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Zahn LA, Lundin-Schiller S. Evidence for microtubule nucleation at the Golgi in breast cancer cells. Cytoskeleton (Hoboken) 2024; 81:193-205. [PMID: 37905740 DOI: 10.1002/cm.21803] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 11/02/2023]
Abstract
Golgi-derived microtubule (MT) arrays are essential to directionally persistent cell migration and vesicle transport. In this study, we have examined MT nucleation sites in two breast cancer cell lines, MDA-MB-231 and MCF-7, with the hypothesis that only the migratory invasive MDA-MB-231 cells exhibit MTs originating from the Golgi. MTs were disassembled and allowed to slightly regrow so individual nucleation sites could then be observed via fluorescently tagged antibodies (α-tubulin, cis-Golgi marker GM130, and EB1-a MT plus-end binding protein) and confocal microscopy. To determine if MT nucleation at the Golgi is more apparent during active migration compared to when cells are stationary, cells were treated with the chemoattractant epidermal growth factor (EGF) and examined for colocalizations between the Golgi, α-tubulin, and γ-tubulin. Images were analyzed qualitatively for color overlap, and quantitatively using Manders Colocalization Coefficients. Differences between groups were tested for significance using one-way analysis of variances and Tukey's post hoc test. Significantly higher colocalization values (coloc) in the highly invasive MDA-MB-231 cells (α-tubulin coloc GM130 = 0.39, GM130 coloc α-tubulin = 0.82, GM130 coloc EB1 = 0.24, and EB1 coloc GM130 = 0.38) compared to the weakly invasive MCF-7 cells (0.15, 0.08, 0.02, and 0.16, respectively) were observed. EGF-treated cells exhibited higher colocalization values than control cells for three of the four protein combinations tested, but EGF-treated MDA-MB-231 cells exhibited significantly higher values (α-tubulin coloc GM130 = 0.20, GM130 coloc α-tubulin = 0.89, and γ-tubulin coloc GM130 = 0.47) than both control groups as well as the EGF-treated MCF-7 cells. Results support the hypothesis that MT nucleation at the Golgi occurs more frequently in the invasive MDA-MB-231 cell line compared to the weakly invasive MCF-7 cells. The presence or absence of Golgi-derived MTs may help to explain the difference in migratory potential commonly exhibited by these two cell lines.
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Affiliation(s)
- Laura A Zahn
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
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2
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Balczon R, Lin MT, Voth S, Nelson AR, Schupp JC, Wagener BM, Pittet JF, Stevens T. Lung endothelium, tau, and amyloids in health and disease. Physiol Rev 2024; 104:533-587. [PMID: 37561137 PMCID: PMC11281824 DOI: 10.1152/physrev.00006.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 06/26/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023] Open
Abstract
Lung endothelia in the arteries, capillaries, and veins are heterogeneous in structure and function. Lung capillaries in particular represent a unique vascular niche, with a thin yet highly restrictive alveolar-capillary barrier that optimizes gas exchange. Capillary endothelium surveys the blood while simultaneously interpreting cues initiated within the alveolus and communicated via immediately adjacent type I and type II epithelial cells, fibroblasts, and pericytes. This cell-cell communication is necessary to coordinate the immune response to lower respiratory tract infection. Recent discoveries identify an important role for the microtubule-associated protein tau that is expressed in lung capillary endothelia in the host-pathogen interaction. This endothelial tau stabilizes microtubules necessary for barrier integrity, yet infection drives production of cytotoxic tau variants that are released into the airways and circulation, where they contribute to end-organ dysfunction. Similarly, beta-amyloid is produced during infection. Beta-amyloid has antimicrobial activity, but during infection it can acquire cytotoxic activity that is deleterious to the host. The production and function of these cytotoxic tau and amyloid variants are the subject of this review. Lung-derived cytotoxic tau and amyloid variants are a recently discovered mechanism of end-organ dysfunction, including neurocognitive dysfunction, during and in the aftermath of infection.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Mike T Lin
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Sarah Voth
- Department of Cell Biology and Physiology, Edward Via College of Osteopathic Medicine, Monroe, Louisiana, United States
| | - Amy R Nelson
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
| | - Jonas C Schupp
- Pulmonary and Critical Care Medicine, Department of Internal Medicine, Yale University, New Haven, Connecticut, United States
- Department of Respiratory Medicine, Hannover Medical School, Hannover, Germany
- German Center for Lung Research (DZL), Hannover, Germany
| | - Brant M Wagener
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Jean-Francois Pittet
- Department of Anesthesiology and Perioperative Medicine, University of Alabama-Birmingham, Birmingham, Alabama, United States
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama, United States
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States
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3
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Hancock EN, Palmer BM, Caporizzo MA. Microtubule destabilization with colchicine increases the work output of myocardial slices. JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY PLUS 2024; 7:100066. [PMID: 38584975 PMCID: PMC10997380 DOI: 10.1016/j.jmccpl.2024.100066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Cardiac microtubules have recently been implicated in mechanical dysfunction during heart failure. However, systemic intolerance and non-cardiac effects of microtubule-depolymerizing compounds have made it challenging to determine the effect of microtubules on myocardial performance. Herein, we leverage recent advancements in living myocardial slices to develop a stable working preparation that recapitulates the complexity of diastole by including early and late phases of diastolic filling. To determine the effect of cardiac microtubule depolymerization on diastolic performance, myocardial slices were perfused with oxygenated media to maintain constant isometric twitch forces for more than 90 min. Force-length work loops were collected before and after 90 min of treatment with either DMSO (vehicle) or colchicine (microtubule depolymerizer). A trapezoidal stretch was added prior to the beginning of ventricular systole to mimic late-stage-diastolic filling driven by atrial systole. Force-length work loops were obtained at fixed preload and afterload, and tissue velocity was obtained during diastole as an analog to trans-mitral Doppler. In isometric twitches, microtubule destabilization accelerated force development, relaxation kinetics, and decreased end diastolic stiffness. In work loops, microtubule destabilization increased stroke length, myocardial output, accelerated isometric contraction and relaxation, and increased the amplitude of early filling. Taken together, these results indicate that the microtubule destabilizer colchicine can improve diastolic performance by accelerating isovolumic relaxation and early filling leading to increase in myocardial work output.
