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Swiderski K, Naim T, Trieu J, Chee A, Herold MJ, Kueh AJ, Goodman CA, Gregorevic P, Lynch GS. Dystrophin S3059 phosphorylation partially attenuates denervation atrophy in mouse tibialis anterior muscles. Physiol Rep 2024; 12:e16145. [PMID: 39001580 PMCID: PMC11245571 DOI: 10.14814/phy2.16145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/02/2024] [Accepted: 07/02/2024] [Indexed: 07/16/2024] Open
Abstract
The dystrophin protein has well-characterized roles in force transmission and maintaining membrane integrity during muscle contraction. Studies have reported decreased expression of dystrophin in atrophying muscles during wasting conditions, and that restoration of dystrophin can attenuate atrophy, suggesting a role in maintaining muscle mass. Phosphorylation of S3059 within the cysteine-rich region of dystrophin enhances binding between dystrophin and β-dystroglycan, and mimicking phosphorylation at this site by site-directed mutagenesis attenuates myotube atrophy in vitro. To determine whether dystrophin phosphorylation can attenuate muscle wasting in vivo, CRISPR-Cas9 was used to generate mice with whole body mutations of S3059 to either alanine (DmdS3059A) or glutamate (DmdS3059E), to mimic a loss of, or constitutive phosphorylation of S3059, on all endogenous dystrophin isoforms, respectively. Sciatic nerve transection was performed on these mice to determine whether phosphorylation of dystrophin S3059 could attenuate denervation atrophy. At 14 days post denervation, atrophy of tibialis anterior (TA) but not gastrocnemius or soleus muscles, was partially attenuated in DmdS3059E mice relative to WT mice. Attenuation of atrophy was associated with increased expression of β-dystroglycan in TA muscles of DmdS3059E mice. Dystrophin S3059 phosphorylation can partially attenuate denervation-induced atrophy, but may have more significant impact in less severe modes of muscle wasting.
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Affiliation(s)
- Kristy Swiderski
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Timur Naim
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Jennifer Trieu
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Annabel Chee
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Marco J. Herold
- The Walter and Eliza Hall Institute of Medical ResearchParkvilleVictoriaAustralia
- Department of Medical BiologyThe University of MelbourneMelbourneVictoriaAustralia
- Olivia Newton‐John Cancer Research InstituteHeidelbergVictoriaAustralia
- School of Cancer MedicineLa Trobe UniversityHeidelbergVictoriaAustralia
| | - Andrew J. Kueh
- The Walter and Eliza Hall Institute of Medical ResearchParkvilleVictoriaAustralia
- Department of Medical BiologyThe University of MelbourneMelbourneVictoriaAustralia
- Olivia Newton‐John Cancer Research InstituteHeidelbergVictoriaAustralia
- School of Cancer MedicineLa Trobe UniversityHeidelbergVictoriaAustralia
| | - Craig A. Goodman
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Paul Gregorevic
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
| | - Gordon S. Lynch
- Department of Anatomy and Physiology, Centre for Muscle ResearchThe University of MelbourneMelbourneVictoriaAustralia
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Tollot-Wegner M, Jessen M, Kim K, Sanz-Moreno A, Spielmann N, Gailus-Durner V, Fuchs H, Hrabe de Angelis M, von Eyss B. TRPS1 maintains luminal progenitors in the mammary gland by repressing SRF/MRTF activity. Breast Cancer Res 2024; 26:74. [PMID: 38702730 PMCID: PMC11067134 DOI: 10.1186/s13058-024-01824-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/12/2024] [Indexed: 05/06/2024] Open
Abstract
The transcription factor TRPS1 is a context-dependent oncogene in breast cancer. In the mammary gland, TRPS1 activity is restricted to the luminal population and is critical during puberty and pregnancy. Its function in the resting state remains however unclear. To evaluate whether it could be a target for cancer therapy, we investigated TRPS1 function in the healthy adult mammary gland using a conditional ubiquitous depletion mouse model where long-term depletion does not affect fitness. Using transcriptomic approaches, flow cytometry and functional assays, we show that TRPS1 activity is essential to maintain a functional luminal progenitor compartment. This requires the repression of both YAP/TAZ and SRF/MRTF activities. TRPS1 represses SRF/MRTF activity indirectly by modulating RhoA activity. Our work uncovers a hitherto undisclosed function of TRPS1 in luminal progenitors intrinsically linked to mechanotransduction in the mammary gland. It may also provide new insights into the oncogenic functions of TRPS1 as luminal progenitors are likely the cells of origin of many breast cancers.
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Affiliation(s)
- Marie Tollot-Wegner
- Transcriptional Control of Tissue Homeostasis Lab, Leibniz Institute on Aging, Fritz Lipmann Institute E.V., Beutenbergstr. 11, 07745, Jena, Germany
| | - Marco Jessen
- Transcriptional Control of Tissue Homeostasis Lab, Leibniz Institute on Aging, Fritz Lipmann Institute E.V., Beutenbergstr. 11, 07745, Jena, Germany
| | - KyungMok Kim
- Transcriptional Control of Tissue Homeostasis Lab, Leibniz Institute on Aging, Fritz Lipmann Institute E.V., Beutenbergstr. 11, 07745, Jena, Germany
| | - Adrián Sanz-Moreno
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, Ingolstaedter Landstr.1, Neuherberg, Germany
| | - Nadine Spielmann
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, Ingolstaedter Landstr.1, Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, Ingolstaedter Landstr.1, Neuherberg, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, Ingolstaedter Landstr.1, Neuherberg, Germany
| | - Martin Hrabe de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, Ingolstaedter Landstr.1, Neuherberg, Germany
- Chair of Experimental Genetics, TUM School of Life Sciences, Technische Universität München, Alte Akademie 8, 85354, Freising, Germany
- German Center for Diabetes Research (DZD), Ingolstaedter Landstraße. 1, 85764, Neuherberg, Germany
| | - Björn von Eyss
- Transcriptional Control of Tissue Homeostasis Lab, Leibniz Institute on Aging, Fritz Lipmann Institute E.V., Beutenbergstr. 11, 07745, Jena, Germany.
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Zhang X, Jackson S, Liu J, Li J, Yang Z, Sun D, Zhang W. Arsenic aggravates the progression of diabetic nephropathy through miRNA-mRNA-autophagy axis. Food Chem Toxicol 2024; 187:114628. [PMID: 38579892 DOI: 10.1016/j.fct.2024.114628] [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: 01/03/2024] [Revised: 02/26/2024] [Accepted: 03/28/2024] [Indexed: 04/07/2024]
Abstract
Environmental factors play an important role in the progression of diabetic nephropathy (DN), and previous study has shown that arsenic exposure can promote kidney damage in DN rats, however there is no relevant mechanism study so far. In this study, an arsenic-exposed (10 mg/L and 25 mg/L) DN mouse model was established through drinking water for 14 weeks. The results showed that 25 mg/L arsenic exposure increased the renal fibrosis in DN mice significantly, and urinary mAlb level increased with the increasing of arsenic exposure level. Transcriptome sequencing showed that autophagy-related pathways were significantly activated under the exposure dose of 25 mg/L, and levels of Beclin1 and p-ATG16L1/ATG16L1 were significantly higher in the 25 mg/L arsenic group compared to the control group. Silico analysis predicted the microRNAs those could regulate the hub genes of Mapk1, Rhoa and Cdc42, and dual-luciferase gene reporter assay was used to verify the targeted binding between these mRNAs and microRNAs. Our results suggested that high arsenic exposure could aggravate the progression of DN by altering autophagy, the miRNA-mRNA axles of let-7a-1-3p, let-7b-3p, let-7f-1-3p, miR-98-3p/Cdc42, Mapk1, Rhoa, could be considered promising targets to explore the mechanisms and therapeutic measures of DN after exposure to high levels of arsenic.
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Affiliation(s)
- Xiaodan Zhang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Harbin, 150081, China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health, Harbin, 150081, China
| | - Sira Jackson
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Harbin, 150081, China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health, Harbin, 150081, China; Department of Biomedical Sciences, University of Ngaoundéré, P.O Box 454, Ngaoundéré, Cameroon
| | - Jianhao Liu
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Harbin, 150081, China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health, Harbin, 150081, China; The Fourth Hospital of Baotou, Baotou, 014030, China
| | - Jinyu Li
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Harbin, 150081, China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health, Harbin, 150081, China
| | - Zhihan Yang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Harbin, 150081, China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health, Harbin, 150081, China
| | - Dianjun Sun
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Harbin, 150081, China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health, Harbin, 150081, China.
| | - Wei Zhang
- Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, China; Key Lab of Etiology and Epidemiology, Education Bureau of Heilongjiang Province & Ministry of Health (23618504), Harbin, 150081, China; Heilongjiang Provincial Key Laboratory of Trace Elements and Human Health, Harbin, 150081, China.
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4
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Li B, Khan MZ, Khan IM, Ullah Q, Cisang ZM, Zhang N, Wu D, Huang B, Ma Y, Khan A, Jiang N, Zahoor M. Genetics, environmental stress, and amino acid supplementation affect lactational performance via mTOR signaling pathway in bovine mammary epithelial cells. Front Genet 2023; 14:1195774. [PMID: 37636261 PMCID: PMC10448190 DOI: 10.3389/fgene.2023.1195774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/26/2023] [Indexed: 08/29/2023] Open
Abstract
Mammary glands are known for their ability to convert nutrients present in the blood into milk contents. In cows, milk synthesis and the proliferation of cow mammary epithelial cells (CMECs) are regulated by various factors, including nutrients such as amino acids and glucose, hormones, and environmental stress. Amino acids, in particular, play a crucial role in regulating cell proliferation and casein synthesis in mammalian epithelial cells, apart from being building blocks for protein synthesis. Studies have shown that environmental factors, particularly heat stress, can negatively impact milk production performance in dairy cattle. The mammalian target of rapamycin complex 1 (mTORC1) pathway is considered the primary signaling pathway involved in regulating cell proliferation and milk protein and fat synthesis in cow mammary epithelial cells in response to amino acids and heat stress. Given the significant role played by the mTORC signaling pathway in milk synthesis and cell proliferation, this article briefly discusses the main regulatory genes, the impact of amino acids and heat stress on milk production performance, and the regulation of mTORC signaling pathway in cow mammary epithelial cells.
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Affiliation(s)
- Bin Li
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Muhammad Zahoor Khan
- Liaocheng Research Institute of Donkey High‐Efficiency Breeding and Ecological Feeding, Agricultural Science and Engineering School, Liaocheng University, Liaocheng, China
- Faculty of Veterinary and Animal Sciences, The University of Agriculture, Dera Ismail Khan, Pakistan
| | - Ibrar Muhammad Khan
- Anhui Province Key Laboratory of Embryo Development and Reproduction Regulation, Anhui Province Key Laboratory of Environmental Hormone and Reproduction, School of Biological and Food Engineering, Fuyang Normal University, Fuyang, China
| | - Qudrat Ullah
- Faculty of Veterinary and Animal Sciences, The University of Agriculture, Dera Ismail Khan, Pakistan
| | - Zhuo-Ma Cisang
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Nan Zhang
- Tibet Autonomous Region Animal Husbandry Station, Lhasa, China
| | - Dan Wu
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Bingjian Huang
- Liaocheng Research Institute of Donkey High‐Efficiency Breeding and Ecological Feeding, Agricultural Science and Engineering School, Liaocheng University, Liaocheng, China
- College of Life Sciences, Liaocheng University, Liaocheng, China
| | - Yulin Ma
- State Key Laboratory of Animal Nutrition, Beijing Engineering Technology Research Center of Raw Milk Quality and Safety Control, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Adnan Khan
- Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Nan Jiang
- Institute of Animal Husbandry and Veterinary, Tibet Autonomous Regional Academy of Agricultural Sciences, Lhasa, China
| | - Muhammad Zahoor
- Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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5
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Berard AR, Brubaker DK, Birse K, Lamont A, Mackelprang RD, Noël-Romas L, Perner M, Hou X, Irungu E, Mugo N, Knodel S, Muwonge TR, Katabira E, Hughes SM, Levy C, Calienes FL, Lauffenburger DA, Baeten JM, Celum C, Hladik F, Lingappa J, Burgener AD. Vaginal epithelial dysfunction is mediated by the microbiome, metabolome, and mTOR signaling. Cell Rep 2023; 42:112474. [PMID: 37149863 PMCID: PMC10242450 DOI: 10.1016/j.celrep.2023.112474] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/15/2023] [Accepted: 04/19/2023] [Indexed: 05/09/2023] Open
Abstract
Bacterial vaginosis (BV) is characterized by depletion of Lactobacillus and overgrowth of anaerobic and facultative bacteria, leading to increased mucosal inflammation, epithelial disruption, and poor reproductive health outcomes. However, the molecular mediators contributing to vaginal epithelial dysfunction are poorly understood. Here we utilize proteomic, transcriptomic, and metabolomic analyses to characterize biological features underlying BV in 405 African women and explore functional mechanisms in vitro. We identify five major vaginal microbiome groups: L. crispatus (21%), L. iners (18%), Lactobacillus (9%), Gardnerella (30%), and polymicrobial (22%). Using multi-omics we show that BV-associated epithelial disruption and mucosal inflammation link to the mammalian target of rapamycin (mTOR) pathway and associate with Gardnerella, M. mulieris, and specific metabolites including imidazole propionate. Experiments in vitro confirm that type strain G. vaginalis and M. mulieris supernatants and imidazole propionate directly affect epithelial barrier function and activation of mTOR pathways. These results find that the microbiome-mTOR axis is a central feature of epithelial dysfunction in BV.
