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Hu Y, Wang R, Liu J, Wang Y, Dong J. Lipid droplet deposition in the regenerating liver: A promoter, inhibitor, or bystander? Hepatol Commun 2023; 7:e0267. [PMID: 37708445 PMCID: PMC10503682 DOI: 10.1097/hc9.0000000000000267] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/29/2023] [Indexed: 09/16/2023] Open
Abstract
Liver regeneration (LR) is a complex process involving intricate networks of cellular connections, cytokines, and growth factors. During the early stages of LR, hepatocytes accumulate lipids, primarily triacylglycerol, and cholesterol esters, in the lipid droplets. Although it is widely accepted that this phenomenon contributes to LR, the impact of lipid droplet deposition on LR remains a matter of debate. Some studies have suggested that lipid droplet deposition has no effect or may even be detrimental to LR. This review article focuses on transient regeneration-associated steatosis and its relationship with the liver regenerative response.
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Affiliation(s)
- Yuelei Hu
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Ruilin Wang
- Department of Cadre’s Wards Ultrasound Diagnostics. Ultrasound Diagnostic Center, The First Hospital of Jilin University, Jilin University, Changchun, China
| | - Juan Liu
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
- Clinical Translational Science Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Yunfang Wang
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
- Clinical Translational Science Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Jiahong Dong
- Department of Hepatobiliary and Pancreatic Surgery, The First Hospital of Jilin University, Jilin University, Changchun, China
- Research Unit of Precision Hepatobiliary Surgery Paradigm, Chinese Academy of Medical Sciences, Beijing, China
- Hepatopancreatobiliary Center, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China
- Institute for Organ Transplant and Bionic Medicine, Tsinghua University, Beijing, China
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2
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Yang J, Pei T, Su G, Duan P, Liu X. AnnexinA6: a potential therapeutic target gene for extracellular matrix mineralization. Front Cell Dev Biol 2023; 11:1201200. [PMID: 37727505 PMCID: PMC10506415 DOI: 10.3389/fcell.2023.1201200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 08/10/2023] [Indexed: 09/21/2023] Open
Abstract
The mineralization of the extracellular matrix (ECM) is an essential and crucial process for physiological bone formation and pathological calcification. The abnormal function of ECM mineralization contributes to the worldwide risk of developing mineralization-related diseases; for instance, vascular calcification is attributed to the hyperfunction of ECM mineralization, while osteoporosis is due to hypofunction. AnnexinA6 (AnxA6), a Ca2+-dependent phospholipid-binding protein, has been extensively reported as an essential target in mineralization-related diseases such as osteoporosis, osteoarthritis, atherosclerosis, osteosarcoma, and calcific aortic valve disease. To date, AnxA6, as the largest member of the Annexin family, has attracted much attention due to its significant contribution to matrix vesicles (MVs) production and release, MVs-ECM interaction, cytoplasmic Ca2+ influx, and maturation of hydroxyapatite, making it an essential target in ECM mineralization. In this review, we outlined the recent advancements in the role of AnxA6 in mineralization-related diseases and the potential mechanisms of AnxA6 under normal and mineralization-related pathological conditions. AnxA6 could promote ECM mineralization for bone regeneration in the manner described previously. Therefore, AnxA6 may be a potential osteogenic target for ECM mineralization.
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Affiliation(s)
| | | | | | | | - Xiaoheng Liu
- Institute of Biomedical Engineering, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
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3
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Chen L, Zhang X, Lin J, Wen Y, Chen Y, Chen CB. Construction and validation of a prognostic model based on stage-associated signature genes of head and neck squamous cell carcinoma: a bioinformatics study. ANNALS OF TRANSLATIONAL MEDICINE 2022; 10:1316. [PMID: 36660709 PMCID: PMC9843360 DOI: 10.21037/atm-22-5427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/25/2022] [Indexed: 12/12/2022]
Abstract
Background Head and neck squamous cell carcinoma (HNSCC) is a malignancy of epithelial origin and with poor prognosis. Exploring the biomarkers and prognostic models that can contribute to early tumor detection is meaningful. A comprehensive analysis was conducted according to the stage-related signature genes of HNSCC, and a prognostic model was developed to validate their ability to predict the prognosis. Methods The transcriptome profiles and clinical information of HNSCC patients were obtained from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) respectively. mRNA expressions of differentially expressed genes (DEGs) were analyzed in stage I-II patients and stage III-IV patients from TCGA by R packages. A protein-protein interaction (PPI) network and core-gene network map were constructed, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to examine pathway enrichment. Kaplan-Meier, least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression were applied to establish a stage-associated signature model. A Spearman analysis was conducted to examine the correlations between the characteristic genes and immune cell infiltration. Kaplan-Meier analysis and a receiver operating characteristic (ROC) curve were used to test the effectiveness of the model. Univariate multivariate Cox regression analyses were used to assess whether the risk score was an independent prognostic indicator for HNSCC. Results In TCGA cohort, 5 genes (i.e., BRINP1, IL17A, ALB, FOXA2, and ZCCHC12) in the constructed prognostic risk model were associated with prognosis. Patients in the low-risk group had a better prognosis outcome than those in the high-risk group. The predictive power was good because all the area under the curve (AUC) of the risk score was higher than 0.6. Risk score [hazard ratio (HR) =1.985; P<0.001] was an independent risk factor for the prognosis of HNSCC. The results in the GEO cohort were consistent with those in the TCGA cohort. Conclusions We constructed and verified a prognostic risk model of stage-related signature genes for HNSCC based on the GEO and TCGA data. Due to the good predictive accuracy of this model, the prognosis of and the tumor immune cell infiltration with patients can be estimated.
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Affiliation(s)
- Lizhu Chen
- Department of Medical Oncology, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China;,Cancer Bio-Immunotherapy Center, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China;,Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, China
| | - Xiaofei Zhang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai, China;,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jie Lin
- Department of Gynecology, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China
| | - Yaoming Wen
- Fujian Institute of Microbiology, Fuzhou, China
| | - Yu Chen
- Department of Medical Oncology, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China;,Cancer Bio-Immunotherapy Center, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China;,Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, China
| | - Chuan-Ben Chen
- Cancer Bio-Immunotherapy Center, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China;,Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fuzhou, China;,Department of Radiation Oncology, Clinical Oncology School of Fujian Medical University, Fujian Cancer Hospital, Fuzhou, China
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4
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Méndez-Barbero N, San Sebastian-Jaraba I, Blázquez-Serra R, Martín-Ventura JL, Blanco-Colio LM. Annexins and cardiovascular diseases: Beyond membrane trafficking and repair. Front Cell Dev Biol 2022; 10:1000760. [PMID: 36313572 PMCID: PMC9614170 DOI: 10.3389/fcell.2022.1000760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 10/03/2022] [Indexed: 12/02/2022] Open
Abstract
Cardiovascular diseases (CVD) remain the leading cause of mortality worldwide. The main cause underlying CVD is associated with the pathological remodeling of the vascular wall, involving several cell types, including endothelial cells, vascular smooth muscle cells, and leukocytes. Vascular remodeling is often related with the development of atherosclerotic plaques leading to narrowing of the arteries and reduced blood flow. Atherosclerosis is known to be triggered by high blood cholesterol levels, which in the presence of a dysfunctional endothelium, results in the retention of lipoproteins in the artery wall, leading to an immune-inflammatory response. Continued hypercholesterolemia and inflammation aggravate the progression of atherosclerotic plaque over time, which is often complicated by thrombus development, leading to the possibility of CV events such as myocardial infarction or stroke. Annexins are a family of proteins with high structural homology that bind phospholipids in a calcium-dependent manner. These proteins are involved in several biological functions, from cell structural organization to growth regulation and vesicle trafficking. In vitro gain- or loss-of-function experiments have demonstrated the implication of annexins with a wide variety of cellular processes independent of calcium signaling such as immune-inflammatory response, cell proliferation, migration, differentiation, apoptosis, and membrane repair. In the last years, the use of mice deficient for different annexins has provided insight into additional functions of these proteins in vivo, and their involvement in different pathologies. This review will focus in the role of annexins in CVD, highlighting the mechanisms involved and the potential therapeutic effects of these proteins.
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Affiliation(s)
- Nerea Méndez-Barbero
- Laboratory of Vascular Pathology, IIS-Fundación Jiménez Díaz, Madrid, Spain
- CIBERCV, Madrid, Spain
| | | | - Rafael Blázquez-Serra
- Laboratory of Vascular Pathology, IIS-Fundación Jiménez Díaz, Madrid, Spain
- CIBERCV, Madrid, Spain
| | - Jose L. Martín-Ventura
- Laboratory of Vascular Pathology, IIS-Fundación Jiménez Díaz, Madrid, Spain
- CIBERCV, Madrid, Spain
- Autonoma University of Madrid, Madrid, Spain
| | - Luis M. Blanco-Colio
- Laboratory of Vascular Pathology, IIS-Fundación Jiménez Díaz, Madrid, Spain
- CIBERCV, Madrid, Spain
- *Correspondence: Luis M. Blanco-Colio,
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Demonbreun AR, Bogdanovic E, Vaught LA, Reiser NL, Fallon KS, Long AM, Oosterbaan CC, Hadhazy M, Page PG, Joseph PRB, Cowen G, Telenson AM, Khatri A, Sadleir KR, Vassar R, McNally EM. A conserved annexin A6-mediated membrane repair mechanism in muscle, heart, and nerve. JCI Insight 2022; 7:158107. [PMID: 35866481 PMCID: PMC9431694 DOI: 10.1172/jci.insight.158107] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 06/08/2022] [Indexed: 11/21/2022] Open
Abstract
Membrane instability and disruption underlie myriad acute and chronic disorders. Anxa6 encodes the membrane-associated protein annexin A6 and was identified as a genetic modifier of muscle repair and muscular dystrophy. To evaluate annexin A6’s role in membrane repair in vivo, we inserted sequences encoding green fluorescent protein (GFP) into the last coding exon of Anxa6. Heterozygous Anxa6gfp mice expressed a normal pattern of annexin A6 with reduced annexin A6GFP mRNA and protein. High-resolution imaging of wounded muscle fibers showed annexin A6GFP rapidly formed a repair cap at the site of injury. Injured cardiomyocytes and neurons also displayed repair caps after wounding, highlighting annexin A6–mediated repair caps as a feature in multiple cell types. Using surface plasmon resonance, we showed recombinant annexin A6 bound phosphatidylserine-containing lipids in a Ca2+- and dose-dependent fashion with appreciable binding at approximately 50 μM Ca2+. Exogenously added recombinant annexin A6 localized to repair caps and improved muscle membrane repair capacity in a dose-dependent fashion without disrupting endogenous annexin A6 localization, indicating annexin A6 promotes repair from both intracellular and extracellular compartments. Thus, annexin A6 orchestrates repair in multiple cell types, and recombinant annexin A6 may be useful in additional chronic disorders beyond skeletal muscle myopathies.
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Affiliation(s)
| | - Elena Bogdanovic
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Lauren A Vaught
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Nina L Reiser
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Katherine S Fallon
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Ashlee M Long
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Claire C Oosterbaan
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Michele Hadhazy
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | | | | | - Gabrielle Cowen
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | | | - Ammaarah Khatri
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Katherine R Sadleir
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Robert Vassar
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Elizabeth M McNally
- Center for Genetic Medicine.,Division of Cardiology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Grewal T, Rentero C, Enrich C, Wahba M, Raabe CA, Rescher U. Annexin Animal Models-From Fundamental Principles to Translational Research. Int J Mol Sci 2021; 22:ijms22073439. [PMID: 33810523 PMCID: PMC8037771 DOI: 10.3390/ijms22073439] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/18/2021] [Accepted: 03/24/2021] [Indexed: 02/07/2023] Open
Abstract
Routine manipulation of the mouse genome has become a landmark in biomedical research. Traits that are only associated with advanced developmental stages can now be investigated within a living organism, and the in vivo analysis of corresponding phenotypes and functions advances the translation into the clinical setting. The annexins, a family of closely related calcium (Ca2+)- and lipid-binding proteins, are found at various intra- and extracellular locations, and interact with a broad range of membrane lipids and proteins. Their impacts on cellular functions has been extensively assessed in vitro, yet annexin-deficient mouse models generally develop normally and do not display obvious phenotypes. Only in recent years, studies examining genetically modified annexin mouse models which were exposed to stress conditions mimicking human disease often revealed striking phenotypes. This review is the first comprehensive overview of annexin-related research using animal models and their exciting future use for relevant issues in biology and experimental medicine.