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Affiliation(s)
- Emmaleigh N. Hancock
- Department of Molecular Physiology and Biophysics, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Bradley M. Palmer
- Department of Molecular Physiology and Biophysics, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Matthew A. Caporizzo
- Department of Molecular Physiology and Biophysics, University of Vermont Larner College of Medicine, Burlington, VT, USA
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4
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Wu L, Islam MR, Lee J, Takase H, Guo S, Andrews AM, Buzhdygan TP, Mathew J, Li W, Arai K, Lo EH, Ramirez SH, Lok J. ErbB3 is a critical regulator of cytoskeletal dynamics in brain microvascular endothelial cells: Implications for vascular remodeling and blood brain barrier modulation. J Cereb Blood Flow Metab 2021; 41:2242-2255. [PMID: 33583260 PMCID: PMC8393293 DOI: 10.1177/0271678x20984976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Neuregulin (NRG)1 - ErbB receptor signaling has been shown to play an important role in the biological function of peripheral microvascular endothelial cells. However, little is known about how NRG1/ErbB signaling impacts brain endothelial function and blood-brain barrier (BBB) properties. NRG1/ErbB pathways are affected by brain injury; when brain trauma was induced in mice in a controlled cortical impact model, endothelial ErbB3 gene expression was reduced to a greater extent than that of other NRG1 receptors. This finding suggests that ErbB3-mediated processes may be significantly compromised after injury, and that an understanding of ErbB3 function would be important in the of study of endothelial biology in the healthy and injured brain. Towards this goal, cultured brain microvascular endothelial cells were transfected with siRNA to ErbB3, resulting in alterations in F-actin organization and microtubule assembly, cell morphology, migration and angiogenic processes. Importantly, a significant increase in barrier permeability was observed when ErbB3 was downregulated, suggesting ErbB3 involvement in BBB regulation. Overall, these results indicate that neuregulin-1/ErbB3 signaling is intricately connected with the cytoskeletal processes of the brain endothelium and contributes to morphological and angiogenic changes as well as to BBB integrity.
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Affiliation(s)
- Limin Wu
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Mohammad R Islam
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Janice Lee
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Hajime Takase
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Shuzhen Guo
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Allison M Andrews
- Department of Pathology & Laboratory Medicine, Temple University School of Medicine, Philadelphia, USA
| | - Tetyana P Buzhdygan
- Department of Pathology & Laboratory Medicine, Temple University School of Medicine, Philadelphia, USA
| | - Justin Mathew
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Wenlu Li
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Ken Arai
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA
| | - Eng H Lo
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA.,Department of Radiology, Massachusetts General Hospital, Boston, USA.,Department of Neurology, Massachusetts General Hospital, Boston, USA
| | - Servio H Ramirez
- Department of Pathology & Laboratory Medicine, Temple University School of Medicine, Philadelphia, USA.,The Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, USA
| | - Josephine Lok
- Neuroprotection Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Charlestown, USA.,Department of Pediatrics, Pediatric Critical Care Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, USA
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5
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Thanuja MY, Suma BS, Dinesh D, Ranganath SH, Srinivas SP. Microtubule Stabilization Protects Hypothermia-Induced Damage to the Cytoskeleton and Barrier Integrity of the Corneal Endothelial Cells. J Ocul Pharmacol Ther 2021; 37:399-411. [PMID: 34227869 DOI: 10.1089/jop.2021.0036] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Purpose: To determine the impact of hypothermia on the barrier function of donor corneal endothelium, thereby enhancing the success of corneal transplantation. Methods: Primary cultures of porcine endothelial cells were subjected to hypothermia (15 h; 4°C). The impact on microtubule assembly, peri-junctional actomyosin ring (PAMR), and ZO-1 was assessed by immunocytochemistry with and without pretreatment with a microtubule-stabilizing agent (Epothilone B; EpoB; 100 nM) and a p38 MAP kinase inhibitor (SB-203580; 20 μM). In addition, EpoB-loaded PLGA nanoparticles (ENPs) prepared by nanoprecipitation technique and coated with poly-L-lysine (PLL-ENPs) were administered one-time for sustained intracellular delivery of EpoB. Results: Exposure to hypothermia led to microtubule disassembly concomitant with the destruction of PAMR and the displacement of ZO-1 at the cellular periphery, suggesting a loss in barrier integrity. These adverse effects were attenuated by pretreatment with EpoB or SB-203580. PLL-ENPs possessed a zeta potential of ∼26 mV and a size of ∼110 nm. Drug loading and entrapment efficiency were 5% (w/w) and ∼87%, respectively, and PLL-ENPs showed a biphasic release in vitro: burst phase (1 day), followed by a sustained phase (∼4 weeks). Pretreatment with PLL-ENPs (0.4 mg/mL) for 24 h stabilized the microtubules and opposed the hypothermia-induced damage to PAMR and the redistribution of ZO-1. Conclusions: Hypothermia induces microtubule disassembly via activation of p38 MAP kinase and subsequently breaks down the barrier function of the endothelium. Sustained intracellular delivery of EpoB using nanoparticles has the potential to overcome endothelial barrier failure during prolonged cold storage of donor cornea.
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Affiliation(s)
- Marasarakottige Y Thanuja
- Bio-INvENT Lab, Department of Chemical Engineering, Siddaganga Institute of Technology, Tumakuru, India
| | - Bangalore S Suma
- Bioimaging Facility, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Divyasree Dinesh
- Department of Biotechnology, Siddaganga Institute of Technology, Tumakuru, India
| | - Sudhir H Ranganath
- Bio-INvENT Lab, Department of Chemical Engineering, Siddaganga Institute of Technology, Tumakuru, India
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6
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Balczon R, Morrow KA, Leavesley S, Francis CM, Stevens TC, Agwaramgbo E, Williams C, Stevens RP, Langham G, Voth S, Cioffi EA, Weintraub SE, Stevens T. Cystatin C regulates the cytotoxicity of infection-induced endothelial-derived β-amyloid. FEBS Open Bio 2020; 10:2464-2477. [PMID: 33030263 PMCID: PMC7609779 DOI: 10.1002/2211-5463.12997] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/25/2020] [Accepted: 10/05/2020] [Indexed: 02/06/2023] Open
Abstract
Infection of rat pulmonary microvascular endothelial cells with the bacterium Pseudomonas aeruginosa induces the production and release of cytotoxic oligomeric tau and beta amyloid (Aβ). Here, we characterized these cytotoxic amyloids. Cytotoxic behavior and oligomeric tau were partially resistant to digestion with proteinase K, but cytotoxicity was abolished by various denaturants including phenol, diethylpyrocarbonate (DEPC), and 1,1,1,3,3,3-hexafluoro-2-isopropanol (HFIP). Ultracentrifugation for 8 h at 150 000 g was required to remove cytotoxic activity from the supernatant. Ultracentrifugation, DEPC treatment, and immunodepletion using antibodies against Aβ also demonstrated that cytoprotective protein(s) are released from endothelial cells during P. aeruginosa infection. Mass spectrometry of endothelial cell culture media following P. aeruginosa infection allowed identification of multiple potential secreted modulators of Aβ, including cystatin C, gelsolin, and ApoJ/clusterin. Immunodepletion, co-immunoprecipitation, and ultracentrifugation determined that the cytoprotective factor released during infection of endothelial cells by P. aeruginosa is cystatin C, which appears to be in a complex with Aβ. Cytoprotective cystatin C may provide a novel therapeutic avenue for protection against the long-term consequences of infection with P. aeruginosa.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular BiologyUniversity of South AlabamaMobileALUSA
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
| | - Kyle A. Morrow
- Department of Cell Biology and PhysiologyEdward Via College of Osteopathic MedicineMonroeLAUSA
