1
|
Holzer E, Martens S, Tulli S. The Role of ATG9 Vesicles in Autophagosome Biogenesis. J Mol Biol 2024:168489. [PMID: 38342428 DOI: 10.1016/j.jmb.2024.168489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/02/2024] [Accepted: 02/07/2024] [Indexed: 02/13/2024]
Abstract
Autophagy mediates the degradation and recycling of cellular material in the lysosomal system. Dysfunctional autophagy is associated with a plethora of diseases including uncontrolled infections, cancer and neurodegeneration. In macroautophagy (hereafter autophagy) this material is encapsulated in double membrane vesicles, the autophagosomes, which form upon induction of autophagy. The precursors to autophagosomes, referred to as phagophores, first appear as small flattened membrane cisternae, which gradually enclose the cargo material as they grow. The assembly of phagophores during autophagy initiation has been a major subject of investigation over the past decades. A special focus has been ATG9, the only conserved transmembrane protein among the core machinery. The majority of ATG9 localizes to small Golgi-derived vesicles. Here we review the recent advances and breakthroughs regarding our understanding of how ATG9 and the vesicles it resides in serve to assemble the autophagy machinery and to establish membrane contact sites for autophagosome biogenesis. We also highlight open questions in the field that need to be addressed in the years to come.
Collapse
Affiliation(s)
- Elisabeth Holzer
- Max Perutz Labs, Vienna BioCenter Campus (VBC), Vienna, Austria; University of Vienna, Max Perutz Labs, Department of Biochemistry and Cell Biology, Vienna, Austria; Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Campus-Vienna-Biocenter 1, Vienna, Austria.
| | - Sascha Martens
- Max Perutz Labs, Vienna BioCenter Campus (VBC), Vienna, Austria; University of Vienna, Max Perutz Labs, Department of Biochemistry and Cell Biology, Vienna, Austria.
| | - Susanna Tulli
- Max Perutz Labs, Vienna BioCenter Campus (VBC), Vienna, Austria; University of Vienna, Max Perutz Labs, Department of Biochemistry and Cell Biology, Vienna, Austria.
| |
Collapse
|
2
|
Lee SY, Choi SH, Kim Y, Ahn HS, Ko YG, Kim K, Chi SW, Kim H. Migrasomal autophagosomes relieve endoplasmic reticulum stress in glioblastoma cells. BMC Biol 2024; 22:23. [PMID: 38287397 PMCID: PMC10826056 DOI: 10.1186/s12915-024-01829-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 01/16/2024] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Glioblastoma (GBM) is more difficult to treat than other intractable adult tumors. The main reason that GBM is so difficult to treat is that it is highly infiltrative. Migrasomes are newly discovered membrane structures observed in migrating cells. Thus, they can be generated from GBM cells that have the ability to migrate along the brain parenchyma. However, the function of migrasomes has not yet been elucidated in GBM cells. RESULTS Here, we describe the composition and function of migrasomes generated along with GBM cell migration. Proteomic analysis revealed that LC3B-positive autophagosomes were abundant in the migrasomes of GBM cells. An increased number of migrasomes was observed following treatment with chloroquine (CQ) or inhibition of the expression of STX17 and SNAP29, which are involved in autophagosome/lysosome fusion. Furthermore, depletion of ITGA5 or TSPAN4 did not relieve endoplasmic reticulum (ER) stress in cells, resulting in cell death. CONCLUSIONS Taken together, our study suggests that increasing the number of autophagosomes, through inhibition of autophagosome/lysosome fusion, generates migrasomes that have the capacity to alleviate cellular stress.
Collapse
Affiliation(s)
- Seon Yong Lee
- Department of Biotechnology, Korea University, Seoul, Republic of Korea
- Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Sang-Hun Choi
- Department of Biotechnology, Korea University, Seoul, Republic of Korea
- Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Yoonji Kim
- Department of Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hee-Sung Ahn
- Convergence Medicine Research Center, Asan Institute for Life Sciences, Asan Medical Center, Seoul, Republic of Korea
| | - Young-Gyu Ko
- Department of Life Sciences, Korea University, Seoul, Republic of Korea
| | - Kyunggon Kim
- Department of Convergence Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Sung Wook Chi
- Department of Life Sciences, Korea University, Seoul, Republic of Korea
- Division of Life Sciences, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hyunggee Kim
- Department of Biotechnology, Korea University, Seoul, Republic of Korea.
- Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea.
| |
Collapse
|
3
|
Sung H, Lloyd TE. Disrupted endoplasmic reticulum-mediated autophagosomal biogenesis in a Drosophila model of C9-ALS-FTD. Autophagy 2024; 20:94-113. [PMID: 37599467 PMCID: PMC10761023 DOI: 10.1080/15548627.2023.2249750] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023] Open
Abstract
ABBREVIATIONS 3R: UAS construct expressing 3 G4C2 repeats (used as control); 3WJ: three-way junction; 12R: UAS construct expressing leader sequence and 12 G4C2 repeats; 30R: UAS construct expressing 30 G4C2 repeats; 36R: UAS construct expressing 36 G4C2 repeats; 44R: UAS construct expressing leader sequence and 44 G4C2 repeats; ALS: amyotrophic lateral sclerosis; Atg: autophagy related; atl: atlastin; C9-ALS-FTD: ALS or FTD caused by hexanuleotide repeat expansion in C9orf72; ER: endoplasmic reticulum; FTD: frontotemporal dementia; HRE: GGGGCC hexanucleotide repeat expansion; HSP: hereditary spastic paraplegia; Lamp1: lysosomal associated membrane protein 1; MT: microtubule; NMJ: neuromuscular junction; Rab: Ras-associated binding GTPase; RAN: repeat associated non-AUG (RAN) translation; RO-36: UAS construct expression "RNA-only" version of 36 G4C2 repeats in which stop codons in all six reading frames are inserted.; Rtnl1: Reticulon-like 1; SN: segmental nerve; TFEB/Mitf: transcription factor EB/microphthalmia associated transcription factor (Drosophila ortholog of TFEB); TrpA1: transient receptor potential cation channel A1; VAPB: VAMP associated protein B and C; VNC: ventral nerve cord (spinal cord in Drosophila larvae).
Collapse
Affiliation(s)
- Hyun Sung
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Thomas E. Lloyd
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|
4
|
Laczkó-Dobos H, Maddali AK, Jipa A, Bhattacharjee A, Végh AG, Juhász G. Lipid profiles of autophagic structures isolated from wild type and Atg2 mutant Drosophila. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1866:158868. [PMID: 33333179 DOI: 10.1016/j.bbalip.2020.158868] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/01/2020] [Accepted: 12/12/2020] [Indexed: 01/15/2023]
Abstract
Autophagy is mediated by membrane-bound organelles and it is an intrinsic catabolic and recycling process of the cell, which is very important for the health of organisms. The biogenesis of autophagic membranes is still incompletely understood. In vitro studies suggest that Atg2 protein transports lipids presumably from the ER to the expanding autophagic structures. Autophagy research has focused heavily on proteins and very little is known about the lipid composition of autophagic membranes. Here we describe a method for immunopurification of autophagic structures from Drosophila melanogaster (an excellent model to study autophagy in a complete organism) for subsequent lipidomic analysis. Western blots of several organelle markers indicate the high purity of the isolated autophagic vesicles, visualized by various microscopy techniques. Mass spectrometry results show that phosphatidylethanolamine (PE) is the dominant lipid class in wild type (control) membranes. We demonstrate that in Atg2 mutants (Atg2-), phosphatidylinositol (PI), negatively charged phosphatidylserine (PS), and phosphatidic acid (PA) with longer fatty acyl chains accumulate on stalled, negatively charged phagophores. Tandem mass spectrometry analysis of lipid species composing the lipid classes reveal the enrichment of unsaturated PE and phosphatidylcholine (PC) in controls versus PI, PS and PA species in Atg2-. Significant differences in the lipid profiles of control and Atg2- flies suggest that the lipid composition of autophagic membranes dynamically changes during their maturation. These lipidomic results also point to the in vivo lipid transport function of the Atg2 protein, pointing to its specific role in the transport of short fatty acyl chain PE species.
Collapse
Affiliation(s)
| | - Asha Kiran Maddali
- Institute of Genetics, Biological Research Centre, Szeged, Hungary; Doctoral School of Biology, University of Szeged, Szeged, Hungary.
| | - András Jipa
- Institute of Genetics, Biological Research Centre, Szeged, Hungary; Doctoral School of Biology, University of Szeged, Szeged, Hungary.
| | | | | | - Gábor Juhász
- Institute of Genetics, Biological Research Centre, Szeged, Hungary; Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest, Hungary.
| |
Collapse
|
5
|
Mugume Y, Kazibwe Z, Bassham DC. Target of Rapamycin in Control of Autophagy: Puppet Master and Signal Integrator. Int J Mol Sci 2020; 21:ijms21218259. [PMID: 33158137 PMCID: PMC7672647 DOI: 10.3390/ijms21218259] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023] Open
Abstract
The target of rapamycin (TOR) is an evolutionarily-conserved serine/threonine kinase that senses and integrates signals from the environment to coordinate developmental and metabolic processes. TOR senses nutrients, hormones, metabolites, and stress signals to promote cell and organ growth when conditions are favorable. However, TOR is inhibited when conditions are unfavorable, promoting catabolic processes such as autophagy. Autophagy is a macromolecular degradation pathway by which cells degrade and recycle cytoplasmic materials. TOR negatively regulates autophagy through phosphorylation of ATG13, preventing activation of the autophagy-initiating ATG1-ATG13 kinase complex. Here we review TOR complex composition and function in photosynthetic and non-photosynthetic organisms. We also review recent developments in the identification of upstream TOR activators and downstream effectors of TOR. Finally, we discuss recent developments in our understanding of the regulation of autophagy by TOR in photosynthetic organisms.