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Affiliation(s)
- Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia;
- Correspondence: (T.G.); (U.R.); Tel.: +61-(0)2-9351-8496 (T.G.); +49-(0)251-83-52121 (U.R.)
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (C.R.); (C.E.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain; (C.R.); (C.E.)
- Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), 08036 Barcelona, Spain
| | - Mohamed Wahba
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW 2006, Australia;
| | - Carsten A. Raabe
- Research Group Regulatory Mechanisms of Inflammation, Center for Molecular Biology of Inflammation (ZMBE) and Cells in Motion Interfaculty Center (CiM), Institute of Medical Biochemistry, University of Muenster, 48149 Muenster, Germany;
| | - Ursula Rescher
- Research Group Regulatory Mechanisms of Inflammation, Center for Molecular Biology of Inflammation (ZMBE) and Cells in Motion Interfaculty Center (CiM), Institute of Medical Biochemistry, University of Muenster, 48149 Muenster, Germany;
- Correspondence: (T.G.); (U.R.); Tel.: +61-(0)2-9351-8496 (T.G.); +49-(0)251-83-52121 (U.R.)
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7
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Meneses-Salas E, Garcia-Forn M, Castany-Pladevall C, Lu A, Fajardo A, Jose J, Wahba M, Bosch M, Pol A, Tebar F, Klein AD, Zanlungo S, Pérez-Navarro E, Grewal T, Enrich C, Rentero C. Lack of Annexin A6 Exacerbates Liver Dysfunction and Reduces Lifespan of Niemann-Pick Type C Protein-Deficient Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 191:475-486. [PMID: 33345999 DOI: 10.1016/j.ajpath.2020.12.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 11/25/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022]
Abstract
Niemann-Pick type C (NPC) disease is a lysosomal storage disorder characterized by cholesterol accumulation caused by loss-of-function mutations in the Npc1 gene. NPC disease primarily affects the brain, causing neuronal damage and affecting motor coordination. In addition, considerable liver malfunction in NPC disease is common. Recently, we found that the depletion of annexin A6 (ANXA6), which is most abundant in the liver and involved in cholesterol transport, ameliorated cholesterol accumulation in Npc1 mutant cells. To evaluate the potential contribution of ANXA6 in the progression of NPC disease, double-knockout mice (Npc1-/-/Anxa6-/-) were generated and examined for lifespan, neurologic and hepatic functions, as well as liver histology and ultrastructure. Interestingly, lack of ANXA6 in NPC1-deficient animals did not prevent the cerebellar degeneration phenotype, but further deteriorated their compromised hepatic functions and reduced their lifespan. Moreover, livers of Npc1-/-/Anxa6-/- mice contained a significantly elevated number of foam cells congesting the sinusoidal space, a feature commonly associated with inflammation. We hypothesize that ANXA6 deficiency in Npc1-/- mice not only does not reverse neurologic and motor dysfunction, but further worsens overall liver function, exacerbating hepatic failure in NPC disease.
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Affiliation(s)
- Elsa Meneses-Salas
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Marta Garcia-Forn
- Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Carla Castany-Pladevall
- Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Lu
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Department of Biochemistry, Stanford University School of Medicine, Stanford, California
| | - Alba Fajardo
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Jaimy Jose
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Mohamed Wahba
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Marta Bosch
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Pol
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), Universidad del Desarrollo, Clínica Alemana de Santiago, Chile
| | - Francesc Tebar
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Andrés D Klein
- Centro de Genética y Genómica, Universidad del Desarrollo, Clínica Alemana de Santiago, Chile
| | - Silvana Zanlungo
- Departamento de Gastroenterología, Facultad de Medicina Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Esther Pérez-Navarro
- Institut de Neurociències, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Carlos Enrich
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
| | - Carles Rentero
- Unitat de Biologia Cel·lular, Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain; Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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8
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Alvarez-Guaita A, Blanco-Muñoz P, Meneses-Salas E, Wahba M, Pollock AH, Jose J, Casado M, Bosch M, Artuch R, Gaus K, Lu A, Pol A, Tebar F, Moss SE, Grewal T, Enrich C, Rentero C. Annexin A6 Is Critical to Maintain Glucose Homeostasis and Survival During Liver Regeneration in Mice. Hepatology 2020; 72:2149-2164. [PMID: 32170749 DOI: 10.1002/hep.31232] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/20/2020] [Accepted: 02/28/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND AIMS Liver regeneration requires the organized and sequential activation of events that lead to restoration of hepatic mass. During this process, other vital liver functions need to be preserved, such as maintenance of blood glucose homeostasis, balancing the degradation of hepatic glycogen stores, and gluconeogenesis (GNG). Under metabolic stress, alanine is the main hepatic gluconeogenic substrate, and its availability is the rate-limiting step in this pathway. Na+ -coupled neutral amino acid transporters (SNATs) 2 and 4 are believed to facilitate hepatic alanine uptake. In previous studies, we demonstrated that a member of the Ca2+ -dependent phospholipid binding annexins, Annexin A6 (AnxA6), regulates membrane trafficking along endo- and exocytic pathways. Yet, although AnxA6 is abundantly expressed in the liver, its function in hepatic physiology remains unknown. In this study, we investigated the potential contribution of AnxA6 in liver regeneration. APPROACH AND RESULTS Utilizing AnxA6 knockout mice (AnxA6-/- ), we challenged liver function after partial hepatectomy (PHx), inducing acute proliferative and metabolic stress. Biochemical and immunofluorescent approaches were used to dissect AnxA6-/- mice liver proliferation and energetic metabolism. Most strikingly, AnxA6-/- mice exhibited low survival after PHx. This was associated with an irreversible and progressive drop of blood glucose levels. Whereas exogenous glucose administration or restoration of hepatic AnxA6 expression rescued AnxA6-/- mice survival after PHx, the sustained hypoglycemia in partially hepatectomized AnxA6-/- mice was the consequence of an impaired alanine-dependent GNG in AnxA6-/- hepatocytes. Mechanistically, cytoplasmic SNAT4 failed to recycle to the sinusoidal plasma membrane of AnxA6-/- hepatocytes 48 hours after PHx, impairing alanine uptake and, consequently, glucose production. CONCLUSIONS We conclude that the lack of AnxA6 compromises alanine-dependent GNG and liver regeneration in mice.
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Affiliation(s)
- Anna Alvarez-Guaita
- Unit of Cell Biology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,Currently at Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom
| | - Patricia Blanco-Muñoz
- Unit of Cell Biology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Elsa Meneses-Salas
- Unit of Cell Biology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Mohamed Wahba
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Abigail H Pollock
- Center for Vascular Research, The University of New South Wales, Sydney, NSW, Australia
| | - Jaimy Jose
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Mercedes Casado
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu and CIBERER, Barcelona, Spain
| | - Marta Bosch
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Rafael Artuch
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu and CIBERER, Barcelona, Spain
| | - Katharina Gaus
- Center for Vascular Research, The University of New South Wales, Sydney, NSW, Australia
| | - Albert Lu
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA
| | - Albert Pol
- Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Francesc Tebar
- Unit of Cell Biology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Stephen E Moss
- Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Carlos Enrich
- Unit of Cell Biology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Carles Rentero
- Unit of Cell Biology, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, University of Barcelona, Barcelona, Spain.,Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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9
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Heinick A, Pluteanu F, Hermes C, Klemme A, Domnik M, Husser X, Gerke V, Schmitz W, Müller FU. Annexin A4 N-terminal peptide inhibits adenylyl cyclase 5 and limits β-adrenoceptor-mediated prolongation of cardiac action potential. FASEB J 2020; 34:10489-10504. [PMID: 32579290 DOI: 10.1096/fj.201902094rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 05/08/2020] [Accepted: 05/26/2020] [Indexed: 11/11/2022]
Abstract
Adenylyl cyclases (AC) are essential for the normal and pathophysiological response of many cells. In cardiomyocytes, the predominant AC isoforms are AC5 and AC6. Specific AC5 inhibition was suggested as an option for the treatment of heart failure potentially advantageous over β-blockers. We previously reported an interaction between the calcium-binding protein annexin A4 (ANXA4) and AC5 in human embryonic kidney 293 (HEK293) cells and an inhibition of cyclic adenosine monophosphate (cAMP) production in cardiomyocytes. Here, we investigated whether ANXA4 is able to differentiate between AC5 and AC6. In transfected HEK293 cells, ANXA4 specifically co-immunoprecipitated with AC5 and not with AC6, via its N-terminal domain. Both ANXA4 and a peptide comprising the ANXA4 N-terminal sequence (A4N1-22 ) decreased the cAMP production in AC5 and not in AC6 expressing cells. In line with ACs inhibition, in myocytes from ANXA4-deficient mice, β-adrenoceptor (βAR) stimulation led to a higher increase of the L-type calcium current (ICaL ) and to an excessive action potential duration (APD) prolongation as compared to wild-type cardiomyocytes. This enhanced response was reversed in the presence of A4N1-22 peptide likely via specific AC5 inhibition. We conclude that via the N-terminal domain ANXA4 inhibits AC5 not AC6, and that A4N1-22 as a specific AC5 inhibitor could serve as a novel therapeutic tool for the treatment of AC5-linked diseases.
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Affiliation(s)
- Alexander Heinick
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Florentina Pluteanu
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Christina Hermes
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Andre Klemme
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Manuel Domnik
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Xenia Husser
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany.,Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany
| | - Wilhelm Schmitz
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Frank U Müller
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
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10
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Anxa4 mediated airway progenitor cell migration promotes distal epithelial cell fate specification. Sci Rep 2018; 8:14344. [PMID: 30254199 PMCID: PMC6156511 DOI: 10.1038/s41598-018-32494-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/07/2018] [Indexed: 12/11/2022] Open
Abstract
Genetic studies have shown that FGF10/FGFR2 signaling is required for airway branching morphogenesis and FGF10 functions as a chemoattractant factor for distal epithelial cells during lung development. However, the detail downstream cellular and molecular mechanisms have not been fully characterized. Using live imaging of ex vivo cultured lungs, we found that tip airway epithelial progenitor cells migrate faster than cleft cells during airway bud formation and this migration process is controlled by FGFR2-mediated ERK1/2 signaling. Additionally, we found that airway progenitor cells that migrate faster tend to become distal airway progenitor cells. We identified that Anxa4 is a downstream target of ERK1/2 signaling. Anxa4-/- airway epithelial cells exhibit a "lag-behind" behavior and tend to stay at the stalk airways. Moreover, we found that Anxa4-overexpressing cells tend to migrate to the bud tips. Finally, we demonstrated that Anxa4 functions redundantly with Anxa1 and Anxa6 in regulating endoderm budding process. Our study demonstrates that ERK1/2/Anxa4 signaling plays a role in promoting the migration of airway epithelial progenitor cells to distal airway tips and ensuring their distal cell fate.
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11
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Cairns R, Fischer AW, Blanco-Munoz P, Alvarez-Guaita A, Meneses-Salas E, Egert A, Buechler C, Hoy AJ, Heeren J, Enrich C, Rentero C, Grewal T. Altered hepatic glucose homeostasis in AnxA6-KO mice fed a high-fat diet. PLoS One 2018; 13:e0201310. [PMID: 30110341 PMCID: PMC6093612 DOI: 10.1371/journal.pone.0201310] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 07/12/2018] [Indexed: 12/12/2022] Open
Abstract
Annexin A6 (AnxA6) controls cholesterol and membrane transport in endo- and exocytosis, and modulates triglyceride accumulation and storage. In addition, AnxA6 acts as a scaffolding protein for negative regulators of growth factor receptors and their effector pathways in many different cell types. Here we investigated the role of AnxA6 in the regulation of whole body lipid metabolism and insulin-regulated glucose homeostasis. Therefore, wildtype (WT) and AnxA6-knockout (KO) mice were fed a high-fat diet (HFD) for 17 weeks. During the course of HFD feeding, AnxA6-KO mice gained less weight compared to controls, which correlated with reduced adiposity. Systemic triglyceride and cholesterol levels of HFD-fed control and AnxA6-KO mice were comparable, with slightly elevated high density lipoprotein (HDL) and reduced triglyceride-rich lipoprotein (TRL) levels in AnxA6-KO mice. AnxA6-KO mice displayed a trend towards improved insulin sensitivity in oral glucose and insulin tolerance tests (OGTT, ITT), which correlated with increased insulin-inducible phosphorylation of protein kinase B (Akt) and ribosomal protein S6 kinase (S6) in liver extracts. However, HFD-fed AnxA6-KO mice failed to downregulate hepatic gluconeogenesis, despite similar insulin levels and insulin signaling activity, as well as expression profiles of insulin-sensitive transcription factors to controls. In addition, increased glycogen storage in livers of HFD- and chow-fed AnxA6-KO animals was observed. Together with an inability to reduce glucose production upon insulin exposure in AnxA6-depleted HuH7 hepatocytes, this implicates AnxA6 contributing to the fine-tuning of hepatic glucose metabolism with potential consequences for the systemic control of glucose in health and disease.