| | - Silas Leavesley
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Chemical and Biomedical EngineeringUniversity of South AlabamaMobileALUSA
| | - Christopher M. Francis
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Trevor C. Stevens
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Ezinne Agwaramgbo
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | | | - Reece P. Stevens
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Geri Langham
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Sarah Voth
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
| | - Eugene A. Cioffi
- Department of PharmacologyUniversity of South AlabamaMobileALUSA
| | - Susan E. Weintraub
- Department of Biochemistry and Structural Biology and Mass Spectrometry LaboratoryUniversity of Texas at San Antonio Health Sciences CenterTXUSA
| | - Troy Stevens
- Center for Lung BiologyUniversity of South AlabamaMobileALUSA
- Department of Physiology and Cell BiologyUniversity of South AlabamaMobileALUSA
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7
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Wu Y, Wang D, Wei F, Xiong F, Zhang S, Gong Z, Shi L, Li X, Xiang B, Ma J, Deng H, He Y, Liao Q, Zhang W, Li X, Li Y, Guo C, Zeng Z, Li G, Xiong W. EBV-miR-BART12 accelerates migration and invasion in EBV-associated cancer cells by targeting tubulin polymerization-promoting protein 1. FASEB J 2020; 34:16205-16223. [PMID: 33094864 DOI: 10.1096/fj.202001508r] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/26/2020] [Accepted: 09/29/2020] [Indexed: 12/16/2022]
Abstract
Epstein-Barr virus (EBV) infection leads to cancers with an epithelial origin, such as nasopharyngeal cancer and gastric cancer, as well as multiple blood cell-based malignant tumors, such as lymphoma. Interestingly, EBV is also the first virus found to carry genes encoding miRNAs. EBV encodes 25 types of pre-miRNAs which are finally processed into 44 mature miRNAs. Most EBV-encoded miRNAs were found to be involved in the occurrence and development of EBV-related tumors. However, the function of EBV-miR-BART12 remains unclear. The findings of the current study revealed that EBV-miR-BART12 binds to the 3'UTR region of Tubulin Polymerization-Promoting Protein 1 (TPPP1) mRNA and downregulates TPPP1, thereby promoting the invasion and migration of EBV-related cancers, such as nasopharyngeal cancer and gastric cancer. The mechanism underlying this process was found to be the inhibition of TPPP1 by EBV-miRNA-BART12, which, in turn, inhibits the acetylation of α-tubulin, and promotes the dynamic assembly of microtubules, remodels the cytoskeleton, and enhances the acetylation of β-catenin. β-catenin activates epithelial to mesenchymal transition (EMT). These two processes synergistically promote the invasion and metastasis of tumor cells. To the best of our knowledge, this is the first study to reveal the role of EBV-miRNA-BART12 in the development of EBV-related tumors as well as the mechanism underlying this process, and suggests potential targets and strategies for the treatment of EBV-related tumors.
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Affiliation(s)
- Yingfen Wu
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Dan Wang
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Fang Wei
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Fang Xiong
- Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China
| | - Shanshan Zhang
- Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhaojian Gong
- Department of Oral and Maxillofacial Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Lei Shi
- Department of Oral and Maxillofacial Surgery, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Xiayu Li
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Bo Xiang
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Jian Ma
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Hao Deng
- Hunan Key Laboratory of Nonresolving Inflammation and Cancer, Disease Genome Research Center, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yi He
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Qianjin Liao
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
| | - Wenling Zhang
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Xiaoling Li
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Yong Li
- Department of Medicine, Dan L Duncan Comprehensive Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Can Guo
- Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Zhaoyang Zeng
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Guiyuan Li
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
| | - Wei Xiong
- NHC Key Laboratory of Carcinogenesis, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China.,Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Cancer Research Institute, Central South University, Changsha, China
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8
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Spastin mutations impair coordination between lipid droplet dispersion and reticulum. PLoS Genet 2020; 16:e1008665. [PMID: 32315314 PMCID: PMC7173978 DOI: 10.1371/journal.pgen.1008665] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Accepted: 02/12/2020] [Indexed: 12/22/2022] Open
Abstract
Lipid droplets (LD) are affected in multiple human disorders. These highly dynamic organelles are involved in many cellular roles. While their intracellular dispersion is crucial to ensure their function and other organelles-contact, underlying mechanisms are still unclear. Here we show that Spastin, one of the major proteins involved in Hereditary Spastic Paraplegia (HSP), controls LD dispersion. Spastin depletion in zebrafish affects metabolic properties and organelle dynamics. These functions are ensured by a conserved complex set of splice variants. M1 isoforms determine LD dispersion in the cell by orchestrating endoplasmic reticulum (ER) shape along microtubules (MTs). To further impact LD fate, Spastin modulates transcripts levels and subcellular location of other HSP key players, notably Seipin and REEP1. In pathological conditions, mutations in human Spastin M1 disrupt this mechanism and impacts LD network. Spastin depletion influences not only other key proteins but also modulates specific neutral lipids and phospholipids, revealing an impact on membrane and organelle components. Altogether our results show that Spastin and its partners converge in a common machinery that coordinates LD dispersion and ER shape along MTs. Any alteration of this system results in HSP clinical features and impacts lipids profile, thus opening new avenues for novel biomarkers of HSP.
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9
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Srivastava S, Panda D. A centrosomal protein STARD9 promotes microtubule stability and regulates spindle microtubule dynamics. Cell Cycle 2018; 17:2052-2068. [PMID: 30160609 DOI: 10.1080/15384101.2018.1513764] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Centrosomal proteins play important roles in the spindle assembly and the segregation of chromosomes in the eukaryotic cells. STARD9, a recently identified centrosomal protein, was reported to influence the spindle pole assembly. However, the role of STARD9 in maintaining the stability and organization of microtubules are not known. Here, we show that STARD9 regulates the assembly and dynamics of both interphase and mitotic microtubules. The knockdown of STARD9 in HeLa or HCT116 cells with siRNA or shRNA induced a strong depolymerization of the interphase microtubules. The over-expression of the motor domain of STARD9 stabilizes microtubules against cold and nocodazole suggesting that STARD9 stabilizes microtubules in HeLa cells. Using fluorescent recovery after photobleaching, we showed that the knockdown of STARD9 strongly reduced microtubule dynamics in the live spindles of HeLa cells. The reassembly of microtubules in the STARD9-depleted cells was strongly reduced as compared to the microtubules in the control cells implying the role of STARD9 in the nucleation of microtubules. Further, the depletion of STARD9 inhibited chromosome separation and the STARD9-depleted HeLa cells were blocked at mitosis. Interestingly, the frequency of multipolar spindle formation increased significantly in the STARD9-depleted HeLa cells in the presence of vinblastine and the STARD9-depleted cells showed much higher sensitivity towards vinblastine than the control cells indicating a new approach for cancer chemotherapy. The evidence suggests that STARD9 regulates the assembly and stability of both interphase and spindle microtubules and thereby, play important roles in the cell cycle progression.