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Affiliation(s)
- Alicia R Berard
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Douglas K Brubaker
- Weldon School of Biomedical Engineering and Regenstrief Center for Healthcare Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Kenzie Birse
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Alana Lamont
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada
| | - Romel D Mackelprang
- Department of Global Health, University of Washington, Seattle, WA 98105, USA
| | - Laura Noël-Romas
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Michelle Perner
- Medical Microbiology and Infectious Disease University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Xuanlin Hou
- Department of Global Health, University of Washington, Seattle, WA 98105, USA
| | - Elizabeth Irungu
- Partners in Health Research and Development, Kenya Medical Research Institute, Mbagathi Road, Nairobi, Kenya
| | - Nelly Mugo
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Partners in Health Research and Development, Kenya Medical Research Institute, Mbagathi Road, Nairobi, Kenya
| | - Samantha Knodel
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Timothy R Muwonge
- Infectious Disease Institute, Makerere University, Makerere, Kampala, Uganda
| | - Elly Katabira
- Infectious Disease Institute, Makerere University, Makerere, Kampala, Uganda
| | - Sean M Hughes
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA
| | - Claire Levy
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA
| | | | | | - Jared M Baeten
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Epidemiology, University of Washington, Seattle, WA 98195, USA; Gilead Sciences, Foster City, CA 94404, USA
| | - Connie Celum
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Epidemiology, University of Washington, Seattle, WA 98195, USA
| | - Florian Hladik
- Department of Obstetrics and Gynecology, University of Washington, Seattle, WA 98195, USA; Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA
| | - Jairam Lingappa
- Department of Global Health, University of Washington, Seattle, WA 98105, USA; Department of Medicine, University of Washington, Seattle, WA 98195, USA; Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Adam D Burgener
- Department of Obstetrics & Gynecology, University of Manitoba, Winnipeg, MB R3E 3P5, Canada; Center for Global Health and Diseases, Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA; Department of Medicine Solna, Karolinska Institutet, Framstegsgatan, 171 64 Solna, Sweden.
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6
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H’ng CH, Khaladkar A, Rosello-Diez A. Look who's TORking: mTOR-mediated integration of cell status and external signals during limb development and endochondral bone growth. Front Cell Dev Biol 2023; 11:1153473. [PMID: 37152288 PMCID: PMC10154674 DOI: 10.3389/fcell.2023.1153473] [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: 01/29/2023] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Abstract
The balance of cell proliferation and size is key for the control of organ development and repair. Moreover, this balance has to be coordinated within tissues and between tissues to achieve robustness in the organ's pattern and size. The tetrapod limb has been used to study these topics during development and repair, and several conserved pathways have emerged. Among them, mechanistic target of rapamycin (mTOR) signaling, despite being active in several cell types and developmental stages, is one of the least understood in limb development, perhaps because of its multiple potential roles and interactions with other pathways. In the body of this review, we have collated and integrated what is known about the role of mTOR signaling in three aspects of tetrapod limb development: 1) limb outgrowth; 2) chondrocyte differentiation after mesenchymal condensation and 3) endochondral ossification-driven longitudinal bone growth. We conclude that, given its ability to interact with the most common signaling pathways, its presence in multiple cell types, and its ability to influence cell proliferation, size and differentiation, the mTOR pathway is a critical integrator of external stimuli and internal status, coordinating developmental transitions as complex as those taking place during limb development. This suggests that the study of the signaling pathways and transcription factors involved in limb patterning, morphogenesis and growth could benefit from probing the interaction of these pathways with mTOR components.
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Affiliation(s)
- Chee Ho H’ng
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Ashwini Khaladkar
- Department of Biochemistry, Central University of Hyderabad, Hyderabad, India
| | - Alberto Rosello-Diez
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Alberto Rosello-Diez, ,
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7
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Athirasala A, Patel S, Menezes PP, Kim J, Tahayeri A, Sahay G, Bertassoni LE. Matrix stiffness regulates lipid nanoparticle-mRNA delivery in cell-laden hydrogels. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2022; 42:102550. [PMID: 35292368 PMCID: PMC9206884 DOI: 10.1016/j.nano.2022.102550] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/16/2022] [Accepted: 03/07/2022] [Indexed: 06/03/2023]
Abstract
mRNA therapeutics have increased in popularity, largely due to the transient and fast nature of protein expression and the low risk of off-target effects. This has increased drastically with the remarkable success of mRNA-based vaccines for COVID-19. Despite advances in lipid nanoparticle (LNP)-based delivery, the mechanisms that regulate efficient endocytic trafficking and translation of mRNA remain poorly understood. Although it is widely acknowledged that the extracellular matrix (ECM) regulates uptake and expression of exogenous nano-complexed genetic material, its specific effects on mRNA delivery and expression have not yet been examined. Here, we demonstrate a critical role for matrix stiffness in modulating both mRNA transfection and expression and uncover distinct mechano-regulatory mechanisms for endocytosis of mRNA through RhoA mediated mTOR signaling and cytoskeletal dynamics. Our findings have implications for effective delivery of therapeutic mRNA to targeted tissues that may be differentially affected by tissue and matrix stiffness.
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Affiliation(s)
- Avathamsa Athirasala
- Department of Biomedical Engineering, Collaborative Life Sciences Building, Oregon Health and Science University, Portland, OR, USA
| | - Siddharth Patel
- Department of Pharmaceutical Sciences, College of Pharmacy, Collaborative Life Science Building, Oregon State University, Portland, OR, USA
| | - Paula P Menezes
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA; Department of Pharmacy, Federal University of Sergipe, Aracaju, Sergipe, Brazil
| | - Jeonghwan Kim
- Department of Pharmaceutical Sciences, College of Pharmacy, Collaborative Life Science Building, Oregon State University, Portland, OR, USA
| | - Anthony Tahayeri
- Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA
| | - Gaurav Sahay
- Department of Biomedical Engineering, Collaborative Life Sciences Building, Oregon Health and Science University, Portland, OR, USA; Department of Pharmaceutical Sciences, College of Pharmacy, Collaborative Life Science Building, Oregon State University, Portland, OR, USA; Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Luiz E Bertassoni
- Department of Biomedical Engineering, Collaborative Life Sciences Building, Oregon Health and Science University, Portland, OR, USA; Division of Biomaterials and Biomechanics, Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, USA; Center for Regenerative Medicine, Oregon Health and Science University, Portland, OR, USA; Cancer Early Detection Advanced Research (CEDAR) Center, Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.
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8
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Crosas-Molist E, Samain R, Kohlhammer L, Orgaz J, George S, Maiques O, Barcelo J, Sanz-Moreno V. RhoGTPase Signalling in Cancer Progression and Dissemination. Physiol Rev 2021; 102:455-510. [PMID: 34541899 DOI: 10.1152/physrev.00045.2020] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Rho GTPases are a family of small G proteins that regulate a wide array of cellular processes related to their key roles controlling the cytoskeleton. On the other hand, cancer is a multi-step disease caused by the accumulation of genetic mutations and epigenetic alterations, from the initial stages of cancer development when cells in normal tissues undergo transformation, to the acquisition of invasive and metastatic traits, responsible for a large number of cancer related deaths. In this review, we discuss the role of Rho GTPase signalling in cancer in every step of disease progression. Rho GTPases contribute to tumour initiation and progression, by regulating proliferation and apoptosis, but also metabolism, senescence and cell stemness. Rho GTPases play a major role in cell migration, and in the metastatic process. They are also involved in interactions with the tumour microenvironment and regulate inflammation, contributing to cancer progression. After years of intensive research, we highlight the importance of relevant models in the Rho GTPase field, and we reflect on the therapeutic opportunities arising for cancer patients.
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Affiliation(s)
- Eva Crosas-Molist
- Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Remi Samain
- Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Leonie Kohlhammer
- Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Jose Orgaz
- Barts Cancer Institute, Queen Mary University of London, London, United Kingdom.,Instituto de Investigaciones Biomédicas 'Alberto Sols', CSIC-UAM, 28029, Madrid, Spain
| | - Samantha George
- Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Oscar Maiques
- Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
| | - Jaume Barcelo
- Barts Cancer Institute, Queen Mary University of London, London, United Kingdom
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9
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Zhou Q, Tang S, Zhang X, Chen L. Targeting PRAS40: a novel therapeutic strategy for human diseases. J Drug Target 2021; 29:703-715. [PMID: 33504218 DOI: 10.1080/1061186x.2021.1882470] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Proline-rich Akt substrate of 40 kD (PRAS40) is not only the substrate of protein kinase B (PKB/Akt), but also the binding protein of 14-3-3 protein. PRAS40 is expressed in a variety of tissues in vivo and has multiple phosphorylation sites, which its activity is closely related to phosphorylation. Studies have shown that PRAS40 is involved in regulating cell growth, cell apoptosis, oxidative stress, autophagy and angiogenesis, as well as various of signalling pathways such as mammalian target of mammalian target rapamycin (mTOR), protein kinase B (PKB/Akt), nuclear factor kappa-B(NF-κB), proto-oncogene serine/threonine-protein kinase PIM-1(PIM1) and pyruvate kinase M2 (PKM2). The interactive roles between PRAS40 and these signal proteins were analysed by bioinformatics in this paper. Moreover, it is of great necessity for analyse the important roles of PRAS40 in some human diseases including cardiovascular disease, ischaemia-reperfusion injury, neurodegenerative disease, cancer, diabetes and other metabolic diseases. Finally, the effects of miRNA on the regulation of PRAS40 function and the occurrence and development of PRAS40-related diseases are also discussed. Overall, PRAS40 is expected to be a drug target and provide a new treatment strategy for human diseases.