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Affiliation(s)
- Rose Cairns
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Alexander W. Fischer
- Department of Biochemistry and Molecular Biology II: Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Patricia Blanco-Munoz
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Anna Alvarez-Guaita
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Elsa Meneses-Salas
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Antonia Egert
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, Regensburg, Germany
| | - Andrew J. Hoy
- Discipline of Physiology, School of Medical Science, Sydney Medical School, Charles Perkins Centre, University of Sydney, Sydney, NSW, Australia
| | - Joerg Heeren
- Department of Biochemistry and Molecular Biology II: Molecular Cell Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- * E-mail: (TG); (CR)
| | - Thomas Grewal
- School of Pharmacy, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
- * E-mail: (TG); (CR)
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12
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Raouf R, Lolignier S, Sexton JE, Millet Q, Santana-Varela S, Biller A, Fuller AM, Pereira V, Choudhary JS, Collins MO, Moss SE, Lewis R, Tordo J, Henckaerts E, Linden M, Wood JN. Inhibition of somatosensory mechanotransduction by annexin A6. Sci Signal 2018; 11:11/535/eaao2060. [PMID: 29921656 DOI: 10.1126/scisignal.aao2060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mechanically activated, slowly adapting currents in sensory neurons have been linked to noxious mechanosensation. The conotoxin NMB-1 (noxious mechanosensation blocker-1) blocks such currents and inhibits mechanical pain. Using a biotinylated form of NMB-1 in mass spectrometry analysis, we identified 67 binding proteins in sensory neurons and a sensory neuron-derived cell line, of which the top candidate was annexin A6, a membrane-associated calcium-binding protein. Annexin A6-deficient mice showed increased sensitivity to mechanical stimuli. Sensory neurons from these mice showed increased activity of the cation channel Piezo2, which mediates a rapidly adapting mechano-gated current linked to proprioception and touch, and a decrease in mechanically activated, slowly adapting currents. Conversely, overexpression of annexin A6 in sensory neurons inhibited rapidly adapting currents that were partially mediated by Piezo2. Furthermore, overexpression of annexin A6 in sensory neurons attenuated mechanical pain in a mouse model of osteoarthritis, a disease in which mechanically evoked pain is particularly problematic. These data suggest that annexin A6 can be exploited to inhibit chronic mechanical pain.
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Affiliation(s)
- Ramin Raouf
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Stéphane Lolignier
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Jane E Sexton
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Queensta Millet
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Sonia Santana-Varela
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Anna Biller
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Alice M Fuller
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Vanessa Pereira
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | | | - Mark O Collins
- Department of Biomedical Science, The University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Stephen E Moss
- Institute of Ophthalmology, UCL, 11-43 Bath Street, London EC1V 9EL, UK
| | - Richard Lewis
- Institute for Molecular Bioscience, University of Queensland, Brisbane, St. Lucia, Queensland 4072, Australia
| | - Julie Tordo
- Department of Infectious Diseases, King's College London School of Medicine, London SE1 9RT, UK
| | - Els Henckaerts
- Department of Infectious Diseases, King's College London School of Medicine, London SE1 9RT, UK
| | - Michael Linden
- Department of Infectious Diseases, King's College London School of Medicine, London SE1 9RT, UK
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London (UCL), Gower Street, London WC1E 6BT, UK.
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13
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Annexin A6 regulates catabolic events in articular chondrocytes via the modulation of NF-κB and Wnt/ß-catenin signaling. PLoS One 2018; 13:e0197690. [PMID: 29771996 PMCID: PMC5957413 DOI: 10.1371/journal.pone.0197690] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/07/2018] [Indexed: 12/22/2022] Open
Abstract
Annexin A6 (AnxA6) is expressed in articular chondrocytes at levels higher than in other mesenchymal cell types. However, the role of AnxA6 in articular chondrocytes is not known. Here we show that complete lack of AnxA6 functions resulted in increased ß-catenin activation in Wnt3a-treated murine articular chondrocytes, whereas AnxA6 expressing articular chondrocytes showed decreased ß-catenin activation. High expression of AnxA6 in human articular chondrocytes showed the highest inhibition of Wnt/ß-catenin signaling. Inhibition of Wnt/ß-catenin signaling activity by AnxA6 together with cytosolic Ca2+ was achieved by interfering with the plasma membrane association of the Wnt signaling complex. AnxA6 also affected the cross-talk between Wnt/ß-catenin signaling and NF-κB signaling by decreasing ß-catenin activity and increasing NF-κB activity in Wnt3a-, interleukin-1beta (IL-1ß)-, and combined Wnt3a/IL-1ß-treated cells. Wnt3a treatment increased the mRNA levels of catabolic markers (cyclooxygenase-2, interleukin-6, inducible nitric oxide synthase) to a much lesser degree than IL-1ß treatment in human articular chondrocytes, and decreased the mRNA levels of matrix metalloproteinase-13 (MMP-13) and articular cartilage markers (aggrecan, type II collagen). Furthermore, Wnt3a decreased the mRNA levels of catabolic markers and MMP-13 in IL-1ß-treated human articular chondrocytes. High expression of AnxA6 resulted in decreased mRNA levels of catabolic markers, and increased MMP-13 and articular cartilage marker mRNA levels in Wnt3a-treated human articular chondrocytes, whereas leading to increased mRNA levels of catabolic markers and MMP-13 in human articular chondrocytes treated with IL-1ß, or combined Wnt3a and IL-1ß. Our findings define a novel role for AnxA6 in articular chondrocytes via its modulation of Wnt/ß-catenin and NF-κB signaling activities and the cross-talk between these two signaling pathways.
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14
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Cairns R, Alvarez-Guaita A, Martínez-Saludes I, Wason SJ, Hanh J, Nagarajan SR, Hosseini-Beheshti E, Monastyrskaya K, Hoy AJ, Buechler C, Enrich C, Rentero C, Grewal T. Role of hepatic Annexin A6 in fatty acid-induced lipid droplet formation. Exp Cell Res 2017; 358:397-410. [PMID: 28712927 DOI: 10.1016/j.yexcr.2017.07.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 01/17/2023]
Abstract
Annexin A6 (AnxA6) has been implicated in the regulation of endo-/exocytic pathways, cholesterol transport, and the formation of multifactorial signaling complexes in many different cell types. More recently, AnxA6 has also been linked to triglyceride storage in adipocytes. Here we investigated the potential role of AnxA6 in fatty acid (FA) - induced lipid droplet (LD) formation in hepatocytes. AnxA6 was associated with LD from rat liver and HuH7 hepatocytes. In oleic acid (OA) -loaded HuH7 cells, substantial amounts of AnxA6 bound to LD in a Ca2+-independent manner. Remarkably, stable or transient AnxA6 overexpression in HuH7 cells led to elevated LD numbers/size and neutral lipid staining under control conditions as well as after OA loading compared to controls. In contrast, overexpression of AnxA1, AnxA2 and AnxA8 did not impact on OA-induced lipid accumulation. On the other hand, incubation of AnxA6-depleted HuH7 cells or primary hepatocytes from AnxA6 KO-mice with OA led to reduced FA accumulation and LD numbers. Furthermore, morphological analysis of liver sections from A6-KO mice revealed significantly lower LD numbers compared to wildtype animals. Interestingly, pharmacological inhibition of cytoplasmic phospholipase A2α (cPLA2α)-dependent LD formation was ineffective in AnxA6-depleted HuH7 cells. We conclude that cPLA2α-dependent pathways contribute to the novel regulatory role of hepatic AnxA6 in LD formation.
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Affiliation(s)
- Rose Cairns
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Anna Alvarez-Guaita
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Inés Martínez-Saludes
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Sundeep J Wason
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Jacky Hanh
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Shilpa R Nagarajan
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Elham Hosseini-Beheshti
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Katia Monastyrskaya
- Urology Research Laboratory, Department Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Andrew J Hoy
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain.
| | - Thomas Grewal
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia.
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15
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Grewal T, Wason SJ, Enrich C, Rentero C. Annexins - insights from knockout mice. Biol Chem 2017; 397:1031-53. [PMID: 27318360 DOI: 10.1515/hsz-2016-0168] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/14/2016] [Indexed: 12/23/2022]
Abstract
Annexins are a highly conserved protein family that bind to phospholipids in a calcium (Ca2+) - dependent manner. Studies with purified annexins, as well as overexpression and knockdown approaches identified multiple functions predominantly linked to their dynamic and reversible membrane binding behavior. However, most annexins are found at multiple locations and interact with numerous proteins. Furthermore, similar membrane binding characteristics, overlapping localizations and shared interaction partners have complicated identification of their precise functions. To gain insight into annexin function in vivo, mouse models deficient of annexin A1 (AnxA1), A2, A4, A5, A6 and A7 have been generated. Interestingly, with the exception of one study, all mice strains lacking one or even two annexins are viable and develop normally. This suggested redundancy within annexins, but examining these knockout (KO) strains under stress conditions revealed striking phenotypes, identifying underlying mechanisms specific for individual annexins, often supporting Ca2+ homeostasis and membrane transport as central for annexin biology. Conversely, mice lacking AnxA1 or A2 show extracellular functions relevant in health and disease that appear independent of membrane trafficking or Ca2+ signaling. This review will summarize the mechanistic insights gained from studies utilizing mouse models lacking members of the annexin family.
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16
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Grewal T, Hoque M, Conway JRW, Reverter M, Wahba M, Beevi SS, Timpson P, Enrich C, Rentero C. Annexin A6-A multifunctional scaffold in cell motility. Cell Adh Migr 2017; 11:288-304. [PMID: 28060548 DOI: 10.1080/19336918.2016.1268318] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Annexin A6 (AnxA6) belongs to a highly conserved protein family characterized by their calcium (Ca2+)-dependent binding to phospholipids. Over the years, immunohistochemistry, subcellular fractionations, and live cell microscopy established that AnxA6 is predominantly found at the plasma membrane and endosomal compartments. In these locations, AnxA6 acts as a multifunctional scaffold protein, recruiting signaling proteins, modulating cholesterol and membrane transport and influencing actin dynamics. These activities enable AnxA6 to contribute to the formation of multifactorial protein complexes and membrane domains relevant in signal transduction, cholesterol homeostasis and endo-/exocytic membrane transport. Hence, AnxA6 has been implicated in many biological processes, including cell proliferation, survival, differentiation, inflammation, but also membrane repair and viral infection. More recently, we and others identified roles for AnxA6 in cancer cell migration and invasion. This review will discuss how the multiple scaffold functions may enable AnxA6 to modulate migratory cell behavior in health and disease.