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Affiliation(s)
- Shalini Srivastava
- a Department of Biosciences & Bioengineering , Indian Institute of Technology Bombay , Mumbai , India
| | - Dulal Panda
- a Department of Biosciences & Bioengineering , Indian Institute of Technology Bombay , Mumbai , India
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10
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Plaud C, Joshi V, Kajevu N, Poüs C, Curmi PA, Burgo A. Functional differences of short and long isoforms of spastin harboring missense mutation. Dis Model Mech 2018; 11:11/9/dmm033704. [PMID: 30213879 PMCID: PMC6177001 DOI: 10.1242/dmm.033704] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 07/03/2018] [Indexed: 01/05/2023] Open
Abstract
Mutations of the SPG4 (SPAST) gene encoding for spastin protein are the main causes of hereditary spastic paraplegia. Spastin binds to microtubules and severs them through the enzymatic activity of its AAA domain. Several missense mutations located in this domain lead to stable, nonsevering spastins that decorate a subset of microtubules, suggesting a possible negative gain-of-function mechanism for these mutants. Of the two main isoforms of spastin, only mutations of the long isoform, M1, are supposed to be involved in the onset of the pathology, leaving the role of the ubiquitously expressed shorter one, M87, not fully investigated and understood. Here, we show that two isoforms of spastin harboring the same missense mutation bind and bundle different subsets of microtubules in HeLa cells, and likely stabilize them by increasing the level of acetylated tubulin. However, only mutated M1 has the ability to interact with wild-type M1, and decorates a subset of perinuclear microtubules associated with the endoplasmic reticulum that display higher resistance to microtubule depolymerization and increased intracellular ionic strength, compared with those decorated by mutated M87. We further show that only mutated M1 decorates microtubules of proximal axons and dendrites, and strongly impairs axonal transport in cortical neurons through a mechanism likely independent of the microtubule-severing activity of this protein. Summary: Long and short isoforms of spastin (SPG4) harboring the same missense mutation show different intracellular localization, resistance to pharmacological treatments and effects on axonal cargo transport.
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Affiliation(s)
- Clément Plaud
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris Saclay, Université d'Evry, 91000 Evry, France
| | - Vandana Joshi
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris Saclay, Université d'Evry, 91000 Evry, France
| | - Natallie Kajevu
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris Saclay, Université d'Evry, 91000 Evry, France
| | - Christian Poüs
- INSERM UMR-S 1193, Faculty of Pharmacy, Univirsité Paris-Sud, Université Paris-Saclay, 92296 Châtenay-Malabry, France
| | - Patrick A Curmi
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris Saclay, Université d'Evry, 91000 Evry, France
| | - Andrea Burgo
- Structure and Activity of Normal and Pathological Biomolecules, INSERM U1204, Université Paris Saclay, Université d'Evry, 91000 Evry, France
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11
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Indibulin dampens microtubule dynamics and produces synergistic antiproliferative effect with vinblastine in MCF-7 cells: Implications in cancer chemotherapy. Sci Rep 2018; 8:12363. [PMID: 30120268 PMCID: PMC6098095 DOI: 10.1038/s41598-018-30376-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/26/2018] [Indexed: 01/05/2023] Open
Abstract
Indibulin, a synthetic inhibitor of tubulin assembly, has shown promising anticancer activity with a minimal neurotoxicity in preclinical animal studies and in Phase I clinical trials for cancer chemotherapy. Using time-lapse confocal microscopy, we show that indibulin dampens the dynamic instability of individual microtubules in live breast cancer cells. Indibulin treatment also perturbed the localization of end-binding proteins at the growing microtubule ends in MCF-7 cells. Indibulin reduced inter-kinetochoric tension, produced aberrant spindles, activated mitotic checkpoint proteins Mad2 and BubR1, and induced mitotic arrest in MCF-7 cells. Indibulin-treated MCF-7 cells underwent apoptosis-mediated cell death. Further, the combination of indibulin with an anticancer drug vinblastine was found to exert synergistic cytotoxic effects on MCF-7 cells. Interestingly, indibulin displayed a stronger effect on the undifferentiated neuroblastoma (SH-SY5Y) cells than the differentiated neuronal cells. Unlike indibulin, vinblastine and colchicine produced similar depolymerizing effects on microtubules in both differentiated and undifferentiated SH-SY5Y cells. The data indicated a possibility that indibulin may reduce chemotherapy-induced peripheral neuropathy in cancer patients.
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12
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Atkinson SJ, Gontarczyk AM, Alghamdi AA, Ellison TS, Johnson RT, Fowler WJ, Kirkup BM, Silva BC, Harry BE, Schneider JG, Weilbaecher KN, Mogensen MM, Bass MD, Parsons M, Edwards DR, Robinson SD. The β3-integrin endothelial adhesome regulates microtubule-dependent cell migration. EMBO Rep 2018; 19:embr.201744578. [PMID: 29794156 PMCID: PMC6030693 DOI: 10.15252/embr.201744578] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 04/25/2018] [Accepted: 04/27/2018] [Indexed: 01/11/2023] Open
Abstract
Integrin β3 is seen as a key anti-angiogenic target for cancer treatment due to its expression on neovasculature, but the role it plays in the process is complex; whether it is pro- or anti-angiogenic depends on the context in which it is expressed. To understand precisely β3's role in regulating integrin adhesion complexes in endothelial cells, we characterised, by mass spectrometry, the β3-dependent adhesome. We show that depletion of β3-integrin in this cell type leads to changes in microtubule behaviour that control cell migration. β3-integrin regulates microtubule stability in endothelial cells through Rcc2/Anxa2-driven control of active Rac1 localisation. Our findings reveal that angiogenic processes, both in vitro and in vivo, are more sensitive to microtubule targeting agents when β3-integrin levels are reduced.
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Affiliation(s)
- Samuel J Atkinson
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Aleksander M Gontarczyk
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Abdullah Aa Alghamdi
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Tim S Ellison
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Robert T Johnson
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Wesley J Fowler
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Benjamin M Kirkup
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Bernardo C Silva
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Bronwen E Harry
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Jochen G Schneider
- Luxembourg Center for Systems Biomedicine (LCSB), Luxembourg & Saarland University Medical Center, Internal Medicine II, University of Luxembourg, Homburg, Germany.,Centre Hospitalier Emily Mayrisch, Esch, Luxembourg
| | - Katherine N Weilbaecher
- Division of Molecular Oncology, Department of Internal Medicine, Washington University in St Louis, St. Louis, MO, USA
| | - Mette M Mogensen
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Mark D Bass
- Department of Biomedical Science, Centre for Membrane Interactions and Dynamics, University of Sheffield, Sheffield, UK
| | - Maddy Parsons
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guys Campus, London, UK
| | - Dylan R Edwards
- Faculty of Medicine and Health Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
| | - Stephen D Robinson
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, UK
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13
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Phengchat R, Takata H, Uchiyama S, Fukui K. Calcium depletion destabilises kinetochore fibres by the removal of CENP-F from the kinetochore. Sci Rep 2017; 7:7335. [PMID: 28779172 PMCID: PMC5544769 DOI: 10.1038/s41598-017-07777-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 07/03/2017] [Indexed: 12/12/2022] Open
Abstract
The attachment of spindle fibres to the kinetochore is an important process that ensures successful completion of the cell division. The Ca2+ concentration increases during the mitotic phase and contributes microtubule stability. However, its role in the spindle organisation in mitotic cells remains controversial. Here, we investigated the role of Ca2+ on kinetochore fibres in living cells. We found that depletion of Ca2+ during mitosis reduced kinetochore fibre stability. Reduction of kinetochore fibre stability was not due to direct inhibition of microtubule polymerisation by Ca2+-depletion but due to elimination of one dynamic component of kinetochore, CENP-F from the kinetochore. This compromised the attachment of kinetochore fibres to the kinetochore which possibly causes mitotic defects induced by the depletion of Ca2+.