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Affiliation(s)
- Qun Zhou
- Hunan Province Key Laboratory for Antibody- Based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, Hunan University of Medicine, Huaihua, China
| | - Shengsong Tang
- Hunan Province Key Laboratory for Antibody- Based Drug and Intelligent Delivery System, School of Pharmaceutical Sciences, Hunan University of Medicine, Huaihua, China
| | - Xianhui Zhang
- Orthopedics Department, Dongkou People's Hospital, Dongkou, China
| | - Linxi Chen
- Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hunan Province Cooperative Innovation Center for Molecular Target, New Drug Study, Institute of Pharmacy and Pharmacology, University of South China, Hengyang, China
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10
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Rial D, Puighermanal E, Chazalon M, Valjent E, Schiffmann SN, de Kerchove d'Exaerde A. Mammalian Target of Rapamycin-RhoA Signaling Impairments in Direct Striatal Projection Neurons Induce Altered Behaviors and Striatal Physiology in Mice. Biol Psychiatry 2020; 88:945-954. [PMID: 32711953 DOI: 10.1016/j.biopsych.2020.05.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND As an integrator of molecular pathways, mTOR (mammalian target of rapamycin) has been associated with diseases including neurodevelopmental, psychiatric, and neurodegenerative disorders such as autism spectrum disorder, schizophrenia, and Huntington's disease. An important brain area involved in all these diseases is the striatum. However, the mechanisms behind how mTOR is involved in striatal physiology and its relative role in distinct neuronal populations in these striatal-related diseases still remain to be clarified. METHODS Using Drd1-Cre mTOR-conditional knockout male mice, we combined behavioral, biochemical, electrophysiological, and morphological analysis aiming to untangle the role of mTOR in direct pathway striatal projection neurons and how this would impact on striatal physiology. RESULTS Our results indicate deep behavioral changes in absence of mTOR in Drd1-expressing neurons such as decreased spontaneous locomotion, impaired social interaction, and decreased marble-burying behavior. These alterations were accompanied by a Kv1.1-induced increase in the fast phase of afterhyperpolarization and coincident decreased distal spine density in striatal direct pathway striatal projection neurons. The physiological changes were mechanistically independent of protein synthesis but sensitive to pharmacological blockade of transforming protein RhoA activity. CONCLUSIONS These results identify mTOR signaling as an important regulator of striatal functions through an intricate mechanism involving RhoA and culminating in Kv1.1 overfunction, which could be targeted to treat striatal-related monogenic disorders associated with the mTOR signaling pathway.
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Affiliation(s)
- Daniel Rial
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Emma Puighermanal
- Institut de Génétique Foncionnelle (IGF), Centre National de la Recherche Scientifique (CNRS), (Institut National de la Santé et de la Recherche Médicale (INSERM), University of Montpellier, Montpellier, France
| | - Marine Chazalon
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Emmanuel Valjent
- Institut de Génétique Foncionnelle (IGF), Centre National de la Recherche Scientifique (CNRS), (Institut National de la Santé et de la Recherche Médicale (INSERM), University of Montpellier, Montpellier, France
| | - Serge N Schiffmann
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - Alban de Kerchove d'Exaerde
- Laboratory of Neurophysiology, ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.
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11
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Church DD, Hirsch KR, Park S, Kim IY, Gwin JA, Pasiakos SM, Wolfe RR, Ferrando AA. Essential Amino Acids and Protein Synthesis: Insights into Maximizing the Muscle and Whole-Body Response to Feeding. Nutrients 2020; 12:E3717. [PMID: 33276485 PMCID: PMC7760188 DOI: 10.3390/nu12123717] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/20/2020] [Accepted: 11/26/2020] [Indexed: 12/21/2022] Open
Abstract
Ingesting protein-containing supplements and foods provides essential amino acids (EAA) necessary to increase muscle and whole-body protein synthesis (WBPS). Large variations exist in the EAA composition of supplements and foods, ranging from free-form amino acids to whole protein foods. We sought to investigate how changes in peripheral EAA after ingesting various protein and free amino acid formats altered muscle and whole-body protein synthesis. Data were compiled from four previous studies that used primed, constant infusions of L-(ring-2H5)-phenylalanine and L-(3,3-2H2)-tyrosine to determine fractional synthetic rate of muscle protein (FSR), WBPS, and circulating EAA concentrations. Stepwise regression indicated that max EAA concentration (EAACmax; R2 = 0.524, p < 0.001), EAACmax (R2 = 0.341, p < 0.001), and change in EAA concentration (ΔEAA; R = 0.345, p < 0.001) were the strongest predictors for postprandial FSR, Δ (change from post absorptive to postprandial) FSR, and ΔWBPS, respectively. Within our dataset, the stepwise regression equation indicated that a 100% increase in peripheral EAA concentrations increases FSR by ~34%. Further, we observed significant (p < 0.05) positive (R = 0.420-0.724) correlations between the plasma EAA area under the curve above baseline, EAACmax, ΔEAA, and rate to EAACmax to postprandial FSR, ΔFSR, and ΔWBPS. Taken together our results indicate that across a large variety of EAA/protein-containing formats and food, large increases in peripheral EAA concentrations are required to drive a robust increase in muscle and whole-body protein synthesis.
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Affiliation(s)
- David D. Church
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.R.H.); (R.R.W.); (A.A.F.)
| | - Katie R. Hirsch
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.R.H.); (R.R.W.); (A.A.F.)
| | - Sanghee Park
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon 21999, Korea; (S.P.); (I.-Y.K.)
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21999, Korea
| | - Il-Young Kim
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, Incheon 21999, Korea; (S.P.); (I.-Y.K.)
- Department of Molecular Medicine, College of Medicine, Gachon University, Incheon 21999, Korea
| | - Jess A. Gwin
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.A.G.); (S.M.P.)
- Oak Ridge Institute for Science and Education, Oak Ridge, TN 37830, USA
| | - Stefan M. Pasiakos
- Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA; (J.A.G.); (S.M.P.)
| | - Robert R. Wolfe
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.R.H.); (R.R.W.); (A.A.F.)
| | - Arny A. Ferrando
- Department of Geriatrics, Donald W. Reynolds Institute on Aging, Center for Translational Research in Aging & Longevity, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (K.R.H.); (R.R.W.); (A.A.F.)
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12
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Chen K, Jiao X, Ashton A, Di Rocco A, Pestell TG, Sun Y, Zhao J, Casimiro MC, Li Z, Lisanti MP, McCue PA, Shen D, Achilefu S, Rui H, Pestell RG. The membrane-associated form of cyclin D1 enhances cellular invasion. Oncogenesis 2020; 9:83. [PMID: 32948740 PMCID: PMC7501870 DOI: 10.1038/s41389-020-00266-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 08/22/2020] [Accepted: 09/02/2020] [Indexed: 02/07/2023] Open
Abstract
The essential G1-cyclin, CCND1, is a collaborative nuclear oncogene that is frequently overexpressed in cancer. D-type cyclins bind and activate CDK4 and CDK6 thereby contributing to G1–S cell-cycle progression. In addition to the nucleus, herein cyclin D1 was also located in the cytoplasmic membrane. In contrast with the nuclear-localized form of cyclin D1 (cyclin D1NL), the cytoplasmic membrane-localized form of cyclin D1 (cyclin D1MEM) induced transwell migration and the velocity of cellular migration. The cyclin D1MEM was sufficient to induce G1–S cell-cycle progression, cellular proliferation, and colony formation. The cyclin D1MEM was sufficient to induce phosphorylation of the serine threonine kinase Akt (Ser473) and augmented extranuclear localized 17β-estradiol dendrimer conjugate (EDC)-mediated phosphorylation of Akt (Ser473). These studies suggest distinct subcellular compartments of cell cycle proteins may convey distinct functions.
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Affiliation(s)
- Ke Chen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Xuanmao Jiao
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Pennsylvania Biotechnology Center, Wynnewood, PA, 19096, USA
| | - Anthony Ashton
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Pennsylvania Biotechnology Center, Wynnewood, PA, 19096, USA
| | - Agnese Di Rocco
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Pennsylvania Biotechnology Center, Wynnewood, PA, 19096, USA
| | - Timothy G Pestell
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Yunguang Sun
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Jun Zhao
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Pennsylvania Biotechnology Center, Wynnewood, PA, 19096, USA
| | - Mathew C Casimiro
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Pennsylvania Biotechnology Center, Wynnewood, PA, 19096, USA.,Dept of Science and Math, Abraham Baldwin Agricultural college, Tifton, GA, 31794, Georgia
| | - Zhiping Li
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Pennsylvania Biotechnology Center, Wynnewood, PA, 19096, USA
| | - Michael P Lisanti
- Biomedical Research Centre (BRC), Translational Medicine, School of Environment and Life Sciences, University of Salford, Manchester, United Kingdom
| | - Peter A McCue
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Duanwen Shen
- Departments of Biomedical Engineering, Washington University, St. Louis, MO, 63110, USA
| | - Samuel Achilefu
- Departments of Biomedical Engineering, Washington University, St. Louis, MO, 63110, USA.,Departments of Radiology, Washington University, St. Louis, MO, 63110, USA.,Departments of Biochemistry & Molecular Biophysics, Washington University, St. Louis, MO, 63110, USA
| | - Hallgeir Rui
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Richard G Pestell
- Pennsylvania Cancer and Regenerative Medicine Research Center, Baruch S. Blumberg Institute, Pennsylvania Biotechnology Center, Wynnewood, PA, 19096, USA. .,The Wistar Cancer Center, Wistar Institute, Philadelphia, PA, 19104, USA.
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13
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Ornatowski W, Lu Q, Yegambaram M, Garcia AE, Zemskov EA, Maltepe E, Fineman JR, Wang T, Black SM. Complex interplay between autophagy and oxidative stress in the development of pulmonary disease. Redox Biol 2020; 36:101679. [PMID: 32818797 PMCID: PMC7451718 DOI: 10.1016/j.redox.2020.101679] [Citation(s) in RCA: 196] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/20/2020] [Accepted: 08/04/2020] [Indexed: 12/16/2022] Open
Abstract
The autophagic pathway involves the encapsulation of substrates in double-membraned vesicles, which are subsequently delivered to the lysosome for enzymatic degradation and recycling of metabolic precursors. Autophagy is a major cellular defense against oxidative stress, or related conditions that cause accumulation of damaged proteins or organelles. Selective forms of autophagy can maintain organelle populations or remove aggregated proteins. Dysregulation of redox homeostasis under pathological conditions results in excessive generation of reactive oxygen species (ROS), leading to oxidative stress and the associated oxidative damage of cellular components. Accumulating evidence indicates that autophagy is necessary to maintain redox homeostasis. ROS activates autophagy, which facilitates cellular adaptation and diminishes oxidative damage by degrading and recycling intracellular damaged macromolecules and dysfunctional organelles. The cellular responses triggered by oxidative stress include the altered regulation of signaling pathways that culminate in the regulation of autophagy. Current research suggests a central role for autophagy as a mammalian oxidative stress response and its interrelationship to other stress defense systems. Altered autophagy phenotypes have been observed in lung diseases such as chronic obstructive lung disease, acute lung injury, cystic fibrosis, idiopathic pulmonary fibrosis, and pulmonary arterial hypertension, and asthma. Understanding the mechanisms by which ROS regulate autophagy will provide novel therapeutic targets for lung diseases. This review highlights our current understanding on the interplay between ROS and autophagy in the development of pulmonary disease.
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Affiliation(s)
- Wojciech Ornatowski
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | - Qing Lu
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | | | - Alejandro E Garcia
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | - Evgeny A Zemskov
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | - Emin Maltepe
- Department of Pediatrics, The University of California, San Francisco, San Francisco, CA, USA
| | - Jeffrey R Fineman
- Department of Pediatrics, The University of California, San Francisco, San Francisco, CA, USA; Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Ting Wang
- Department of Internal Medicine, The University of Arizona Health Sciences, Phoenix, AZ, USA
| | - Stephen M Black
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA.
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14
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Melick CH, Jewell JL. Regulation of mTORC1 by Upstream Stimuli. Genes (Basel) 2020; 11:genes11090989. [PMID: 32854217 PMCID: PMC7565831 DOI: 10.3390/genes11090989] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/22/2020] [Accepted: 08/23/2020] [Indexed: 01/08/2023] Open
Abstract
The mammalian target of rapamycin (mTOR) is an evolutionary conserved Ser/Thr protein kinase that senses multiple upstream stimuli to control cell growth, metabolism, and autophagy. mTOR is the catalytic subunit of mTOR complex 1 (mTORC1). A significant amount of research has uncovered the signaling pathways regulated by mTORC1, and the involvement of these signaling cascades in human diseases like cancer, diabetes, and ageing. Here, we review advances in mTORC1 regulation by upstream stimuli. We specifically focus on how growth factors, amino acids, G-protein coupled receptors (GPCRs), phosphorylation, and small GTPases regulate mTORC1 activity and signaling.
