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Lv Y, Ma X, Liu Q, Long Z, Li S, Tan Z, Wang D, Xing X, Chen L, Chen W, Wang Q, Wei Q, Hou M, Xiao Y. c-Jun targets miR-451a to regulate HQ-induced inhibition of erythroid differentiation via the BATF/SETD5/ARHGEF3 axis. Toxicology 2024; 505:153843. [PMID: 38801936 DOI: 10.1016/j.tox.2024.153843] [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: 02/19/2024] [Revised: 05/11/2024] [Accepted: 05/22/2024] [Indexed: 05/29/2024]
Abstract
Benzene, a widely used industrial chemical, has been clarified to cause hematotoxicity. Our previous study suggested that miR-451a may play a role in benzene-induced impairment of erythroid differentiation. However, the mechanism underlying remains unclear. In this study, we explored the role of miR-451a and its underlying mechanisms in hydroquinone (HQ)-induced suppression of erythroid differentiation in K562 cells. 0, 1.0, 2.5, 5.0, 10.0, and 50 μM HQ treatment of K562 cells resulted in a dose-dependent inhibition of erythroid differentiation, as well as the expression of miR-451a. Bioinformatics analysis was conducted to predict potential target genes of miR-451a and dual-luciferase reporter assays confirmed that miR-451a can directly bind to the 3'-UTR regions of BATF, SETD5, and ARHGEF3 mRNAs. We further demonstrated that over-expression or down-regulation of miR-451a altered the expression of BATF, SETD5, and ARHGEF3, and also modified erythroid differentiation. In addition, BATF, SETD5, and ARHGEF3 were verified to play a role in HQ-induced inhibition of erythroid differentiation in this study. Knockdown of SETD5 and ARHGEF3 reversed HQ-induced suppression of erythroid differentiation while knockdown of BATF had the opposite effect. On the other hand, we also identified c-Jun as a potential transcriptional regulator of miR-451a. Forced expression of c-Jun increased miR-451a expression and reversed the inhibition of erythroid differentiation induced by HQ, whereas knockdown of c-Jun had the opposite effect. And the binding site of c-Jun and miR-451a was verified by dual-luciferase reporter assay. Collectively, our findings indicate that miR-451a and its downstream targets BATF, SETD5, and ARHGEF3 are involved in HQ-induced erythroid differentiation disorder, and c-Jun regulates miR-451a as a transcriptional regulator in this process.
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Affiliation(s)
- Yanrong Lv
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiaoju Ma
- Department of Hospital Acquired Infection Control and Public Health Management, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 517108, China
| | - Qing Liu
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Zihao Long
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Shuangqi Li
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Zhaoqing Tan
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Dongsheng Wang
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiumei Xing
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Liping Chen
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Wen Chen
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Qing Wang
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Qing Wei
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Mengjun Hou
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China
| | - Yongmei Xiao
- Department of Occupational and Environmental Health, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China; Joint International Research Laboratory of Environment and Health, Ministry of Education, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
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Ragupathi A, Kim C, Jacinto E. The mTORC2 signaling network: targets and cross-talks. Biochem J 2024; 481:45-91. [PMID: 38270460 PMCID: PMC10903481 DOI: 10.1042/bcj20220325] [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: 10/02/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.
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Affiliation(s)
- Aparna Ragupathi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Christian Kim
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
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You JS, Kim Y, Lee S, Bashir R, Chen J. RhoA/ROCK signalling activated by ARHGEF3 promotes muscle weakness via autophagy in dystrophic mdx mice. J Cachexia Sarcopenia Muscle 2023. [PMID: 37311604 PMCID: PMC10401546 DOI: 10.1002/jcsm.13278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/16/2023] [Accepted: 05/01/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND Duchenne muscular dystrophy (DMD), caused by dystrophin deficiency, leads to progressive and fatal muscle weakness through yet-to-be-fully deciphered molecular perturbations. Emerging evidence implicates RhoA/Rho-associated protein kinase (ROCK) signalling in DMD pathology, yet its direct role in DMD muscle function, and related mechanisms, are unknown. METHODS Three-dimensionally engineered dystrophin-deficient mdx skeletal muscles and mdx mice were used to test the role of ROCK in DMD muscle function in vitro and in situ, respectively. The role of ARHGEF3, one of the RhoA guanine nucleotide exchange factors (GEFs), in RhoA/ROCK signalling and DMD pathology was examined by generating Arhgef3 knockout mdx mice. The role of RhoA/ROCK signalling in mediating the function of ARHGEF3 was determined by evaluating the effects of wild-type or GEF-inactive ARHGEF3 overexpression with ROCK inhibitor treatment. To gain more mechanistic insights, autophagy flux and the role of autophagy were assessed in various conditions with chloroquine. RESULTS Inhibition of ROCK with Y-27632 improved muscle force production in 3D-engineered mdx muscles (+25% from three independent experiments, P < 0.05) and in mice (+25%, P < 0.001). Unlike suggested by previous studies, this improvement was independent of muscle differentiation or quantity and instead related to increased muscle quality. We found that ARHGEF3 was elevated and responsible for RhoA/ROCK activation in mdx muscles, and that depleting ARHGEF3 in mdx mice restored muscle quality (up to +36%, P < 0.01) and morphology without affecting regeneration. Conversely, overexpressing ARHGEF3 further compromised mdx muscle quality (-13% vs. empty vector control, P < 0.01) in GEF activity- and ROCK-dependent manner. Notably, ARHGEF3/ROCK inhibition exerted the effects by rescuing autophagy which is commonly impaired in dystrophic muscles. CONCLUSIONS Our findings uncover a new pathological mechanism of muscle weakness in DMD involving the ARHGEF3-ROCK-autophagy pathway and the therapeutic potential of targeting ARHGEF3 in DMD.
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Affiliation(s)
- Jae-Sung You
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Nick J. Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yongdeok Kim
- Nick J. Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Soohyun Lee
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Rashid Bashir
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Nick J. Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
- Department of Biomedical and Translational Sciences, Carle Illinois College of Medicine, Urbana, Illinois, USA
| | - Jie Chen
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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Integration of Transcriptomics and Non-Targeted Metabolomics Reveals the Underlying Mechanism of Skeletal Muscle Development in Duck during Embryonic Stage. Int J Mol Sci 2023; 24:ijms24065214. [PMID: 36982289 PMCID: PMC10049352 DOI: 10.3390/ijms24065214] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 03/02/2023] [Accepted: 03/03/2023] [Indexed: 03/11/2023] Open
Abstract
Skeletal muscle is an important economic trait in duck breeding; however, little is known about the molecular mechanisms of its embryonic development. Here, the transcriptomes and metabolomes of breast muscle of Pekin duck from 15 (E15_BM), 21 (E21_BM), and 27 (E27_BM) days of incubation were compared and analyzed. The metabolome results showed that the differentially accumulated metabolites (DAMs), including the up-regulated metabolites, l-glutamic acid, n-acetyl-1-aspartylglutamic acid, l-2-aminoadipic acid, 3-hydroxybutyric acid, bilirubin, and the significantly down-regulated metabolites, palmitic acid, 4-guanidinobutanoate, myristic acid, 3-dehydroxycarnitine, and s-adenosylmethioninamine, were mainly enriched in metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of cofactors, protein digestion and absorption, and histidine metabolism, suggesting that these pathways may play important roles in the muscle development of duck during the embryonic stage. Moreover, a total of 2142 (1552 up-regulated and 590 down-regulated), 4873 (3810 up-regulated and 1063 down-regulated), and 2401 (1606 up-regulated and 795 down-regulated) DEGs were identified from E15_BM vs. E21_BM, E15_BM vs. E27_BM and E21_BM vs. E27_BM in the transcriptome, respectively. The significantly enriched GO terms from biological processes were positive regulation of cell proliferation, regulation of cell cycle, actin filament organization, and regulation of actin cytoskeleton organization, which were associated with muscle or cell growth and development. Seven significant pathways, highly enriched by FYN, PTK2, PXN, CRK, CRKL, PAK, RHOA, ROCK, INSR, PDPK1, and ARHGEF, were focal adhesion, regulation of actin cytoskeleton, wnt signaling pathway, insulin signaling pathway, extracellular matrix (ECM)-receptor interaction, cell cycle, and adherens junction, which participated in regulating the development of skeletal muscle in Pekin duck during the embryonic stage. KEGG pathway analysis of the integrated transcriptome and metabolome indicated that the pathways, including arginine and proline metabolism, protein digestion and absorption, and histidine metabolism, were involved in regulating skeletal muscle development in embryonic Pekin duck. These findings suggested that the candidate genes and metabolites involved in crucial biological pathways may regulate muscle development in the Pekin duck at the embryonic stage, and increased our understanding of the molecular mechanisms underlying the avian muscle development.