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Affiliation(s)
- Thomas Grewal
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - Monira Hoque
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - James R W Conway
- b The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St Vincent's Clinical School, Faculty of Medicine , University of New South Wales , Sydney , NSW , Australia
| | - Meritxell Reverter
- c Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina , Universitat de Barcelona , Barcelona , Spain
| | - Mohamed Wahba
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - Syed S Beevi
- a Faculty of Pharmacy , University of Sydney , Sydney , NSW , Australia
| | - Paul Timpson
- b The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St Vincent's Clinical School, Faculty of Medicine , University of New South Wales , Sydney , NSW , Australia
| | - Carlos Enrich
- c Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina , Universitat de Barcelona , Barcelona , Spain
| | - Carles Rentero
- c Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina , Universitat de Barcelona , Barcelona , Spain
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17
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Krautbauer S, Haberl EM, Eisinger K, Pohl R, Rein-Fischboeck L, Rentero C, Alvarez-Guaita A, Enrich C, Grewal T, Buechler C, Neumeier M. Annexin A6 regulates adipocyte lipid storage and adiponectin release. Mol Cell Endocrinol 2017; 439:419-430. [PMID: 27702590 DOI: 10.1016/j.mce.2016.09.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 09/30/2016] [Accepted: 09/30/2016] [Indexed: 12/28/2022]
Abstract
Lipid storage and adipokine secretion are critical features of adipocytes. Annexin A6 (AnxA6) is a lipid-binding protein regulating secretory pathways and its role in adiponectin release was examined. The siRNA-mediated AnxA6 knock-down in 3T3-L1 preadipocytes impaired proliferation, and differentiation of AnxA6-depleted cells to mature adipocytes was associated with higher soluble adiponectin and increased triglyceride storage. The latter was partly attributed to reduced lipolysis. Accordingly, AnxA6 overexpression in 3T3-L1 adipocytes lowered cellular triglycerides and adiponectin secretion. Indeed, serum adiponectin was increased in AnxA6 deficient mice. Expression analysis identified AnxA6 protein to be more abundant in intra-abdominal compared to subcutaneous adipose tissues of mice and men. AnxA6 protein levels increased in white adipose tissues of obese mice and here, levels were highest in subcutaneous fat. AnxA6 protein in adipocytes was upregulated by oxidative stress which might trigger AnxA6 induction in adipose tissues and contribute to impaired fat storage and adiponectin release.
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Affiliation(s)
- Sabrina Krautbauer
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Elisabeth M Haberl
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Kristina Eisinger
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Rebekka Pohl
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Lisa Rein-Fischboeck
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Carles Rentero
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036, Barcelona, Spain
| | - Anna Alvarez-Guaita
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036, Barcelona, Spain
| | - Carlos Enrich
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036, Barcelona, Spain
| | - Thomas Grewal
- Faculty of Pharmacy, University of Sydney, Sydney, NSW, 2006, Australia
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany.
| | - Markus Neumeier
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
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Enrich C, Rentero C, Grewal T. Annexin A6 in the liver: From the endocytic compartment to cellular physiology. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:933-946. [PMID: 27984093 DOI: 10.1016/j.bbamcr.2016.10.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 12/15/2022]
Abstract
Annexin A6 (AnxA6) belongs to the conserved annexin family - a group of Ca2+-dependent membrane binding proteins. AnxA6 is the largest of all annexins and highly expressed in smooth muscle, hepatocytes, endothelial cells and cardiomyocytes. Upon activation, AnxA6 binds to negatively charged phospholipids in a wide range of intracellular localizations, in particular the plasma membrane, late endosomes/pre-lysosomes, but also synaptic vesicles and sarcolemma. In these cellular sites, AnxA6 is believed to contribute to the organization of membrane microdomains, such as cholesterol-rich lipid rafts and confer multiple regulatory functions, ranging from vesicle fusion, endocytosis and exocytosis to programmed cell death and muscle contraction. Growing evidence supports that Ca2+ and Ca2+-binding proteins control endocytosis and autophagy. Their regulatory role seems to operate at the level of the signalling pathways that initiate autophagy or at later stages, when autophagosomes fuse with endolysosomal compartments. The convergence of the autophagic and endocytic vesicles to lysosomes shares several features that depend on Ca2+ originating from lysosomes/late endosomes and seems to depend on proteins that are subsequently activated by this cation. However, the involvement of Ca2+ and its effector proteins in these autophagic and endocytic stages still remains poorly understood. Although AnxA6 makes up almost 0.25% of total protein in the liver, little is known about its function in hepatocytes. Within the endocytic route, we identified AnxA6 in endosomes and autophagosomes of hepatocytes. Hence, AnxA6 and possibly other annexins might represent new Ca2+ effectors that regulate converging steps of autophagy and endocytic trafficking in hepatocytes. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech.
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Affiliation(s)
- Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cellular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain.
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cellular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Thomas Grewal
- Faculty of Pharmacy A15, University of Sydney, Sydney, NSW 2006, Australia
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19
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Annexin A6 regulates interleukin-2-mediated T-cell proliferation. Immunol Cell Biol 2016; 94:543-53. [PMID: 26853809 DOI: 10.1038/icb.2016.15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 12/10/2015] [Accepted: 01/10/2016] [Indexed: 02/06/2023]
Abstract
Annexin A6 (AnxA6) has been implicated in cell signalling by contributing to the organisation of the plasma membrane. Here we examined whether AnxA6 regulates signalling and proliferation in T cells. We used a contact hypersensitivity model to immune challenge wild-type (WT) and AnxA6(-/-) mice and found that the in vivo proliferation of CD4(+) T cells, but not CD8(+) T cells, was impaired in AnxA6(-/-) relative to WT mice. However, T-cell migration and signalling through the T-cell receptor ex vivo was similar between T cells isolated from AnxA6(-/-) and WT mice. In contrast, interleukin-2 (IL-2) signalling was reduced in AnxA6(-/-) compared with WT T cells. Further, AnxA6-deficient T cells had reduced membrane order and cholesterol levels. Taken together, our data suggest that AnxA6 regulates IL-2 homeostasis and sensitivity in T cells by sustaining a lipid raft-like membrane environment.
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Abstract
Since an intact membrane is required for normal cellular homeostasis, membrane repair is essential for cell survival. Human genetic studies, combined with the development of novel animal models and refinement of techniques to study cellular injury, have now uncovered series of repair proteins highly relevant for human health. Many of the deficient repair pathways manifest in skeletal muscle, where defective repair processes result in myopathies or other forms of muscle disease. Dysferlin is a membrane-associated protein implicated in sarcolemmal repair and also linked to other membrane functions including the maintenance of transverse tubules in muscle. MG53, annexins, and Eps15 homology domain-containing proteins interact with dysferlin to form a membrane repair complex and similarly have roles in membrane trafficking in muscle. These molecular features of membrane repair are not unique to skeletal muscle, but rather skeletal muscle, due to its high demands, is more dependent on an efficient repair process. Phosphatidylserine and phosphatidylinositol 4,5-bisphosphate, as well as Ca(2+), are central regulators of membrane organization during repair. Given the importance of muscle health in disease and in aging, these pathways are targets to enhance muscle function and recovery from injury.
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21
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Banerjee P, Chander V, Bandyopadhyay A. Balancing functions of annexin A6 maintain equilibrium between hypertrophy and apoptosis in cardiomyocytes. Cell Death Dis 2015; 6:e1873. [PMID: 26335715 PMCID: PMC4650436 DOI: 10.1038/cddis.2015.231] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Revised: 07/09/2015] [Accepted: 07/10/2015] [Indexed: 01/11/2023]
Abstract
Pathological cardiac hypertrophy is a major risk factor associated with heart failure, a state concomitant with increased cell death. However, the mechanism governing progression of hypertrophy to apoptosis at the single-cell level remains elusive. Here, we demonstrate annexin A6 (Anxa6), a calcium (Ca(2+))-dependent phospholipid-binding protein critically regulates the transition of chronic hypertrophied cardiomyocytes to apoptosis. Treatment of the H9c2(2-1) cardiomyocytes with hypertrophic agonists upregulates and relocalizes Anxa6 with increased cytosolic punctate appearance. Live cell imaging revealed that chronic exposure to hypertrophic agonists such as phenylephrine (PE) compromises the mitochondrial membrane potential (ΔΨm) and morphological dynamics. Such chronic hypertrophic induction also activated the caspases 9 and 3 and induced cleavage of the poly-(ADP-ribose) polymerase 1 (Parp1), which are the typical downstream events in the mitochondrial pathways of apoptosis. An increased rate of apoptosis was evident in the hypertrophied cardiomyocytes after 48-72 h of treatment with the hypertrophic agonists. Anxa6 was progressively associated with the mitochondrial fraction under chronic hypertrophic stimulation, and Anxa6 knockdown severely abrogated mitochondrial network and dynamics. Ectopically expressed Anxa6 protected the mitochondrial morphology and dynamics under PE treatment, and also increased the cellular susceptibility to apoptosis. Biochemical analysis showed that Anxa6 interacts with Parp1 and its 89 kDa cleaved product in a Ca(2+)-dependent manner through the N-terminal residues (1-28). Furthermore, expression of Anxa6(S13E), a mutant dominant negative with respect to Parp1 binding, served as an enhancer of mitochondrial dynamics, even under chronic PE treatment. Chemical inhibition of Parp1 activity released the cellular vulnerability to apoptosis in Anxa6-expressing stable cell lines, thereby shifting the equilibrium away from cell death. Taken together, the present study depicts a dual regulatory function of Anxa6 that is crucial for balancing hypertrophy with apoptosis in cardiomyocytes.
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Affiliation(s)
- P Banerjee
- Cell Biology and Physiology Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology, 4, Raja SC Mullick Road, Kolkata 700 032, West Bengal, India
| | - V Chander
- Cell Biology and Physiology Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology, 4, Raja SC Mullick Road, Kolkata 700 032, West Bengal, India
| | - A Bandyopadhyay
- Cell Biology and Physiology Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology, 4, Raja SC Mullick Road, Kolkata 700 032, West Bengal, India
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22
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Linke B, Abeler-Dörner L, Jahndel V, Kurz A, Mahr A, Pfrang S, Linke L, Krammer PH, Weyd H. The tolerogenic function of annexins on apoptotic cells is mediated by the annexin core domain. THE JOURNAL OF IMMUNOLOGY 2015; 194:5233-42. [PMID: 25917090 DOI: 10.4049/jimmunol.1401299] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 03/30/2015] [Indexed: 12/19/2022]
Abstract
Immunological tolerance is constantly being maintained in the periphery by dendritic cells processing material from apoptotic cells (ACs) in the steady-state. Although research has focused on the uptake of ACs by phagocytes, tolerogenic signals exposed by the ACs are much less well defined. In this article, we show that the annexin (Anx) family members AnxA5 and AnxA13 translocate to the surface of ACs to function as redundant tolerogenic signals in vitro and in vivo. Exposure of bone marrow-derived dendritic cells to AnxA5 or AnxA13 in vitro resulted in the inhibition of both proinflammatory cytokine secretion and the upregulation of costimulatory molecules upon TLR stimulation. The highly conserved Anx core domain was sufficient to mediate these effects, whereas recognition by N-formyl peptide receptor family members was dispensable. In vivo, coinjection of OVA-expressing and Anx-expressing ACs prevented induction of Ag-specific CD8(+) T cells. Moreover, mice immunized with Anx-expressing ACs became refractory to an antigenic challenge. These results suggest that several Anxs contribute to AC-induced suppression of dendritic cell activation. Therefore, manipulating Anx-mediated immunosuppression may prove beneficial for patients with cancer or autoimmune diseases and chronic inflammatory disorders.
