: 10.1093/nsr/nwz171] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 12/22/2022] Open
Abstract
Abstract
The mammalian target of rapamycin (mTOR) is an evolutionarily conserved Ser/Thr protein kinase with essential cellular function via processing various extracellular and intracellular inputs. Two distinct multi-protein mTOR complexes (mTORC), mTORC1 and mTORC2, have been identified and well characterized in eukaryotic cells from yeast to human. Sin1, which stands for Sty1/Spc1-interacting protein1, also known as mitogen-activated protein kinase (MAPK) associated protein (MAPKAP)1, is an evolutionarily conserved adaptor protein. Mammalian Sin1 interacts with many cellular proteins, but it has been widely studied as an essential component of mTORC2, and it is crucial not only for the assembly of mTORC2 but also for the regulation of its substrate specificity. In this review, we summarize our current knowledge of the structure and functions of Sin1, focusing specifically on its protein interaction network and its roles in the mTOR pathway that could account for various cellular functions of mTOR in growth, metabolism, immunity and cancer.
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Affiliation(s)
- Chun Ruan
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xinxing Ouyang
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Hongzhi Liu
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Song Li
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jingsi Jin
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Weiyi Tang
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yu Xia
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bing Su
- Shanghai Institute of Immunology, Department of Immunology and Microbiology, and the Minister of Education Key Laboratory of Cell Death and Differentiation, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
- Zhiyuan College, Shanghai Jiao Tong University, Shanghai 200240, China
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23
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Li X, Luo F, Li J, Luo C. MiR-183 delivery attenuates murine lupus nephritis-related injuries via targeting mTOR. Scand J Immunol 2019; 90:e12810. [PMID: 31325389 DOI: 10.1111/sji.12810] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/11/2019] [Accepted: 07/15/2019] [Indexed: 12/17/2022]
Abstract
MicroRNAs (miRNAs) play a vital role in the occurrence and development of many human diseases, including systemic lupus erythematosus (SLE). SLE is an autoimmune disease characterized by the production of autoantibodies against nuclear antigens and multiorgan involvement. Study of miRNAs involved in SLE provides new insights into the pathogenesis of SLE and might lead to the identification of new therapeutic interventions. The aim of this study was to investigate the effect of miR-183 injection on the progression of SLE by using MRL/lpr mouse model. The expression levels of miR-183 and mTOR mRNA were detected by quantitative real-time PCR assay. The effect of miR-183 on the course of spontaneous disease progression in the MRL/lpr mice was examined by intraperitoneal injection of miR-183 into mice and followed by monitoring lifespan, anti-dsDNA antibody levels, urinary albumin levels, blood urea nitrogen (BUN) levels, and Tregs and Th17 cell population. We found that miR-183 injection resulted in reduction of anti-DNA antibody and immune complex component levels, restoration of Tregs and Th17 cell population and prolongation of survival. Our findings suggest that miR-183 injection may serve as an effective therapeutic treatment for delaying or easing pathologic features of SLE.
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Affiliation(s)
- Xiuzhen Li
- Department of Nephrology, Liaocheng People's Hospital, Liaocheng, China
| | - Feng Luo
- Department of Emergency, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Jie Li
- Department of Nephrology, Liaocheng People's Hospital, Liaocheng, China
| | - Congjuan Luo
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao, China
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24
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Xu M, Almasi S, Yang Y, Yan C, Sterea AM, Rizvi Syeda AK, Shen B, Richard Derek C, Huang P, Gujar S, Wang J, Zong WX, Trebak M, El Hiani Y, Dong XP. The lysosomal TRPML1 channel regulates triple negative breast cancer development by promoting mTORC1 and purinergic signaling pathways. Cell Calcium 2019; 79:80-88. [PMID: 30889511 PMCID: PMC6698368 DOI: 10.1016/j.ceca.2019.02.010] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 02/21/2019] [Indexed: 01/05/2023]
Abstract
The triple-negative breast cancer (TNBC) that comprises approximately 10%-20% of breast cancers is an aggressive subtype lacking effective therapeutics. Among various signaling pathways, mTORC1 and purinergic signals have emerged as potentially fruitful targets for clinical therapy of TNBC. Unfortunately, drugs targeting these signaling pathways do not successfully inhibit the progression of TNBC, partially due to the fact that these signaling pathways are essential for the function of all types of cells. In this study, we report that TRPML1 is specifically upregulated in TNBCs and that its genetic downregulation and pharmacological inhibition suppress the growth of TNBC. Mechanistically, we demonstrate that TRPML1 regulates TNBC development, at least partially, through controlling mTORC1 activity and the release of lysosomal ATP. Because TRPML1 is specifically activated by cellular stresses found in tumor microenvironments, antagonists of TRPML1 could represent anticancer drugs with enhanced specificity and potency. Our findings are expected to have a major impact on drug targeting of TNBCs.
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Affiliation(s)
- Mengnan Xu
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada; Department of Physiology, School of Basic Medicine, Anhui Medical University, Hefei, Anhui 230032, China
| | - Shekoufeh Almasi
- Department of Biology, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Yiming Yang
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Chi Yan
- Department of Microbiology & Immunology, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Andra Mihaela Sterea
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Alia Kazim Rizvi Syeda
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Bing Shen
- Department of Physiology, School of Basic Medicine, Anhui Medical University, Hefei, Anhui 230032, China
| | - Clements Richard Derek
- Department of Microbiology & Immunology, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Peng Huang
- College of Basic Medicine, Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Shashi Gujar
- Department of Microbiology & Immunology, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Jun Wang
- Department of Microbiology & Immunology, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada
| | - Wei-Xing Zong
- Department of Chemical Biology, Ernest Mario School of Pharmacy, Rutgers University, 164 Frelinghuysen Road, Piscataway NJ08854, USA
| | - Mohamed Trebak
- Department of Cellular and Molecular Physiology, Penn State University College of Medicine, Hershey PA 17033, USA
| | - Yassine El Hiani
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada.
| | - Xian-Ping Dong
- Department of Physiology and Biophysics, Dalhousie University, 5850 College Street, Halifax, B3H 4R2, Nova Scotia, Canada; Department of Physiology, School of Basic Medicine, Anhui Medical University, Hefei, Anhui 230032, China.
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25
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Wu CE, Chen MH, Yeh CN. mTOR Inhibitors in Advanced Biliary Tract Cancers. Int J Mol Sci 2019; 20:E500. [PMID: 30682771 PMCID: PMC6386826 DOI: 10.3390/ijms20030500] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 01/19/2019] [Accepted: 01/22/2019] [Indexed: 12/19/2022] Open
Abstract
Patients with advanced biliary tract cancers (BTCs), including cholangiocarcinoma (CCA), have poor prognosis so novel treatment is warranted for advanced BTC. In current review, we discuss the limitations of current treatment in BTC, the importance of mTOR signalling in BTC, and the possible role of mTOR inhibitors as a future treatment in BTC. Chemotherapy with gemcitabine-based chemotherapy is still the standard of care and no targeted therapy has been established in advanced BTC. PI3K/AKT/mTOR signaling pathway linking to several other pathways and networks regulates cancer proliferation and progression. Emerging evidences reveal mTOR activation is associated with tumorigenesis and drug-resistance in BTC. Rapalogs, such as sirolimus and everolimus, partially inhibit mTOR complex 1 (mTORC1) and exhibit anti-cancer activity in vitro and in vivo in BTC. Rapalogs in clinical trials demonstrate some activity in patients with advanced BTC. New-generation mTOR inhibitors against ATP-binding pocket inhibit both TORC1 and TORC2 and demonstrate more potent anti-tumor effects in vitro and in vivo, however, prospective clinical trials are warranted to prove its efficacy in patients with advanced BTC.