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ARHGEF3 regulates the stability of ACLY to promote the proliferation of lung cancer. Cell Death Dis 2022; 13:870. [PMID: 36241648 PMCID: PMC9568610 DOI: 10.1038/s41419-022-05297-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 11/18/2022]
Abstract
Rho GTPases play an essential role in many cellular processes, including cell cycle progress, cell motility, invasion, migration, and transformation. Several studies indicated that the dysregulation of Rho GTPase signaling is closely related to tumorigenesis. Rho GEFs considered being positive regulators of Rho GTPase, promoting the dissociation of Rho protein from GDP and binding to GTP, thus activating the downstream signaling pathway. Herein, we demonstrated that ARHGEF3, a member of the Rho GEFs family, played an important role in non-small cell lung cancer (NSCLC). We found that ARHGEF3 was highly expressed in non-small cell lung cancer and facilitated cancer cell proliferation of NSCLC cells in vitro and in vivo. Further studies demonstrated that ARHGEF3 enhanced the protein homeostasis of ATP-citrate lyase (ACLY) by reducing its acetylation on Lys17 and Lys86, leading to the dissociation between ACLY and its E3 ligase-NEDD4. Interestingly, this function of ARHGEF3 on the protein homeostasis of ACLY was independent of its GEF activity. Taken together, our findings uncover a novel function of ARHGEF3, suggesting that ARHGEF3 is a promising therapeutic target in non-small cell lung cancer.
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Bamford CGG, Aranday-Cortes E, Sanchez-Velazquez R, Mullan C, Kohl A, Patel AH, Wilson SJ, McLauchlan J. A Human and Rhesus Macaque Interferon-Stimulated Gene Screen Shows That Over-Expression of ARHGEF3/XPLN Inhibits Replication of Hepatitis C Virus and Other Flavivirids. Viruses 2022; 14:v14081655. [PMID: 36016278 PMCID: PMC9414520 DOI: 10.3390/v14081655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/11/2022] [Accepted: 07/26/2022] [Indexed: 12/30/2022] Open
Abstract
Natural hepatitis C virus (HCV) infection is restricted to humans, whereas other primates such as rhesus macaques are non-permissive for infection. To identify human and rhesus macaque genes that differ or share the ability to inhibit HCV replication, we conducted a medium-throughput screen of lentivirus-expressed host genes that disrupt replication of HCV subgenomic replicon RNA expressing secreted Gaussia luciferase. A combined total of >800 interferon-stimulated genes (ISGs) were screened. Our findings confirmed established anti-HCV ISGs, such as IRF1, PKR and DDX60. Novel species−specific inhibitors were also identified and independently validated. Using a cell-based system that recapitulates productive HCV infection, we identified that over-expression of the ‘Rho Guanine Nucleotide Exchange Factor 3’ gene (ARHGEF3) from both species inhibits full-length virus replication. Additionally, replication of two mosquito-borne flaviviruses, yellow fever virus (YFV) and Zika virus (ZIKV), were also reduced in cell lines over-expressing ARHGEF3 compared to controls. In conclusion, we ascribe novel antiviral activity to the cellular gene ARHGEF3 that inhibits replication of HCV and other important human viral pathogens belonging to the Flaviviridae, and which is conserved between humans and rhesus macaques.
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Affiliation(s)
- Connor G. G. Bamford
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
- Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, Belfast BT7 1NN, UK
| | - Elihu Aranday-Cortes
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
| | - Ricardo Sanchez-Velazquez
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
- BioNTech SE, 55131 Mainz, Germany
| | - Catrina Mullan
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
| | - Alain Kohl
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
| | - Arvind H. Patel
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
| | - Sam J. Wilson
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
| | - John McLauchlan
- MRC-University of Glasgow Centre for Virus Research, 464 Bearsden Rd, Bearsden, Glasgow G61 1QH, UK; (C.G.G.B.); (E.A.-C.); (R.S.-V.); (C.M.); (A.K.); (A.H.P.); (S.J.W.)
- Correspondence:
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Simcox J, Lamming DW. The central moTOR of metabolism. Dev Cell 2022; 57:691-706. [PMID: 35316619 PMCID: PMC9004513 DOI: 10.1016/j.devcel.2022.02.024] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/20/2022] [Accepted: 02/24/2022] [Indexed: 12/21/2022]
Abstract
The protein kinase mechanistic target of rapamycin (mTOR) functions as a central regulator of metabolism, integrating diverse nutritional and hormonal cues to control anabolic processes, organismal physiology, and even aging. This review discusses the current state of knowledge regarding the regulation of mTOR signaling and the metabolic regulation of the four macromolecular building blocks of the cell: carbohydrate, nucleic acid, lipid, and protein by mTOR. We review the role of mTOR in the control of organismal physiology and aging through its action in key tissues and discuss the potential for clinical translation of mTOR inhibition for the treatment and prevention of diseases of aging.
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Affiliation(s)
- Judith Simcox
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA.
| | - Dudley W Lamming
- William S. Middleton Memorial Veterans Hospital, Madison, WI, USA; Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA.
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Khaliq SA, Umair Z, Yoon MS. Role of ARHGEF3 as a GEF and mTORC2 Regulator. Front Cell Dev Biol 2022; 9:806258. [PMID: 35174167 PMCID: PMC8841341 DOI: 10.3389/fcell.2021.806258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 12/24/2021] [Indexed: 11/26/2022] Open
Abstract
Guanine nucleotide exchange factors (GEFs) activate GTPases by stimulating the release of guanosine diphosphate to permit the binding of guanosine triphosphate. ARHGEF3 or XPLN (exchange factor found in platelets, leukemic, and neuronal tissues) is a selective guanine nucleotide exchange factor for Rho GTPases (RhoGEFs) that activates RhoA and RhoB but not RhoC, RhoG, Rac1, or Cdc42. ARHGEF3 contains the diffuse B-cell lymphoma homology and pleckstrin homology domains but lacks similarity with other known functional domains. ARHGEF3 also binds the mammalian target of rapamycin complex 2 (mTORC2) and subsequently inhibits mTORC2 and Akt. In vivo investigation has also indicated the communication between ARHGEF3 and autophagy-related muscle pathologies. Moreover, studies on genetic variation in ARHGEF3 and genome-wide association studies have predicted exciting novel roles of ARHGEF3 in controlling bone mineral density, platelet formation and differentiation, and Hirschsprung disease. In conclusion, we hypothesized that additional biochemical and functional studies are required to elucidate the detailed mechanism of ARHGEF3-related pathologies and therapeutics.
