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Eubanks HB, Lavoie EG, Goree J, Kamykowski JA, Gokden N, Fausther M, Dranoff JA. Reduction in SNAP-23 Alters Microfilament Organization in Myofibrobastic Hepatic Stellate Cells. Gene Expr 2020; 20:25-37. [PMID: 31757226 PMCID: PMC7284106 DOI: 10.3727/105221619x15742818049365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Hepatic stellate cells (HSC) are critical effector cells of liver fibrosis. In the injured liver, HSC differentiate into a myofibrobastic phenotype. A critical feature distinguishing myofibroblastic from quiescent HSC is cytoskeletal reorganization. Soluble NSF attachment receptor (SNARE) proteins are important in trafficking of newly synthesized proteins to the plasma membrane for release into the extracellular environment. The goals of this project were to determine the expression of specific SNARE proteins in myofibroblastic HSC and to test whether their alteration changed the HSC phenotype in vitro and progression of liver fibrosis in vivo. We found that HSC lack the t-SNARE protein, SNAP-25, but express a homologous protein, SNAP-23. Downregulation of SNAP-23 in HSC induced reduction in polymerization and disorganization of the actin cytoskeleton associated with loss of cell movement. In contrast, reduction in SNAP-23 in mice by monogenic deletion delayed but did not prevent progression of liver fibrosis to cirrhosis. Taken together, these findings suggest that SNAP-23 is an important regular of actin dynamics in myofibroblastic HSC, but that the role of SNAP-23 in the progression of liver fibrosis in vivo is unclear.
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Affiliation(s)
- Haleigh B. Eubanks
- *Division of Gastroenterology and Hepatology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Elise G. Lavoie
- *Division of Gastroenterology and Hepatology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jessica Goree
- *Division of Gastroenterology and Hepatology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jeffrey A. Kamykowski
- †Department of Physiology and Biophysics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Neriman Gokden
- ‡Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Michel Fausther
- *Division of Gastroenterology and Hepatology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Jonathan A. Dranoff
- *Division of Gastroenterology and Hepatology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
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Wei Y, Wang D, Jin F, Bian Z, Li L, Liang H, Li M, Shi L, Pan C, Zhu D, Chen X, Hu G, Liu Y, Zhang CY, Zen K. Pyruvate kinase type M2 promotes tumour cell exosome release via phosphorylating synaptosome-associated protein 23. Nat Commun 2017; 8:14041. [PMID: 28067230 PMCID: PMC5228053 DOI: 10.1038/ncomms14041] [Citation(s) in RCA: 189] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 11/23/2016] [Indexed: 12/29/2022] Open
Abstract
Tumour cells secrete exosomes that are involved in the remodelling of the tumour-stromal environment and promoting malignancy. The mechanisms governing tumour exosome release, however, remain incompletely understood. Here we show that tumour cell exosomes secretion is controlled by pyruvate kinase type M2 (PKM2), which is upregulated and phosphorylated in tumours. During exosome secretion, phosphorylated PKM2 serves as a protein kinase to phosphorylate synaptosome-associated protein 23 (SNAP-23), which in turn enables the formation of the SNARE complex to allow exosomes release. Direct phosphorylation assay and mass spectrometry confirm that PKM2 phosphorylates SNAP-23 at Ser95. Ectopic expression of non-phosphorylated SNAP-23 mutant (Ser95→Ala95) significantly reduces PKM2-mediated exosomes release whereas expression of selective phosphomimetic SNAP-23 mutants (Ser95→Glu95 but not Ser20→Glu20) rescues the impaired exosomes release induced by PKM2 knockdown. Our findings reveal a non-metabolic function of PKM2, an enzyme associated with tumour cell reliance on aerobic glycolysis, in promoting tumour cell exosome release.
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Affiliation(s)
- Yao Wei
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
- School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Dong Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Fangfang Jin
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Zhen Bian
- Center for Immunology, Inflammation and Infectious Diseases & Department of Biology, Georgia State University, Atlanta, Georgia 30302, USA
| | - Limin Li
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Hongwei Liang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Mingzhen Li
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Lei Shi
- Center for Immunology, Inflammation and Infectious Diseases & Department of Biology, Georgia State University, Atlanta, Georgia 30302, USA
| | - Chaoyun Pan
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Dihan Zhu
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Xi Chen
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Gang Hu
- School of Medicine and Life Sciences, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, China
| | - Yuan Liu
- Center for Immunology, Inflammation and Infectious Diseases & Department of Biology, Georgia State University, Atlanta, Georgia 30302, USA
| | - Chen-Yu Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
| | - Ke Zen
- State Key Laboratory of Pharmaceutical Biotechnology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Nanjing Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Nanjing, Jiangsu 210093, China
- Center for Immunology, Inflammation and Infectious Diseases & Department of Biology, Georgia State University, Atlanta, Georgia 30302, USA
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Jun Y, Thorngren N, Starai VJ, Fratti RA, Collins K, Wickner W. Reversible, cooperative reactions of yeast vacuole docking. EMBO J 2006; 25:5260-9. [PMID: 17082764 PMCID: PMC1636623 DOI: 10.1038/sj.emboj.7601413] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 10/05/2006] [Indexed: 11/08/2022] Open
Abstract
Homotypic yeast vacuole fusion occurs in three stages: (i) priming reactions, which are independent of vacuole clustering, (ii) docking, in which vacuoles cluster and accumulate fusion proteins and fusion regulatory lipids at a ring-shaped microdomain surrounding the apposed membranes of each docked vacuole, where fusion will occur, and (iii) bilayer fusion/compartment mixing. These stages require vacuolar SNAREs, SNARE-chaperones, GTPases, effector complexes, and chemically minor but functionally important lipids. For each, we have developed specific ligands that block fusion and conditions that reverse each block. Using them, we test whether docking entails a linearly ordered series of catalytic events, marked by sequential acquisition of resistance to inhibitors, or whether docking subreactions are cooperative and/or reversible. We find that each fusion protein and regulatory lipid is needed throughout docking, indicative of a reversible or highly cooperative assembly of the fusion-competent vertex ring. In accord with this cooperativity, vertices enriched in one fusion catalyst are enriched in others. Docked vacuoles finally assemble SNARE complexes, yet still require physiological temperature and lipid rearrangements to complete fusion.
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Affiliation(s)
- Youngsoo Jun
- Department of Biochemistry, Dartmouth Medical School, Hanover, NH, USA
| | - Naomi Thorngren
- Department of Biochemistry, Dartmouth Medical School, Hanover, NH, USA
| | - Vincent J Starai
- Department of Biochemistry, Dartmouth Medical School, Hanover, NH, USA
| | - Rutilio A Fratti
- Department of Biochemistry, Dartmouth Medical School, Hanover, NH, USA
| | - Kevin Collins
- Department of Biochemistry, Dartmouth Medical School, Hanover, NH, USA
| | - William Wickner
- Department of Biochemistry, Dartmouth Medical School, Hanover, NH, USA
- Department of Biochemistry, Dartmouth Medical School, 7200 Vail Building, Room 425 Remsen Hanover, NH 03755-3844, USA. Tel.: +1 603 650 1701; Fax: +1 603 650 1353; E-mail:
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