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Affiliation(s)
- Chase H. Melick
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA;
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jenna L. Jewell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA;
- Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Correspondence:
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15
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Bao HR, Chen JL, Li F, Zeng XL, Liu XJ. Relationship between PI3K/mTOR/RhoA pathway-regulated cytoskeletal rearrangements and phagocytic capacity of macrophages. ACTA ACUST UNITED AC 2020; 53:e9207. [PMID: 32520207 PMCID: PMC7279697 DOI: 10.1590/1414-431x20209207] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 03/26/2020] [Indexed: 12/02/2022]
Abstract
The objective of this study was to investigate the relationship between PI3K/mTOR/RhoA signaling regulated cytoskeletal rearrangements and phagocytic capacity of macrophages. RAW264.7 macrophages were divided into four groups; blank control, negative control, PI3K-RNAi, and mTOR-RNAi. The cytoskeletal changes in the macrophages were observed. Furthermore, the phagocytic capacity of macrophages against Escherichia coli is reported as mean fluorescence intensity (MFI) and percent phagocytosis. Transfection yielded 82.1 and 81.5% gene-silencing efficiencies against PI3K and mTOR, respectively. The PI3K-RNAi group had lower mRNA and protein expression levels of PI3K, mTOR, and RhoA than the blank and negative control groups (Р<0.01). The mTOR-RNAi group had lower mRNA and protein levels of mTOR and RhoA than the blank and the negative control groups (Р<0.01). Macrophages in the PI3K-RNAi group exhibited stiff and inflexible morphology with short, disorganized filopodia and reduced number of stress fibers. Macrophages in the mTOR-RNAi group displayed pronounced cellular deformations with long, dense filopodia and an increased number of stress fibers. The PI3K-RNAi group exhibited lower MFI and percent phagocytosis than blank and negative control groups, whereas the mTOR-RNAi group displayed higher MFI and percent phagocytosis than the blank and negative controls (Р<0.01). Before and after transfection, the mRNA and protein levels of PI3K were both positively correlated with mTOR and RhoA (Р<0.05), but the mRNA and protein levels of mTOR were negatively correlated with those of RhoA (Р<0.05). Changes in the phagocytic capacity of macrophages were associated with cytoskeletal rearrangements and were regulated by the PI3K/mTOR/RhoA signaling pathway.
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Affiliation(s)
- H R Bao
- Department of Gerontal Respiratory Medicine, The First Hospital of Lanzhou University, Lanzhou, Gansu, China
| | - J L Chen
- Department of Gerontal Respiratory Medicine, The First Hospital of Lanzhou University, Lanzhou, Gansu, China
| | - F Li
- Department of Gerontal Respiratory Medicine, The First Hospital of Lanzhou University, Lanzhou, Gansu, China
| | - X L Zeng
- Department of Gerontal Respiratory Medicine, The First Hospital of Lanzhou University, Lanzhou, Gansu, China
| | - X J Liu
- Department of Gerontal Respiratory Medicine, The First Hospital of Lanzhou University, Lanzhou, Gansu, China
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16
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Roberson PA, Shimkus KL, Welles JE, Xu D, Whitsell AL, Kimball EM, Jefferson LS, Kimball SR. A time course for markers of protein synthesis and degradation with hindlimb unloading and the accompanying anabolic resistance to refeeding. J Appl Physiol (1985) 2020; 129:36-46. [PMID: 32407240 DOI: 10.1152/japplphysiol.00155.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Skeletal muscle atrophy is associated with disease, aging, and disuse. Hindlimb unloading (HU) in animals provides an experimental model to study muscle atrophy. A comprehensive time course for how HU affects biomarkers of protein synthesis and degradation acutely and chronically and the associated resistance to an anabolic stimulus following disuse remain undocumented. Sixteen-week-old C57BL/6 mice underwent 0, 1, 12, 24, 72, 168, or 336 h of HU. Following 336 h of HU, mice were reloaded for 1, 24, or 72 h. Another group of mice underwent 120 h of HU, were fasted or refed, and were then compared with similar condition control animals (CTL). Protein content and phosphorylation of biomarkers of protein synthesis, degradation, and autophagy were assessed in the soleus muscle. Gastrocnemius, soleus, and plantaris muscles atrophied within 120 h of HU. Protein synthesis trended toward decrease following 24 h of HU. p70S6K phosphorylation and protein synthesis increased with reloading. Following HU, changes in MAFbx and DEPTOR expression and DEPTOR phosphorylation were consistent with development of a catabolic state. DEPTOR expression recovered following reloading. Animals that underwent 120 h of HU exhibited attenuation of refeeding-induced p70S6K phosphorylation compared with CTL counterparts. Following 120 h of HU, protein synthesis, eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) phosphorylation, and DEPTOR, MAFbx, and Sestrin1 expression indicated a catabolic state. Following 120 h of HU, autophagy markers, including p62 expression, REDD1 expression, LC3 ratio, and Unc-51-like autophagy-activating kinase 1 (ULK1) phosphorylation, indicated impaired autophagy. HU promotes a deleterious balance between protein synthesis and degradation. The time course herein provides scientists information about when the associated biomarkers become affected.NEW & NOTEWORTHY Hindlimb unloading causes significant skeletal muscle atrophy by adversely affecting the balance between protein synthesis and breakdown. This study demonstrates a more complete time course for changes in biomarkers associated with protein synthesis and breakdown and investigates the associated anabolic resistance to an anabolic stimulus following hindlimb unloading. These data in concert with information from other studies provide a basis for designing future experiments to optimally interrogate a desired cellular biomarker or pathway.
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Affiliation(s)
- Paul A Roberson
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
| | - Kevin L Shimkus
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
| | - Jaclyn E Welles
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
| | - Dandan Xu
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
| | - Abigale L Whitsell
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
| | - Eric M Kimball
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
| | - Leonard S Jefferson
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
| | - Scot R Kimball
- Pennsylvania State University, Department of Cellular and Molecular Physiology, College of Medicine, Hershey, Pennsylvania
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17
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Zhu M, Wang XQ. Regulation of mTORC1 by Small GTPases in Response to Nutrients. J Nutr 2020; 150:1004-1011. [PMID: 31965176 DOI: 10.1093/jn/nxz301] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/07/2019] [Accepted: 11/18/2019] [Indexed: 12/15/2022] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a highly evolutionarily conserved serine/threonine kinase that regulates cell growth and metabolism in response to multiple environmental cues, such as nutrients, hormones, energy, and stress. Deregulation of mTORC1 can lead to diseases such as diabetes, obesity, and cancer. A series of small GTPases, including Rag, Ras homolog enriched in brain (Rheb), adenosine diphosphate ribosylation factor 1 (Arf1), Ras-related protein Ral-A, Ras homolog (Rho), and Rab, are involved in regulating mTORC1 in response to nutrients, and mTORC1 is differentially regulated via these small GTPases according to specific conditions. Leucine and arginine sensing are considered to be well-confirmed amino acid-sensing signals, activating mTORC1 via a Rag GTPase-dependent mechanism as well as the Ragulator complex and vacuolar H+-adenosine triphosphatase (v-ATPase). Glutamine promotes mTORC1 activation via Arf1 independently of the Rag GTPase. In this review, we summarize current knowledge regarding the regulation of mTORC1 activity by small GTPases in response to nutrients, focusing on the function of small GTPases in mTORC1 activation and how small GTPases are regulated by nutrients.
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Affiliation(s)
- Min Zhu
- College of Animal Science, South China Agricultural University/Guangdong Provincial Key Laboratory of Animal Nutrition Control/National Engineering Research Center for Breeding Swine Industry, Guangzhou, Guangdong, China
| | - Xiu-Qi Wang
- College of Animal Science, South China Agricultural University/Guangdong Provincial Key Laboratory of Animal Nutrition Control/National Engineering Research Center for Breeding Swine Industry, Guangzhou, Guangdong, China
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18
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Yang T, Yang WX. The dynamics and regulation of microfilament during spermatogenesis. Gene 2020; 744:144635. [PMID: 32244053 DOI: 10.1016/j.gene.2020.144635] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 02/28/2020] [Accepted: 03/30/2020] [Indexed: 12/22/2022]
Abstract
Spermatogenesis is a highly complex physiological process which contains spermatogonia proliferation, spermatocyte meiosis and spermatid morphogenesis. In the past decade, actin binding proteins and signaling pathways which are critical for regulating the actin cytoskeleton in testis had been found. In this review, we summarized 5 actin-binding proteins that have been proven to play important roles in the seminiferous epithelium. Lack of them perturbs spermatids polarity and the transport of spermatids. The loss of Arp2/3 complex, Formin1, Eps8, Palladin and Plastin3 cause sperm release failure suggesting their irreplaceable role in spermatogenesis. Actin regulation relies on multiple signal pathways. The PI3K/Akt signaling pathway positively regulate the mTOR pathway to promote actin reorganization in seminiferous epithelium. Conversely, TSC1/TSC2 complex, the upstream of mTOR, is activated by the LKB1/AMPK pathway to inhibit cell proliferation, differentiation and migration. The increasing researches focus on the function of actin binding proteins (ABPs), however, their collaborative regulation of actin patterns and potential regulatory signaling networks remains unclear. We reviewed ABPs that play important roles in mammalian spermatogenesis and signal pathways involved in the regulation of microfilaments. We suggest that more relevant studies should be performed in the future.
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Affiliation(s)
- Tong Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
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19
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Klein SD, Nguyen DC, Bhakta V, Wong D, Chang VY, Davidson TB, Martinez-Agosto JA. Mutations in the sonic hedgehog pathway cause macrocephaly-associated conditions due to crosstalk to the PI3K/AKT/mTOR pathway. Am J Med Genet A 2019; 179:2517-2531. [PMID: 31639285 PMCID: PMC7346528 DOI: 10.1002/ajmg.a.61368] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 06/12/2019] [Accepted: 09/09/2019] [Indexed: 12/26/2022]
Abstract
The hedgehog (Hh) pathway is highly conserved and required for embryonic patterning and determination. Mutations in the Hh pathway are observed in sporadic tumors as well as under syndromic conditions. Common to these syndromes are the findings of polydactyly/syndactyly and brain overgrowth. The latter is also a finding most commonly observed in the cases of mutations in the PI3K/AKT/mTOR pathway. We have identified novel Hh pathway mutations and structural copy number variations in individuals with somatic overgrowth, macrocephaly, dysmorphic facial features, and developmental delay, which phenotypically closely resemble patients with phosphatase and tensin homolog (PTEN) mutations. We hypothesized that brain overgrowth and phenotypic overlap with syndromic overgrowth syndromes in these cases may be due to crosstalk between the Hh and PI3K/AKT/mTOR pathways. To test this, we modeled disease-associated variants by generating PTCH1 and Suppressor of Fused (SUFU) heterozygote cell lines using the CRISPR/Cas9 system. These cells demonstrate activation of PI3K signaling and increased phosphorylation of its downstream target p4EBP1 as well as a distinct cellular phenotype. To further investigate the mechanism underlying this crosstalk, we treated human neural stem cells with sonic hedgehog (SHH) ligand and performed transcriptional analysis of components of the mTOR pathway. These studies identified decreased expression of a set of mTOR negative regulators, leading to its activation. We conclude that there is a significant crosstalk between the SHH and PI3K/AKT/mTOR. We propose that this crosstalk is responsible for why mutations in PTCH1 and SUFU lead to macrocephaly phenotypes similar to those observed in PTEN hamartoma and other overgrowth syndromes associated with mutations in PI3K/AKT/mTOR pathway genes.
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Affiliation(s)
- Steven D. Klein
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Dzung C. Nguyen
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Viraj Bhakta
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Derek Wong
- Division of Medical Genetics, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Vivian Y. Chang
- Division of Hematology-Oncology, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Tom B. Davidson
- Division of Hematology-Oncology, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
- Jonsson Comprehensive Cancer Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Julian A. Martinez-Agosto
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
- Division of Medical Genetics, Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
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Abstract
Autophagy is a highly conserved catabolic process induced under various conditions of cellular stress, which prevents cell damage and promotes survival in the event of energy or nutrient shortage and responds to various cytotoxic insults. Thus, autophagy has primarily cytoprotective functions and needs to be tightly regulated to respond correctly to the different stimuli that cells experience, thereby conferring adaptation to the ever-changing environment. It is now apparent that autophagy is deregulated in the context of various human pathologies, including cancer and neurodegeneration, and its modulation has considerable potential as a therapeutic approach.