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Affiliation(s)
- Sana Abdul Khaliq
- Department of Molecular Medicine, Gachon University College of Medicine, Incheon, South Korea
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, South Korea
| | - Zobia Umair
- Department of Molecular Medicine, Gachon University College of Medicine, Incheon, South Korea
- *Correspondence: Zobia Umair, ; Mee-Sup Yoon,
| | - Mee-Sup Yoon
- Department of Molecular Medicine, Gachon University College of Medicine, Incheon, South Korea
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, South Korea
- Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, South Korea
- *Correspondence: Zobia Umair, ; Mee-Sup Yoon,
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Yoon J, Kumar V, Goutam RS, Kim SC, Park S, Lee U, Kim J. Bmp Signal Gradient Modulates Convergent Cell Movement via Xarhgef3.2 during Gastrulation of Xenopus Embryos. Cells 2021; 11:44. [PMID: 35011606 PMCID: PMC8750265 DOI: 10.3390/cells11010044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/20/2021] [Accepted: 12/21/2021] [Indexed: 01/31/2023] Open
Abstract
Gastrulation is a critical step in the establishment of a basic body plan during development. Convergence and extension (CE) cell movements organize germ layers during gastrulation. Noncanonical Wnt signaling has been known as major signaling that regulates CE cell movement by activating Rho and Rac. In addition, Bmp molecules are expressed in the ventral side of a developing embryo, and the ventral mesoderm region undergoes minimal CE cell movement while the dorsal mesoderm undergoes dynamic cell movements. This suggests that Bmp signal gradient may affect CE cell movement. To investigate whether Bmp signaling negatively regulates CE cell movements, we performed microarray-based screening and found that the transcription of Xenopus Arhgef3.2 (Rho guanine nucleotide exchange factor) was negatively regulated by Bmp signaling. We also showed that overexpression or knockdown of Xarhgef3.2 caused gastrulation defects. Interestingly, Xarhgef3.2 controlled gastrulation cell movements through interacting with Disheveled (Dsh2) and Dsh2-associated activator of morphogenesis 1 (Daam1). Our results suggest that Bmp gradient affects gastrulation cell movement (CE) via negative regulation of Xarhgef3.2 expression.
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Affiliation(s)
- Jaeho Yoon
- Department of Biochemistry, Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 24252, Korea; (J.Y.); (V.K.); (R.S.G.); (S.-C.K.)
- National Cancer Institute, Frederick, MD 21702, USA
| | - Vijay Kumar
- Department of Biochemistry, Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 24252, Korea; (J.Y.); (V.K.); (R.S.G.); (S.-C.K.)
| | - Ravi Shankar Goutam
- Department of Biochemistry, Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 24252, Korea; (J.Y.); (V.K.); (R.S.G.); (S.-C.K.)
| | - Sung-Chan Kim
- Department of Biochemistry, Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 24252, Korea; (J.Y.); (V.K.); (R.S.G.); (S.-C.K.)
| | - Soochul Park
- Department of Biological Sciences, Sookmyung Women’s University, Seoul 04310, Korea;
| | - Unjoo Lee
- Department of Electrical Engineering, Hallym University, Chuncheon 24252, Korea;
| | - Jaebong Kim
- Department of Biochemistry, Institute of Cell Differentiation and Aging, College of Medicine, Hallym University, Chuncheon 24252, Korea; (J.Y.); (V.K.); (R.S.G.); (S.-C.K.)
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Redefining the specificity of phosphoinositide-binding by human PH domain-containing proteins. Nat Commun 2021; 12:4339. [PMID: 34267198 PMCID: PMC8282632 DOI: 10.1038/s41467-021-24639-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/18/2021] [Indexed: 01/02/2023] Open
Abstract
Pleckstrin homology (PH) domains are presumed to bind phosphoinositides (PIPs), but specific interaction with and regulation by PIPs for most PH domain-containing proteins are unclear. Here we employ a single-molecule pulldown assay to study interactions of lipid vesicles with full-length proteins in mammalian whole cell lysates. Of 67 human PH domain-containing proteins initially examined, 36 (54%) are found to have affinity for PIPs with various specificity, the majority of which have not been reported before. Further investigation of ARHGEF3 reveals distinct structural requirements for its binding to PI(4,5)P2 and PI(3,5)P2, and functional relevance of its PI(4,5)P2 binding. We generate a recursive-learning algorithm based on the assay results to analyze the sequences of 242 human PH domains, predicting that 49% of them bind PIPs. Twenty predicted binders and 11 predicted non-binders are assayed, yielding results highly consistent with the prediction. Taken together, our findings reveal unexpected lipid-binding specificity of PH domain-containing proteins. Pleckstrin homology (PH) domains are presumed to bind phosphoinositides (PIPs) but only few specific interactions are known. Using TIRF microscopy based assays, functional studies and an experimentally validated prediction algorithm, the authors show that specific PIP binding is widespread among human PH domains.
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11
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Panagopoulos I, Gorunova L, Andersen K, Lobmaier I, Heim S. Several Fusion Genes Identified in a Spermatic Cord Leiomyoma With Rearrangements of Chromosome Arms 3p and 21q. Cancer Genomics Proteomics 2021; 18:531-542. [PMID: 34183386 DOI: 10.21873/cgp.20278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 05/11/2021] [Accepted: 05/18/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND/AIM Benign smooth-muscle tumors, leiomyomas, occur in nearly every organ but are most common in the uterus. Whereas much is known about the genetics of uterine leiomyomas, little genetic information exists about leiomyomas of other organs. Here, we report and discuss the genetic findings in a para-testicular leiomyoma. MATERIALS AND METHODS Cytogenetic, array comparative genomic hybridization (aCGH) RNA sequencing, reverse-transcription polymerase chain reaction (RT- PCR), and Sanger sequencing analyses were performed on a leiomyoma of the spermatic cord removed from a 61-year-old man. RESULTS The karyotype was 48~50,XY,add(3) (p21),+4,+7,+8,+9,add(21)(q22)[cp9]/46,XY[2]. aCGH confirmed the trisomies and also detected multiple gains and losses from 3p and 21q. RNA sequencing detected the chimeras ARHGEF3-CACNA2D2, TRAK1-TIMP4, ITPR1- DT-NR2C2, CLASP2-IL17RD, ZNF621-LARS2, CNTN4- RHOA, and NR2C2-CFAP410. All chimeras were confirmed by RT-PCR and Sanger sequencing. CONCLUSION Our data, together with those previously published, indicate that a group of leiomyomas may be cytogenetically characterized by aberrations of 3p and the formation of fusion genes.
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Affiliation(s)
- Ioannis Panagopoulos
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway;
| | - Ludmila Gorunova
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Kristin Andersen
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Ingvild Lobmaier
- Department of Pathology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway
| | - Sverre Heim
- Section for Cancer Cytogenetics, Institute for Cancer Genetics and Informatics, The Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
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12
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You JS, Singh N, Reyes-Ordonez A, Khanna N, Bao Z, Zhao H, Chen J. ARHGEF3 Regulates Skeletal Muscle Regeneration and Strength through Autophagy. Cell Rep 2021; 34:108594. [PMID: 33406419 DOI: 10.1016/j.celrep.2020.108594] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 09/15/2020] [Accepted: 12/10/2020] [Indexed: 12/18/2022] Open
Abstract
Skeletal muscle regeneration after injury is essential for maintaining muscle function throughout aging. ARHGEF3, a RhoA/B-specific GEF, negatively regulates myoblast differentiation through Akt signaling independently of its GEF activity in vitro. Here, we report ARHGEF3's role in skeletal muscle regeneration revealed by ARHGEF3-KO mice. These mice exhibit indiscernible phenotype under basal conditions. Upon acute injury, however, ARHGEF3 deficiency enhances the mass/fiber size and function of regenerating muscles in both young and regeneration-defective middle-aged mice. Surprisingly, these effects occur independently of Akt but via the GEF activity of ARHGEF3. Consistently, overexpression of ARHGEF3 inhibits muscle regeneration in a Rho-associated kinase-dependent manner. We further show that ARHGEF3 KO promotes muscle regeneration through activation of autophagy, a process that is also critical for maintaining muscle strength. Accordingly, ARHGEF3 depletion in old mice prevents muscle weakness by restoring autophagy. Taken together, our findings identify a link between ARHGEF3 and autophagy-related muscle pathophysiology.