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Affiliation(s)
- Chao-En Wu
- Division of Hematology-Oncology, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou branch, Chang Gung University, Taoyuan 333, Taiwan.
| | - Ming-Huang Chen
- School of Medicine, National Yang-Ming University, Taipei 112, Taiwan.
- Department of Oncology, Taipei Veterans General Hospital, Taipei 112, Taiwan.
| | - Chun-Nan Yeh
- Department of General Surgery and Liver Research Center, Chang Gung Memorial Hospital, Linkou branch, Chang Gung University, Taoyuan 333, Taiwan.
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26
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Jung SH, Hwang HJ, Kang D, Park HA, Lee HC, Jeong D, Lee K, Park HJ, Ko YG, Lee JS. mTOR kinase leads to PTEN-loss-induced cellular senescence by phosphorylating p53. Oncogene 2018; 38:1639-1650. [PMID: 30337688 PMCID: PMC6755978 DOI: 10.1038/s41388-018-0521-8] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 08/16/2018] [Accepted: 09/09/2018] [Indexed: 12/12/2022]
Abstract
Loss of PTEN, the major negative regulator of the PI3K/AKT pathway induces a cellular senescence as a failsafe mechanism to defend against tumorigenesis, which is called PTEN-loss-induced cellular senescence (PICS). Although many studies have indicated that the mTOR pathway plays a critical role in cellular senescence, the exact functions of mTORC1 and mTORC2 in PICS are not well understood. In this study, we show that mTOR acts as a critical relay molecule downstream of PI3K/AKT and upstream of p53 in PICS. We found that PTEN depletion induces cellular senescence via p53-p21 signaling without triggering DNA damage response. mTOR kinase, a major component of mTORC1 and mTORC2, directly binds p53 and phosphorylates it at serine 15. mTORC1 and mTORC2 compete with MDM2 and increase the stability of p53 to induce cellular senescence via accumulation of the cell cycle inhibitor, p21. In embryonic fibroblasts of PTEN-knockout mice, PTEN deficiency also induces mTORC1 and mTORC2 to bind to p53 instead of MDM2, leading to cellular senescence. These results collectively demonstrate for the first time that mTOR plays a critical role in switching cells from proliferation signaling to senescence signaling via a direct link between the growth-promoting activity of AKT and the growth-suppressing activity of p53.
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Affiliation(s)
- Seung Hee Jung
- Department of Molecular Medicine, College of Medicine, Inha University, Incheon, 22212, Korea.,Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon, 22212, Korea
| | - Hyun Jung Hwang
- Department of Molecular Medicine, College of Medicine, Inha University, Incheon, 22212, Korea.,Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon, 22212, Korea
| | - Donghee Kang
- Department of Molecular Medicine, College of Medicine, Inha University, Incheon, 22212, Korea.,Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon, 22212, Korea
| | - Hyun A Park
- Department of Molecular Medicine, College of Medicine, Inha University, Incheon, 22212, Korea.,Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon, 22212, Korea
| | - Hyung Chul Lee
- Department of Molecular Medicine, College of Medicine, Inha University, Incheon, 22212, Korea.,Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon, 22212, Korea
| | - Daecheol Jeong
- Department of Biomedical Science, Hallym University, Chuncheon, Gangwon-do, 24252, Korea
| | - Keunwook Lee
- Department of Biomedical Science, Hallym University, Chuncheon, Gangwon-do, 24252, Korea
| | - Heon Joo Park
- Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon, 22212, Korea.,Department of Microbiology, College of Medicine, Inha University, Incheon, 22212, Korea
| | - Young-Gyu Ko
- Division of Life Sciences, Korea University, Seoul, 02841, Korea
| | - Jae-Seon Lee
- Department of Molecular Medicine, College of Medicine, Inha University, Incheon, 22212, Korea. .,Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon, 22212, Korea.
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27
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Abstract
Background The protein kinase Target Of Rapamycin (TOR) is a nexus for the regulation of eukaryotic cell growth. TOR assembles into one of two distinct signalling complexes, TOR complex 1 (TORC1) and TORC2 (mTORC1/2 in mammals), with a set of largely non-overlapping protein partners. (m)TORC1 activation occurs in response to a series of stimuli relevant to cell growth, including nutrient availability, growth factor signals and stress, and regulates much of the cell's biosynthetic activity, from proteins to lipids, and recycling through autophagy. mTORC1 regulation is of great therapeutic significance, since in humans many of these signalling complexes, alongside subunits of mTORC1 itself, are implicated in a wide variety of pathophysiologies, including multiple types of cancer, neurological disorders, neurodegenerative diseases and metabolic disorders including diabetes. Methodology Recent years have seen numerous structures determined of (m)TOR, which have provided mechanistic insight into (m)TORC1 activation in particular, however the integration of cellular signals occurs upstream of the kinase and remains incompletely understood. Here we have collected and analysed in detail as many as possible of the molecular and structural studies which have shed light on (m)TORC1 repression, activation and signal integration. Conclusions A molecular understanding of this signal integration pathway is required to understand how (m)TORC1 activation is reconciled with the many diverse and contradictory stimuli affecting cell growth. We discuss the current level of molecular understanding of the upstream components of the (m)TORC1 signalling pathway, recent progress on this key biochemical frontier, and the future studies necessary to establish a mechanistic understanding of this master-switch for eukaryotic cell growth.
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Affiliation(s)
- Kailash Ramlaul
- Section of Structural Biology, Department of Medicine, Imperial College London, SW7 2AZ, UK
| | - Christopher H S Aylett
- Section of Structural Biology, Department of Medicine, Imperial College London, SW7 2AZ, UK
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28
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Brown MC, Gromeier M. MNK Controls mTORC1:Substrate Association through Regulation of TELO2 Binding with mTORC1. Cell Rep 2017; 18:1444-1457. [PMID: 28178522 DOI: 10.1016/j.celrep.2017.01.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 12/09/2016] [Accepted: 01/11/2017] [Indexed: 01/20/2023] Open
Abstract
The mechanistic target of rapamycin (mTOR) integrates numerous stimuli and coordinates the adaptive response of many cellular processes. To accomplish this, mTOR associates with distinct co-factors that determine its signaling output. While many of these co-factors are known, in many cases their function and regulation remain opaque. The MAPK-interacting kinase (MNK) contributes to rapamycin resistance in cancer cells. Here, we demonstrate that MNK sustains mTORC1 activity following rapamycin treatment and contributes to mTORC1 signaling following T cell activation and growth stimuli in cancer cells. We determine that MNK engages with mTORC1, promotes mTORC1 association with the phosphatidyl inositol 3' kinase-related kinase (PIKK) stabilizer, TELO2, and facilitates mTORC1:substrate binding. Moreover, our data suggest that DEPTOR, the endogenous inhibitor of mTOR, opposes mTORC1:substrate association by preventing TELO2:mTORC1 binding. Thus, MNK orchestrates counterbalancing forces that regulate mTORC1 enzymatic activity.