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Affiliation(s)
- Rinyaporn Phengchat
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Osaka, Japan
| | - Hideaki Takata
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Osaka, Japan. .,Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31, Midorigaoka, Ikeda, 563-8577, Osaka, Japan.
| | - Susumu Uchiyama
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Osaka, Japan
| | - Kiichi Fukui
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, 565-0871, Osaka, Japan. .,Chromosome Engineering Research Centre, Tottori University, 86 Nishimachi, Yonago, 683-0826, Tottori, Japan.
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14
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Borgas D, Chambers E, Newton J, Ko J, Rivera S, Rounds S, Lu Q. Cigarette Smoke Disrupted Lung Endothelial Barrier Integrity and Increased Susceptibility to Acute Lung Injury via Histone Deacetylase 6. Am J Respir Cell Mol Biol 2017; 54:683-96. [PMID: 26452072 DOI: 10.1165/rcmb.2015-0149oc] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Epidemiologic evidence indicates that cigarette smoke (CS) is associated with the development of acute lung injury (ALI). We have previously shown that brief CS exposure exacerbates lipopolysaccharide (LPS)-induced ALI in vivo and endothelial barrier dysfunction in vitro. In this study, we found that CS also exacerbated Pseudomonas-induced ALI in mice. We demonstrated that lung microvascular endothelial cells (ECs) isolated from mice exposed to CS had a greater permeability or incomplete recovery after challenges by LPS and thrombin. Histone deacetylase (HDAC) 6 deacetylates proteins essential for maintenance of endothelial barrier function. We found that HDAC6 phosphorylation at serine-22 was increased in lung tissues of mice exposed to CS and in lung ECs exposed to cigarette smoke extract (CSE). Inhibition of HDAC6 attenuated CSE-induced increases in EC permeability and CS priming of ALI. Similar barrier protection was provided by the microtubule stabilizer taxol, which preserved α-tubulin acetylation. CSE decreased α-tubulin acetylation and caused microtubule depolymerization. In coordination with increased HDAC6 phosphorylation, CSE inhibited Akt and activated glycogen synthase kinase (GSK)-3β; these effects were ameliorated by the antioxidant N-acetyl cysteine. Our results suggest that CS increases lung EC permeability, thereby enhancing susceptibility to ALI, likely through oxidative stress-induced Akt inactivation and subsequent GSK-3β activation. Activated GSK-3β may activate HDAC6 via phosphorylation of serine-22, leading to α-tubulin deacetylation and microtubule disassembly. Inhibition of HDAC6 may be a novel therapeutic option for ALI in cigarette smokers.
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Affiliation(s)
- Diana Borgas
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Eboni Chambers
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Julie Newton
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Junsuk Ko
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Stephanie Rivera
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Sharon Rounds
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
| | - Qing Lu
- Vascular Research Laboratory, Providence Veterans Affairs Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, Rhode Island
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15
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Balczon R, Morrow KA, Zhou C, Edmonds B, Alexeyev M, Pittet JF, Wagener BM, Moser SA, Leavesley S, Zha X, Frank DW, Stevens T. Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids. FASEB J 2017; 31:2785-2796. [PMID: 28314768 DOI: 10.1096/fj.201601042rr] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 02/26/2017] [Indexed: 12/28/2022]
Abstract
Patients who recover from pneumonia subsequently have elevated rates of death after hospital discharge as a result of secondary organ damage, the causes of which are unknown. We used the bacterium Pseudomonas aeruginosa, a common cause of hospital-acquired pneumonia, as a model for investigating this phenomenon. We show that infection of pulmonary endothelial cells by P. aeruginosa induces production and release of a cytotoxic amyloid molecule with prion characteristics, including resistance to various nucleases and proteases. This cytotoxin was self-propagating, was neutralized by anti-amyloid Abs, and induced death of endothelial cells and neurons. Moreover, the cytotoxin induced edema in isolated lungs. Endothelial cells and isolated lungs were protected from cytotoxin-induced death by stimulation of signal transduction pathways that are linked to prion protein. Analysis of bronchoalveolar lavage fluid collected from human patients with P. aeruginosa pneumonia demonstrated cytotoxic activity, and lavage fluid contained amyloid molecules, including oligomeric τ and Aβ. Demonstration of long-lived cytotoxic agents after Pseudomonas infection may establish a molecular link to the high rates of death as a result of end-organ damage in the months after recovery from pneumonia, and modulation of signal transduction pathways that have been linked to prion protein may provide a mechanism for intervention.-Balczon, R., Morrow, K. A., Zhou, C., Edmonds, B., Alexeyev, M., Pittet, J.-F., Wagener, B. M., Moser, S. A., Leavesley, S., Zha, X., Frank, D. W., Stevens, T. Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids.
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Affiliation(s)
- Ron Balczon
- Department of Biochemistry and Molecular Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA; .,Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - K Adam Morrow
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Chun Zhou
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Bradley Edmonds
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Mikhail Alexeyev
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Jean-Francois Pittet
- Department of Anesthesia and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Brant M Wagener
- Department of Anesthesia and Perioperative Medicine, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Stephen A Moser
- Department of Pathology, University of Alabama at Birmingham School of Medicine, Birmingham, Alabama, USA
| | - Silas Leavesley
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Chemical and Biomedical Engineering, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Xiangming Zha
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Troy Stevens
- Center for Lung Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA.,Department of Physiology and Cell Biology, College of Medicine, University of South Alabama, Mobile, Alabama, USA
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16
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Yu J, Ma Z, Shetty S, Ma M, Fu J. Selective HDAC6 inhibition prevents TNF-α-induced lung endothelial cell barrier disruption and endotoxin-induced pulmonary edema. Am J Physiol Lung Cell Mol Physiol 2016; 311:L39-47. [PMID: 27190059 DOI: 10.1152/ajplung.00051.2016] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 05/17/2016] [Indexed: 12/16/2022] Open
Abstract
Lung endothelial damage contributes to the pathogenesis of acute lung injury. New strategies against lung endothelial barrier dysfunction may provide therapeutic benefits against lung vascular injury. Cell-cell junctions and microtubule cytoskeleton are basic components in maintaining endothelial barrier integrity. HDAC6, a deacetylase primarily localized in the cytoplasm, has been reported to modulate nonnuclear protein function through deacetylation. Both α-tubulin and β-catenin are substrates for HDAC6. Here, we examined the effects of tubastatin A, a highly selective HDAC6 inhibitor, on TNF-α induced lung endothelial cell barrier disruption and endotoxin-induced pulmonary edema. Selective HDAC6 inhibition by tubastatin A blocked TNF-α-induced lung endothelial cell hyperpermeability, which was associated with increased α-tubulin acetylation and microtubule stability. Tubastatin A pretreatment inhibited TNF-α-induced endothelial cell contraction and actin stress fiber formation with reduced myosin light chain phosphorylation. Selective HDAC6 inhibition by tubastatin A also induced β-catenin acetylation in human lung endothelial cells, which was associated with increased membrane localization of β-catenin and stabilization of adherens junctions. HDAC6 knockdown by small interfering RNA also prevented TNF-α-induced barrier dysfunction and increased α-tubulin and β-catenin acetylation in endothelial cells. Furthermore, in a mouse model of endotoxemia, tubastatin A was able to prevent endotoxin-induced deacetylation of α-tubulin and β-catenin in lung tissues, which was associated with reduced pulmonary edema. Collectively, our data indicate that selective HDAC6 inhibition by tubastatin A is a potent approach against lung endothelial barrier dysfunction.