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Affiliation(s)
- Ivan Dikic
- Institute of Biochemistry II, School of Medicine, Goethe University, Frankfurt am Main, Germany. .,Buchmann Institute for Molecular Life Sciences, Goethe University, Frankfurt am Main, Germany.
| | - Zvulun Elazar
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
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21
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Kaczorowski M, Biecek P, Donizy P, Pieniazek M, Matkowski R, Halon A. Low RhoA expression is associated with adverse outcome in melanoma patients: a clinicopathological analysis. Am J Transl Res 2019; 11:4524-4532. [PMID: 31396356 PMCID: PMC6684925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 06/11/2019] [Indexed: 06/10/2023]
Abstract
RhoA GTPase is physiologically involved in the formation of stress fibers, cellular contractility and polarity, maintenance of cell cycle and transcriptional control. During tumorigenesis, it plays roles in cancer cell proliferation, apoptosis, adhesion, invasion and metastasis. While RhoA seems to act as a tumor promotor in most malignancies, data regarding its function in skin melanoma are fragmentary and conflicting. We aimed to clarify the clinical significance of RhoA expression in melanoma by immunohistochemical evaluation of 134 primary tumors and subsequent statistical analysis with clinicopathological profiles of patients. Increased RhoA expression was associated with thinner tumors, higher grade of tumor-infiltrating lymphocytes and lack of disease recurrence. Moreover, we observed a trend towards higher RhoA expression in cases without concurrent metastases. Recurrence-free survival and melanoma-specific survival of patients with high RhoA-expressing tumors were significantly prolonged. Multivariable regression model adjusting for melanoma thickness and status of regional lymph nodes confirmed independent prognostic value of RhoA immunoreactivity. In summary, we found associations between RhoA expression and histopathological phenotype of primary tumors as well as patient survival which suggest a suppressive role of RhoA in skin melanoma.
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Affiliation(s)
- Maciej Kaczorowski
- Department of Pathomorphology and Oncological Cytology, Wroclaw Medical UniversityBorowska 213, Wroclaw, Poland
| | - Przemyslaw Biecek
- Faculty of Mathematics and Information Science, Warsaw University of TechnologyKoszykowa 75, Warsaw, Poland
| | - Piotr Donizy
- Department of Pathomorphology and Oncological Cytology, Wroclaw Medical UniversityBorowska 213, Wroclaw, Poland
| | - Malgorzata Pieniazek
- Department of Clinical Oncology, Tadeusz Koszarowski Regional Oncology CentreKatowicka 66a, Opole, Poland
| | - Rafal Matkowski
- Department of Oncology and Division of Surgical Oncology, Wroclaw Medical UniversityHirszfelda 12, Wroclaw, Poland
- Lower Silesian Oncology CentreHirszfelda 12, Wroclaw, Poland
| | - Agnieszka Halon
- Department of Pathomorphology and Oncological Cytology, Wroclaw Medical UniversityBorowska 213, Wroclaw, Poland
- Lower Silesian Oncology CentreHirszfelda 12, Wroclaw, Poland
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22
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Septin6 regulates cell growth and casein synthesis in dairy cow mammary epithelial cells via mTORC1 pathway. J DAIRY RES 2019; 86:181-187. [PMID: 31122298 DOI: 10.1017/s0022029919000268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
This research paper addresses the hypothesis that Septin6 is a key regulatory factor influencing amino acid (AA)-mediated cell growth and casein synthesis in dairy cow mammary epithelial cells (DCMECs). DCMECs were treated with absence of AA (AA-), restricted concentrations of AA (AAr) or normal concentrations of AA (AA+) for 24 h. Cell growth, expression of CSN2 and Septin6 were increased in response to AA supply. Overexpressing or inhibiting Septin6 demonstrated that cell growth, expression of CSN2, mTOR, p-mTOR, S6K1 and p-S6K1 were up-regulated by Septin6. Furthermore, overexpressing or inhibiting mTOR demonstrated that the increase in cell growth and expression of CSN2 in response to Septin6 overexpression were inhibited by mTOR inhibition, and vice versa. Our hypothesis was supported; we were able to show that Septin6 is an important positive factor for cell growth and casein synthesis, it up-regulates AA-mediated cell growth and casein synthesis through activating mTORC1 pathway in DCMECs.
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23
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Kloc M, Ghobrial RM, Wosik J, Lewicka A, Lewicki S, Kubiak JZ. Macrophage functions in wound healing. J Tissue Eng Regen Med 2018; 13:99-109. [PMID: 30445662 DOI: 10.1002/term.2772] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/31/2018] [Accepted: 11/13/2018] [Indexed: 12/31/2022]
Abstract
Macrophages play a crucial role in regeneration and consecutive phases of wound healing. In this review, we summarise current knowledge on the ontogeny, origin, phenotypical heterogeneity, and functional exchangeability of macrophages participating in these processes. We also describe the genetic, pharmacologic, and bioengineering methods for manipulation of macrophage phenotype and functions and their potential for development of the novel, clinically applicable therapies.
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Affiliation(s)
- Malgorzata Kloc
- Immunobiology, The Houston Methodist Research Institute, Houston, Texas, USA.,Department of Surgery, The Houston Methodist Hospital, Houston, Texas, USA.,MD Anderson Cancer Center, University of Texas, Houston, Texas, USA
| | - Rafik M Ghobrial
- Immunobiology, The Houston Methodist Research Institute, Houston, Texas, USA.,Department of Surgery, The Houston Methodist Hospital, Houston, Texas, USA
| | - Jarek Wosik
- Electrical and Computer Engineering Department, University of Houston, Houston, Texas, USA.,Texas Center for Superconductivity, University of Houston, Houston, Texas, USA
| | - Aneta Lewicka
- Laboratory of Epidemiology, Military Institute of Hygiene and Epidemiology (WIHE), Warsaw, Poland
| | - Sławomir Lewicki
- Department of Regenerative Medicine and Cell Biology, Military Institute of Hygiene and Epidemiology (WIHE), Warsaw, Poland
| | - Jacek Z Kubiak
- Department of Regenerative Medicine and Cell Biology, Military Institute of Hygiene and Epidemiology (WIHE), Warsaw, Poland.,Cell Cycle Group, Faculty of Medicine, Univ Rennes, UMR 6290, CNRS, Institute of Genetics and Development of Rennes, Rennes, France
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24
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Chen W, Chen W, Li XC, Ghobrial RM, Kloc M. Coinhibition of mTORC1/mTORC2 and RhoA /ROCK pathways prevents chronic rejection of rat cardiac allografts. TRANSPLANTATION REPORTS 2018. [DOI: 10.1016/j.tpr.2018.09.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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25
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Li D, Zhang P, Yao X, Li H, Shen H, Li X, Wu J, Lu X. Exosomes Derived From miR-133b-Modified Mesenchymal Stem Cells Promote Recovery After Spinal Cord Injury. Front Neurosci 2018; 12:845. [PMID: 30524227 PMCID: PMC6262643 DOI: 10.3389/fnins.2018.00845] [Citation(s) in RCA: 119] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 10/29/2018] [Indexed: 12/30/2022] Open
Abstract
Dysregulation of microRNAs (miRNAs) has been found in injured spinal cords after spinal cord injury (SCI). Previous studies have shown that miR-133b plays an important role in the differentiation of neurons and the outgrowth of neurites. Recently, exosomes have been used as novel biological vehicles to transfer miRNAs locally or systemically, but little is known about the effect of the delivery of exosome-mediated miRNAs on the treatment of SCI. In the present study, we observed that mesenchymal stem cells, the most common cell types known to produce exosomes, could package miR-133b into secreted exosomes. After SCI, tail vein injection of miR-133b exosomes into rats significantly improved the recovery of hindlimb function when compared to control groups. Additionally, treatment with miR-133b exosomes reduced the volume of the lesion, preserved neuronal cells, and promoted the regeneration of axons after SCI. We next observed that the expression of RhoA, a direct target of miR-133b, was decreased in the miR-133b exosome group. Moreover, we showed that miR-133b exosomes activated ERK1/2, STAT3, and CREB, which are signaling pathway proteins involved in the survival of neurons and the regeneration of axons. In summary, these findings demonstrated that systemically injecting miR-133b exosomes preserved neurons, promoted the regeneration of axons, and improved the recovery of hindlimb locomotor function following SCI, suggesting that the transfer of exosome-mediated miRNAs represents a novel therapeutic approach for the treatment of SCI.
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Affiliation(s)
- Dong Li
- Department of Neurosurgery, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, China
| | - Peng Zhang
- Department of Neurosurgery, Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiyang Yao
- Department of Neurosurgery, Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haiying Li
- Department of Neurosurgery, Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haitao Shen
- Department of Neurosurgery, Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiang Li
- Department of Neurosurgery, Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jiang Wu
- Department of Neurosurgery, Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiaocheng Lu
- Department of Neurosurgery, Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University, Suzhou, China
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26
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Chen W, Chen S, Chen W, Li XC, Ghobrial RM, Kloc M. Screening RhoA/ROCK inhibitors for the ability to prevent chronic rejection of mouse cardiac allografts. Transpl Immunol 2018; 50:15-25. [DOI: 10.1016/j.trim.2018.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 12/18/2022]
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27
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RhoA G17V is sufficient to induce autoimmunity and promotes T-cell lymphomagenesis in mice. Blood 2018; 132:935-947. [DOI: 10.1182/blood-2017-11-818617] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2017] [Accepted: 05/07/2018] [Indexed: 11/20/2022] Open
Abstract
Key Points
Expression of RhoA G17V in CD4+ cells results in cellular and humoral autoimmunity. RhoA G17V expression with Tet2 loss induces T-cell lymphomas with features of AITL.
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28
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Emerging Role of mTOR Signaling-Related miRNAs in Cardiovascular Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:6141902. [PMID: 30305865 PMCID: PMC6165581 DOI: 10.1155/2018/6141902] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Accepted: 07/04/2018] [Indexed: 12/21/2022]
Abstract
Mechanistic/mammalian target of rapamycin (mTOR), an atypical serine/threonine kinase of the phosphoinositide 3-kinase- (PI3K-) related kinase family, elicits a vital role in diverse cellular processes, including cellular growth, proliferation, survival, protein synthesis, autophagy, and metabolism. In the cardiovascular system, the mTOR signaling pathway integrates both intracellular and extracellular signals and serves as a central regulator of both physiological and pathological processes. MicroRNAs (miRs), a class of short noncoding RNA, are an emerging intricate posttranscriptional modulator of critical gene expression for the development and maintenance of homeostasis across a wide array of tissues, including the cardiovascular system. Over the last decade, numerous studies have revealed an interplay between miRNAs and the mTOR signaling circuit in the different cardiovascular pathophysiology, like myocardial infarction, hypertrophy, fibrosis, heart failure, arrhythmia, inflammation, and atherosclerosis. In this review, we provide a comprehensive state of the current knowledge regarding the mechanisms of interactions between the mTOR signaling pathway and miRs. We have also highlighted the latest advances on mTOR-targeted therapy in clinical trials and the new perspective therapeutic strategies with mTOR-targeting miRs in cardiovascular diseases.