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Affiliation(s)
- Michael C Brown
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA.
| | - Matthias Gromeier
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA
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Marques-Ramos A, Candeias MM, Menezes J, Lacerda R, Willcocks M, Teixeira A, Locker N, Romão L. Cap-independent translation ensures mTOR expression and function upon protein synthesis inhibition. RNA (NEW YORK, N.Y.) 2017; 23:1712-1728. [PMID: 28821580 PMCID: PMC5648038 DOI: 10.1261/rna.063040.117] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/15/2017] [Indexed: 06/07/2023]
Abstract
The mechanistic/mammalian target of rapamycin (mTOR) is a conserved serine/threonine kinase that integrates cellular signals from the nutrient and energy status to act, namely, on the protein synthesis machinery. While major advances have emerged regarding the regulators and effects of the mTOR signaling pathway, little is known about the regulation of mTOR gene expression. Here, we show that the human mTOR transcript can be translated in a cap-independent manner, and that its 5' untranslated region (UTR) is a highly folded RNA scaffold capable of binding directly to the 40S ribosomal subunit. We further demonstrate that mTOR is able to bypass the cap requirement for translation both in normal and hypoxic conditions. Moreover, our data reveal that the cap-independent translation of mTOR is necessary for its ability to induce cell-cycle progression into S phase. These results suggest a novel regulatory mechanism for mTOR gene expression that integrates the global protein synthesis changes induced by translational inhibitory conditions.
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Affiliation(s)
- Ana Marques-Ramos
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Marco M Candeias
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Laboratory of Bioimaging and Cell Signaling, Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Juliane Menezes
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Rafaela Lacerda
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Margaret Willcocks
- Microbial and Cellular Sciences Department, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7TE, United Kingdom
| | - Alexandre Teixeira
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
| | - Nicolas Locker
- Microbial and Cellular Sciences Department, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7TE, United Kingdom
| | - Luísa Romão
- Departamento de Genética Humana, Instituto Nacional de Saúde Doutor Ricardo Jorge, 1649-016 Lisboa, Portugal
- Biosystems and Integrative Sciences Institute (BioISI), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
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Rezabakhsh A, Ahmadi M, Khaksar M, Montaseri A, Malekinejad H, Rahbarghazi R, Garjani A. Rapamycin inhibits oxidative/nitrosative stress and enhances angiogenesis in high glucose-treated human umbilical vein endothelial cells: Role of autophagy. Biomed Pharmacother 2017; 93:885-894. [DOI: 10.1016/j.biopha.2017.07.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/26/2017] [Accepted: 07/09/2017] [Indexed: 11/30/2022] Open
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31
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Gu Y, Albuquerque CP, Braas D, Zhang W, Villa GR, Bi J, Ikegami S, Masui K, Gini B, Yang H, Gahman TC, Shiau AK, Cloughesy TF, Christofk HR, Zhou H, Guan KL, Mischel PS. mTORC2 Regulates Amino Acid Metabolism in Cancer by Phosphorylation of the Cystine-Glutamate Antiporter xCT. Mol Cell 2017. [PMID: 28648777 DOI: 10.1016/j.molcel.2017.05.030] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mutations in cancer reprogram amino acid metabolism to drive tumor growth, but the molecular mechanisms are not well understood. Using an unbiased proteomic screen, we identified mTORC2 as a critical regulator of amino acid metabolism in cancer via phosphorylation of the cystine-glutamate antiporter xCT. mTORC2 phosphorylates serine 26 at the cytosolic N terminus of xCT, inhibiting its activity. Genetic inhibition of mTORC2, or pharmacologic inhibition of the mammalian target of rapamycin (mTOR) kinase, promotes glutamate secretion, cystine uptake, and incorporation into glutathione, linking growth factor receptor signaling with amino acid uptake and utilization. These results identify an unanticipated mechanism regulating amino acid metabolism in cancer, enabling tumor cells to adapt to changing environmental conditions.
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Affiliation(s)
- Yuchao Gu
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Claudio P Albuquerque
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Daniel Braas
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; UCLA Metabolomics Center, Los Angeles, CA 90095, USA
| | - Wei Zhang
- Department of Medicine, UCSD School of Medicine, La Jolla, CA 92093, USA
| | - Genaro R Villa
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; Medical Scientist Training Program, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Junfeng Bi
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Shiro Ikegami
- Division of Neurological Surgery, Chiba Cancer Center, Chiba 260-8717, Japan
| | - Kenta Masui
- Department of Pathology, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Beatrice Gini
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Huijun Yang
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Timothy C Gahman
- Small Molecule Discovery Program, Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrew K Shiau
- Small Molecule Discovery Program, Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA
| | - Timothy F Cloughesy
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Heather R Christofk
- Department of Molecular and Medical Pharmacology, David Geffen UCLA School of Medicine, Los Angeles, CA 90095, USA; UCLA Metabolomics Center, Los Angeles, CA 90095, USA
| | - Huilin Zhou
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, UCSD School of Medicine, La Jolla, CA 92093, USA; Moores Cancer Center, UCSD School of Medicine, La Jolla, CA 92093 USA
| | - Kun-Liang Guan
- Department of Pharmacology, UCSD School of Medicine, La Jolla, CA 92093, USA; Moores Cancer Center, UCSD School of Medicine, La Jolla, CA 92093 USA
| | - Paul S Mischel
- Ludwig Institute for Cancer Research, University of California, San Diego, La Jolla, CA 92093, USA; Department of Pathology, UCSD School of Medicine, La Jolla, CA 92093 USA; Moores Cancer Center, UCSD School of Medicine, La Jolla, CA 92093 USA.
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Hussner J, Sünwoldt J, Seibert I, Gliesche DG, Zu Schwabedissen HEM. Pimecrolimus increases the expression of interferon-inducible genes that modulate human coronary artery cells proliferation. Eur J Pharmacol 2016; 784:137-46. [PMID: 27212382 DOI: 10.1016/j.ejphar.2016.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 04/21/2016] [Accepted: 05/18/2016] [Indexed: 10/21/2022]
Abstract
The pharmacodynamics of the loaded compounds defines clinical failure or success of a drug-eluting device. Various limus derivatives have entered clinics due to the observed positive outcome after stent implantation, which is explained by their antiproliferative activity resulting from inhibition of the cytosolic immunophilin FK506-binding protein 12. Although pimecrolimus also binds to this protein, pimecrolimus-eluting stents failed in clinics. However, despite its impact on T lymphocytes little is known about the pharmacodynamics of pimecrolimus in cultured human coronary artery cells. We were able to show that pimecrolimus exerts antiproliferative activity in human smooth muscle and endothelial cells. Furthermore in those cells pimecrolimus induced transcription of interferon-inducible genes which in part are known to modulate cell proliferation. Modulation of gene expression may be part of an interaction between calcineurin, the downstream target of the pimecrolimus/FK506-binding protein 12-complex, and the toll-like receptor 4. In accordance are our findings showing that silencing of toll-like receptor 4 by siRNA in A549 a lung carcinoma cell line reduced the activation of interferon-inducible genes upon pimecrolimus treatment in those cells. Based on our findings we hypothesize that calcineurin inhibition may induce the toll-like receptor 4 mediated activation of type I interferon signaling finally inducing the observed effect in endothelial and smooth muscle cells. The crosstalk of interferon and toll-like receptor signaling may be a molecular mechanism that contributed to the failure of pimecrolimus-eluting stents in humans.