Collapse
|
6
|
Ornatowski W, Lu Q, Yegambaram M, Garcia AE, Zemskov EA, Maltepe E, Fineman JR, Wang T, Black SM. Complex interplay between autophagy and oxidative stress in the development of pulmonary disease. Redox Biol 2020; 36:101679. [PMID: 32818797 PMCID: PMC7451718 DOI: 10.1016/j.redox.2020.101679] [Citation(s) in RCA: 187] [Impact Index Per Article: 46.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/20/2020] [Accepted: 08/04/2020] [Indexed: 12/16/2022] Open
Abstract
The autophagic pathway involves the encapsulation of substrates in double-membraned vesicles, which are subsequently delivered to the lysosome for enzymatic degradation and recycling of metabolic precursors. Autophagy is a major cellular defense against oxidative stress, or related conditions that cause accumulation of damaged proteins or organelles. Selective forms of autophagy can maintain organelle populations or remove aggregated proteins. Dysregulation of redox homeostasis under pathological conditions results in excessive generation of reactive oxygen species (ROS), leading to oxidative stress and the associated oxidative damage of cellular components. Accumulating evidence indicates that autophagy is necessary to maintain redox homeostasis. ROS activates autophagy, which facilitates cellular adaptation and diminishes oxidative damage by degrading and recycling intracellular damaged macromolecules and dysfunctional organelles. The cellular responses triggered by oxidative stress include the altered regulation of signaling pathways that culminate in the regulation of autophagy. Current research suggests a central role for autophagy as a mammalian oxidative stress response and its interrelationship to other stress defense systems. Altered autophagy phenotypes have been observed in lung diseases such as chronic obstructive lung disease, acute lung injury, cystic fibrosis, idiopathic pulmonary fibrosis, and pulmonary arterial hypertension, and asthma. Understanding the mechanisms by which ROS regulate autophagy will provide novel therapeutic targets for lung diseases. This review highlights our current understanding on the interplay between ROS and autophagy in the development of pulmonary disease.
Collapse
Affiliation(s)
- Wojciech Ornatowski
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | - Qing Lu
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | | | - Alejandro E Garcia
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | - Evgeny A Zemskov
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA
| | - Emin Maltepe
- Department of Pediatrics, The University of California, San Francisco, San Francisco, CA, USA
| | - Jeffrey R Fineman
- Department of Pediatrics, The University of California, San Francisco, San Francisco, CA, USA; Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Ting Wang
- Department of Internal Medicine, The University of Arizona Health Sciences, Phoenix, AZ, USA
| | - Stephen M Black
- Department of Medicine, The University of Arizona Health Sciences, Tucson, AZ, USA.
| |
Collapse
|
7
|
Zhuang Z, Dai J, Yu M, Li J, Shen P, Hu R, Lou X, Zhao Z, Tang BZ. Type I photosensitizers based on phosphindole oxide for photodynamic therapy: apoptosis and autophagy induced by endoplasmic reticulum stress. Chem Sci 2020; 11:3405-3417. [PMID: 34745515 PMCID: PMC8515424 DOI: 10.1039/d0sc00785d] [Citation(s) in RCA: 137] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 02/20/2020] [Indexed: 12/21/2022] Open
Abstract
Photodynamic therapy (PDT) is considered a pioneering and effective modality for cancer treatment, but it is still facing challenges of hypoxic tumors. Recently, Type I PDT, as an effective strategy to address this issue, has drawn considerable attention. Few reports are available on the capability for Type I reactive oxygen species (ROS) generation of purely organic photosensitizers (PSs). Herein, we report two new Type I PSs, α-TPA-PIO and β-TPA-PIO, from phosphindole oxide-based isomers with efficient Type I ROS generation abilities. A detailed study on photophysical and photochemical mechanisms is conducted to shed light on the molecular design of PSs based on the Type I mechanism. The in vitro results demonstrate that these two PSs can selectively accumulate in a neutral lipid region, particularly in the endoplasmic reticulum (ER), of cells and efficiently induce ER-stress mediated apoptosis and autophagy in PDT. In vivo models indicate that β-TPA-PIO successfully achieves remarkable tumor ablation. The ROS-based ER stress triggered by β-TPA-PIO-mediated PDT has high potential as a precursor of the immunostimulatory effect for immunotherapy. This work presents a comprehensive protocol for Type I-based purely organic PSs and highlights the significance of considering the working mechanism in the design of PSs for the optimization of cancer treatment protocols. Phosphindole oxide-based photosensitizers with Type I reactive oxygen species generation ability are developed and used for endoplasmic reticulum stress-mediated photodynamic therapy of tumors.![]()