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Affiliation(s)
- Björn Linke
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Lucie Abeler-Dörner
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Veronika Jahndel
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Alexandra Kurz
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Andrea Mahr
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Sandra Pfrang
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Linda Linke
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Peter H Krammer
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
| | - Heiko Weyd
- Division of Immunogenetics, Tumor Immunology Program, German Cancer Research Center, 69120 Heidelberg, Germany
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Alvarez-Guaita A, Vilà de Muga S, Owen DM, Williamson D, Magenau A, García-Melero A, Reverter M, Hoque M, Cairns R, Cornely R, Tebar F, Grewal T, Gaus K, Ayala-Sanmartín J, Enrich C, Rentero C. Evidence for annexin A6-dependent plasma membrane remodelling of lipid domains. Br J Pharmacol 2015; 172:1677-90. [PMID: 25409976 DOI: 10.1111/bph.13022] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 11/11/2014] [Accepted: 11/14/2014] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE Annexin A6 (AnxA6) is a calcium-dependent phospholipid-binding protein that can be recruited to the plasma membrane to function as a scaffolding protein to regulate signal complex formation, endo- and exocytic pathways as well as distribution of cellular cholesterol. Here, we have investigated how AnxA6 influences the membrane order. EXPERIMENTAL APPROACH We used Laurdan and di-4-ANEPPDHQ staining in (i) artificial membranes; (ii) live cells to investigate membrane packing and ordered lipid phases; and (iii) a super-resolution imaging (photoactivated localization microscopy, PALM) and Ripley's K second-order point pattern analysis approach to assess how AnxA6 regulates plasma membrane order domains and protein clustering. KEY RESULTS In artificial membranes, purified AnxA6 induced a global increase in membrane order. However, confocal microscopy using di-4-ANEPPDHQ in live cells showed that cells expressing AnxA6, which reduces plasma membrane cholesterol levels and modifies the actin cytoskeleton meshwork, displayed a decrease in membrane order (∼15 and 30% in A431 and MEF cells respectively). PALM data from Lck10 and Src15 membrane raft/non-raft markers revealed that AnxA6 expression induced clustering of both raft and non-raft markers. Altered clustering of Lck10 and Src15 in cells expressing AnxA6 was also observed after cholesterol extraction with methyl-β-cyclodextrin or actin cytoskeleton disruption with latrunculin B. CONCLUSIONS AND IMPLICATIONS AnxA6-induced plasma membrane remodelling indicated that elevated AnxA6 expression decreased membrane order through the regulation of cellular cholesterol homeostasis and the actin cytoskeleton. This study provides the first evidence from live cells that support current models of annexins as membrane organizers.
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Affiliation(s)
- Anna Alvarez-Guaita
- Departament de Biologia Cel·lular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain
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24
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Campbell KA, Minashima T, Zhang Y, Hadley S, Lee YJ, Giovinazzo J, Quirno M, Kirsch T. Annexin A6 interacts with p65 and stimulates NF-κB activity and catabolic events in articular chondrocytes. ACTA ACUST UNITED AC 2014; 65:3120-9. [PMID: 24022118 DOI: 10.1002/art.38182] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 08/27/2013] [Indexed: 12/15/2022]
Abstract
OBJECTIVE ANXA6, the gene for annexin A6, is highly expressed in osteoarthritic (OA) articular chondrocytes but not in healthy articular chondrocytes. This study was undertaken to determine whether annexin A6 affects catabolic events in these cells. METHODS Articular chondrocytes were isolated from Anxa6-knockout mice, wild-type (WT) mice, and human articular cartilage in which ANXA6 was overexpressed. Cells were treated with interleukin-1β (IL-1β) or tumor necrosis factor α (TNFα), and expression of catabolic genes and activation of NF-κB were determined by real-time polymerase chain reaction and luciferase reporter assay. Anxa6(-/-) and WT mouse knee joints were injected with IL-1β or the medial collateral ligament was transected and partial resection of the medial meniscus was performed to determine the role of Anxa6 in IL-1β-mediated cartilage destruction and OA progression. The mechanism by which Anxa6 stimulates NF-κB activity was determined by coimmunoprecipitation and immunoblot analysis of nuclear and cytoplasmic fractions of IL-1β-treated Anxa6(-/-) and WT mouse chondrocytes for p65 and Anxa6. RESULTS Loss of Anxa6 resulted in decreased NF-κB activation and catabolic marker messenger RNA (mRNA) levels in IL-1β- or TNFα-treated articular chondrocytes, whereas overexpression of ANXA6 resulted in increased NF-κB activity and catabolic marker mRNA levels. Annexin A6 interacted with p65, and loss of Anxa6 caused decreased nuclear translocation and retention of the active p50/p65 NF-κB complex. Cartilage destruction in Anxa6(-/-) mouse knee joints after IL-1β injection or partial medial meniscectomy was reduced as compared to that in WT mouse joints. CONCLUSION Our data define a role of annexin A6 in the modulation of NF-κB activity and in the stimulation of catabolic events in articular chondrocytes.
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Affiliation(s)
- Kirk A Campbell
- New York University School of Medicine and Hospital for Joint Diseases, New York, New York
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25
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Banerjee P, Bandyopadhyay A. Cytosolic dynamics of annexin A6 trigger feedback regulation of hypertrophy via atrial natriuretic peptide in cardiomyocytes. J Biol Chem 2014; 289:5371-85. [PMID: 24403064 DOI: 10.1074/jbc.m113.514810] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Malfunctions in regulatory pathways that control cell size are prominent in pathological cardiac hypertrophy. Here, we show annexin A6 (Anxa6) to be a crucial regulator of atrial natriuretic peptide (ANP)-mediated counterhypertrophic responses in cardiomyocytes. Adrenergic stimulation of H9c2 cardiomyocytes by phenylephrine (PE) increased the cell size with enhanced expression of biochemical markers of hypertrophy, concomitant with elevated expression and subcellular redistribution of Anxa6. Stable cell lines with controlled increase in Anxa6 levels were protected against PE-induced adverse changes, whereas Anxa6 knockdown augmented the hypertrophic responses. Strikingly, Anxa6 knockdown also abrogated PE-induced juxtanuclear accumulation of secretory granules (SG) containing ANP propeptides (pro-ANP), a signature of maladaptive hypertrophy having counteractive functions. Mechanistically, PE treatment prompted a dynamic association of Anxa6 with pro-ANP-SG, parallel to their participation in anterograde traffic, in an isoform-specific fashion. Moreover, Anxa6 mutants that failed to associate with pro-ANP hindered ANP-mediated protection against hypertrophy, which was rescued, at least partially, by WT Anxa6. Additionally, elevated intracellular calcium (Ca(2+)) stimulated Anxa6-pro-ANP colocalization and membrane association. It also rescued pro-ANP translocation in cells expressing an Anxa6 mutant (Anxa6(ΔC)). Furthermore, stable overexpression of Anxa6(T356D), a mutant with superior flexibility, provided enhanced protection against PE, compared with WT, presumably due to enhanced membrane-binding capacity. Together, the present study delivers a cooperative mechanism where Anxa6 potentiates ANP-dependent counterhypertrophic responses in cardiomyocytes by facilitating regulated traffic of pro-ANP.
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Affiliation(s)
- Priyam Banerjee
- From the Cell Biology and Physiology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata-700 032, West Bengal, India
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26
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White JK, Gerdin AK, Karp NA, Ryder E, Buljan M, Bussell JN, Salisbury J, Clare S, Ingham NJ, Podrini C, Houghton R, Estabel J, Bottomley JR, Melvin DG, Sunter D, Adams NC, Tannahill D, Logan DW, Macarthur DG, Flint J, Mahajan VB, Tsang SH, Smyth I, Watt FM, Skarnes WC, Dougan G, Adams DJ, Ramirez-Solis R, Bradley A, Steel KP. Genome-wide generation and systematic phenotyping of knockout mice reveals new roles for many genes. Cell 2013; 154:452-64. [PMID: 23870131 PMCID: PMC3717207 DOI: 10.1016/j.cell.2013.06.022] [Citation(s) in RCA: 378] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 05/10/2013] [Accepted: 06/17/2013] [Indexed: 02/06/2023]
Abstract
Mutations in whole organisms are powerful ways of interrogating gene function in a realistic context. We describe a program, the Sanger Institute Mouse Genetics Project, that provides a step toward the aim of knocking out all genes and screening each line for a broad range of traits. We found that hitherto unpublished genes were as likely to reveal phenotypes as known genes, suggesting that novel genes represent a rich resource for investigating the molecular basis of disease. We found many unexpected phenotypes detected only because we screened for them, emphasizing the value of screening all mutants for a wide range of traits. Haploinsufficiency and pleiotropy were both surprisingly common. Forty-two percent of genes were essential for viability, and these were less likely to have a paralog and more likely to contribute to a protein complex than other genes. Phenotypic data and more than 900 mutants are openly available for further analysis. PaperClip
Large openly available resource of targeted mouse mutants and phenotypic data Screen for broad range of disease features and traits Many novel phenotypes suggest functions for both studied and unstudied genes Haploinsufficiency and pleiotropy are common
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27
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Chlystun M, Campanella M, Law AL, Duchen MR, Fatimathas L, Levine TP, Gerke V, Moss SE. Regulation of mitochondrial morphogenesis by annexin A6. PLoS One 2013; 8:e53774. [PMID: 23341998 PMCID: PMC3544845 DOI: 10.1371/journal.pone.0053774] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 12/03/2012] [Indexed: 11/18/2022] Open
Abstract
Mitochondrial homeostasis is critical in meeting cellular energy demands, shaping calcium signals and determining susceptibility to apoptosis. Here we report a role for anxA6 in the regulation of mitochondrial morphogenesis, and show that in cells lacking anxA6 mitochondria are fragmented, respiration is impaired and mitochondrial membrane potential is reduced. In fibroblasts from AnxA6−/− mice, mitochondrial Ca2+ uptake is reduced and cytosolic Ca2+ transients are elevated. These observations led us to investigate possible interactions between anxA6 and proteins with roles in mitochondrial fusion and fission. We found that anxA6 associates with Drp1 and that mitochondrial fragmentation in AnxA6−/− fibroblasts was prevented by the Drp1 inhibitor mdivi-1. In normal cells elevation of intracellular Ca2+ disrupted the interaction between anxA6 and Drp1, displacing anxA6 to the plasma membrane and promoting mitochondrial fission. Our results suggest that anxA6 inhibits Drp1 activity, and that Ca2+-binding to anxA6 relieves this inhibition to permit Drp1-mediated mitochondrial fission.
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Affiliation(s)
- Marcin Chlystun
- Department of Cell Biology, University College London (UCL) Institute of Ophthalmology, London, United Kingdom
| | - Michelangelo Campanella
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, London, United Kingdom
- Consortium for Mitochondrial Research (CfMR), University College London, London, United Kingdom
| | - Ah-Lai Law
- Department of Cell Biology, University College London (UCL) Institute of Ophthalmology, London, United Kingdom
| | - Michael R. Duchen
- Department of Cell and Developmental Biology, Mitochondrial Biology Group, University College London, London, United Kingdom
- Consortium for Mitochondrial Research (CfMR), University College London, London, United Kingdom
| | - Lux Fatimathas
- Department of Cell Biology, University College London (UCL) Institute of Ophthalmology, London, United Kingdom
| | - Tim P. Levine
- Department of Cell Biology, University College London (UCL) Institute of Ophthalmology, London, United Kingdom
| | - Volker Gerke
- University of Muenster, Institute of Medical Biochemistry, Muenster, Germany
| | - Stephen E. Moss
- Department of Cell Biology, University College London (UCL) Institute of Ophthalmology, London, United Kingdom
- * E-mail:
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28
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Grskovic I, Kutsch A, Frie C, Groma G, Stermann J, Schlötzer-Schrehardt U, Niehoff A, Moss SE, Rosenbaum S, Pöschl E, Chmielewski M, Rappl G, Abken H, Bateman JF, Cheah KS, Paulsson M, Brachvogel B. Depletion of annexin A5, annexin A6, and collagen X causes no gross changes in matrix vesicle-mediated mineralization, but lack of collagen X affects hematopoiesis and the Th1/Th2 response. J Bone Miner Res 2012; 27:2399-412. [PMID: 22692895 DOI: 10.1002/jbmr.1682] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Numerous biochemical studies have pointed to an essential role of annexin A5 (AnxA5), annexin A6 (AnxA6), and collagen X in matrix vesicle-mediated biomineralization during endochondral ossification and in osteoarthritis. By binding to the extracellular matrix protein collagen X and matrix vesicles, annexins were proposed to anchor matrix vesicles in the extracellular space of hypertrophic chondrocytes to initiate the calcification of cartilage. However, mineralization appears to be normal in mice lacking AnxA5 and AnxA6, whereas collagen X-deficient mice show only subtle alterations in the growth plate organization. We hypothesized that the simultaneous lack of AnxA5, AnxA6, and collagen X in vivo induces more pronounced changes in the growth plate development and the initiation of mineralization. In this study, we generated and analyzed mice deficient for AnxA5, AnxA6, and collagen X. Surprisingly, mice were viable, fertile, and showed no obvious abnormalities. Assessment of growth plate development indicated that the hypertrophic zone was expanded in Col10a1(-/-) and AnxA5(-/-) AnxA6(-/-) Col10a1(-/-) newborns, whereas endochondral ossification and mineralization were not affected in 13-day- and 1-month-old mutants. In peripheral quantitative computed tomography, no changes in the degree of biomineralization were found in femora of 1-month- and 1-year-old mutants even though the diaphyseal circumference was reduced in Col10a1(-/-) and AnxA5(-/-) AnxA6(-/-) Col10a1(-/-) mice. The percentage of naive immature IgM(+) /IgM(+) B cells and peripheral T-helper cells were increased in Col10a1(-/-) and AnxA5(-/-) AnxA6(-/-) Col10a1(-/-) mutants, and activated splenic T cells isolated from Col10a1(-/-) mice secreted elevated levels of IL-4 and GM-CSF. Hence, collagen X is needed for hematopoiesis during endochondral ossification and for the immune response, but the interaction of annexin A5, annexin A6, and collagen X is not essential for physiological calcification of growth plate cartilage. Therefore, annexins and collagen X may rather fulfill functions in growth plate cartilage not directly linked to the mineralization process.