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29
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Zhao T, Li R, Tan X, Zhang J, Fan C, Zhao Q, Deng Y, Xu A, Lukong KE, Genth H, Xiang J. Simulated Microgravity Reduces Focal Adhesions and Alters Cytoskeleton and Nuclear Positioning Leading to Enhanced Apoptosis via Suppressing FAK/RhoA-Mediated mTORC1/NF-κB and ERK1/2 Pathways. Int J Mol Sci 2018; 19:ijms19071994. [PMID: 29986550 PMCID: PMC6073227 DOI: 10.3390/ijms19071994] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/04/2018] [Accepted: 07/06/2018] [Indexed: 12/16/2022] Open
Abstract
Simulated-microgravity (SMG) promotes cell-apoptosis. We demonstrated that SMG inhibited cell proliferation/metastasis via FAK/RhoA-regulated mTORC1 pathway. Since mTORC1, NF-κB, and ERK1/2 signaling are important in cell apoptosis, we examined whether SMG-enhanced apoptosis is regulated via these signals controlled by FAK/RhoA in BL6-10 melanoma cells under clinostat-modelled SMG-condition. We show that SMG promotes cell-apoptosis, alters cytoskeleton, reduces focal adhesions (FAs), and suppresses FAK/RhoA signaling. SMG down-regulates expression of mTORC1-related Raptor, pS6K, pEIF4E, pNF-κB, and pNF-κB-regulated Bcl2, and induces relocalization of pNF-κB from the nucleus to the cytoplasm. In addition, SMG also inhibits expression of nuclear envelope proteins (NEPs) lamin-A, emerin, sun1, and nesprin-3, which control nuclear positioning, and suppresses nuclear positioning-regulated pERK1/2 signaling. Moreover, rapamycin, the mTORC1 inhibitor, also enhances apoptosis in cells under 1 g condition via suppressing the mTORC1/NF-κB pathway. Furthermore, the FAK/RhoA activator, toxin cytotoxic necrotizing factor-1 (CNF1), reduces cell apoptosis, restores the cytoskeleton, FAs, NEPs, and nuclear positioning, and converts all of the above SMG-induced changes in molecular signaling in cells under SMG. Therefore, our data demonstrate that SMG reduces FAs and alters the cytoskeleton and nuclear positioning, leading to enhanced cell apoptosis via suppressing the FAK/RhoA-regulated mTORC1/NF-κB and ERK1/2 pathways. The FAK/RhoA regulatory network may, thus, become a new target for the development of novel therapeutics for humans under spaceflight conditions with stressed physiological challenges, and for other human diseases.
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Affiliation(s)
- Tuo Zhao
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Rong Li
- Cancer Research, Saskatchewan Cancer Agency, Saskatoon, SK S7N 4H4, Canada.
- Department of Oncology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Xin Tan
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Jun Zhang
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Cuihong Fan
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Qin Zhao
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Yulin Deng
- School of Life Sciences, Beijing Institute of Technology, Beijing 10081, China.
| | - Aizhang Xu
- Cancer Research, Saskatchewan Cancer Agency, Saskatoon, SK S7N 4H4, Canada.
- Department of Oncology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Kiven Erique Lukong
- Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
| | - Harald Genth
- Institute of Toxicology, Hannover Medical School, D-30625 Hannover, Germany.
| | - Jim Xiang
- Cancer Research, Saskatchewan Cancer Agency, Saskatoon, SK S7N 4H4, Canada.
- Department of Oncology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
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30
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Chen W, Ghobrial RM, Li XC, Kloc M. Inhibition of RhoA and mTORC2/Rictor by Fingolimod (FTY720) induces p21-activated kinase 1, PAK-1 and amplifies podosomes in mouse peritoneal macrophages. Immunobiology 2018; 223:634-647. [PMID: 30005970 DOI: 10.1016/j.imbio.2018.07.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/25/2018] [Accepted: 07/05/2018] [Indexed: 02/08/2023]
Abstract
Macrophage functions in the immune response depend on their ability to infiltrate tissues and organs. The penetration between and within the tissues requires degradation of extracellular matrix (ECM), a function performed by the specialized, endopeptidase- and actin filament- rich organelles located at the ventral surface of macrophage, called the podosomes. Podosome formation requires local inhibition of small GTPase RhoA activity, and depends on Rac 1/Rho guanine nucleotide exchange factor 7, β-PIX and its binding partner the p21-activated kinase (PAK-1). The activity of RhoA and Rac 1 is in turn regulated by mTOR/mTORC2 pathway. Here we showed that a fungus metabolite Fingolimod (FTY720, Gilenya), which is clinically approved for the treatment of multiple sclerosis, down-regulates Rictor, which is a signature molecule of mTORC2 and dictates its substrate (actin cytoskeleton) specificity, down-regulates RhoA, up-regulates PAK-1, and causes amplification of podosomes in mouse peritoneal macrophages.
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Affiliation(s)
- Wei Chen
- Houston Methodist Research Institute, Houston, TX, USA; Department of Nephrology, Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Rafik M Ghobrial
- Houston Methodist Research Institute, Houston, TX, USA; Weill Cornell Medical College, 407 E 61st St, New York, USA
| | - Xian C Li
- Houston Methodist Research Institute, Houston, TX, USA; Weill Cornell Medical College, 407 E 61st St, New York, USA
| | - Malgorzata Kloc
- Houston Methodist Research Institute, Houston, TX, USA; Weill Cornell Medical College, 407 E 61st St, New York, USA; University of Texas, MD Anderson Cancer Center, Department of Genetics, Houston, TX, USA.
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31
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Simulated microgravity inhibits cell focal adhesions leading to reduced melanoma cell proliferation and metastasis via FAK/RhoA-regulated mTORC1 and AMPK pathways. Sci Rep 2018; 8:3769. [PMID: 29491429 PMCID: PMC5830577 DOI: 10.1038/s41598-018-20459-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 01/18/2018] [Indexed: 12/25/2022] Open
Abstract
Simulated microgravity (SMG) was reported to affect tumor cell proliferation and metastasis. However, the underlying mechanism is elusive. In this study, we demonstrate that clinostat-modelled SMG reduces BL6-10 melanoma cell proliferation, adhesion and invasiveness in vitro and decreases tumor lung metastasis in vivo. It down-regulates metastasis-related integrin α6β4, MMP9 and Met72 molecules. SMG significantly reduces formation of focal adhesions and activation of focal adhesion kinase (FAK) and Rho family proteins (RhoA, Rac1 and Cdc42) and of mTORC1 kinase, but activates AMPK and ULK1 kinases. We demonstrate that SMG inhibits NADH induction and glycolysis, but induces mitochondrial biogenesis. Interestingly, administration of a RhoA activator, the cytotoxic necrotizing factor-1 (CNF1) effectively converts SMG-triggered alterations and effects on mitochondria biogenesis or glycolysis. CNF1 also converts the SMG-altered cell proliferation and tumor metastasis. In contrast, mTORC inhibitor, rapamycin, produces opposite responses and mimics SMG-induced effects in cells at normal gravity. Taken together, our observations indicate that SMG inhibits focal adhesions, leading to inhibition of signaling FAK and RhoA, and the mTORC1 pathway, which results in activation of the AMPK pathway and reduced melanoma cell proliferation and metastasis. Overall, our findings shed a new light on effects of microgravity on cell biology and human health.
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32
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Zhang Y, Wang P, Lin S, Mercier Y, Yin H, Song Y, Zhang X, Che L, Lin Y, Xu S, Feng B, De Wu, Fang Z. mTORC1 signaling-associated protein synthesis in porcine mammary glands was regulated by the local available methionine depending on methionine sources. Amino Acids 2017; 50:105-115. [PMID: 28983783 DOI: 10.1007/s00726-017-2496-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2017] [Accepted: 09/21/2017] [Indexed: 10/18/2022]
Abstract
Mechanistic target of rapamycin complex1 (mTORC1) activation and protein synthesis varied with methionine sources; however, the related mechanisms are largely unknown. Porcine mammary epithelial cells (PMEC) and mammary tissue slices (MTS) were used to test whether methionine precursors differ in providing the available methionine and thus differ in mTORC1 signaling-associated protein synthesis. PMEC with methionine deprivation for 8 h and MTS from lactating sows were cultured for 24 and 2 h, respectively, with treatment media without methionine (negative control, NC) or supplemented with 0.6 mM (for PMEC) and 0.1 mM (for MTS) of L-methionine (L-MET), D-methionine (D-MET), DL-2-hydroxy-4-(methylthio) butyric acid (HMTBA), or keto-methyl(thio)butanoic acid (KMB). The measurements included: phosphorylation of mTORC1 signaling, fractional protein synthesis rate (FSR), amino acids (AA) profile, and enzyme activities. Compared with the NC treatment, activated mTORC1 signaling as manifested by higher (P < 0.05) protein abundance of phosphorylated-S6 Kinase 1 (P-S6K1) and phosphorylated-4E-binding Protein 1 (P-4E-BP1) in PMEC and MTS, and increased protein synthesis as indicated by higher (P < 0.05) FSR in MTS occurred in L-MET and HMTBA treatments rather than in D-MET treatment. Compared with the NC treatment, methionine concentration and ratio of methionine to lysine in MTS increased (P < 0.05) in L-MET and HMTBA treatments but not in D-MET treatment, and activities of enzymes responsible for conversion of D-MET and HMTBA to keto-methionine in mammary tissues were about 10 and 50%, respectively, of that in liver. Taken together, mTORC1 signaling-associated protein synthesis in porcine mammary glands was regulated by the local available methionine depending on methionine sources.
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Affiliation(s)
- Yalin Zhang
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Peng Wang
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Sen Lin
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | | | - Huajun Yin
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Yumo Song
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Xiaoling Zhang
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Lianqiang Che
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Yan Lin
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Shengyu Xu
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Bin Feng
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - De Wu
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China
| | - Zhengfeng Fang
- Key Laboratory for Animal Disease Resistance Nutrition of the Ministry of Education, Animal Nutrition Institute, Sichuan Agricultural University, Chengdu, 611130, People's Republic of China.
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Nguyen TP, Frank AR, Jewell JL. Amino acid and small GTPase regulation of mTORC1. CELLULAR LOGISTICS 2017; 7:e1378794. [PMID: 29296509 PMCID: PMC5739091 DOI: 10.1080/21592799.2017.1378794] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 09/06/2017] [Accepted: 09/08/2017] [Indexed: 11/03/2022]
Abstract
The mammalian target of rapamycin (mTOR) is an evolutionarily conserved serine/threonine kinase that belongs to the phosphatidylinositol 3-kinase-related kinase (PIKK) family. mTOR is the catalytic subunit of mTOR complex 1 (mTORC1), which integrates multiple environmental signals to control cell growth and metabolism. Nutrients, specifically amino acids, are the most potent stimuli for mTORC1 activation. Multiple studies have focused on how leucine and arginine activate mTORC1 through the Rag GTPases, with mechanistic details slowly emerging. Recently, a Rag GTPase-independent glutamine signaling pathway to mTORC1 has been identified, suggesting that mTORC1 is differentially regulated through distinct pathways by specific amino acids. In this review, we summarize our current understanding of how amino acids modulate mTORC1, and the role of other small GTPases in the regulation of mTORC1 activity.
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Affiliation(s)
- Thu P Nguyen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX USA.,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Anderson R Frank
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX USA.,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Jenna L Jewell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX USA.,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX USA
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Steiner JL, Fukuda DH, Rossetti ML, Hoffman JR, Gordon BS. Castration alters protein balance after high-frequency muscle contraction. J Appl Physiol (1985) 2016; 122:264-272. [PMID: 27909227 DOI: 10.1152/japplphysiol.00740.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/07/2016] [Accepted: 11/23/2016] [Indexed: 01/07/2023] Open
Abstract
Resistance exercise increases muscle mass by shifting protein balance in favor of protein accretion. Androgens independently alter protein balance, but it is unknown whether androgens alter this measure after resistance exercise. To answer this, male mice were subjected to sham or castration surgery 7-8 wk before undergoing a bout of unilateral, high-frequency, electrically induced muscle contractions in the fasted or refed state. Puromycin was injected 30 min before euthanasia to measure protein synthesis. The tibialis anterior was analyzed 4 h postcontraction. In fasted mice, neither basal nor stimulated rates of protein synthesis were affected by castration despite lower phosphorylation of mechanistic target of rapamycin in complex 1 (mTORC1) substrates [p70S6K1 (Thr389) and 4E-BP1 (Ser65)]. Markers of autophagy (LC3 II/I ratio and p62 protein content) were elevated by castration, and these measures remained elevated above sham values after contractions. Furthermore, in fasted mice, the protein content of Regulated in Development and DNA Damage 1 (REDD1) was correlated with LC3 II/I in noncontracted muscle, whereas phosphorylation of uncoordinated like kinase 1 (ULK1) (Ser757) was correlated with LC3 II/I in the contracted muscle. When mice were refed before contractions, protein synthesis and mTORC1 signaling were not affected by castration in either the noncontracted or contracted muscle. Conversely, markers of autophagy remained elevated in the muscles of refed, castrated mice even after contractions. These data suggest the castration-mediated elevation in baseline autophagy reduces the absolute positive shift in protein balance after muscle contractions in the refed or fasted states. NEW & NOTEWORTHY In the absence of androgens, markers of autophagy were elevated, and these could not be normalized by muscle contractions. In the fasted state, REDD1 was identified as a potential contributor to autophagy in noncontracted muscle, whereas phosphorylation of ULK1 may contribute to this process in the contracted muscle. In the refed state, markers of autophagy remain elevated in both noncontracted and contracted muscles, but the relationship with REDD1 and ULK1 (Ser757) no longer existed.