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Affiliation(s)
- Janine Hussner
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Juliane Sünwoldt
- Institute of Pharmacology, Center of Drug Absorption and Transport, University Medicine, Ernst Moritz Arndt University Greifswald, Felix-Hausdorff-Strasse 3, 17489 Greifswald, Germany
| | - Isabell Seibert
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Daniel G Gliesche
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
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Abstract
Since the early 1980s, the combination of cyclosporine, azathioprine, and prednisone has been the mainstay tripledrug immunosuppressive regimen used in transplantation. However, advances in drug research, design, and development have allowed for the introduction of new agents that have greatly increased the number of immunosuppressive agents available for use in transplant recipients. Particularly, the newer antiproliferative immunosuppressive drugs (agents that directly inhibit the proliferation of T and B lymphocytes) have had an important impact on patient outcomes posttransplant. These agents are mycophenolate mofetil and sirolimus.
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Affiliation(s)
- Theodore M. Sievers
- Transplant Pharmacokinetic Laboratory, Dumont-UCLA Transplant Center, 10833 LeConte Avenue, Room 77-120, Los Angeles, CA 90025
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Abstract
Cardiovascular disease is a leading cause of death and disability worldwide. Current treatment strategies aimed at treating the symptoms and consequences of obstructive vascular disease have embraced both optimal medical therapy and catheter-based percutaneous coronary intervention with drug-eluting stents. Drug-eluting stents elute antiproliferative drugs inhibiting vascular smooth muscle cell proliferation, which occurs in response to injury and thus prevents restenosis. However, all drugs currently approved for use in drug-eluting stents do not discriminate between proliferating vascular smooth muscle cells and endothelial cells, thus delaying re-endothelialization and subsequent vascular healing.
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Affiliation(s)
- Anwer Habib
- Division of Cardiology, Department of Internal Medicine, Emory University School of Medicine, 101 Woodruff Circle, Atlanta, GA 30322, USA
| | - Aloke Virmani Finn
- CVPath Institute Inc, 19 Firstfield Road, Gaithersburg, MD 20878, USA; Division of Cardiology, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
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35
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Andersen TG, Nintemann SJ, Marek M, Halkier BA, Schulz A, Burow M. Improving analytical methods for protein-protein interaction through implementation of chemically inducible dimerization. Sci Rep 2016; 6:27766. [PMID: 27282591 PMCID: PMC4901268 DOI: 10.1038/srep27766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 05/24/2016] [Indexed: 01/11/2023] Open
Abstract
When investigating interactions between two proteins with complementary reporter tags in yeast two-hybrid or split GFP assays, it remains troublesome to discriminate true- from false-negative results and challenging to compare the level of interaction across experiments. This leads to decreased sensitivity and renders analysis of weak or transient interactions difficult to perform. In this work, we describe the development of reporters that can be chemically induced to dimerize independently of the investigated interactions and thus alleviate these issues. We incorporated our reporters into the widely used split ubiquitin-, bimolecular fluorescence complementation (BiFC)- and Förster resonance energy transfer (FRET)- based methods and investigated different protein-protein interactions in yeast and plants. We demonstrate the functionality of this concept by the analysis of weakly interacting proteins from specialized metabolism in the model plant Arabidopsis thaliana. Our results illustrate that chemically induced dimerization can function as a built-in control for split-based systems that is easily implemented and allows for direct evaluation of functionality.
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Affiliation(s)
- Tonni Grube Andersen
- Center for Dynamic Molecular Interactions (DynaMo), Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Sebastian J. Nintemann
- Center for Dynamic Molecular Interactions (DynaMo), Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Magdalena Marek
- Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Barbara A. Halkier
- Center for Dynamic Molecular Interactions (DynaMo), Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Alexander Schulz
- Center for Dynamic Molecular Interactions (DynaMo), Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Meike Burow
- Center for Dynamic Molecular Interactions (DynaMo), Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
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Rui YN, Xu Z, Chen Z, Zhang S. The GST-BHMT assay reveals a distinct mechanism underlying proteasome inhibition-induced macroautophagy in mammalian cells. Autophagy 2016; 11:812-32. [PMID: 25984893 DOI: 10.1080/15548627.2015.1034402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
By monitoring the fragmentation of a GST-BHMT (a protein fusion of glutathionine S-transferase N-terminal to betaine-homocysteine S-methyltransferase) reporter in lysosomes, the GST-BHMT assay has previously been established as an endpoint, cargo-based assay for starvation-induced autophagy that is largely nonselective. Here, we demonstrate that under nutrient-rich conditions, proteasome inhibition by either pharmaceutical or genetic manipulations induces similar autophagy-dependent GST-BHMT processing. However, mechanistically this proteasome inhibition-induced autophagy is different from that induced by starvation as it does not rely on regulation by MTOR (mechanistic target of rapamycin [serine/threonine kinase]) and PRKAA/AMPK (protein kinase, AMP-activated, α catalytic subunit), the upstream central sensors of cellular nutrition and energy status, but requires the presence of the cargo receptors SQSTM1/p62 (sequestosome 1) and NBR1 (neighbor of BRCA1 gene 1) that are normally involved in the selective autophagy pathway. Further, it depends on ER (endoplasmic reticulum) stress signaling, in particular ERN1/IRE1 (endoplasmic reticulum to nucleus signaling 1) and its main downstream effector MAPK8/JNK1 (mitogen-activated protein kinase 8), but not XBP1 (X-box binding protein 1), by regulating the phosphorylation-dependent disassociation of BCL2 (B-cell CLL/lymphoma 2) from BECN1 (Beclin 1, autophagy related). Moreover, the multimerization domain of GST-BHMT is required for its processing in response to proteasome inhibition, in contrast to its dispensable role in starvation-induced processing. Together, these findings support a model in which under nutrient-rich conditions, proteasome inactivation induces autophagy-dependent processing of the GST-BHMT reporter through a distinct mechanism that bears notable similarity with the yeast Cvt (cytoplasm-to-vacuole targeting) pathway, and suggest the GST-BHMT reporter might be employed as a convenient assay to study selective macroautophagy in mammalian cells.