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Affiliation(s)
- Ivan Grskovic
- Center for Biochemistry, Medical Faculty, University of Cologne, Cologne, Germany
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29
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Roostalu U, Strähle U. In vivo imaging of molecular interactions at damaged sarcolemma. Dev Cell 2012; 22:515-29. [PMID: 22421042 DOI: 10.1016/j.devcel.2011.12.008] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 10/25/2011] [Accepted: 12/14/2011] [Indexed: 12/30/2022]
Abstract
Muscle cells have a remarkable capability to repair plasma membrane lesions. Mutations in dysferlin (dysf) are known to elicit a progressive myopathy in humans, probably due to impaired sarcolemmal repair. We show here that loss of Dysf and annexin A6 (Anxa6) function lead to myopathy in zebrafish. By use of high-resolution imaging of myofibers in intact animals, we reveal sequential phases in sarcolemmal repair. Initially, membrane vesicles enriched in Dysf together with cytoplasmic Anxa6 form a tight patch at the lesion independently of one another. In the subsequent steps, annexin A2a (Anxa2a) followed by annexin A1a (Anxa1a) accumulate at the patch; the recruitment of these annexins depends on Dysf and Anxa6. Thus, sarcolemmal repair relies on the ordered assembly of a protein-membrane scaffold. Moreover, we provide several lines of evidence that the membrane for sarcolemmal repair is derived from a specialized plasma membrane compartment.
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Affiliation(s)
- Urmas Roostalu
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology and University of Heidelberg, Eggenstein-Leopoldshafen, Germany.
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30
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Minashima T, Small W, Moss SE, Kirsch T. Intracellular modulation of signaling pathways by annexin A6 regulates terminal differentiation of chondrocytes. J Biol Chem 2012; 287:14803-15. [PMID: 22399299 DOI: 10.1074/jbc.m111.297861] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Annexin A6 (AnxA6) is highly expressed in hypertrophic and terminally differentiated growth plate chondrocytes. Rib chondrocytes isolated from newborn AnxA6-/- mice showed delayed terminal differentiation as indicated by reduced terminal differentiation markers, including alkaline phosphatase, matrix metalloproteases-13, osteocalcin, and runx2, and reduced mineralization. Lack of AnxA6 in chondrocytes led to a decreased intracellular Ca(2+) concentration and protein kinase C α (PKCα) activity, ultimately resulting in reduced extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) activities. The 45 C-terminal amino acids of AnxA6 (AnxA6(1-627)) were responsible for the direct binding of AnxA6 to PKCα. Consequently, transfection of AnxA6-/- chondrocytes with full-length AnxA6 rescued the reduced expression of terminal differentiation markers, whereas transfection of AnxA6-/- chondrocytes with AnxA6(1-627) did not or only partially rescued the decreased mRNA levels of terminal differentiation markers. In addition, lack of AnxA6 in matrix vesicles, which initiate the mineralization process in growth plate cartilage, resulted in reduced alkaline phosphatase activity and Ca(2+) and inorganic phosphate (P(i)) content and the inability to form hydroxyapatite-like crystals in vitro. Histological analysis of femoral, tibial, and rib growth plates from newborn mice revealed that the hypertrophic zone of growth plates from newborn AnxA6-/- mice was reduced in size. In addition, reduced mineralization was evident in the hypertrophic zone of AnxA6-/- growth plate cartilage, although apoptosis was not altered compared with wild type growth plates. In conclusion, AnxA6 via its stimulatory actions on PKCα and its role in mediating Ca(2+) flux across membranes regulates terminal differentiation and mineralization events of chondrocytes.
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Affiliation(s)
- Takeshi Minashima
- Musculoskeletal Research Center, Department of Orthopaedic Surgery, New York University Hospital for Joint Diseases, New York, New York 10003, USA
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Tjota M, Lee SK, Wu J, Williams JA, Khanna MR, Thomas GH. Annexin B9 binds to β(H)-spectrin and is required for multivesicular body function in Drosophila. J Cell Sci 2012; 124:2914-26. [PMID: 21878499 DOI: 10.1242/jcs.078667] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role of the cytoskeleton in protein trafficking is still being defined. Here, we describe a relationship between the small Ca(2+)-dependent membrane-binding protein Annexin B9 (AnxB9), apical β(Heavy)-spectrin (β(H)) and the multivesicular body (MVB) in Drosophila. AnxB9 binds to a subset of β(H) spliceoforms, and loss of AnxB9 results in an increase in basolateral β(H) and its appearance on cytoplasmic vesicles that overlap with the MVB markers Hrs, Vps16 and EPS15. Similar colocalizations are seen when β(H)-positive endosomes are generated either by upregulation of β(H) in pak mutants or through the expression of the dominant-negative version of β(H). In common with other mutations disrupting the MVB, we also show that there is an accumulation of ubiquitylated proteins and elevated EGFR signaling in the absence of AnxB9 or β(H). Loss of AnxB9 or β(H) function also causes the redistribution of the DE-Cadherin (encoded by shotgun) to endosomal vesicles, suggesting a rationale for the previously documented destabilization of the zonula adherens in karst (which encodes β(H)) mutants. Reduction of AnxB9 results in degradation of the apical-lateral boundary and the appearance of the basolateral proteins Coracle and Dlg on internal vesicles adjacent to β(H). These results indicate that AnxB9 and β(H) are intimately involved in endosomal trafficking to the MVB and play a role in maintaining high-fidelity segregation of the apical and lateral domains.
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Affiliation(s)
- Monika Tjota
- Department of Biology, 208 Mueller Laboratory, The Pennsylvania State University, University Park, PA 16802, USA
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Deficiency of annexins A5 and A6 induces complex changes in the transcriptome of growth plate cartilage but does not inhibit the induction of mineralization. J Bone Miner Res 2010; 25:141-53. [PMID: 19580468 DOI: 10.1359/jbmr.090710] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Initiation of mineralization during endochondral ossification is a multistep process and has been assumed to correlate with specific interactions of annexins A5 and A6 and collagens. However, skeletal development appears to be normal in mice deficient for either A5 or A6, and the highly conserved structures led to the assumption that A5 and A6 may fulfill redundant functions. We have now generated mice deficient of both proteins. These mice were viable and fertile and showed no obvious abnormalities. Assessment of skeletal elements using histologic, ultrastructural, and peripheral quantitative computed tomographic methods revealed that mineralization and development of the skeleton were not significantly affected in mutant mice. Otherwise, global gene expression analysis showed subtle changes at the transcriptome level of genes involved in cell growth and intermediate metabolism. These results indicate that annexins A5 and A6 may not represent the essential annexins that promote mineralization in vivo.
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Abstract
At the cell surface, activation of the epidermal growth factor (EGF) receptor triggers a complex network of signalling events that regulate a variety of cellular processes. For signal termination, the activated EGF receptor is internalised and targeted to lysosomes for degradation. Microdomain localization at the plasma membrane and endocytic transport of the EGFR is important for the formation of compartment-specific signalling complexes and is regulated by scaffolding and targeting proteins. This includes Ca2+-effector proteins, such as calmodulin and annexins (Anx), in particular AnxA1, AnxA2, AnxA6 and as shown recently,AnxA8. Given that these annexins show differences in their expression patterns, subcellular localization and mode of action, they are likely to differentially contribute and cooperate in the fine-tuning of EGFR activity. In support of this hypothesis, current literature suggests these annexins to be involved in different steps that control the endocytic transport and signalling of the EGF receptor. This review summarizes how the coordinated activity of AnxA1, AnxA2, AnxA6 and AnxA8 can contribute to regulate EGF receptor localization and activity.
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Affiliation(s)
- Thomas Grewal
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Sydney, Sydney, Australia.
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Strzelecka-Kiliszek A, Buszewska ME, Podszywalow-Bartnicka P, Pikula S, Otulak K, Buchet R, Bandorowicz-Pikula J. Calcium- and pH-dependent localization of annexin A6 isoforms in Balb/3T3 fibroblasts reflecting their potential participation in vesicular transport. J Cell Biochem 2008; 104:418-34. [PMID: 18044716 DOI: 10.1002/jcb.21632] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Annexin A6 (AnxA6), calcium- and membrane-binding protein, is involved in membrane dynamics. It exists in the cell in two isoforms, AnxA6-1 and AnxA6-2, varying only by the VAAEIL sequence. In most cells, AnxA6-1 predominates. A limited number of observations suggests that both isoforms differ from each other functionally. The EGF-dependent Ca(2+) influx in A431 cells is inhibited only by AnxA6-1. Moreover, AnxA6-2 was found to exhibit higher affinity for Ca(2+). In this report we addressed the potential significance of the VAAEIL deletion in AnxA6-2. For this purpose, we expressed AnxA6 isoform cDNAs in bacteria or mouse Balb/3T3 fibroblasts. The recombinant AnxA6-2 was characterized by a less extended molecular shape than that of AnxA6-1 and required a narrower [Ca(2+)] range to bind liposomes. Upon lowering pH in the presence of EGTA recombinant AnxA6-2 became less hydrophobic than AnxA6-1 as revealed by the Triton X-114 partition. Furthermore, AnxA6-2 revealed stronger F-actin binding than that of AnxA6-1. Immunofluorescence microscopy showed that the EGFP-tagged AnxA6 isoforms expressed in Balb/3T3 fibroblasts relocate in a Ca(2+)- and H(+)-sensitive manner to the vesicular structures in a perinuclear region or in cytosol. Cell fractionation showed that in resting conditions AnxA6-1 is associated with early endosomes and AnxA6-2 with late endosomes, and an increase in [Ca(2+)] and/or [H(+)] induced their opposite distribution. These findings suggest a potentially independent regulation, localization, and function of AnxA6 isoforms in Balb/3T3 fibroblasts. More generally, our findings suggest distinct functions of AnxA6 isoforms in membrane dynamics.
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Cubells L, Vilà de Muga S, Tebar F, Wood P, Evans R, Ingelmo-Torres M, Calvo M, Gaus K, Pol A, Grewal T, Enrich C. Annexin A6-induced alterations in cholesterol transport and caveolin export from the Golgi complex. Traffic 2007; 8:1568-89. [PMID: 17822395 PMCID: PMC3003291 DOI: 10.1111/j.1600-0854.2007.00640.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Annexin A6 (AnxA6) belongs to a family of Ca(2+)-dependent membrane-binding proteins and is involved in the regulation of endocytic and exocytic pathways. We previously demonstrated that AnxA6 regulates receptor-mediated endocytosis and lysosomal targeting of low-density lipoproteins and translocates to cholesterol-enriched late endosomes (LE). As cholesterol modulates the membrane binding and the cellular location of AnxA6, but also affects the intracellular distribution of caveolin, we investigated the localization and trafficking of caveolin in AnxA6-expressing cells. Here, we show that cells expressing high levels of AnxA6 are characterized by an accumulation of caveolin-1 (cav-1) in the Golgi complex. This is associated with a sequestration of cholesterol in the LE and lower levels of cholesterol in the Golgi and the plasma membrane, both likely contributing to retention of caveolin in the Golgi apparatus and a reduced number of caveolae at the cell surface. Further strengthening these findings, knock down of AnxA6 and the ectopic expression of the Niemann-Pick C1 protein in AnxA6-overexpressing cells restore the cellular distribution of cav-1 and cholesterol, respectively. In summary, this study demonstrates that elevated expression levels of AnxA6 perturb the intracellular distribution of cholesterol, which indirectly inhibits the exit of caveolin from the Golgi complex.