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Affiliation(s)
- Jinyan Yu
- The Second Hospital of Jilin University, Jilin, China; Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, Kentucky; Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, Kentucky; and
| | - Zhongsen Ma
- The Second Hospital of Jilin University, Jilin, China
| | - Sreerama Shetty
- Center for Biomedical Research, University of Texas Health Science Center, Tyler, Texas
| | - Mengshi Ma
- The Second Hospital of Jilin University, Jilin, China; Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Jian Fu
- Center for Research on Environmental Disease, College of Medicine, University of Kentucky, Lexington, Kentucky; Department of Toxicology and Cancer Biology, College of Medicine, University of Kentucky, Lexington, Kentucky; and
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17
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Kandil S, Wymant JM, Kariuki BM, Jones AT, McGuigan C, Westwell AD. Novel cis-selective and non-epimerisable C3 hydroxy azapodophyllotoxins targeting microtubules in cancer cells. Eur J Med Chem 2015; 110:311-25. [PMID: 26854430 PMCID: PMC4762250 DOI: 10.1016/j.ejmech.2015.12.037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 11/16/2015] [Accepted: 12/20/2015] [Indexed: 11/18/2022]
Abstract
Podophyllotoxin (PT) and its clinically used analogues are known to be powerful antitumour agents. These compounds contain a trans fused strained γ-lactone system, a feature that correlates to the process of epimerisation, whereby the trans γ-lactone system of ring D opens and converts to the more thermodynamically stable cis epimer. Since these cis epimers are known to be either less active or lacking antitumour activity, epimerisation is an undesirable feature from a chemotherapeutic point of view. To circumvent this problem, considerable efforts have been reported, amongst which is the synthesis of azapodophyllotoxins where the stereocentres at C2 and C3 are removed in order to preclude epimerisation. Herein we report the identification of a novel C3 hydroxy, cis-selective γ-lactone configuration of ring C in the azapodophyllotoxin scaffold, through an efficient stereoselective multicomponent reaction (MCR) involving fluorinated and non-fluorinated aldehydes. This configuration releases the highly strained trans γ-lactone system in podophyllotoxin analogues into the more thermodynamically stable cis γ-lactone motif and yet retains significantly potent activity. These compounds were evaluated against the human cancer lines MCF-7 and 22Rv1 in vitro. Fourteen out of the seventeen tested compounds exhibited sub-micromolar activity with IC50 values in the range of 0.11-0.91 μM, which is comparable and in some cases better than the activity profile of etoposide in this assay. Interestingly, we obtained strong evidence from spectroscopic and X-ray data analyses that the previously reported structure of similar analogues is not accurate. Molecular modelling performed using the podophyllotoxin binding site on β tubulin revealed a novel binding mode of these analogues. Furthermore, sub-cellular study of our compounds using immunolabelling and confocal microscopy analyses showed strong microtubule disruptive activity, particularly in dividing cells.
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Affiliation(s)
- Sahar Kandil
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff, CF10 3NB, Wales, United Kingdom
| | - Jennifer M Wymant
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff, CF10 3NB, Wales, United Kingdom
| | - Benson M Kariuki
- School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, Wales, United Kingdom
| | - Arwyn T Jones
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff, CF10 3NB, Wales, United Kingdom
| | - Christopher McGuigan
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff, CF10 3NB, Wales, United Kingdom
| | - Andrew D Westwell
- Cardiff School of Pharmacy & Pharmaceutical Sciences, Cardiff University, King Edward VII Avenue, Cardiff, CF10 3NB, Wales, United Kingdom.
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18
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Morrow KA, Ochoa CD, Balczon R, Zhou C, Cauthen L, Alexeyev M, Schmalzer KM, Frank DW, Stevens T. Pseudomonas aeruginosa exoenzymes U and Y induce a transmissible endothelial proteinopathy. Am J Physiol Lung Cell Mol Physiol 2015; 310:L337-53. [PMID: 26637633 DOI: 10.1152/ajplung.00103.2015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 12/02/2015] [Indexed: 11/22/2022] Open
Abstract
We tested the hypothesis that Pseudomonas aeruginosa type 3 secretion system effectors exoenzymes Y and U (ExoY and ExoU) induce release of a high-molecular-weight endothelial tau, causing transmissible cell injury characteristic of an infectious proteinopathy. Both the bacterial delivery of ExoY and ExoU and the conditional expression of an activity-attenuated ExoU induced time-dependent pulmonary microvascular endothelial cell gap formation that was paralleled by the loss of intracellular tau and the concomitant appearance of high-molecular-weight extracellular tau. Transfer of the high-molecular-weight tau in filtered supernatant to naïve endothelial cells resulted in intracellular accumulation of tau clusters, which was accompanied by cell injury, interendothelial gap formation, decreased endothelial network stability in Matrigel, and increased lung permeability. Tau oligomer monoclonal antibodies captured monomeric tau from filtered supernatant but did not retrieve higher-molecular-weight endothelial tau and did not rescue the injurious effects of tau. Enrichment and transfer of high-molecular-weight tau to naïve cells was sufficient to cause injury. Thus we provide the first evidence for a pathophysiological stimulus that induces release and transmissibility of high-molecular-weight endothelial tau characteristic of an endothelial proteinopathy.