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Key Words
- Skeletal muscle, Regeneration, Aging, Strength, Muscle quality, ARHGEF3, XPLN, Akt, RhoA, ROCK, Autophagy
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Affiliation(s)
- Jae-Sung You
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Nilmani Singh
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Adriana Reyes-Ordonez
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Nidhi Khanna
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Modalis Therapeutics, Cambridge, MA 02138, USA
| | - Zehua Bao
- Department of Chemical and Biomolecular Engineering and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Biomedical Engineering and Biological Design Center, Boston University, Boston, MA 02215, USA
| | - Huimin Zhao
- Department of Chemical and Biomolecular Engineering and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Jie Chen
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
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13
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Gutierrez-Camino A, Richer C, St-Onge P, Lopez-Lopez E, Bañeres AC, de Andoin NG, Sastre A, Astigarraga I, Martin-Guerrero I, Sinnett D, Garcia-Orad A. Role of rs10406069 in miR-5196 in hyperdiploid childhood acute lymphoblastic leukemia. Epigenomics 2020; 12:1949-1955. [PMID: 33245684 DOI: 10.2217/epi-2020-0152] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To determine the role of single nucleotide polymorphisms (SNPs) in noncoding RNAs in childhood acute lymphoblastic leukemia (ALL) subtypes. Materials & methods: We screened all SNPs in 130 pre-miRNA genes to assess their role in the susceptibility of the most common subtypes of ALL: hyperdiploid and ETV6-RUNX1. Results: In two independent cohorts, we found a significant association between rs10406069 in miR-5196 and the risk of developing hyperdiploid ALL. This observation could be explained by the impact of the SNP on miR-5196 expression and in turn, in its target genes. Indeed, rs10406069 was associated with expression changes in SMC1A, a gene involved in sister chromatin cohesion. Conclusion: rs10406069 in miR-5196 may have a relevant role in hyperdiploid ALL risk.
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Affiliation(s)
- Angela Gutierrez-Camino
- Department of Genetics, Physical Anthropology & Animal Physiology, Faculty of Medicine & Nursing, University of the Basque Country, UPV/EHU, Leioa, Spain.,Pediatric Oncology Group, BioCruces Bizkaia Health Research Institute, Barakaldo, Spain.,Division of Hematology-Oncology, CHU Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Chantal Richer
- Division of Hematology-Oncology, CHU Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Pascal St-Onge
- Division of Hematology-Oncology, CHU Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada
| | - Elixabet Lopez-Lopez
- Department of Genetics, Physical Anthropology & Animal Physiology, Faculty of Medicine & Nursing, University of the Basque Country, UPV/EHU, Leioa, Spain.,Pediatric Oncology Group, BioCruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Ana Carbone Bañeres
- Department of Paediatrics, University Hospital Miguel Servet, Zaragoza, Spain
| | - Nagore Garcia de Andoin
- Department of Paediatrics, University Hospital Donostia, San Sebastian, Spain.,Unit of Pediatric Oncohematology, BioDonostia Health Research Institute, San Sebastian, Spain.,Department of Pediatrics, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Ana Sastre
- Department of Oncohematology, University Hospital La Paz, Madrid, Spain
| | - Itziar Astigarraga
- Pediatric Oncology Group, BioCruces Bizkaia Health Research Institute, Barakaldo, Spain.,Department of Pediatrics, University of the Basque Country, UPV/EHU, Leioa, Spain.,Department of Paediatrics, University Hospital Cruces, Barakaldo, Spain
| | - Idoia Martin-Guerrero
- Department of Genetics, Physical Anthropology & Animal Physiology, Faculty of Medicine & Nursing, University of the Basque Country, UPV/EHU, Leioa, Spain.,Pediatric Oncology Group, BioCruces Bizkaia Health Research Institute, Barakaldo, Spain
| | - Daniel Sinnett
- Division of Hematology-Oncology, CHU Sainte-Justine Research Center, Montreal, QC H3T 1C5, Canada.,Department of Pediatrics, Faculty of Medicine, University of Montreal, Montreal, QC H3T 1C5, Canada
| | - Africa Garcia-Orad
- Department of Genetics, Physical Anthropology & Animal Physiology, Faculty of Medicine & Nursing, University of the Basque Country, UPV/EHU, Leioa, Spain.,Pediatric Oncology Group, BioCruces Bizkaia Health Research Institute, Barakaldo, Spain
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14
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Yoon MS. Nanotechnology-Based Targeting of mTOR Signaling in Cancer. Int J Nanomedicine 2020; 15:5767-5781. [PMID: 32821100 PMCID: PMC7418174 DOI: 10.2147/ijn.s254574] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 05/13/2020] [Indexed: 12/20/2022] Open
Abstract
Mammalian target of rapamycin (mTOR) is a master regulator of cell growth and metabolism, which is activated in response to intra- and extracellular signals, including nutrients, growth factors, and cellular energy levels. The frequent dysregulation of mTOR signaling in cancer makes it an attractive therapeutic target, and several types of mTOR inhibitors have been developed. Nanoparticle-based mTOR modulators are predicted to target various cancers and deliver as well as release drugs in a controlled manner, resulting in enhanced bioavailability and reduced side effects. This mini-review is focused on the molecular mechanism of nanoparticle-based mTOR modulator action as well as the current development of mTOR inhibitors using nanoparticles. Understanding the biological function of nanoparticle-based mTOR modulators will contribute to the development of efficient nano-therapeutics for the treatment of cancers.
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Affiliation(s)
- Mee-Sup Yoon
- Department of Molecular Medicine, School of Medicine, Lee Gil Ya Cancer and Diabetes Institute, Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon 21999, Republic of Korea
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15
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Vav2 pharmaco-mimetic mice reveal the therapeutic value and caveats of the catalytic inactivation of a Rho exchange factor. Oncogene 2020; 39:5098-5111. [PMID: 32528129 PMCID: PMC7610363 DOI: 10.1038/s41388-020-1353-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/29/2020] [Accepted: 06/03/2020] [Indexed: 11/20/2022]
Abstract
The current paradigm holds that the inhibition of Rho guanosine nucleotide exchange factors (GEFs), the enzymes that stimulate Rho GTPases, can be a valuable therapeutic strategy to treat Rho-dependent tumors. However, formal validation of this idea using in vivo models is still missing. In this context, it is worth remembering that many Rho GEFs can mediate both catalysis-dependent and independent responses, thus raising the possibility that the inhibition of their catalytic activities might not be sufficient per se to block tumorigenic processes. On the other hand, the inhibition of these enzymes can trigger collateral side effects that could preclude the practical implementation of anti-GEF therapies. To address those issues, we have generated mouse models to mimic the effect of the systemic application of an inhibitor for the catalytic activity of the Rho GEF Vav2 at the organismal level. Our results indicate that lowering the catalytic activity of Vav2 below specific thresholds is sufficient to block skin tumor initiation, promotion, and progression. They also reveal that the negative side effects typically induced by the loss of Vav2 can be bypassed depending on the overall level of Vav2 inhibition achieved in vivo. These data underscore the pros and cons of anti-Rho GEF therapies for cancer treatment. They also support the idea that Vav2 could represent a viable drug target.