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Affiliation(s)
- Laia Cubells
- Departament de Biologia Cel·lular, Facultat de Medicina, Universitat de BarcelonaCasanova 143, 08036-Barcelona, Spain
| | - Sandra Vilà de Muga
- Departament de Biologia Cel·lular, Facultat de Medicina, Universitat de BarcelonaCasanova 143, 08036-Barcelona, Spain
| | - Francesc Tebar
- Departament de Biologia Cel·lular, Facultat de Medicina, Universitat de BarcelonaCasanova 143, 08036-Barcelona, Spain
| | - Peta Wood
- Centre for Immunology, St. Vincent’s Hospital, University of New South WalesSydney, NSW 2010, Australia
| | - Rachael Evans
- Centre for Immunology, St. Vincent’s Hospital, University of New South WalesSydney, NSW 2010, Australia
| | - Mercedes Ingelmo-Torres
- Departament de Biologia Cel·lular, Facultat de Medicina, Universitat de BarcelonaCasanova 143, 08036-Barcelona, Spain
| | - Maria Calvo
- Institut d’Investigacions Biomèdiques August Pi Sunyer (IDIBAPS), Facultat de Medicina, Universitat de BarcelonaBarcelona, Spain
- Unitat de Microscòpia Confocal, Serveis Cientificotècnics, Facultat de Medicina, Universitat de BarcelonaBarcelona, Spain
| | - Katharina Gaus
- Centre of Vascular Research, School of Medical Sciences, University of New South WalesSydney, NSW 2052, Australia
| | - Albert Pol
- Institut d’Investigacions Biomèdiques August Pi Sunyer (IDIBAPS), Facultat de Medicina, Universitat de BarcelonaBarcelona, Spain
| | - Thomas Grewal
- Centre for Immunology, St. Vincent’s Hospital, University of New South WalesSydney, NSW 2010, Australia
| | - Carlos Enrich
- Departament de Biologia Cel·lular, Facultat de Medicina, Universitat de BarcelonaCasanova 143, 08036-Barcelona, Spain
- Institut d’Investigacions Biomèdiques August Pi Sunyer (IDIBAPS), Facultat de Medicina, Universitat de BarcelonaBarcelona, Spain
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Cook SJ, Lockyer PJ. Recent advances in Ca2+-dependent Ras regulation and cell proliferation. Cell Calcium 2006; 39:101-12. [PMID: 16343616 DOI: 10.1016/j.ceca.2005.10.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2005] [Revised: 10/17/2005] [Accepted: 10/27/2005] [Indexed: 12/20/2022]
Abstract
Our understanding of the mechanisms whereby growth factors stimulate cell proliferation through the Ras pathway stems largely from studies of the canonical pathway involving recruitment of Ras activators and inhibitors to the vicinity of receptor tyrosine kinases via phosphotyrosine-binding adaptor proteins. Ca(2+) has seldom joined the party, despite the identification of phospholipase Cgamma and Ca(2+) entry as receptor tyrosine kinase-dependent signals. Mechanisms by which Ca(2+) can directly influence Ras activity have remained relatively elusive. Similarly, the mechanisms whereby Ca(2+) modulates the cell cycle have been equally murky, and yet there are some interesting parallels in the role of Ras and Ca(2+) in cell cycle re-entry. This review focuses on a number of novel mechanisms that link Ca(2+) with the regulation of Ras activity and signaling output. Their collective discovery adds to the complexities of Ras regulation and raises further questions about the role of Ca(2+) signals in Ras-dependent cell proliferation.
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Affiliation(s)
- Simon J Cook
- Laboratory of Molecular Signaling, The Babraham Institute, Babraham Research Campus, Cambridge CB2 4AT, UK
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Grewal T, Enrich C. Molecular mechanisms involved in Ras inactivation: the annexin A6–p120GAP complex. Bioessays 2006; 28:1211-20. [PMID: 17120209 DOI: 10.1002/bies.20503] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In mammalian cells, a complex network of signaling pathways tightly regulates a variety of cellular processes, such as proliferation and differentiation. New insights from one of the most-important signaling cascades involved in oncogenesis, the Ras-Raf-MAPK pathway, suggest that the subcellular localisation and assembly of signaling modules of this pathway is crucial to control the biological response. This commonly requires membrane targeting events that are mediated by adaptor/scaffold proteins. Of particular interest is the translocation and complex formation of GTPase-activating proteins (GAPs), such as p120GAP, at the plasma membrane to inactivate Ras. Recent studies indicate that one member of the annexin family, annexin A6 acts as a targeting protein for p120GAP. This review discusses how annexin A6 modulates the involvement of negative regulators of the Ras-Raf-MAPK pathway contributing to Ras inactivation.
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Affiliation(s)
- Thomas Grewal
- Centre for Immunology, St. Vincent's Hospital, University of New South Wales, Sydney, Australia.
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Grewal T, Evans R, Rentero C, Tebar F, Cubells L, de Diego I, Kirchhoff MF, Hughes WE, Heeren J, Rye KA, Rinninger F, Daly RJ, Pol A, Enrich C. Annexin A6 stimulates the membrane recruitment of p120GAP to modulate Ras and Raf-1 activity. Oncogene 2005; 24:5809-20. [PMID: 15940262 DOI: 10.1038/sj.onc.1208743] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Annexin A6 is a calcium-dependent membrane-binding protein that interacts with signalling proteins, including the GTPase-activating protein p120GAP, one of the most important inactivators of Ras. Since we have demonstrated that annexin A6 inhibits EGF- and TPA-induced Ras signalling, we investigated whether modulation of Ras activity by annexin A6 was mediated via altered subcellular localization of p120GAP. First, we exploited our observation that high-density lipoproteins (HDL) can activate the Ras/MAP kinase pathway. Expression of annexin A6 caused a significant reduction in HDL-induced activation of Ras and Raf-1. Annexin A6 promoted membrane binding of p120GAP in vitro, and plasma membrane targeting of p120GAP in living cells, both in a Ca(2+)-dependent manner, which is consistent with annexin A6 promoting the Ca(2+)-dependent assembly of p120GAP-Ras at the plasma membrane. We then extended these studies to other cell types and stimuli. Expression of annexin A6 in A431 cells reduced, while RNAi-mediated suppression of annexin A6 in HeLa cells enhanced EGF-induced Ras and Erk activation. Importantly, the enhancement of Ras activation following RNAi-mediated reduction in p120GAP levels was more marked in annexin A6-expressing A431 cells than controls, indicating that the effect of annexin A6 on Ras was mediated via p120GAP. Finally, we demonstrated that annexin A6 promotes plasma membrane targeting of p120GAP in A431 cells in response to a variety of stimuli, resulting in colocalization with H-Ras. These findings demonstrate an important role for annexin A6 in regulating plasma membrane localization of p120GAP and hence Ras activity.
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Affiliation(s)
- Thomas Grewal
- Centre for Immunology, St Vincent's Hospital. University of New South Wales, Australia
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39
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Zaunreiter M, Brandstätter R, Donato R, Hermann A. Localisation of annexins in the retina of the rainbow trout-light and electron microscopical investigations. Brain Res 2005; 1032:1-10. [PMID: 15680935 DOI: 10.1016/j.brainres.2004.10.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2004] [Indexed: 01/08/2023]
Abstract
We present a first description of annexin immunoreactivity within the teleost retina. Antibodies against annexins V and VI were used in light and electron microscopic sections of light- and dark-adapted retinae. Strong immunoreactivity could be found in retinal layers with high synaptic input, such as the outer and inner plexiform layers and dendritic regions within the inner plexiform layer, in cells that are involved in negative feedback control such as horizontal and amacrine cells, in the membrane metabolism of photoreceptor outer segments, and in close relation to cytoskeletal components. Our findings suggest that both annexins V and VI are involved in the regulation of transmitter release, particularly of transmitters that are not directly involved in phototransduction. The annexins appear also to be involved with structures that support morphological changes in light and dark adaptation.
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Affiliation(s)
- Monika Zaunreiter
- Division Animal Physiology, Department Cell Biology, University Salzburg, Hellbrunnerstrasse 34, Salzburg A-5020, Austria
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40
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Abstract
Annexins are a well-known multigene family of Ca(2+)-regulated phospholipid-binding and membrane-binding proteins. Recent work employing annexin-knockdown or - knockout models has provided new insights into the biological functions of different annexin proteins. Transient annexin depletion by RNA interference and the expression of dominant-negative mutant proteins has revealed roles for the proteins in membrane processes ranging from the control of membrane structure to certain membrane transport phenomena. Although such functions correlate well with the ability of annexins to interact with cellular membranes in a reversible and regulated manner, some activities are membrane independent, probably because annexins can also engage in specific protein-protein interactions. Among other things, this is evident in annexin A1- and A2-knockout mice, which show impaired regulation of neutrophil extravasation and defects in plasmin generation, respectively.
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Affiliation(s)
- Ursula Rescher
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, von-Esmarch-Strasse 56, Münster 48149, Germany
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41
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Abstract
The actin cytoskeleton is a malleable framework of polymerised actin monomers that may be rapidly restructured to enable diverse cellular activities such as motility, endocytosis and cytokinesis. The regulation of actin dynamics involves the coordinated activity of numerous proteins, among which members of the annexin family of Ca2+- and phospholipid-binding proteins play an important role. Although the roles of annexins in actin dynamics are not understood at a mechanistic level, annexins have the requisite properties to integrate Ca2+-signaling with actin dynamics at membrane contact sites. In this review we discuss the current state of knowledge on this topic, and consider how and where annexins may fit into the complex molecular machinery that regulates the actin cytoskeleton.
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Affiliation(s)
- Matthew J Hayes
- Division of Cell Biology, Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK
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Tomas A, Futter C, Moss SE. Annexin 11 is required for midbody formation and completion of the terminal phase of cytokinesis. ACTA ACUST UNITED AC 2004; 165:813-22. [PMID: 15197175 PMCID: PMC2172404 DOI: 10.1083/jcb.200311054] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Annexins are Ca(2+)-binding, membrane-fusogenic proteins with diverse but poorly understood functions. Here, we show that during cell cycle progression annexin 11 translocates from the nucleus to the spindle poles in metaphase and to the spindle midzone in anaphase. Annexin 11 is recruited to the midbody in late telophase, where it forms part of the detergent-resistant matrix that also contains CHO1. To investigate the significance of these observations, we used RNA interference to deplete cells of annexin 11. A combination of confocal and video time-lapse microscopy revealed that cells lacking annexin 11 fail to establish a functional midbody. Instead, daughter cells remain connected by intercellular bridges that contain bundled microtubules and cytoplasmic organelles but exclude normal midbody components such as MKLP1 and Aurora B. Annexin 11-depleted cells failed to complete cytokinesis and died by apoptosis. These findings demonstrate an essential role for annexin 11 in the terminal phase of cytokinesis.
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Affiliation(s)
- Alejandra Tomas
- Division of Cell Biology, Institute of Ophthalmology, 11-43 Bath St., London EC1V 9EL, England, UK
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43
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Abstract
Annexins are traditionally thought of as calcium-dependent phospholipid-binding proteins, but recent work suggests a more complex set of functions. More than a thousand proteins of the annexin superfamily have been identified in major eukaryotic phyla, but annexins are absent from yeasts and prokaryotes. Annexins are traditionally thought of as calcium-dependent phospholipid-binding proteins, but recent work suggests a more complex set of functions. More than a thousand proteins of the annexin superfamily have been identified in major eukaryotic phyla, but annexins are absent from yeasts and prokaryotes. The unique annexin core domain is made up of four similar repeats approximately 70 amino acids long, each of which usually contains a characteristic 'type 2' motif for binding calcium ions. Animal and fungal annexins also have non-homologous amino-terminal domains of varying length and sequence, which are responsible for the distinct localizations and specialized functions of the proteins through post-translational modification and binding to other proteins. Annexins interact with various cell-membrane components that are involved in the structural organization of the cell, intracellular signaling by enzyme modulation and ion fluxes, growth control, and they can act as atypical calcium channels. Analysis of site-specific conservation in the core domain suggests a role for certain buried residues in the calcium-channel activity of vertebrate annexins and in the structural stability of their core domains. Evolutionarily significant differences between subfamilies are preferentially localized to accessible sites on the protein surface that determine membrane binding and interactions with cytosolic proteins.