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Key Words
- ACACA/B, acetyl-CoA carboxylase α/β
- ACTB, actin, β
- ATF4, activating transcription factor 4
- ATF6, activating transcription factor 6
- ATG7, autophagy-related 7
- BCL2, B-cell CLL/lymphoma 2
- BECN1, Beclin 1, autophagy-related
- BHMT
- BHMT, betaine-homocysteine S-methyltransferase
- Baf A1, bafilomycin A1
- CTNNB1, catenin (cadherin-associated protein), β 1, 88kDa
- Cvt, cytoplasm-to-vacuole-targeting
- DDIT3, DNA-damage-inducible transcript 3
- EBSS, Earle's Balanced Salt Solution
- EIF2AK3, eukaryotic translation initiation factor 2-α, kinase 3
- EIF4EBP1, eukaryotic translation initiation factor 4E binding protein 1
- ER, endoplasmic reticulum
- ERN1, endoplasmic reticulum to nucleus signaling 1
- GST, glutathionine S-transferase
- GST-BHMT(FRAG), an autophagy-mediated cleavage product of the GST-BHMT reporter
- GST-BHMT, a fusion protein of glutathionine S-transferase N-terminal to betaine-homocysteine S-methyltransferase
- HA, hemagglutinin
- HSPA5, heat shock 70kDa protein 5 (glucose-regulated protein, 78kDa)
- LSCS, linker-specific cleavage site
- MAP1LC3, microtubule-associated protein 1 light chain 3
- MAP2K7, mitogen-activated protein kinase kinase 7
- MAPK8, mitogen-activated protein kinase 8
- MTOR
- MTOR, mechanistic target of rapamycin (serine/threonine kinase)
- MTORC1, MTOR complex 1
- NBR1, neighbor of BRCA1 gene 1
- P4HB, prolyl 4-hydroxylase, β polypeptide
- PRKAA, protein kinase, AMP-activated, α catalytic subunit
- PRKAA/AMPK
- RHEB, Ras homolog enriched in brain
- RM, rich medium
- RPS6KB1, ribosomal protein S6 kinase, 70kDa, polypeptide 1
- SQSTM1, sequestosome 1
- TSC1/2, tuberous sclerosis 1/2
- ULK1, unc-51 like autophagy activating kinase 1
- UPR, unfolded protein response
- UPS, ubiquitin proteasome system
- XBP1, X-box binding protein 1
- cargo receptors SQSTM1/p62 and NBR1
- proteasome inhibition
- selective macroautophagy
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Affiliation(s)
- Yan-Ning Rui
- a The Brown Foundation Institute of Molecular Medicine
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Yin Y, Hua H, Li M, Liu S, Kong Q, Shao T, Wang J, Luo Y, Wang Q, Luo T, Jiang Y. mTORC2 promotes type I insulin-like growth factor receptor and insulin receptor activation through the tyrosine kinase activity of mTOR. Cell Res 2015; 26:46-65. [PMID: 26584640 DOI: 10.1038/cr.2015.133] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 09/15/2015] [Accepted: 10/08/2015] [Indexed: 02/05/2023] Open
Abstract
Mammalian target of rapamycin (mTOR) is a core component of raptor-mTOR (mTORC1) and rictor-mTOR (mTORC2) complexes that control diverse cellular processes. Both mTORC1 and mTORC2 regulate several elements downstream of type I insulin-like growth factor receptor (IGF-IR) and insulin receptor (InsR). However, it is unknown whether and how mTOR regulates IGF-IR and InsR themselves. Here we show that mTOR possesses unexpected tyrosine kinase activity and activates IGF-IR/InsR. Rapamycin induces the tyrosine phosphorylation and activation of IGF-IR/InsR, which is largely dependent on rictor and mTOR. Moreover, mTORC2 promotes ligand-induced activation of IGF-IR/InsR. IGF- and insulin-induced IGF-IR/InsR phosphorylation is significantly compromised in rictor-null cells. Insulin receptor substrate (IRS) directly interacts with SIN1 thereby recruiting mTORC2 to IGF-IR/InsR and promoting rapamycin- or ligand-induced phosphorylation of IGF-IR/InsR. mTOR exhibits tyrosine kinase activity towards the general tyrosine kinase substrate poly(Glu-Tyr) and IGF-IR/InsR. Both recombinant mTOR and immunoprecipitated mTORC2 phosphorylate IGF-IR and InsR on Tyr1131/1136 and Tyr1146/1151, respectively. These effects are independent of the intrinsic kinase activity of IGF-IR/InsR, as determined by assays on kinase-dead IGF-IR/InsR mutants. While both rictor and mTOR immunoprecitates from rictor(+/+) MCF-10A cells exhibit tyrosine kinase activity towards IGF-IR and InsR, mTOR immunoprecipitates from rictor(-/-) MCF-10A cells do not induce IGF-IR and InsR phosphorylation. Phosphorylation-deficient mutation of residue Tyr1131 in IGF-IR or Tyr1146 in InsR abrogates the activation of IGF-IR/InsR by mTOR. Finally, overexpression of rictor promotes IGF-induced cell proliferation. Our work identifies mTOR as a dual-specificity kinase and clarifies how mTORC2 promotes IGF-IR/InsR activation.
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Affiliation(s)
- Yancun Yin
- State Key Laboratory of Biotherapy, Section of Oncogene, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Hui Hua
- Laboratory of Stem Cell Biology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Minjing Li
- Medicine and Pharmacy Research Center, Binzhou Medical University, Yantai, Shandong 264003, China
| | - Shu Liu
- State Key Laboratory of Biotherapy, Section of Oncogene, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Qingbin Kong
- State Key Laboratory of Biotherapy, Section of Oncogene, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Ting Shao
- State Key Laboratory of Biotherapy, Section of Oncogene, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Jiao Wang
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 610075, China
| | - Yuanming Luo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qian Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ting Luo
- Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Yangfu Jiang
- State Key Laboratory of Biotherapy, Section of Oncogene, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
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Swer PB, Mishra H, Lohia R, Saran S. Overexpression of TOR (target of rapamycin) inhibits cell proliferation inDictyostelium discoideum. J Basic Microbiol 2015; 56:510-9. [DOI: 10.1002/jobm.201500313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 09/29/2015] [Indexed: 11/07/2022]
Affiliation(s)
- Pynskhem Bok Swer
- School of Life Sciences; Jawaharlal Nehru University; New Delhi India
| | - Himanshu Mishra
- School of Life Sciences; Jawaharlal Nehru University; New Delhi India
| | - Rakhee Lohia
- School of Life Sciences; Jawaharlal Nehru University; New Delhi India
| | - Shweta Saran
- School of Life Sciences; Jawaharlal Nehru University; New Delhi India
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Annexin A1 Preferentially Predicts Poor Prognosis of Basal-Like Breast Cancer Patients by Activating mTOR-S6 Signaling. PLoS One 2015; 10:e0127678. [PMID: 26000884 PMCID: PMC4441370 DOI: 10.1371/journal.pone.0127678] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 04/17/2015] [Indexed: 11/24/2022] Open
Abstract
Introduction Annexin A1 (ANXA1) is an anti-inflammatory protein reported to play a role in cell proliferation and apoptosis, and to be deregulated in breast cancer. The exact role of annexin A1 in the biology of breast cancer remains unclear. We hypothesized that the annexin A1 plays an oncogenic role in basal subtype of breast cancer by modulating key growth pathway(s). Methods By mining the Cancer Genome Atlas (TCGA)-Breast Cancer dataset and manipulating annexin A1 levels in breast cancer cell lines, we studied the role of annexin A1 in breast cancer and underlying signaling pathways. Results Our in-silico analysis of TCGA-breast cancer dataset demonstrated that annexin A1 mRNA expression is higher in basal subtype compared to luminal and HER2 subtypes. Within the basal subtype, patients show significantly poorer overall survival associated with higher expression of annexin A1. In both TCGA patient samples and cell lines, annexin A1 levels were significantly higher in basal-like breast cancer than luminal and Her2/neu-positive breast cancer. Stable annexin A1 knockdown in TNBC cell lines suppressed the mTOR-S6 pathway likely through activation of AMPK but had no impact on the MAPK, c-Met, and EGFR pathways. In a cell migration assay, annexin A1-depleted TNBC cells showed delayed migration as compared to wild-type cells, which could be responsible for poor patient prognosis in basal like breast cancers that are known to express higher annexin A1. Conclusions Our data suggest that annexin A1 is prognostic only in patients with basal like breast cancer. This appears to be in part due to the role of annexin A1 in activating mTOR-pS6 pathway.