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Affiliation(s)
- K Adam Morrow
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Cristhiaan D Ochoa
- Physician-Scientist Training Program, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas, Texas; Division of Pulmonary and Critical Care, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - Ron Balczon
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Chun Zhou
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Laura Cauthen
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Mikhail Alexeyev
- Department of Biochemistry and Molecular Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - Katherine M Schmalzer
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin; Division of Hematology/Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Dara W Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin; and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Troy Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama;
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19
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Morrow KA, Seifert R, Kaever V, Britain AL, Sayner SL, Ochoa CD, Cioffi EA, Frank DW, Rich TC, Stevens T. Heterogeneity of pulmonary endothelial cyclic nucleotide response to Pseudomonas aeruginosa ExoY infection. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1199-207. [PMID: 26386118 PMCID: PMC4652153 DOI: 10.1152/ajplung.00165.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 09/11/2015] [Indexed: 01/16/2023] Open
Abstract
Here, we tested the hypothesis that a promiscuous bacterial cyclase synthesizes purine and pyrimidine cyclic nucleotides in the pulmonary endothelium. To test this hypothesis, pulmonary endothelial cells were infected with a strain of the Gram-negative bacterium Pseudomonas aeruginosa that introduces only exoenzyme Y (PA103 ΔexoUexoT::Tc pUCPexoY; ExoY(+)) via a type III secretion system. Purine and pyrimidine cyclic nucleotides were simultaneously detected using mass spectrometry. Pulmonary artery (PAECs) and pulmonary microvascular (PMVECs) endothelial cells both possess basal levels of four different cyclic nucleotides in the following rank order: cAMP > cUMP ≈ cGMP ≈ cCMP. Endothelial gap formation was induced in a time-dependent manner following ExoY(+) intoxication. In PAECs, intercellular gaps formed within 2 h and progressively increased in size up to 6 h, when the experiment was terminated. cGMP concentrations increased within 1 h postinfection, whereas cAMP and cUMP concentrations increased within 3 h, and cCMP concentrations increased within 4 h postinfection. In PMVECs, intercellular gaps did not form until 4 h postinfection. Only cGMP and cUMP concentrations increased at 3 and 6 h postinfection, respectively. PAECs generated higher cyclic nucleotide levels than PMVECs, and the cyclic nucleotide levels increased earlier in response to ExoY(+) intoxication. Heterogeneity of the cyclic nucleotide signature in response to P. aeruginosa infection exists between PAECs and PMVECs, suggesting the intracellular milieu in PAECs is more conducive to cNMP generation.
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Affiliation(s)
- K A Morrow
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - R Seifert
- Institute of Pharmacology, Hannover Medical School, Hannover, Germany
| | - V Kaever
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - A L Britain
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - S L Sayner
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - C D Ochoa
- Physician-Scientist Training Program, Department of Medicine, University of Texas-Southwestern Medical Center, Dallas, Texas; Physician-Scientist Training Program, Division of Pulmonary and Critical Care, University of Texas-Southwestern Medical Center, Dallas, Texas
| | - E A Cioffi
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - D W Frank
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin; and Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - T C Rich
- Department of Pharmacology, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama
| | - T Stevens
- Department of Physiology and Cell Biology, University of South Alabama, Mobile, Alabama; Department of Medicine, University of South Alabama, Mobile, Alabama; Center for Lung Biology, University of South Alabama, Mobile, Alabama;
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20
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Gory-Fauré S, Windscheid V, Brocard J, Montessuit S, Tsutsumi R, Denarier E, Fukata Y, Bosc C, Delaroche J, Collomb N, Fukata M, Martinou JC, Pernet-Gallay K, Andrieux A. Non-microtubular localizations of microtubule-associated protein 6 (MAP6). PLoS One 2014; 9:e114905. [PMID: 25526643 PMCID: PMC4272302 DOI: 10.1371/journal.pone.0114905] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 11/11/2014] [Indexed: 01/29/2023] Open
Abstract
MAP6 proteins (MAP6s), which include MAP6-N (also called Stable Tubule Only Polypeptide, or STOP) and MAP6d1 (MAP6 domain-containing protein 1, also called STOP-Like protein 21 kD, or SL21), bind to and stabilize microtubules. MAP6 deletion in mice severely alters integrated brain functions and is associated with synaptic defects, suggesting that MAP6s may also have alternative cellular roles. MAP6s reportedly associate with the Golgi apparatus through palmitoylation of their N-terminal domain, and specific isoforms have been shown to bind actin. Here, we use heterologous systems to investigate several biochemical properties of MAP6 proteins. We demonstrate that the three N-terminal cysteines of MAP6d1 are palmitoylated by a subset of DHHC-type palmitoylating enzymes. Analysis of the subcellular localization of palmitoylated MAP6d1, including electron microscopic analysis, reveals possible localization to the Golgi and the plasma membrane but no association with the endoplasmic reticulum. Moreover, we observed localization of MAP6d1 to mitochondria, which requires the N-terminus of the protein but does not require palmitoylation. We show that endogenous MAP6d1 localized at mitochondria in mature mice neurons as well as at the outer membrane and in the intermembrane space of purified mouse mitochondria. Last, we found that MAP6d1 can multimerize via a microtubule-binding module. Interestingly, most of these properties of MAP6d1 are shared by MAP6-N. Together, these results describe several properties of MAP6 proteins, including their intercellular localization and multimerization activity, which may be relevant to neuronal differentiation and synaptic functions.
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Affiliation(s)
- Sylvie Gory-Fauré
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
- * E-mail: (SGF); (AA)
| | - Vanessa Windscheid
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
| | - Jacques Brocard
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
| | - Sylvie Montessuit
- Department of Cell Biology, University of Geneva, Sciences III, Geneva, Switzerland
| | - Ryouhei Tsutsumi
- Division of Membrane Physiology, Department of Cell Physiology, National Institute for Physiological Sciences, Aichi, Japan
| | - Eric Denarier
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
- Commissariat à l'énergie atomique, Institut de Recherches en Technologies et Sciences pour le Vivant, Groupe Physiopathologie du Cytosquelette, Grenoble, France
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Cell Physiology, National Institute for Physiological Sciences, Aichi, Japan
| | - Christophe Bosc
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
| | - Julie Delaroche
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
| | - Nora Collomb
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Cell Physiology, National Institute for Physiological Sciences, Aichi, Japan
| | - Jean-Claude Martinou
- Department of Cell Biology, University of Geneva, Sciences III, Geneva, Switzerland
| | - Karin Pernet-Gallay
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
| | - Annie Andrieux
- Inserm, U836, Physiopathologie du cytosquelette, BP170, Grenoble, France
- University Grenoble Alpes, Grenoble Institut des Neurosciences, BP170, Grenoble, France
- Commissariat à l'énergie atomique, Institut de Recherches en Technologies et Sciences pour le Vivant, Groupe Physiopathologie du Cytosquelette, Grenoble, France
- * E-mail: (SGF); (AA)
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21
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Balczon R, Prasain N, Ochoa C, Prater J, Zhu B, Alexeyev M, Sayner S, Frank DW, Stevens T. Pseudomonas aeruginosa exotoxin Y-mediated tau hyperphosphorylation impairs microtubule assembly in pulmonary microvascular endothelial cells. PLoS One 2013; 8:e74343. [PMID: 24023939 PMCID: PMC3762819 DOI: 10.1371/journal.pone.0074343] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 08/01/2013] [Indexed: 12/21/2022] Open
Abstract
Pseudomonas aeruginosa uses a type III secretion system to introduce the adenylyl and guanylyl cyclase exotoxin Y (ExoY) into the cytoplasm of endothelial cells. ExoY induces Tau hyperphosphorylation and insolubility, microtubule breakdown, barrier disruption and edema, although the mechanism(s) responsible for microtubule breakdown remain poorly understood. Here we investigated both microtubule behavior and centrosome activity to test the hypothesis that ExoY disrupts microtubule dynamics. Fluorescence microscopy determined that infected pulmonary microvascular endothelial cells contained fewer microtubules than control cells, and further studies demonstrated that the microtubule-associated protein Tau was hyperphosphorylated following infection and dissociated from microtubules. Disassembly/reassembly studies determined that microtubule assembly was disrupted in infected cells, with no detectable effects on either microtubule disassembly or microtubule nucleation by centrosomes. This effect of ExoY on microtubules was abolished when the cAMP-dependent kinase phosphorylation site (Ser-214) on Tau was mutated to a non-phosphorylatable form. These studies identify Tau in microvascular endothelial cells as the target of ExoY in control of microtubule architecture following pulmonary infection by Pseudomonas aeruginosa and demonstrate that phosphorylation of tau following infection decreases microtubule assembly.