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Affiliation(s)
- Stephen E Moss
- Division of Cell Biology, Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK.
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44
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Gillette JM, Chan DC, Nielsen-Preiss SM. Annexin 2 expression is reduced in human osteosarcoma metastases. J Cell Biochem 2004; 92:820-32. [PMID: 15211578 DOI: 10.1002/jcb.20117] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Osteosarcoma is an aggressive primary bone cancer affecting primarily children and young adults. The development of valuable diagnostic indicators and therapeutic agents will be enhanced by the identification and characterization of genes that contribute to its aggressive behavior. We used representational difference analysis to isolate genes differentially expressed between primary human osteosarcoma tumors and subsequent metastatic lung lesions to identify genes potentially involved in metastatic potential. Several genes were differentially expressed between the two tumor populations, including annexin2. The levels of annexin2 mRNA and protein inversely correlated with metastatic potential in a subset of human osteosarcoma tumor specimens, as well as in a human osteosarcoma cell line selected for increased metastatic potential. Annexin2 has been described in several cellular localizations with various functional implications, many of which may be relevant to metastatic potential. Therefore, the subcellular localization of endogenous annexin2 protein was evaluated biochemically by subcellular fractionation and immunologically by flow cytometry and immunofluorescence in osteoblastic cells. Annexin2 was localized to the cytoplasm and intracellular aspect of the plasma membrane, excluded from the nucleus and undetectable on the cell surface or in the conditioned medium. Overexpression of annexin2 in osteosarcoma cells did not alter several in vitro phenotypes often used to assess metastatic potential including motility, adhesion, and proliferation. However, our previous data have implicated annexin2 in the mineralization process of osteoblastic cells in vitro. Consistent with an increase in differentiation-induced mineralization, there was diminished tumorigenicity and experimental metastatic potential of osteosarcoma cells overexpressing annexin2. These data suggest that annexin2 may downregulate osteosarcoma aggressiveness by inducing a more differentiated state in osteoblastic cells.
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Affiliation(s)
- Jennifer M Gillette
- Department of Cellular and Developmental Biology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
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Draeger A, Monastyrskaya K, Burkhard FC, Wobus AM, Moss SE, Babiychuk EB. Membrane segregation and downregulation of raft markers during sarcolemmal differentiation in skeletal muscle cells. Dev Biol 2003; 262:324-34. [PMID: 14550795 DOI: 10.1016/s0012-1606(03)00398-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Muscle contraction implies flexibility in combination with force resistance and requires a high degree of sarcolemmal organization. Smooth muscle cells differentiate largely from mesenchymal precursor cells and gradually assume a highly periodic sarcolemmal organization. Skeletal muscle undergoes an even more striking differentiation programme, leading to cell fusion and alignment into myofibrils. The lipid bilayer of each cell type is further segregated into raft and non-raft microdomains of distinct lipid composition. Considering the extent of developmental rearrangement in skeletal muscle, we investigated sarcolemmal microdomain organization in skeletal and smooth muscle cells. The rafts in both muscle types are characterized by marker proteins belonging to the annexin family which localize to the inner membrane leaflet, as well as glycosyl-phosphatidyl-inositol (GPI)-anchored enzymes attached to the outer leaflet. We demonstrate that the profound structural rearrangements that occur during skeletal muscle maturation coincide with a striking decrease in membrane lipid segregation, downregulation of annexins 2 and 6, and a significant decrease in raft-associated 5'-nucleotidase activity. The relative paucity of lipid rafts in mature skeletal in contrast to smooth muscle suggests that the organization of sarcolemmal microdomains contributes to the muscle-specific differences in stimulatory responses and contractile properties.
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Affiliation(s)
- A Draeger
- Department of Cell Biology, Institute of Anatomy, University of Bern, Switzerland.
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Brachvogel B, Dikschas J, Moch H, Welzel H, von der Mark K, Hofmann C, Pöschl E. Annexin A5 is not essential for skeletal development. Mol Cell Biol 2003; 23:2907-13. [PMID: 12665588 PMCID: PMC152556 DOI: 10.1128/mcb.23.8.2907-2913.2003] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Annexins are highly conserved proteins that are characterized by their ability to interact with phospholipids in a calcium-dependent manner. Although diverse functions have been ascribed to annexins based on in vitro analyses, their in vivo functions still remain unclear. The intensively studied annexin A5 has been identified by its effects on blood coagulation, and subsequently, its function as a calcium-specific ion channel was described. In vitro experiments and expression studies suggested a potential role of annexin A5 during calcification processes in vivo, especially in endochondral ossification. To gain insights into the relevance of annexin A5 in this process, we generated an annexin A5-deficient mouse mutant. Mice lacking annexin A5 are viable, are fertile, and reveal no significant alterations in the biochemical parameters characteristic for metabolic or functional defects. Neither the development of skeletal elements nor the in vitro calcification properties of isolated chondrocytes is significantly impaired by the absence of annexin A5. Therefore, annexin A5 is dispensable for the formation and maintenance of skeletal elements in the mouse and may possibly be pointing to a compensatory effect of other members from the annexin family due to their high functional and structural similarity.
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Affiliation(s)
- Bent Brachvogel
- Universität Erlangen-Nürnberg, Nikolaus-Fiebiger-Zentrum, Experimentelle Medizin I, Erlangen, Germany
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47
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Hannon R, Croxtall JD, Getting SJ, Roviezzo F, Yona S, Paul-Clark MJ, Gavins FNE, Perretti M, Morris JF, Buckingham JC, Flower RJ. Aberrant inflammation and resistance to glucocorticoids in annexin 1-/- mouse. FASEB J 2003; 17:253-5. [PMID: 12475898 DOI: 10.1096/fj.02-0239fje] [Citation(s) in RCA: 288] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The 37-kDa protein annexin 1 (Anx-1; lipocortin 1) has been implicated in the regulation of phagocytosis, cell signaling, and proliferation and is postulated to be a mediator of glucocorticoid action in inflammation and in the control of anterior pituitary hormone release. Here, we report that mice lacking the Anx-1 gene exhibit a complex phenotype that includes an altered expression of other annexins as well as of COX-2 and cPLA2. In carrageenin- or zymosan-induced inflammation, Anx-1-/- mice exhibit an exaggerated response to the stimuli characterized by an increase in leukocyte emigration and IL-1beta generation and a partial or complete resistance to the antiinflammatory effects of glucocorticoids. Anx-1-/- polymorphonuclear leucocytes exhibited increased spontaneous migratory behavior in vivo whereas in vitro, leukocytes from Anx-1-/- mice had reduced cell surface CD 11b (MAC-1) but enhanced CD62L (L-selectin) expression and Anx-1-/- macrophages exhibited anomalies in phagocytosis. There are also gender differences in activated leukocyte behavior in the Anx-1-/- mice that are not seen in the wild-type animals, suggesting an interaction between sex hormones and inflammation in Anx-1-/- animals.
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Affiliation(s)
- Robert Hannon
- Department of Biochemical Pharmacology, William Harvey Research Institute, Queen Mary, University of London, Charterhouse Square, EC1M 6BQ, UK
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48
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Thomas DDH, Kaspar KM, Taft WB, Weng N, Rodenkirch LA, Groblewski GE. Identification of annexin VI as a Ca2+-sensitive CRHSP-28-binding protein in pancreatic acinar cells. J Biol Chem 2002; 277:35496-502. [PMID: 12105190 DOI: 10.1074/jbc.m110917200] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
CRHSP-28 is a member of the tumor protein D52 protein family that was recently shown to regulate Ca(2+)-stimulated secretory activity in streptolysin-O-permeabilized acinar cells (Thomas, D. H., Taft, W. B., Kaspar, K. M., and Groblewski, G. E. (2001) J. Biol. Chem. 276, 28866-28872). In the present study, the Ca(2+)-sensitive phospholipid-binding protein annexin VI was purified from rat pancreas as a CRHSP-28-binding protein. The interaction between CRHSP-28 and annexin VI was demonstrated by coimmunoprecipitation and gel-overlay assays and was shown to require low micromolar levels of free Ca(2+), indicating these molecules likely interact under physiological conditions. Immunofluorescence microscopy confirmed a dual localization of CRHSP-28 and annexin VI, which appeared in a punctate pattern in the supranuclear and apical cytoplasm of acini. Stimulation of cells for 5 min with the secretagogue cholecystokinin enhanced the colocalization of CRHSP-28 and annexin VI within regions of acini immediately below the apical plasma membrane. Tissue fractionation revealed that CRHSP-28 is a peripheral membrane protein that is highly enriched in smooth microsomal fractions of pancreas. Further, the content of CRHSP-28 in microsomes was significantly reduced in pancreatic tissue obtained from rats that had been infused with a secretory dose of cholecystokinin for 40 min, demonstrating that secretagogue stimulation transiently alters the association of CRHSP-28 with membranes in cells. Collectively, the Ca(2+)-dependent binding of CRHSP-28 and annexin VI, together with their colocalization in the apical cytoplasm, is consistent with a role for these molecules in acinar cell membrane trafficking events that are essential for digestive enzyme secretion.
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Affiliation(s)
- Diana D H Thomas
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA
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Liu L, Enright E, Sun P, Tsai SY, Mehta P, Beckman DL, Terrian DM. Inactivation of annexin II tetramer by S-nitrosoglutathione. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:4277-86. [PMID: 12199706 DOI: 10.1046/j.1432-1033.2002.03118.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We investigated the effect of nitric oxide (NO) donors on the activities of annexin II tetramer (AIIt), a member of the Ca2+- dependent phospholipid-binding protein family. Incubation of purified AIIt with S-nitrosoglutathione (GSNO) led to the inhibition of AIIt-mediated liposome aggregation. This effect was dose-dependent with an IC50 of approximately 100 micro m. Sodium nitroprusside, another NO donor also inhibited AIIt-mediated liposome aggregation, whereas reduced glutathione, nitrate, or nitrite had no effects. GSNO also inhibited AIIt-mediated membrane fusion, but not the binding of AIIt to the membrane. GSNO only has a modest effect on liposome aggregation mediated by annexins I, III or IV. The binding of AIIt to the membrane protected the reactive sites of GSNO on AIIt. GSNO did not inhibit AIIt-mediated liposome aggregation in the presence of dithiothreitol. Taken together, our results suggest that GSNO inactivates AIIt possibly via S-nitrosylation and/or the formation of disulfide bonds.
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Affiliation(s)
- Lin Liu
- Department of Physiological Sciences, Oklahoma State University, Stillwater 74078, USA.
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Song G, Harding SE, Duchen MR, Tunwell R, O'Gara P, Hawkins TE, Moss SE. Altered mechanical properties and intracellular calcium signaling in cardiomyocytes from annexin 6 null-mutant mice. FASEB J 2002; 16:622-4. [PMID: 11919174 DOI: 10.1096/fj.01-0892fje] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Annexin 6 is one of a widely expressed family of calcium-binding proteins found in most mammalian tissues, including the heart. Several studies have implicated annexin 6 in the regulation of intracellular Ca2+ signaling, and it has been shown in vitro to act as a modulator of the sarcoplasmic reticulum Ca2+-release channel, cardiac L-type calcium channel, and Na+/Ca2+ exchanger. To investigate the role of annexin 6 in intact cardiomyocytes, we used mice containing a targeted disruption of the annexin 6 gene. Compared with controls, the myocytes of annexin 6 null-mutant mice demonstrated a significant increase in the rates of shortening and relengthening. Intracellular Ca2+ transients in fura-2-loaded cardiomyocytes induced by caffeine showed a normal baseline and amplitude, whereas the rate of decay was doubled in annexin 6-/- myocytes compared with control mice. These results show that annexin 6 knockout in the mouse leads to an increase in myocyte contractility and faster diastolic Ca2+ removal from the cytoplasm. In light of published findings showing annexin 6 to be down-regulated in end-stage heart failure, these results are consistent with a role for annexin 6 as a negative inotropic factor in the regulation of cardiomyocyte mechanics.
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Affiliation(s)
- Guojie Song
- Division of Cell Biology, Institute of Ophthalmology, University College London, London EC1V 9EL, UK
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