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16
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Aashaq S, Batool A, Andrabi KI. TAK1 mediates convergence of cellular signals for death and survival. Apoptosis 2020; 24:3-20. [PMID: 30288639 DOI: 10.1007/s10495-018-1490-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
TGF-β activated kinase 1, a MAPK kinase kinase family serine threonine kinase has been implicated in regulating diverse range of cellular processes that include embryonic development, differentiation, autophagy, apoptosis and cell survival. TAK1 along with its binding partners TAB1, TAB2 and TAB3 displays a complex pattern of regulation that includes serious crosstalk with major signaling pathways including the C-Jun N-terminal kinase (JNK), p38 MAPK, and I-kappa B kinase complex (IKK) involved in establishing cellular commitments for death and survival. This review also highlights how TAK1 orchestrates regulation of energy homeostasis via AMPK and its emerging role in influencing mTORC1 pathway to regulate death or survival in tandem.
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Affiliation(s)
- Sabreena Aashaq
- Department of Biotechnology, University of Kashmir, Hazratbal, Srinagar, 190006, India.
| | - Asiya Batool
- Department of Biotechnology, University of Kashmir, Hazratbal, Srinagar, 190006, India
| | - Khurshid I Andrabi
- Department of Biotechnology, University of Kashmir, Hazratbal, Srinagar, 190006, India
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17
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Suvorov A, Naumov V, Shtratnikova V, Logacheva M, Shershebnev A, Wu H, Gerasimov E, Zheludkevich A, Pilsner JR, Sergeyev O. Rat liver epigenome programing by perinatal exposure to 2,2',4'4'-tetrabromodiphenyl ether. Epigenomics 2019; 12:235-249. [PMID: 31833787 DOI: 10.2217/epi-2019-0315] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Perinatal exposures to polybrominated diphenyl ethers permanently reprogram liver metabolism and induce a nonalcoholic fatty liver disease-like phenotype and insulin resistance in rodents. Aim: To test if these changes are associated with altered liver epigenome. Materials & methods: Expression of small RNA and changes in DNA methylation in livers of adult rats were analyzed following perinatal exposure to 2,2',4,4'-tetrabromodiphenyl ether, the polybrominated diphenyl ether congener most prevalent in human tissues. Results: We identified 33 differentially methylated DNA regions and 15 differentially expressed miRNAs. These changes were enriched for terms related to lipid and carbohydrate metabolism, insulin signaling, Type-2 diabetes and nonalcoholic fatty liver disease. Conclusion: Changes in the liver epigenome are a likely candidate mechanism of long-term maintenance of an aberrant metabolic phenotype.
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Affiliation(s)
- Alexander Suvorov
- Department of Environmental Health Sciences, School of Public Health & Health Sciences, University of Massachusetts 686 North Pleasant Street Amherst, MA 01003, USA.,A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Leninskye Gory, House 1, Building 40, 119992, Moscow, Russia
| | - Vladimir Naumov
- Kulakov National Medical Research Center of Obstetrics, Gynecology & Perinatology, Ministry of Health of the Russian Federation, Oparina 4, 117997, Moscow, Russia
| | - Victoria Shtratnikova
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Leninskye Gory, House 1, Building 40, 119992, Moscow, Russia.,Center for Data-Intensive Biomedicine & Biotechnology, Skolkovo Institute of Science & Technology, 143028, Moscow, Russia
| | - Maria Logacheva
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Leninskye Gory, House 1, Building 40, 119992, Moscow, Russia.,Center for Data-Intensive Biomedicine & Biotechnology, Skolkovo Institute of Science & Technology, 143028, Moscow, Russia
| | - Alex Shershebnev
- Department of Environmental Health Sciences, School of Public Health & Health Sciences, University of Massachusetts 686 North Pleasant Street Amherst, MA 01003, USA
| | - Haotian Wu
- Department of Environmental Health Sciences, School of Public Health & Health Sciences, University of Massachusetts 686 North Pleasant Street Amherst, MA 01003, USA.,Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, 722 W 168th St, New York, NY 10032, USA
| | - Evgeny Gerasimov
- E.I. Martsinovsky Institute of Medical Parasitology & Tropical Medicine, I.M. Sechenov First Moscow State Medical University, 20 Malaya Pirogovskaya, 119435, Moscow, Russia.,Faculty of Biology, Lomonosov Moscow State University, 119992, Moscow, Russia
| | | | - Jonathan R Pilsner
- Department of Environmental Health Sciences, School of Public Health & Health Sciences, University of Massachusetts 686 North Pleasant Street Amherst, MA 01003, USA
| | - Oleg Sergeyev
- A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Leninskye Gory, House 1, Building 40, 119992, Moscow, Russia.,Chapaevsk Medical Association, 3a Meditsinskaya St., Samara region, 446100, Chapaevsk, Russia
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18
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Rybchyn MS, Islam KS, Brennan-Speranza TC, Cheng Z, Brennan SC, Chang W, Mason RS, Conigrave AD. Homer1 mediates CaSR-dependent activation of mTOR complex 2 and initiates a novel pathway for AKT-dependent β-catenin stabilization in osteoblasts. J Biol Chem 2019; 294:16337-16350. [PMID: 31527082 PMCID: PMC6827303 DOI: 10.1074/jbc.ra118.006587] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 08/19/2019] [Indexed: 11/06/2022] Open
Abstract
The calcium-sensing receptor (CaSR) is critical for skeletal development, but its mechanism of action in osteoblasts is not well-characterized. In the central nervous system (CNS), Homer scaffolding proteins form signaling complexes with two CaSR-related members of the G protein-coupled receptor (GPCR) family C, metabotropic glutamate receptor 1 (mGluR1) and mGluR5. Here, we show that CaSR and Homer1 are co-expressed in mineralized mouse bone and also co-localize in primary human osteoblasts. Co-immunoprecipitation experiments confirmed that Homer1 associates with CaSR in primary human osteoblasts. The CaSR-Homer1 protein complex, whose formation was increased in response to extracellular Ca2+, was bound to mechanistic target of rapamycin (mTOR) complex 2 (mTORC2), a protein kinase that phosphorylates and activates AKT Ser/Thr kinase (AKT) at Ser473 siRNA-based gene-silencing assays with primary osteoblasts revealed that both CaSR and Homer1 are required for extracellular Ca2+-stimulated AKT phosphorylation and thereby inhibit apoptosis and promote AKT-dependent β-catenin stabilization and cellular differentiation. To confirm the role of the CaSR-Homer1 complex in AKT initiation, we show that in HEK-293 cells, co-transfection with both Homer1c and CaSR, but neither with Homer1c nor CaSR alone, establishes sensitivity of AKT-Ser473 phosphorylation to increases in extracellular Ca2+ concentrations. These findings indicate that Homer1 mediates CaSR-dependent AKT activation via mTORC2 and thereby stabilizes β-catenin in osteoblasts.