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Yoon MS, Rosenberger CL, Wu C, Truong N, Sweedler JV, Chen J. Rapid mitogenic regulation of the mTORC1 inhibitor, DEPTOR, by phosphatidic acid. Mol Cell 2015; 58:549-56. [PMID: 25936805 DOI: 10.1016/j.molcel.2015.03.028] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 01/23/2015] [Accepted: 03/23/2015] [Indexed: 02/06/2023]
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) is regulated, in part, by the endogenous inhibitor DEPTOR. However, the mechanism of DEPTOR regulation with regard to rapid mTORC1 activation remains unknown. We report that DEPTOR is rapidly and temporarily dissociated from mTORC1 upon mitogenic stimulation, suggesting a mechanism underlying acute mTORC1 activation. This mitogen-stimulated DEPTOR dissociation is blocked by inhibition or depletion of the mTORC1 regulator, phospholipase D (PLD), and recapitulated with the addition of the PLD product phosphatidic acid (PA). Our mass spectrometry analysis has independently identified DEPTOR as an mTOR binding partner dissociated by PA. Interestingly, only PA species with unsaturated fatty acid chains, such as those produced by PLD, are capable of displacing DEPTOR and activating mTORC1, with high affinity for the FRB domain of mTOR. Our findings reveal a mechanism of mTOR regulation and provide a molecular explanation for the exquisite specificity of PA function.
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Affiliation(s)
- Mee-Sup Yoon
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA; Department of Molecular Medicine, Graduate School of Medicine, Gachon University, Incheon 406-840, Republic of Korea.
| | - Christina L Rosenberger
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Cong Wu
- Departments of Chemistry and Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Nga Truong
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Jonathan V Sweedler
- Departments of Chemistry and Biochemistry, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA
| | - Jie Chen
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, Urbana, IL 61801, USA.
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Wu X, Bhayani MK, Dodge CT, Nicoloso MS, Chen Y, Yan X, Adachi M, Thomas L, Galer CE, Jiffar T, Pickering CR, Kupferman ME, Myers JN, Calin GA, Lai SY. Coordinated targeting of the EGFR signaling axis by microRNA-27a*. Oncotarget 2014; 4:1388-98. [PMID: 23963114 PMCID: PMC3824521 DOI: 10.18632/oncotarget.1239] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Epidermal growth factor receptor (EGFR) has been characterized as a critical factor in the development and progression of multiple solid tumors, including head and neck squamous cell carcinoma (HNSCC). However, monotherapy with EGFR-specific agents has not been as dramatic as preclinical studies have suggested. Since complex regulation of the EGFR signaling axis might confound current attempts to inhibit EGFR directly, we searched for microRNAs (miRNAs) that may target the EGFR signaling axis. We identified miR-27a (miR-27a-3p) and its complementary or star (*) strand, miR-27a* (miR-27a-5p), as novel miRNAs targeting EGFR, which were significantly downregulated in multiple HNSCC cell lines. Analysis of human specimens demonstrated that miR-27a* is significantly underexpressed in HNSCC as compared to normal mucosa. Increased expression of miR-27a* in HNSCC produced a profound cytotoxic effect not seen with miR-27a. Analysis for potential targets of miR-27a* led to the identification of AKT1 (protein kinase B) and mTOR (mammalian target of rapamycin) within the EGFR signaling axis. Treatment with miR-27a* led to coordinated downregulation of EGFR, AKT1 and mTOR. Overexpression of EGFR signaling pathway components decreased the overall effect of miR-27a* on HNSCC cell viability. Constitutive and inducible expression of miR-27a* in a murine orthotopic xenograft model of oral cavity cancer led to decreased tumor growth. Direct intratumoral injection of miR-27a* inhibited tumor growth in vivo. These findings identify miR-27a* as a functional star sequence that exhibits novel coordinated regulation of the EGFR pathway in solid tumors and potentially represents a novel therapeutic option.
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Affiliation(s)
- Xiaoli Wu
- Department of Head and Neck Surgery, University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
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New Medical/Biologic Paradigms in the Treatment of Bone Tumors. CURRENT SURGERY REPORTS 2014. [DOI: 10.1007/s40137-014-0055-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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He Y, Li D, Cook SL, Yoon MS, Kapoor A, Rao CV, Kenis PJA, Chen J, Wang F. Mammalian target of rapamycin and Rictor control neutrophil chemotaxis by regulating Rac/Cdc42 activity and the actin cytoskeleton. Mol Biol Cell 2013; 24:3369-80. [PMID: 24006489 PMCID: PMC3814157 DOI: 10.1091/mbc.e13-07-0405] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Rictor, a component of mammalian target of rapamycin complex 2 (mTORC2), controls neutrophil chemotaxis by regulating the dynamics of the actin cytoskeleton via Rac and Cdc42. This function of Rictor is independent of mTORC2 and the kinase activity of mTOR. Chemotaxis allows neutrophils to seek out sites of infection and inflammation. The asymmetric accumulation of filamentous actin (F-actin) at the leading edge provides the driving force for protrusion and is essential for the development and maintenance of neutrophil polarity. The mechanism that governs actin cytoskeleton dynamics and assembly in neutrophils has been extensively explored and is still not fully understood. By using neutrophil-like HL-60 cells, we describe a pivotal role for Rictor, a component of mammalian target of rapamycin complex 2 (mTORC2), in regulating assembly of the actin cytoskeleton during neutrophil chemotaxis. Depletion of mTOR and Rictor, but not Raptor, impairs actin polymerization, leading-edge establishment, and directional migration in neutrophils stimulated with chemoattractants. Of interest, depletion of mSin1, an integral component of mTORC2, causes no detectable defects in neutrophil polarity and chemotaxis. In addition, experiments with chemical inhibition and kinase-dead mutants indicate that mTOR kinase activity and AKT phosphorylation are dispensable for chemotaxis. Instead, our results suggest that the small Rho GTPases Rac and Cdc42 serve as downstream effectors of Rictor to regulate actin assembly and organization in neutrophils. Together our findings reveal an mTORC2- and mTOR kinase–independent function and mechanism of Rictor in the regulation of neutrophil chemotaxis.