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Affiliation(s)
- Ron Balczon
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail:
| | - Nutan Prasain
- Department of Pediatrics, University of Indiana School of Medicine, Indianapolis, Indiana, United States of America
| | - Cristhiaan Ochoa
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
| | - Jason Prater
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- Department of Medicine, University of South Alabama, Mobile, Alabama, United States of America
| | - Bing Zhu
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
| | - Mikhail Alexeyev
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Sarah Sayner
- Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Dara W. Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Troy Stevens
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Department of Medicine, University of South Alabama, Mobile, Alabama, United States of America
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22
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Delphin C, Bouvier D, Seggio M, Couriol E, Saoudi Y, Denarier E, Bosc C, Valiron O, Bisbal M, Arnal I, Andrieux A. MAP6-F is a temperature sensor that directly binds to and protects microtubules from cold-induced depolymerization. J Biol Chem 2012; 287:35127-35138. [PMID: 22904321 DOI: 10.1074/jbc.m112.398339] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Microtubules are dynamic structures that present the peculiar characteristic to be ice-cold labile in vitro. In vivo, microtubules are protected from ice-cold induced depolymerization by the widely expressed MAP6/STOP family of proteins. However, the mechanism by which MAP6 stabilizes microtubules at 4 °C has not been identified. Moreover, the microtubule cold sensitivity and therefore the needs for microtubule stabilization in the wide range of temperatures between 4 and 37 °C are unknown. This is of importance as body temperatures of animals can drop during hibernation or torpor covering a large range of temperatures. Here, we show that in the absence of MAP6, microtubules in cells below 20 °C rapidly depolymerize in a temperature-dependent manner whereas they are stabilized in the presence of MAP6. We further show that in cells, MAP6-F binding to and stabilization of microtubules is temperature- dependent and very dynamic, suggesting a direct effect of the temperature on the formation of microtubule/MAP6 complex. We also demonstrate using purified proteins that MAP6-F binds directly to microtubules through its Mc domain. This binding is temperature-dependent and coincides with progressive conformational changes of the Mc domain as revealed by circular dichroism. Thus, MAP6 might serve as a temperature sensor adapting its conformation according to the temperature to maintain the cellular microtubule network in organisms exposed to temperature decrease.
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Affiliation(s)
- Christian Delphin
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France.
| | - Denis Bouvier
- the European Molecular Biology Laboratory, Grenoble Outstation, 6 rue Jules Horowitz, BP181, 38042 Grenoble Cedex 9, France
| | - Maxime Seggio
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Emilie Couriol
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Yasmina Saoudi
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Eric Denarier
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Christophe Bosc
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Odile Valiron
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Mariano Bisbal
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Isabelle Arnal
- Team 13 Dynamic and Structural Regulation of Cytoskeleton, Institut National de la Santé et de la Recherche Médicale, U836-GIN, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
| | - Annie Andrieux
- Team 1 Physiopathology of Cytoskeleton; Commissariat à I'Energie Atomique, Institut National de la Santé et de la Recherche Médicale, U836-GIN iRTSV-GPC, Site Santé La Tronche, BP170, 38042 Grenoble, Cedex 9, France
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23
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Sidhaye VK, Chau E, Srivastava V, Sirimalle S, Balabhadrapatruni C, Aggarwal NR, D'Alessio FR, Robinson DN, King LS. A novel role for aquaporin-5 in enhancing microtubule organization and stability. PLoS One 2012; 7:e38717. [PMID: 22715407 PMCID: PMC3371026 DOI: 10.1371/journal.pone.0038717] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Accepted: 05/11/2012] [Indexed: 11/18/2022] Open
Abstract
Aquaporin-5 (AQP5) is a water-specific channel located on the apical surface of airway epithelial cells. In addition to regulating transcellular water permeability, AQP5 can regulate paracellular permeability, though the mechanisms by which this occurs have not been determined. Microtubules also regulate paracellular permeability. Here, we report that AQP5 promotes microtubule assembly and helps maintain the assembled microtubule steady state levels with slower turnover dynamics in cells. Specifically, reduced levels of AQP5 correlated with lower levels of assembled microtubules and decreased paracellular permeability. In contrast, overexpression of AQP5 increased assembly of microtubules, with evidence of increased MT stability, and promoted the formation of long straight microtubules in the apical domain of the epithelial cells. These findings indicate that AQP5-mediated regulation of microtubule dynamics modulates airway epithelial barrier properties and epithelial function.
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Affiliation(s)
- Venkataramana K Sidhaye
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, The Johns Hopkins University School of Medicine, Johns Hopkins University, Baltimore, Maryland, United States of America.
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24
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Ochoa CD, Alexeyev M, Pastukh V, Balczon R, Stevens T. Pseudomonas aeruginosa exotoxin Y is a promiscuous cyclase that increases endothelial tau phosphorylation and permeability. J Biol Chem 2012; 287:25407-18. [PMID: 22637478 DOI: 10.1074/jbc.m111.301440] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Exotoxin Y (ExoY) is a type III secretion system effector found in ~ 90% of the Pseudomonas aeruginosa isolates. Although it is known that ExoY causes inter-endothelial gaps and vascular leak, the mechanisms by which this occurs are poorly understood. Using both a bacteria-delivered and a codon-optimized conditionally expressed ExoY, we report that this toxin is a dual soluble adenylyl and guanylyl cyclase that results in intracellular cAMP and cGMP accumulation. The enzymatic activity of ExoY caused phosphorylation of endothelial Tau serine 214, accumulation of insoluble Tau, inter-endothelial cell gap formation, and increased macromolecular permeability. To discern whether the cAMP or cGMP signal was responsible for Tau phosphorylation and barrier disruption, pulmonary microvascular endothelial cells were engineered for the conditional expression of either wild-type guanylyl cyclase, which synthesizes cGMP, or a mutated guanylyl cyclase, which synthesizes cAMP. Sodium nitroprusside stimulation of the cGMP-generating cyclase resulted in transient Tau serine 214 phosphorylation and gap formation, whereas stimulation of the cAMP-generating cyclase induced a robust increase in Tau serine 214 phosphorylation, gap formation, and macromolecular permeability. These results indicate that the cAMP signal is the dominant stimulus for Tau phosphorylation. Hence, ExoY is a promiscuous cyclase and edema factor that uses cAMP and, to some extent, cGMP to induce the hyperphosphorylation and insolubility of endothelial Tau. Because hyperphosphorylated and insoluble Tau are hallmarks in neurodegenerative tauopathies such as Alzheimer disease, acute Pseudomonas infections cause a pathophysiological sequela in endothelium previously recognized only in chronic neurodegenerative diseases.
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Affiliation(s)
- Cristhiaan D Ochoa
- Department of Pharmacology, College of Medicine, University of South Alabama, Mobile, Alabama 36688, USA
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