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Affiliation(s)
- Mark S Rybchyn
- Discipline of Physiology, School of Medical Sciences and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Kazi S Islam
- School of Life and Environmental Science, Charles Perkins Centre (D17) and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Tara C Brennan-Speranza
- Discipline of Physiology, School of Medical Sciences and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Zhiqiang Cheng
- School of Medicine, University of California, San Francisco, California 94121
| | - Sarah C Brennan
- School of Life and Environmental Science, Charles Perkins Centre (D17) and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Wenhan Chang
- School of Medicine, University of California, San Francisco, California 94121
| | - Rebecca S Mason
- Discipline of Physiology, School of Medical Sciences and Bosch Institute, University of Sydney, New South Wales 2006, Australia
| | - Arthur David Conigrave
- School of Life and Environmental Science, Charles Perkins Centre (D17) and Bosch Institute, University of Sydney, New South Wales 2006, Australia
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19
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Hua H, Kong Q, Zhang H, Wang J, Luo T, Jiang Y. Targeting mTOR for cancer therapy. J Hematol Oncol 2019; 12:71. [PMID: 31277692 PMCID: PMC6612215 DOI: 10.1186/s13045-019-0754-1] [Citation(s) in RCA: 511] [Impact Index Per Article: 102.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Accepted: 06/14/2019] [Indexed: 02/05/2023] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a protein kinase regulating cell growth, survival, metabolism, and immunity. mTOR is usually assembled into several complexes such as mTOR complex 1/2 (mTORC1/2). In cooperation with raptor, rictor, LST8, and mSin1, key components in mTORC1 or mTORC2, mTOR catalyzes the phosphorylation of multiple targets such as ribosomal protein S6 kinase β-1 (S6K1), eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1), Akt, protein kinase C (PKC), and type-I insulin-like growth factor receptor (IGF-IR), thereby regulating protein synthesis, nutrients metabolism, growth factor signaling, cell growth, and migration. Activation of mTOR promotes tumor growth and metastasis. Many mTOR inhibitors have been developed to treat cancer. While some of the mTOR inhibitors have been approved to treat human cancer, more mTOR inhibitors are being evaluated in clinical trials. Here, we update recent advances in exploring mTOR signaling and the development of mTOR inhibitors for cancer therapy. In addition, we discuss the mechanisms underlying the resistance to mTOR inhibitors in cancer cells.
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Affiliation(s)
- Hui Hua
- State Key Laboratory of Biotherapy, Laboratory of Stem Cell Biology, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Qingbin Kong
- Laboratory of Oncogene, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Hongying Zhang
- Laboratory of Oncogene, Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiao Wang
- School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Ting Luo
- Cancer Center, West China Hospital, Sichuan University, Chengdu, China
| | - Yangfu Jiang
- Laboratory of Oncogene, Cancer Center, West China Hospital, Sichuan University, Chengdu, China.
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20
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Chia LY, Evans BA, Mukaida S, Bengtsson T, Hutchinson DS, Sato M. Adrenoceptor regulation of the mechanistic target of rapamycin in muscle and adipose tissue. Br J Pharmacol 2019; 176:2433-2448. [PMID: 30740664 PMCID: PMC6592864 DOI: 10.1111/bph.14616] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/08/2019] [Accepted: 01/21/2019] [Indexed: 12/16/2022] Open
Abstract
A vital role of adrenoceptors in metabolism and energy balance has been well documented in the heart, skeletal muscle, and adipose tissue. It has been only recently demonstrated, however, that activation of the mechanistic target of rapamycin (mTOR) makes a significant contribution to various metabolic and physiological responses to adrenoceptor agonists. mTOR exists as two distinct complexes named mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) and has been shown to play a critical role in protein synthesis, cell proliferation, hypertrophy, mitochondrial function, and glucose uptake. This review will describe the physiological significance of mTORC1 and 2 as a novel paradigm of adrenoceptor signalling in the heart, skeletal muscle, and adipose tissue. Understanding the detailed signalling cascades of adrenoceptors and how they regulate physiological responses is important for identifying new therapeutic targets and identifying novel therapeutic interventions. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Ling Yeong Chia
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Bronwyn A. Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Saori Mukaida
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner‐Gren InstituteStockholm UniversityStockholmSweden
| | - Dana S. Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical SciencesMonash UniversityMelbourneVictoriaAustralia
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21
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Kmietczyk V, Riechert E, Kalinski L, Boileau E, Malovrh E, Malone B, Gorska A, Hofmann C, Varma E, Jürgensen L, Kamuf-Schenk V, Altmüller J, Tappu R, Busch M, Most P, Katus HA, Dieterich C, Völkers M. m 6A-mRNA methylation regulates cardiac gene expression and cellular growth. Life Sci Alliance 2019; 2:e201800233. [PMID: 30967445 PMCID: PMC6458851 DOI: 10.26508/lsa.201800233] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 03/22/2019] [Accepted: 03/22/2019] [Indexed: 01/25/2023] Open
Abstract
Conceptually similar to modifications of DNA, mRNAs undergo chemical modifications, which can affect their activity, localization, and stability. The most prevalent internal modification in mRNA is the methylation of adenosine at the N6-position (m6A). This returns mRNA to a role as a central hub of information within the cell, serving as an information carrier, modifier, and attenuator for many biological processes. Still, the precise role of internal mRNA modifications such as m6A in human and murine-dilated cardiac tissue remains unknown. Transcriptome-wide mapping of m6A in mRNA allowed us to catalog m6A targets in human and murine hearts. Increased m6A methylation was found in human cardiomyopathy. Knockdown and overexpression of the m6A writer enzyme Mettl3 affected cell size and cellular remodeling both in vitro and in vivo. Our data suggest that mRNA methylation is highly dynamic in cardiomyocytes undergoing stress and that changes in the mRNA methylome regulate translational efficiency by affecting transcript stability. Once elucidated, manipulations of methylation of specific m6A sites could be a powerful approach to prevent worsening of cardiac function.
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Affiliation(s)
- Vivien Kmietczyk
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Eva Riechert
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Laura Kalinski
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Etienne Boileau
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Ellen Malovrh
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Brandon Malone
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Agnieszka Gorska
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Christoph Hofmann
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Eshita Varma
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Lonny Jürgensen
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Verena Kamuf-Schenk
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Janine Altmüller
- Cologne Center for Genomics, University Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Rewati Tappu
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Martin Busch
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Patrick Most
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Christoph Dieterich
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
- Section of Bioinformatics and Systems Cardiology, Department of Cardiology, Angiology, and Pneumology and Klaus Tschira Institute for Integrative Computational Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Mirko Völkers
- Department of Cardiology, Angiology, and Pneumology, University Hospital Heidelberg, University of Heidelberg, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
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22
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Differential regulation of mTORC1 and mTORC2 is critical for 8-Br-cAMP-induced decidualization. Exp Mol Med 2018; 50:1-11. [PMID: 30374127 PMCID: PMC6206090 DOI: 10.1038/s12276-018-0165-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 06/24/2018] [Accepted: 07/02/2018] [Indexed: 12/20/2022] Open
Abstract
Human endometrium decidualization, a differentiation process involving biochemical and morphological changes, is a prerequisite for embryo implantation and successful pregnancy. Here, we show that the mammalian target of rapamycin (mTOR) is a crucial regulator of 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP)-induced decidualization in human endometrial stromal cells. The level of mSin1 in mTOR complex 2 (mTORC2) and DEPTOR in mTOR complex 1 (mTORC1) decreases during 8-Br-cAMP-induced decidualization, resulting in decreased mTORC2 activity and increased mTORC1 activity. Notably, DEPTOR displacement increases the association between raptor and insulin receptor substrate-1 (IRS-1), facilitating IRS-1 phosphorylation at serine 636/639. Finally, both S473 and T308 phosphorylation of Akt are reduced during decidualization, followed by a decrease in forkhead box O1 (FOXO1) phosphorylation and an increase in the mRNA levels of the decidualization markers prolactin (PRL) and insulin-like growth factor-binding protein-1 (IGFBP-1). Taken together, our findings reveal a critical role for mTOR in decidualization, involving the differential regulation of mTORC1 and mTORC2.
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23
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Bustelo XR. RHO GTPases in cancer: known facts, open questions, and therapeutic challenges. Biochem Soc Trans 2018; 46:741-760. [PMID: 29871878 PMCID: PMC7615761 DOI: 10.1042/bst20170531] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/17/2018] [Accepted: 05/03/2018] [Indexed: 02/06/2023]
Abstract
RHO GTPases have been traditionally associated with protumorigenic functions. While this paradigm is still valid in many cases, recent data have unexpectedly revealed that RHO proteins can also play tumor suppressor roles. RHO signaling elements can also promote both pro- and antitumorigenic effects using GTPase-independent mechanisms, thus giving an extra layer of complexity to the role of these proteins in cancer. Consistent with these variegated roles, both gain- and loss-of-function mutations in RHO pathway genes have been found in cancer patients. Collectively, these observations challenge long-held functional archetypes for RHO proteins in both normal and cancer cells. In this review, I will summarize these data and discuss new questions arising from them such as the functional and clinical relevance of the mutations found in patients, the mechanistic orchestration of those antagonistic functions in tumors, and the pros and cons that these results represent for the development of RHO-based anticancer drugs.