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Affiliation(s)
- Jennifer L Steiner
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - David H Fukuda
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and
| | - Michael L Rossetti
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and
| | - Jay R Hoffman
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and.,Burnett School of Biomedical Sciences, The University of Central Florida, Orlando, Florida
| | - Bradley S Gordon
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida; and
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Pazoki-Toroudi H, Amani H, Ajami M, Nabavi SF, Braidy N, Kasi PD, Nabavi SM. Targeting mTOR signaling by polyphenols: A new therapeutic target for ageing. Ageing Res Rev 2016; 31:55-66. [PMID: 27453478 DOI: 10.1016/j.arr.2016.07.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 06/19/2016] [Accepted: 07/15/2016] [Indexed: 12/19/2022]
Abstract
Current ageing research is aimed not only at the promotion of longevity, but also at improving health span through the discovery and development of new therapeutic strategies by investigating molecular and cellular pathways involved in cellular senescence. Understanding the mechanism of action of polyphenolic compounds targeting mTOR (mechanistic target of rapamycin) and related pathways opens up new directions to revolutionize ways to slow down the onset and development of age-dependent degeneration. Herein, we will discuss the mechanisms by which polyphenols can delay the molecular pathogenesis of ageing via manipulation or more specifically inhibition of mTOR-signaling pathways. We will also discuss the implications of polyphenols in targeting mTOR and its related pathways on health life span extension and longevity..
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Yang J, Bassuk AG, Merl-Pham J, Hsu CW, Colgan DF, Li X, Au KS, Zhang L, Smemo S, Justus S, Nagahama Y, Grossbach AJ, Howard MA, Kawasaki H, Feldstein NA, Dobyns WB, Northrup H, Hauck SM, Ueffing M, Mahajan VB, Tsang SH. Catenin delta-1 (CTNND1) phosphorylation controls the mesenchymal to epithelial transition in astrocytic tumors. Hum Mol Genet 2016; 25:4201-4210. [PMID: 27516388 DOI: 10.1093/hmg/ddw253] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/14/2016] [Accepted: 07/21/2016] [Indexed: 11/14/2022] Open
Abstract
Inactivating mutations of the TSC1/TSC2 complex (TSC1/2) cause tuberous sclerosis (TSC), a hereditary syndrome with neurological symptoms and benign hamartoma tumours in the brain. Since TSC effectors are largely unknown in the human brain, TSC patient cortical tubers were used to uncover hyperphosphorylation unique to TSC primary astrocytes, the cell type affected in the brain. We found abnormal hyperphosphorylation of catenin delta-1 S268, which was reversible by mTOR-specific inhibitors. In contrast, in three metastatic astrocytoma cell lines, S268 was under phosphorylated, suggesting S268 phosphorylation controls metastasis. TSC astrocytes appeared epithelial (i.e. tightly adherent, less motile, and epithelial (E)-cadherin positive), whereas wild-type astrocytes were mesenchymal (i.e. E-cadherin negative and highly motile). Despite their epithelial phenotype, TSC astrocytes outgrew contact inhibition, and monolayers sporadically generated tuberous foci, a phenotype blocked by the mTOR inhibitor, Torin1. Also, mTOR-regulated phosphokinase C epsilon (PKCe) activity induced phosphorylation of catenin delta-1 S268, which in turn mediated cell-cell adhesion in astrocytes. The mTOR-dependent, epithelial phenotype of TSC astrocytes suggests TSC1/2 and mTOR tune the phosphorylation level of catenin delta-1 by controlling PKCe activity, thereby regulating the mesenchymal-epithelial-transition (MET). Thus, some forms of TSC could be treated with PKCe inhibitors, while metastasis of astrocytomas might be blocked by PKCe stimulators.
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Affiliation(s)
- Jin Yang
- Barbara & Donald Jonas Stem Cell Laboratory, and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Institute of Human Nutrition, Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Tianjin Medical University Eye Hospital, Tianjin, People's Republic of China.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Alexander G Bassuk
- Department of Pediatrics and Neurology, Departments of Neurosurgery, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, IA, USA
| | - Juliane Merl-Pham
- Research Unit Protein Science, Helmholtz Zentrum Munich, German Research Center for Environmental Health (GmbH), Munich, Germany
| | - Chun-Wei Hsu
- Barbara & Donald Jonas Stem Cell Laboratory, and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Institute of Human Nutrition, Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | | | - Xiaorong Li
- Tianjin Medical University Eye Hospital, Tianjin, People's Republic of China
| | - Kit Sing Au
- Division of Medical Genetics, Department of Pediatrics, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Lijuan Zhang
- Barbara & Donald Jonas Stem Cell Laboratory, and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Institute of Human Nutrition, Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA.,Shanxi Eye Hospital, affiliated with Shanxi Medical University, Xinghualing, Taiyuan, Shanxi, China
| | - Scott Smemo
- Barbara & Donald Jonas Stem Cell Laboratory, and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Institute of Human Nutrition, Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Sally Justus
- Barbara & Donald Jonas Stem Cell Laboratory, and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Institute of Human Nutrition, Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
| | - Yasunori Nagahama
- Department of Pediatrics and Neurology, Departments of Neurosurgery, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, IA, USA
| | - Andrew J Grossbach
- Department of Pediatrics and Neurology, Departments of Neurosurgery, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, IA, USA
| | - Matthew A Howard
- Department of Pediatrics and Neurology, Departments of Neurosurgery, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, IA, USA
| | - Hiroto Kawasaki
- Department of Pediatrics and Neurology, Departments of Neurosurgery, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, IA, USA
| | - Neil A Feldstein
- Departments of Neurosurgery, New York-Presbyterian Hospital, Columbia University Medical Center, New York, NY, USA
| | - William B Dobyns
- Division of Genetic Medicine, Department of Pediatrics, Seattle Children's Hospital, University of Washington, Seattle, Washington, USA Departments of Pediatrics and Neurology, University of Washington, Seattle, Washington, WA, USA
| | - Hope Northrup
- Division of Medical Genetics, Department of Pediatrics, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Stefanie M Hauck
- Research Unit Protein Science, Helmholtz Zentrum Munich, German Research Center for Environmental Health (GmbH), Munich, Germany
| | - Marius Ueffing
- Institute for Ophthalmic Research, Center of Ophthalmology, University Medical Center, University of Tübingen, Germany
| | - Vinit B Mahajan
- Department of Pediatrics and Neurology, Departments of Neurosurgery, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa, IA, USA.,Omics Laboratory, University of Iowa, Iowa, IA, USA
| | - Stephen H Tsang
- Barbara & Donald Jonas Stem Cell Laboratory, and Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Institute of Human Nutrition, Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, New York, NY, USA .,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, NY, USA
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Gordon BS, Liu C, Steiner JL, Nader GA, Jefferson LS, Kimball SR. Loss of REDD1 augments the rate of the overload-induced increase in muscle mass. Am J Physiol Regul Integr Comp Physiol 2016; 311:R545-57. [PMID: 27465734 DOI: 10.1152/ajpregu.00159.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/20/2016] [Indexed: 12/12/2022]
Abstract
The overload-induced increase in muscle mass is accompanied by protein accretion; however, the initiating events are poorly understood. Regulated in Development and DNA Damage 1 (REDD1), a repressor of the mechanistic target of rapamycin in complex 1 (mTORC1), blunts the elevation in protein synthesis induced by acute muscle contractions. Therefore, this study was designed to determine whether REDD1 alters the rate of the overload-induced increase in muscle mass. Wild-type (WT) and REDD1-null mice underwent unilateral functional overload (OV) of the plantaris, while the contralateral sham leg served as a control. After 3 and 5 days of OV, puromycin incorporation was used as a measurement of protein synthesis. The percent increase in plantaris wet weight and protein content was greater in REDD1-null mice after 3, 5, and 10 days OV. The overload-stimulated rate of protein synthesis in the plantaris was similar between genotypes after 3 days OV, but translational capacity was lower in REDD1-null mice, indicating elevated translational efficiency. This was likely due to elevated absolute mTORC1 signaling [phosphorylation of p70S6K1 (Thr-389) and 4E-BP1 (Ser-65)]. By 5 days of OV, the rate of protein synthesis in REDD1-null mice was lower than WT mice with no difference in absolute mTORC1 signaling. Additionally, markers of autophagy (LC3II/I ratio and p62 protein) were decreased to a greater absolute extent after 3 days OV in REDD1-null mice. These data suggest that loss of REDD1 augments the rate of the OV-induced increase in muscle mass by altering multiple protein balance pathways.
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Affiliation(s)
- Bradley S Gordon
- Institute of Exercise Physiology and Wellness, The University of Central Florida, Orlando, Florida;
| | - Chang Liu
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania; and
| | - Jennifer L Steiner
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Gustavo A Nader
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania; and
| | - Leonard S Jefferson
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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Kimball SR, Gordon BS, Moyer JE, Dennis MD, Jefferson LS. Leucine induced dephosphorylation of Sestrin2 promotes mTORC1 activation. Cell Signal 2016; 28:896-906. [PMID: 27010498 DOI: 10.1016/j.cellsig.2016.03.008] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 03/08/2016] [Accepted: 03/18/2016] [Indexed: 01/08/2023]
Abstract
The studies described herein were designed to explore the role of Sestrin2 in mediating the selective action of leucine to activate mTORC1. The results demonstrate that Sestrin2 is a phosphoprotein and that its phosphorylation state is responsive to the availability of leucine, but not other essential amino acids. Moreover, leucine availability-induced alterations in Sestrin2 phosphorylation correlated temporally and dose dependently with the activation state of mTORC1, there being a reciprocal relationship between the degree of phosphorylation of Sestrin2 and the extent of repression of mTORC1. With leucine deprivation, Sestrin2 became more highly phosphorylated and interacted more strongly with proteins of the GATOR2 complex. Notably, in cells lacking the protein kinase ULK1, the activation state of mTORC1 was elevated in leucine-deficient medium, such that the effect of re-addition of the amino acid was blunted. In contrast, overexpression of ULK1 led to hyperphosphorylation of Sestrin2 and enhanced its interaction with GATOR2. Neither rapamycin nor Torin2 had any effect on Sestrin2 phosphorylation, suggesting that leucine deprivation-induced repression of mTORC1 was not responsible for the action of ULK1 on Sestrin2. Mass spectrometry analysis of Sestrin2 revealed three phosphorylation sites that are conserved across mammalian species. Mutation of the three sites to phospho-mimetic amino acids in exogenously expressed Sestrin2 promoted its interaction with GATOR2 and dramatically repressed mTORC1 even in the presence of leucine. Overall, the results support a model in which leucine selectively promotes dephosphorylation of Sestrin2, causing it to dissociate from and thereby activate GATOR2, leading to activation of mTORC1.