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Affiliation(s)
- Yuan He
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801 Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
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Habib A, Karmali V, Polavarapu R, Akahori H, Cheng Q, Pachura K, Kolodgie FD, Finn AV. Sirolimus-FKBP12.6 impairs endothelial barrier function through protein kinase C-α activation and disruption of the p120-vascular endothelial cadherin interaction. Arterioscler Thromb Vasc Biol 2013; 33:2425-31. [PMID: 23887639 DOI: 10.1161/atvbaha.113.301659] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE Sirolimus (SRL) is an immunosuppressant drug used to prevent rejection in organ transplantation and neointimal hyperplasia when delivered from drug-eluting stents. Major side effects of SRL include edema and local collection of intimal lipid deposits at drug-eluting stent sites, suggesting that SRL impairs endothelial barrier function (EBF). The aim of this study was to address the role of SRL on impaired EBF and the potential mechanisms involved. APPROACH AND RESULTS Cultured human aortic endothelial cells (HAECs) and intact human and mouse endothelium was examined to determine the effect of SRL, which binds FKBP12.6 to inhibit the mammalian target of rapamycin, on EBF. EBF, measured by transendothelial electrical resistance, was impaired in HAECs when treated with SRL or small interfering RNA for FKBP12.6 and reversed when pretreated with ryanodine, a stabilizer of ryanodine receptor 2 intracellular calcium release channels. Intracellular calcium increased in HAECs treated with SRL and normalized with ryanodine pretreatment. SRL-treated HAECs demonstrated increases in protein kinase C-α phosphorylation, a calcium sensitive serine/threonine kinase important in vascular endothelial (VE) cadherin barrier function through its interaction with p120-catenin (p120). Immunostaining of HAECs, human coronary and mouse aortic endothelium treated with SRL showed disruption of p120-VE cadherin interaction treated with SRL. SRL impairment of HAEC EBF was reduced with protein kinase C-α small interfering RNA. Mice treated with SRL demonstrated increased vascular permeability by Evans blue albumin extravasation in the lungs, heart, and aorta. CONCLUSIONS SRL-FKBP12.6 impairs EBF by activation of protein kinase C-α and downstream disruption of the p120-VE cadherin interaction in vascular endothelium. These data suggest this mechanism may be an important contributor of SRL side effects related to impaired EBF.
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Affiliation(s)
- Anwer Habib
- From the Department of Medicine, Emory University School of Medicine, Atlanta, GA (A.H., V.K., R.P., H.A., K.P., A.V.F.); and CV Path Institute, Inc, Gaithersburg, MD (Q.C., F.D.K.)
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Ando K, Heymann MF, Stresing V, Mori K, Rédini F, Heymann D. Current therapeutic strategies and novel approaches in osteosarcoma. Cancers (Basel) 2013; 5:591-616. [PMID: 24216993 PMCID: PMC3730336 DOI: 10.3390/cancers5020591] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/28/2013] [Accepted: 05/09/2013] [Indexed: 12/14/2022] Open
Abstract
Osteosarcoma is the most frequent malignant primary bone tumor and a main cause of cancer-related death in children and adolescents. Although long-term survival in localized osteosarcoma has improved to about 60% during the 1960s and 1970s, long-term survival in both localized and metastatic osteosarcoma has stagnated in the past several decades. Thus, current conventional therapy consists of multi-agent chemotherapy, surgery and radiation, which is not fully adequate for osteosarcoma treatment. Innovative drugs and approaches are needed to further improve outcome in osteosarcoma patients. This review describes the current management of osteosarcoma as well as potential new therapies.
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Affiliation(s)
- Kosei Ando
- INSERM, UMR 957, 1 Rue Gaston Veil, 44035 Nantes, France; E-Mails: (M.-F.H.); (V.S.); (F.R.); (D.H.)
- Physiopathologie de la Résorption Osseuse et Therapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, 1 Rue Gaston Veil, 44035 Nantes, France
- Equipe Labellisee Ligue 2012, Nantes, 44035 France
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +33-(0)-240-412-895; Fax: +33-(0)-272-641-132
| | - Marie-Françoise Heymann
- INSERM, UMR 957, 1 Rue Gaston Veil, 44035 Nantes, France; E-Mails: (M.-F.H.); (V.S.); (F.R.); (D.H.)
- Physiopathologie de la Résorption Osseuse et Therapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, 1 Rue Gaston Veil, 44035 Nantes, France
- Equipe Labellisee Ligue 2012, Nantes, 44035 France
- Nantes University Hospital, Nantes 44035, France
| | - Verena Stresing
- INSERM, UMR 957, 1 Rue Gaston Veil, 44035 Nantes, France; E-Mails: (M.-F.H.); (V.S.); (F.R.); (D.H.)
- Physiopathologie de la Résorption Osseuse et Therapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, 1 Rue Gaston Veil, 44035 Nantes, France
- Nantes University Hospital, Nantes 44035, France
| | - Kanji Mori
- Department of Orthopaedic Surgery, Shiga University of Medical Science, Tsukinowa-cho, Seta, Otsu, Shiga 520-2192, Japan; E-Mail:
| | - Françoise Rédini
- INSERM, UMR 957, 1 Rue Gaston Veil, 44035 Nantes, France; E-Mails: (M.-F.H.); (V.S.); (F.R.); (D.H.)
- Physiopathologie de la Résorption Osseuse et Therapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, 1 Rue Gaston Veil, 44035 Nantes, France
- Equipe Labellisee Ligue 2012, Nantes, 44035 France
- Nantes University Hospital, Nantes 44035, France
| | - Dominique Heymann
- INSERM, UMR 957, 1 Rue Gaston Veil, 44035 Nantes, France; E-Mails: (M.-F.H.); (V.S.); (F.R.); (D.H.)
- Physiopathologie de la Résorption Osseuse et Therapie des Tumeurs Osseuses Primitives, Université de Nantes, Nantes Atlantique Universités, 1 Rue Gaston Veil, 44035 Nantes, France
- Equipe Labellisee Ligue 2012, Nantes, 44035 France
- Nantes University Hospital, Nantes 44035, France
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Yang H, Rudge DG, Koos JD, Vaidialingam B, Yang HJ, Pavletich NP. mTOR kinase structure, mechanism and regulation. Nature 2013; 497:217-23. [PMID: 23636326 PMCID: PMC4512754 DOI: 10.1038/nature12122] [Citation(s) in RCA: 738] [Impact Index Per Article: 67.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 03/26/2013] [Indexed: 12/30/2022]
Abstract
The mammalian target of rapamycin (mTOR), a phosphoinositide 3-kinase-related protein kinase, controls cell growth in response to nutrients and growth factors and is frequently deregulated in cancer. Here we report co-crystal structures of a complex of truncated mTOR and mammalian lethal with SEC13 protein 8 (mLST8) with an ATP transition state mimic and with ATP-site inhibitors. The structures reveal an intrinsically active kinase conformation, with catalytic residues and a catalytic mechanism remarkably similar to canonical protein kinases. The active site is highly recessed owing to the FKBP12-rapamycin-binding (FRB) domain and an inhibitory helix protruding from the catalytic cleft. mTOR-activating mutations map to the structural framework that holds these elements in place, indicating that the kinase is controlled by restricted access. In vitro biochemistry shows that the FRB domain acts as a gatekeeper, with its rapamycin-binding site interacting with substrates to grant them access to the restricted active site. Rapamycin-FKBP12 inhibits the kinase by directly blocking substrate recruitment and by further restricting active-site access. The structures also reveal active-site residues and conformational changes that underlie inhibitor potency and specificity.