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Affiliation(s)
- Xosé R Bustelo
- Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer, and Centro de Investigación Biomédica en Red de Cáncer (CIBERONC), Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, 37007 Salamanca, Spain
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24
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Genomic analysis of 220 CTCLs identifies a novel recurrent gain-of-function alteration in RLTPR (p.Q575E). Blood 2017; 130:1430-1440. [PMID: 28694326 PMCID: PMC5609333 DOI: 10.1182/blood-2017-02-768234] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 06/26/2017] [Indexed: 12/26/2022] Open
Abstract
Cutaneous T-cell lymphoma (CTCL) is an incurable non-Hodgkin lymphoma of the skin-homing T cell. In early-stage disease, lesions are limited to the skin, but in later-stage disease, the tumor cells can escape into the blood, the lymph nodes, and at times the visceral organs. To clarify the genomic basis of CTCL, we performed genomic analysis of 220 CTCLs. Our analyses identify 55 putative driver genes, including 17 genes not previously implicated in CTCL. These novel mutations are predicted to affect chromatin (BCOR, KDM6A, SMARCB1, TRRAP), immune surveillance (CD58, RFXAP), MAPK signaling (MAP2K1, NF1), NF-κB signaling (PRKCB, CSNK1A1), PI-3-kinase signaling (PIK3R1, VAV1), RHOA/cytoskeleton remodeling (ARHGEF3), RNA splicing (U2AF1), T-cell receptor signaling (PTPRN2, RLTPR), and T-cell differentiation (RARA). Our analyses identify recurrent mutations in 4 genes not previously identified in cancer. These include CK1α (encoded by CSNK1A1) (p.S27F; p.S27C), PTPRN2 (p.G526E), RARA (p.G303S), and RLTPR (p.Q575E). Last, we functionally validate CSNK1A1 and RLTPR as putative oncogenes. RLTPR encodes a recently described scaffolding protein in the T-cell receptor signaling pathway. We show that RLTPR (p.Q575E) increases binding of RLTPR to downstream components of the NF-κB signaling pathway, selectively upregulates the NF-κB pathway in activated T cells, and ultimately augments T-cell-receptor-dependent production of interleukin 2 by 34-fold. Collectively, our analysis provides novel insights into CTCL pathogenesis and elucidates the landscape of potentially targetable gene mutations.
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25
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XPLN is modulated by HDAC inhibitors and negatively regulates SPARC expression by targeting mTORC2 in human lung fibroblasts. Pulm Pharmacol Ther 2017; 44:61-69. [DOI: 10.1016/j.pupt.2017.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/12/2017] [Indexed: 11/19/2022]
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26
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In B cells, phosphatidylinositol 5-phosphate 4-kinase-α synthesizes PI(4,5)P2 to impact mTORC2 and Akt signaling. Proc Natl Acad Sci U S A 2016; 113:10571-6. [PMID: 27601656 DOI: 10.1073/pnas.1522478113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Phosphatidylinositol 5-phosphate 4-kinases (PI5P4Ks) are enigmatic lipid kinases with physiological functions that are incompletely understood, not the least because genetic deletion and cell transfection have led to contradictory data. Here, we used the genetic tractability of DT40 cells to create cell lines in which endogenous PI5P4Kα was removed, either stably by genetic deletion or transiently (within 1 h) by tagging the endogenous protein genomically with the auxin degron. In both cases, removal impacted Akt phosphorylation, and by leaving one PI5P4Kα allele present but mutating it to be kinase-dead or have PI4P 5-kinase activity, we show that all of the effects on Akt phosphorylation were dependent on the ability of PI5P4Kα to synthesize phosphatidylinositol (4,5)-bisphosphate [PI(4,5)P2] rather than to remove PI5P. Although stable removal of PI5P4Kα resulted in a pronounced decrease in Akt phosphorylation at Thr308 and Ser473, in part because of reduced plasma membrane PIP3, its acute removal led to an increase in Akt phosphorylation only at Ser473. This process invokes activation primarily of mammalian target of rapamycin complex 2 (mTORC2), which was confirmed by increased phosphorylation of other mTORC2 substrates. These findings establish PI5P4Kα as a kinase that synthesizes a physiologically relevant pool of PI(4,5)P2 and as a regulator of mTORC2, and show a phenomenon similar to the "butterfly effect" described for phosphatidylinositol 3-kinase Iα [Hart JR, et al. (2015) Proc Natl Acad Sci USA 112(4):1131-1136], whereby through apparently the same underlying mechanism, the removal of a protein's activity from a cell can have widely divergent effects depending on the time course of that removal.
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27
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The Mechanistic Target of Rapamycin: The Grand ConducTOR of Metabolism and Aging. Cell Metab 2016; 23:990-1003. [PMID: 27304501 PMCID: PMC4910876 DOI: 10.1016/j.cmet.2016.05.009] [Citation(s) in RCA: 367] [Impact Index Per Article: 45.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 05/17/2016] [Accepted: 05/24/2016] [Indexed: 12/21/2022]
Abstract
Since the discovery that rapamycin, a small molecule inhibitor of the protein kinase mTOR (mechanistic target of rapamycin), can extend the lifespan of model organisms including mice, interest in understanding the physiological role and molecular targets of this pathway has surged. While mTOR was already well known as a regulator of growth and protein translation, it is now clear that mTOR functions as a central coordinator of organismal metabolism in response to both environmental and hormonal signals. This review discusses recent developments in our understanding of how mTOR signaling is regulated by nutrients and the role of the mTOR signaling pathway in key metabolic tissues. Finally, we discuss the molecular basis for the negative metabolic side effects associated with rapamycin treatment, which may serve as barriers to the adoption of rapamycin or similar compounds for the treatment of diseases of aging and metabolism.
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28
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Gaubitz C, Prouteau M, Kusmider B, Loewith R. TORC2 Structure and Function. Trends Biochem Sci 2016; 41:532-545. [PMID: 27161823 DOI: 10.1016/j.tibs.2016.04.001] [Citation(s) in RCA: 137] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/30/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022]
Abstract
The target of rapamycin (TOR) kinase functions in two multiprotein complexes, TORC1 and TORC2. Although both complexes are evolutionarily conserved, only TORC1 is acutely inhibited by rapamycin. Consequently, only TORC1 signaling is relatively well understood; and, at present, only mammalian TORC1 is a validated drug target, pursued in immunosuppression and oncology. However, the knowledge void surrounding TORC2 is dissipating. Acute inhibition of TORC2 with small molecules is now possible and structural studies of both TORC1 and TORC2 have recently been reported. Here we review these recent advances as well as observations made from tissue-specific mTORC2 knockout mice. Together these studies help define TORC2 structure-function relationships and suggest that mammalian TORC2 may one day also become a bona fide clinical target.
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Affiliation(s)
- Christl Gaubitz
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland
| | - Manoel Prouteau
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland
| | - Beata Kusmider
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland
| | - Robbie Loewith
- Department of Molecular Biology, and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest Ansermet, CH1211 Geneva, Switzerland; National Centre of Competence in Research "Chemical Biology", University of Geneva, Geneva CH-1211, Switzerland.