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Affiliation(s)
- Scot R Kimball
- The Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, PO Box 850, Hershey, PA 17033, United States.
| | - Bradley S Gordon
- The Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, PO Box 850, Hershey, PA 17033, United States
| | - Jenna E Moyer
- The Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, PO Box 850, Hershey, PA 17033, United States
| | - Michael D Dennis
- The Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, PO Box 850, Hershey, PA 17033, United States
| | - Leonard S Jefferson
- The Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, PO Box 850, Hershey, PA 17033, United States
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Regulator of cullins-1 expression knockdown suppresses the malignant progression of muscle-invasive transitional cell carcinoma by regulating mTOR/DEPTOR pathway. Br J Cancer 2016; 114:305-13. [PMID: 26742010 PMCID: PMC4742580 DOI: 10.1038/bjc.2015.444] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 11/23/2015] [Accepted: 11/30/2015] [Indexed: 01/16/2023] Open
Abstract
Background: Regulator of cullins-1 (ROC1) is a key subunit in the cullin–RING ligase (CRL) protein complex. Our previous study indicated that ROC1 was essential for bladder cancer cell survival and that ROC1 knockdown inhibited CRL activity, triggering G2 phase arrest and senescence. However, the role of ROC1 in the malignant progression of bladder cancer remained unknown. Methods: ROC1 expression in cancer cells was knocked down by siRNA silencing. The effects of ROC1 silencing were evaluated by in vitro assays for cell migration and by an in vivo mouse metastasis model. Epithelial–mesenchymal transition (EMT) induction was evaluated by immunofluorescence staining and western blotting of EMT-associated proteins. ROC1 expression in human tumours was further evaluated by immunohistochemical analysis. Results: ROC1 knockdown suppresses bladder cancer cell migration by inhibiting EMT. ROC1 knockdown inhibited EMT by inhibiting mammalian target of rapamycin (mTOR) activity via the accumulation of the mTOR-inhibitory protein DEPTOR, a CRL substrate. DEPTOR knockdown partially rescued ROC1 knockdown-inhibited EMT and the ROC1-induced inhibition of cancer cell migration. Furthermore, in vivo studies using a nude mouse metastasis model confirmed the in vitro data. Finally, tissue microarray analysis of clinical bladder cancer specimens indicated a positive correlation between ROC1 expression and EMT. Conclusions: ROC1 has an important role in the malignant progression of bladder cancer via the mTOR/DEPTOR pathway. ROC1 may serve as a novel therapeutic target for the treatment of muscle-invasive transitional cell carcinoma.
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Li R, Tan S, Yu M, Jundt MC, Zhang S, Wu M. Annexin A2 Regulates Autophagy in Pseudomonas aeruginosa Infection through the Akt1-mTOR-ULK1/2 Signaling Pathway. THE JOURNAL OF IMMUNOLOGY 2015; 195:3901-11. [PMID: 26371245 DOI: 10.4049/jimmunol.1500967] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 08/06/2015] [Indexed: 02/05/2023]
Abstract
Earlier studies reported that a cell membrane protein, Annexin A2 (AnxA2), plays multiple roles in the development, invasion, and metastasis of cancer. Recent studies demonstrated that AnxA2 also functions in immunity against infection, but the underlying mechanism remains largely elusive. Using a mouse infection model, we reveal a crucial role for AnxA2 in host defense against Pseudomonas aeruginosa, as anxa2(-/-) mice manifested severe lung injury, systemic dissemination, and increased mortality compared with wild-type littermates. In addition, anxa2(-/-) mice exhibited elevated inflammatory cytokines (TNF-α, IL-6, IL-1β, and IFN-γ), decreased bacterial clearance by macrophages, and increased superoxide release in the lung. We further identified an unexpected molecular interaction between AnxA2 and Fam13A, which activated Rho GTPase. P. aeruginosa infection induced autophagosome formation by inhibiting Akt1 and mTOR. Our results indicate that AnxA2 regulates autophagy, thereby contributing to host immunity against bacteria through the Akt1-mTOR-ULK1/2 signaling pathway.
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Affiliation(s)
- Rongpeng Li
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 211800, People's Republic of China
| | - Shirui Tan
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; College of Agriculture, Yunnan University, Kunming 650091, People's Republic of China
| | - Min Yu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; Department of Thoracic Oncology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, People's Republic of China; and
| | - Michael C Jundt
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203
| | - Shuang Zhang
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203; State Key Laboratory of Biotherapy and Cancer Center/Collaborative Innovation Center of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China
| | - Min Wu
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, ND 58203;
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Gordon BS, Williamson DL, Lang CH, Jefferson LS, Kimball SR. Nutrient-induced stimulation of protein synthesis in mouse skeletal muscle is limited by the mTORC1 repressor REDD1. J Nutr 2015; 145:708-13. [PMID: 25716553 PMCID: PMC4381770 DOI: 10.3945/jn.114.207621] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/29/2015] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND In skeletal muscle, the nutrient-induced stimulation of protein synthesis requires signaling through the mechanistic target of rapamycin complex 1 (mTORC1). Expression of the repressor of mTORC1 signaling, regulated in development and DNA damage 1 (REDD1), is elevated in muscle during various atrophic conditions and diminished under hypertrophic conditions. The question arises as to what extent REDD1 limits the nutrient-induced stimulation of protein synthesis. OBJECTIVE The objective was to examine the role of REDD1 in limiting the response of muscle protein synthesis and mTORC1 signaling to a nutrient stimulus. METHODS Wild type REDD1 gene (REDD1(+/+)) and disruption in the REDD1 gene (REDD1(-/-)) mice were feed deprived for 16 h and randomized to remain feed deprived or refed for 15 or 60 min. The tibialis anterior was then removed for analysis of protein synthesis and mTORC1 signaling. RESULTS In feed-deprived mice, protein synthesis and mTORC1 signaling were significantly lower in REDD1(+/+) than in REDD1(-/-) mice. Thirty minutes after the start of refeeding, protein synthesis in REDD1(+/+) mice was stimulated by 28%, reaching a value similar to that observed in feed-deprived REDD1(-/-) mice, and was accompanied by increased phosphorylation of mTOR (Ser2448), p70S6K1 (Thr389), and 4E-BP1 (Ser65) by 81%, 167%, and 207%, respectively. In refed REDD1(-/-) mice, phosphorylation of mTOR (Ser2448), p70S6K1 (Thr389), and 4E-BP1 (Ser65) were significantly augmented above the values observed in refed REDD1(+/+) mice by 258%, 405%, and 401%, respectively, although protein synthesis was not coordinately increased. Seventy-five minutes after refeeding, REDD1 expression in REDD1(+/+) mice was reduced (∼15% of feed-deprived REDD1(+/+) values), and protein synthesis and mTORC1 signaling were not different between refed REDD1(+/+) mice and REDD1(-/-) mice. CONCLUSIONS The results show that REDD1 expression limits protein synthesis in mouse skeletal muscle by inhibiting mTORC1 signaling during periods of feed deprivation and that a reduction in its expression is necessary for maximal stimulation of protein synthesis in response to refeeding.
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Affiliation(s)
- Bradley S Gordon
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA; and
| | - David L Williamson
- Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY
| | - Charles H Lang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA; and
| | - Leonard S Jefferson
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA; and
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA; and
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Kelleher AR, Pereira SL, Jefferson LS, Kimball SR. REDD2 expression in rat skeletal muscle correlates with nutrient-induced activation of mTORC1: responses to aging, immobilization, and remobilization. Am J Physiol Endocrinol Metab 2015; 308:E122-9. [PMID: 25406262 PMCID: PMC4297780 DOI: 10.1152/ajpendo.00341.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In a previous study (Kelleher AR, Kimball SR, Dennis MD, Schilder RJ, and Jefferson LS. Am J Physiol Endocrinol Metab 304: E229-236, 2013.), we observed a rapid (i.e., 1-3 days) immobilization-induced repression of mechanistic target of rapamycin complex 1 (mTORC1) signaling in hindlimb skeletal muscle of young (2-mo-old) rats that was associated with elevated expression of regulated in development and DNA-damage response (REDD) 1 and REDD2. The present study extends that observation to include an assessment of those parameters in soleus muscle of the immobilized hindlimb of various-aged rats as well as in response to remobilization. Male Sprague-Dawley rats aged 2, 9, and 18 mo were subjected to unilateral hindlimb immobilization for 7 days, whereas one group of the 9-mo-old animals underwent 7 days of remobilization. Soleus muscle mass-to-body mass ratio declined with age, with the loss of muscle mass following hindlimb immobilization being inversely proportional to age. Compared with 2-mo-old rats, the older rats exhibited reduced mTORC1 signaling in the nonimmobilized limb in association with elevated REDD2, but not REDD1, mRNA expression. In the 2-mo-old rats, 7 days of hindlimb immobilization attenuated mTORC1 signaling and induced REDD2, but not REDD1, mRNA expression. In contrast, hindlimb immobilization did not further attenuate the age-related reduction in mTORC1 signaling nor further enhance the age-related induction of REDD2 mRNA expression in 9- and 18-mo-old rats. Across ages, REDD1 mRNA was not impacted by immobilization. Finally, remobilization elevated mTORC1 signaling and lowered REDD2 mRNA expression, with no impact on REDD1 gene expression. In conclusion, changes in mTORC1 signaling associated with aging, immobilization, and remobilization were inversely proportional to alterations in REDD2 mRNA expression.
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Affiliation(s)
- Andrew R Kelleher
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
| | | | - Leonard S Jefferson
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania; and
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Gordon BS, Steiner JL, Lang CH, Jefferson LS, Kimball SR. Reduced REDD1 expression contributes to activation of mTORC1 following electrically induced muscle contraction. Am J Physiol Endocrinol Metab 2014; 307:E703-11. [PMID: 25159324 PMCID: PMC4200302 DOI: 10.1152/ajpendo.00250.2014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Regulated in DNA damage and development 1 (REDD1) is a repressor of mTOR complex 1 (mTORC1) signaling. In humans, REDD1 mRNA expression in skeletal muscle is repressed following resistance exercise in association with activation of mTORC1. However, whether REDD1 protein expression is also reduced after exercise and if so to what extent the loss contributes to exercise-induced activation of mTORC1 is unknown. Thus, the purpose of the present study was to examine the role of REDD1 in governing the response of mTORC1 and protein synthesis to a single bout of muscle contractions. Eccentric contractions of the tibialis anterior were elicited via electrical stimulation of the sciatic nerve in male mice in either the fasted or fed state or in fasted wild-type or REDD1-null mice. Four hours postcontractions, mTORC1 signaling and protein synthesis were elevated in fasted mice in association with repressed REDD1 expression relative to nonstimulated controls. Feeding coupled with contractions further elevated mTORC1 signaling, whereas REDD1 protein expression was repressed compared with either feeding or contractions alone. Basal mTORC1 signaling and protein synthesis were elevated in REDD1-null compared with wild-type mice. The magnitude of the increase in mTORC1 signaling was similar in both wild-type and REDD1-null mice, but, unlike wild-type mice, muscle contractions did not stimulate protein synthesis in mice deficient for REDD1, presumably because basal rates were already elevated. Overall, the data demonstrate that REDD1 expression contributes to the modulation of mTORC1 signaling following feeding- and contraction-induced activation of the pathway.
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Affiliation(s)
- Bradley S Gordon
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Jennifer L Steiner
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Charles H Lang
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Leonard S Jefferson
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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44
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Fader CM, Aguilera MO, Colombo MI. Autophagy response: manipulating the mTOR-controlled machinery by amino acids and pathogens. Amino Acids 2014; 47:2101-12. [PMID: 25234192 DOI: 10.1007/s00726-014-1835-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 09/03/2014] [Indexed: 02/06/2023]
Abstract
Macroautophagy is a self-degradative process that normally maintains cellular homeostasis via a lysosomal pathway. It is induced by different stress signals, including nutrients and growth factors' restriction as well as pathogen invasions. These stimuli are modulated by the serine/threonine protein kinase mammalian target of rapamycin (mTOR) which control not only autophagy but also protein translation and gene expression. This review focuses on the important role of mTOR as a master regulator of cell growth and the autophagy pathway. Here, we have discussed the role of intracellular amino acid availability and intracellular pH in the redistribution of autophagic structures, which may contribute to mammalian target of rapamycin complex 1 (mTORC1) activity regulation. We have also discussed that mTORC1 complex and components of the autophagy machinery are localized at the lysosomal surface, representing a fascinating mechanism to control the metabolism, cellular clearance and also to restrain invading intracellular pathogens.
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Affiliation(s)
- Claudio Marcelo Fader
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, (5500), Mendoza, Argentina
| | - Milton Osmar Aguilera
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, (5500), Mendoza, Argentina
| | - María Isabel Colombo
- Laboratorio de Biología Celular y Molecular, Instituto de Histología y Embriología (IHEM)-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Casilla de Correo 56, Centro Universitario, Parque General San Martín, (5500), Mendoza, Argentina.
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