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Affiliation(s)
- Haijuan Yang
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065, USA
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Cang C, Zhou Y, Navarro B, Seo YJ, Aranda K, Shi L, Battaglia-Hsu S, Nissim I, Clapham DE, Ren D. mTOR regulates lysosomal ATP-sensitive two-pore Na(+) channels to adapt to metabolic state. Cell 2013; 152:778-790. [PMID: 23394946 DOI: 10.1016/j.cell.2013.01.023] [Citation(s) in RCA: 292] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 08/31/2012] [Accepted: 01/14/2013] [Indexed: 12/11/2022]
Abstract
Survival in the wild requires organismal adaptations to the availability of nutrients. Endosomes and lysosomes are key intracellular organelles that couple nutrition and metabolic status to cellular responses, but how they detect cytosolic ATP levels is not well understood. Here, we identify an endolysosomal ATP-sensitive Na(+) channel (lysoNa(ATP)). The channel is a complex formed by two-pore channels (TPC1 and TPC2), ion channels previously thought to be gated by nicotinic acid adenine dinucleotide phosphate (NAADP), and the mammalian target of rapamycin (mTOR). The channel complex detects nutrient status, becomes constitutively open upon nutrient removal and mTOR translocation off the lysosomal membrane, and controls the lysosome's membrane potential, pH stability, and amino acid homeostasis. Mutant mice lacking lysoNa(ATP) have much reduced exercise endurance after fasting. Thus, TPCs make up an ion channel family that couples the cell's metabolic state to endolysosomal function and are crucial for physical endurance during food restriction.
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Affiliation(s)
- Chunlei Cang
- Department of Biology, University of Pennsylvania, 415 S. University Ave., Philadelphia, Pennsylvania 19104, USA
| | - Yandong Zhou
- Department of Biology, University of Pennsylvania, 415 S. University Ave., Philadelphia, Pennsylvania 19104, USA
| | - Betsy Navarro
- Howard Hughes Medical Institute, Department of Cardiology, Children's Hospital, Boston, Massachusetts 02115, USA
| | - Young-Jun Seo
- Department of Biology, University of Pennsylvania, 415 S. University Ave., Philadelphia, Pennsylvania 19104, USA
| | - Kimberly Aranda
- Department of Biology, University of Pennsylvania, 415 S. University Ave., Philadelphia, Pennsylvania 19104, USA
| | - Lucy Shi
- Department of Biology, University of Pennsylvania, 415 S. University Ave., Philadelphia, Pennsylvania 19104, USA
| | - Shyuefang Battaglia-Hsu
- INSERM U954, Nutrition Génétique et exposition aux risques environnementaux Faculté de Médecine - BP 184, Université de Lorraine, 54505 VANDOEUVRE LES NANCY CEDEX, FRANCE
| | - Itzhak Nissim
- Division of Child Development and Metabolic Disease, Children's Hospital of Philadelphia, Department of Pediatrics, Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - David E Clapham
- Howard Hughes Medical Institute, Department of Cardiology, Children's Hospital, Boston, Massachusetts 02115, USA
| | - Dejian Ren
- Department of Biology, University of Pennsylvania, 415 S. University Ave., Philadelphia, Pennsylvania 19104, USA
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Abstract
The immunosuppressant and anticancer drug rapamycin works by inducing inhibitory protein complexes with the kinase mTOR, an important regulator of growth and proliferation. The obligatory accessory partner of rapamycin is believed to be FK506-binding protein 12 (FKBP12). Here we show that rapamycin complexes of larger FKBP family members can tightly bind to mTOR and potently inhibit its kinase activity. Cocrystal structures with FKBP51 and FKBP52 reveal the modified molecular binding mode of these alternative ternary complexes in detail. In cellular model systems, FKBP12 can be functionally replaced by larger FKBPs. When the rapamycin dosage is limiting, mTOR inhibition of S6K phosphorylation can be enhanced by FKBP51 overexpression in mammalian cells, whereas FKBP12 is dispensable. FKBP51 could also enable the rapamycin-induced hyperphosphorylation of Akt, which depended on higher FKBP levels than rapamycin-induced inhibition of S6K phosphorylation. These insights provide a mechanistic rationale for preferential mTOR inhibition in specific cell or tissue types by engaging specific FKBP homologs.
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You JS, Frey JW, Hornberger TA. Mechanical stimulation induces mTOR signaling via an ERK-independent mechanism: implications for a direct activation of mTOR by phosphatidic acid. PLoS One 2012; 7:e47258. [PMID: 23077579 PMCID: PMC3471816 DOI: 10.1371/journal.pone.0047258] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 09/10/2012] [Indexed: 11/18/2022] Open
Abstract
Signaling by mTOR is a well-recognized component of the pathway through which mechanical signals regulate protein synthesis and muscle mass. However, the mechanisms involved in the mechanical regulation of mTOR signaling have not been defined. Nevertheless, recent studies suggest that a mechanically-induced increase in phosphatidic acid (PA) may be involved. There is also evidence which suggests that mechanical stimuli, and PA, utilize ERK to induce mTOR signaling. Hence, we reasoned that a mechanically-induced increase in PA might promote mTOR signaling via an ERK-dependent mechanism. To test this, we subjected mouse skeletal muscles to mechanical stimulation in the presence or absence of a MEK/ERK inhibitor, and then measured several commonly used markers of mTOR signaling. Transgenic mice expressing a rapamycin-resistant mutant of mTOR were also used to confirm the validity of these markers. The results demonstrated that mechanically-induced increases in p70(s6k) T389 and 4E-BP1 S64 phosphorylation, and unexpectedly, a loss in total 4E-BP1, were fully mTOR-dependent signaling events. Furthermore, we determined that mechanical stimulation induced these mTOR-dependent events, and protein synthesis, through an ERK-independent mechanism. Similar to mechanical stimulation, exogenous PA also induced mTOR-dependent signaling via an ERK-independent mechanism. Moreover, PA was able to directly activate mTOR signaling in vitro. Combined, these results demonstrate that mechanical stimulation induces mTOR signaling, and protein synthesis, via an ERK-independent mechanism that potentially involves a direct interaction of PA with mTOR. Furthermore, it appears that a decrease in total 4E-BP1 may be part of the mTOR-dependent mechanism through which mechanical stimuli activate protein synthesis.
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Affiliation(s)
- Jae Sung You
- Program in Cellular and Molecular Biology, University of Wisconsin- Madison, Madison, Wisconsin, United States of America
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - John W. Frey
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
| | - Troy A. Hornberger
- Program in Cellular and Molecular Biology, University of Wisconsin- Madison, Madison, Wisconsin, United States of America
- Department of Comparative Biosciences in the School of Veterinary Medicine, University of Wisconsin - Madison, Madison, Wisconsin, United States of America
- * E-mail:
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