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29
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Lamming DW. Inhibition of the Mechanistic Target of Rapamycin (mTOR)-Rapamycin and Beyond. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025924. [PMID: 27048303 DOI: 10.1101/cshperspect.a025924] [Citation(s) in RCA: 100] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Rapamycin is a Food and Drug Administration (FDA)-approved immunosuppressant and anticancer agent discovered in the soil of Easter Island in the early 1970s. Rapamycin is a potent and selective inhibitor of the mechanistic target of rapamycin (mTOR) protein kinase, which acts as a central integrator of nutrient signaling pathways. During the last decade, genetic and pharmaceutical inhibition of mTOR pathway signaling has been found to promote longevity in yeast, worms, flies, and mice. In this article, we will discuss the molecular biology underlying the effects of rapamycin and its physiological effects, evidence for rapamycin as an antiaging compound, mechanisms by which rapamycin may extend life span, and the potential limitations of rapamycin as an antiaging molecule. Finally, we will discuss possible strategies that may allow us to inhibit mTOR signaling safely while minimizing side effects, and reap the health, social, and economic benefits from slowing the aging process.
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Affiliation(s)
- Dudley W Lamming
- Division of Endocrinology, Department of Medicine, University of Wisconsin-Madison and William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin 53705
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30
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The role of amino acid-induced mammalian target of rapamycin complex 1(mTORC1) signaling in insulin resistance. Exp Mol Med 2016; 48:e201. [PMID: 27534530 PMCID: PMC4686696 DOI: 10.1038/emm.2015.93] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/16/2015] [Accepted: 10/02/2015] [Indexed: 01/07/2023] Open
Abstract
Mammalian target of rapamycin (mTOR) controls cell growth and metabolism in response to nutrients, energy, and growth factors. Recent findings have placed the lysosome at the core of mTOR complex 1 (mTORC1) regulation by amino acids. Two parallel pathways, Rag GTPase-Ragulator and Vps34-phospholipase D1 (PLD1), regulate mTOR activation on the lysosome. This review describes the recent advances in understanding amino acid-induced mTOR signaling with a particular focus on the role of mTOR in insulin resistance.
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31
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Gab1 is essential for membrane translocation, activity and integrity of mTORCs after EGF stimulation in urothelial cell carcinoma. Oncotarget 2015; 6:1478-89. [PMID: 25596749 PMCID: PMC4359308 DOI: 10.18632/oncotarget.2756] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 11/16/2014] [Indexed: 11/30/2022] Open
Abstract
Urothelial carcinoma is the most common type of malignancy in long-term dialysis patients and kidney transplant recipients in Taiwan. mTORCs (mammalian target of rapamycin complexes) and EGF are important in urothelial carcinoma. To identify the regulation of mTORCs upon EGF stimulation is necessary. mTOR integrates signals from growth factors via mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2). The mechanism of mTORC1 action has been widely studied; however, the regulation of mTORC2 has not been well studied. Here, we demonstrate that Gab1 is an important upstream regulator in EGF-mediated activation of mTORCs. In our study, we confirm that mTORCs translocate from the cytoplasm to the plasma membrane via the PH domain of Gab1 upon EGF stimulation. Moreover, Gab1 associates with mTORCs. This association stabilizes the integrity of mTORCs and induces mTORC activity. Compared to normal bladder tissue, the expression of Gab1 and activity of mTORCs are elevated in urothelial carcinoma. Collectively, our results suggest that Gab1 is an essential regulator of the EGF-mediated mTORC pathways and may potentially be used as a biomarker for urothelial carcinoma to predict diagnosis and drug response.
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32
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Identification of a Vav2-dependent mechanism for GDNF/Ret control of mesolimbic DAT trafficking. Nat Neurosci 2015; 18:1084-93. [PMID: 26147533 DOI: 10.1038/nn.4060] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 06/11/2015] [Indexed: 11/08/2022]
Abstract
Dopamine (DA) homeostasis is essential for a variety of brain activities. Dopamine transporter (DAT)-mediated DA reuptake is one of the most critical mechanisms for normal DA homeostasis. However, the molecular mechanisms underlying the regulation of DAT activity in the brain remain poorly understood. Here we show that the Rho-family guanine nucleotide exchange factor protein Vav2 is required for DAT cell surface expression and transporter activity modulated by glial cell line-derived neurotrophic factor (GDNF) and its cognate receptor Ret. Mice deficient in either Vav2 or Ret displayed elevated DAT activity, which was accompanied by an increase in intracellular DA selectively in the nucleus accumbens. Vav2(-/-) mice exposed to cocaine showed reduced DAT activity and diminished behavioral cocaine response. Our data demonstrate that Vav2 is a determinant of DAT trafficking in vivo and contributes to the maintenance of DA homeostasis in limbic DA neuron terminals.
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33
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Tao R, Xiong X, Liangpunsakul S, Dong XC. Sestrin 3 protein enhances hepatic insulin sensitivity by direct activation of the mTORC2-Akt signaling. Diabetes 2015; 64:1211-23. [PMID: 25377878 PMCID: PMC4375082 DOI: 10.2337/db14-0539] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Sestrin proteins have been implicated in multiple biological processes including resistance to oxidative and genotoxic stresses, protection against aging-related pathologies, and promotion of metabolic homeostasis; however, the underlying mechanisms are incompletely understood. Some evidence suggests that sestrins may inhibit mTORC1 (mechanistic target of rapamycin complex 1) through inhibition of RagA/B GTPases or activation of AMPK; however, whether sestrins are also involved in mTORC2 regulation and function is unclear. To investigate the functions and mechanisms of Sestrin 3 (Sesn3), we generated Sesn3 liver-specific transgenic and knockout mice. Our data show that Sesn3 liver-specific knockout mice exhibit insulin resistance and glucose intolerance, and Sesn3 transgenic mice were protected against insulin resistance induced by a high-fat diet. Using AMPK liver-specific knockout mice, we demonstrate that the Sesn3 insulin-sensitizing effect is largely independent of AMPK. Biochemical analysis reveals that Sesn3 interacts with and activates mTORC2 and subsequently stimulates Akt phosphorylation at Ser473. These findings suggest that Sesn3 can activate Akt via mTORC2 to regulate hepatic insulin sensitivity and glucose metabolism.
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Affiliation(s)
- Rongya Tao
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
| | - Xiwen Xiong
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
| | - Suthat Liangpunsakul
- Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, Roudebush Veterans Administration Medical Center, Indianapolis, IN
| | - X Charlie Dong
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN
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34
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Xie J, Proud CG. Signaling crosstalk between the mTOR complexes. ACTA ACUST UNITED AC 2014; 2:e28174. [PMID: 26779402 PMCID: PMC4705829 DOI: 10.4161/trla.28174] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/12/2014] [Accepted: 02/10/2014] [Indexed: 12/16/2022]
Abstract
mTOR is a protein kinase which integrates a variety of environmental and intracellular stimuli to positively regulate many anabolic processes of the cell, including protein synthesis. It exists within two highly conserved multi-protein complexes known as mTORC1 and 2 mTORC2. Each of these complexes phosphorylates different downstream targets, and play roles in different cellular functions. They also show distinctive sensitivity to the mTOR inhibitor rapamycin. Nevertheless, despite their biochemical and functional differences, recent studies have suggested that the regulation of these complexes is tightly linked to each other. For instance, both mTORC1 and 2 share some common upstream signaling molecules, such as PI3K and tuberous sclerosis complex TSC, which control their activation. Stimulation of the mTOR complexes may also trigger both positive and negative feedback mechanisms, which then in turn either further enhance or suppress their activation. Here, we summarize some recently discovered features relating to the crosstalk between mTORC1 and 2. We then discuss how aberrant mTOR complex crosstalk mechanisms may have an impact on the development of human diseases and drug resistance.
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Affiliation(s)
- Jianling Xie
- Centre for Biological Sciences; University of Southampton; Southampton, UK
| | - Chris G Proud
- Centre for Biological Sciences; University of Southampton; Southampton, UK
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