Collapse
Affiliation(s)
- Zeyan Zhuang
- State Key Laboratory of Luminescent Materials and Devices
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
- South China University of Technology
- Guangzhou 510640
- China
| | - Jun Dai
- Department of Obstetrics and Gynecology
- Tongji Hospital
- Tongji Medical College
- Huazhong University of Science and Technology
- Wuhan 430074
| | - Maoxing Yu
- State Key Laboratory of Luminescent Materials and Devices
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
- South China University of Technology
- Guangzhou 510640
- China
| | - Jianqing Li
- State Key Laboratory of Luminescent Materials and Devices
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
- South China University of Technology
- Guangzhou 510640
- China
| | - Pingchuan Shen
- State Key Laboratory of Luminescent Materials and Devices
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
- South China University of Technology
- Guangzhou 510640
- China
| | - Rong Hu
- State Key Laboratory of Luminescent Materials and Devices
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
- South China University of Technology
- Guangzhou 510640
- China
| | - Xiaoding Lou
- Engineering Research Center of Nano-Geomaterials of Ministry of Education
- Faculty of Materials Science and Chemistry
- China University of Geosciences
- Wuhan 430074
- China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
- South China University of Technology
- Guangzhou 510640
- China
| | - Ben Zhong Tang
- State Key Laboratory of Luminescent Materials and Devices
- Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates
- South China University of Technology
- Guangzhou 510640
- China
| |
Collapse
|
8
|
Sabir N, Hussain T, Liao Y, Wang J, Song Y, Shahid M, Cheng G, Mangi MH, Yao J, Yang L, Zhao D, Zhou X. Kallikrein 12 Regulates Innate Resistance of Murine Macrophages against Mycobacterium bovis Infection by Modulating Autophagy and Apoptosis. Cells 2019; 8:cells8050415. [PMID: 31060300 PMCID: PMC6562459 DOI: 10.3390/cells8050415] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 12/27/2022] Open
Abstract
Mycobacterium bovis (M. bovis) is a member of the Mycobacterium tuberculosis (Mtb) complex causing bovine tuberculosis (TB) and imposing a high zoonotic threat to human health. Kallikreins (KLKs) belong to a subgroup of secreted serine proteases. As their role is established in various physiological and pathological processes, it is likely that KLKs expression may mediate a host immune response against the M. bovis infection. In the current study, we report in vivo and in vitro upregulation of KLK12 in the M. bovis infection. To define the role of KLK12 in immune response regulation of murine macrophages, we produced KLK12 knockdown bone marrow derived macrophages (BMDMs) by using siRNA transfection. Interestingly, the knockdown of KLK12 resulted in a significant downregulation of autophagy and apoptosis in M. bovis infected BMDMs. Furthermore, we demonstrated that this KLK12 mediated regulation of autophagy and apoptosis involves mTOR/AMPK/TSC2 and BAX/Bcl-2/Cytochrome c/Caspase 3 pathways, respectively. Similarly, inflammatory cytokines IL-1β, IL-6, IL-12 and TNF-α were significantly downregulated in KLK12 knockdown macrophages but the difference in IL-10 and IFN-β expression was non-significant. Taken together, these findings suggest that upregulation of KLK12 in M. bovis infected murine macrophages plays a substantial role in the protective immune response regulation by modulating autophagy, apoptosis and pro-inflammatory pathways. To our knowledge, this is the first report on expression and the role of KLK12 in the M. bovis infection and the data may contribute to a new paradigm for diagnosis and treatment of bovine TB.
Collapse
Affiliation(s)
- Naveed Sabir
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Tariq Hussain
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Yi Liao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Jie Wang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Yinjuan Song
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Muhammad Shahid
- Department of Clinical Veterinary Medicine, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Guangyu Cheng
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Mazhar Hussain Mangi
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Jiao Yao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Lifeng Yang
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Deming Zhao
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| | - Xiangmei Zhou
- Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
| |
Collapse
|
9
|
Trejo-Solís C, Serrano-Garcia N, Escamilla-Ramírez Á, Castillo-Rodríguez RA, Jimenez-Farfan D, Palencia G, Calvillo M, Alvarez-Lemus MA, Flores-Nájera A, Cruz-Salgado A, Sotelo J. Autophagic and Apoptotic Pathways as Targets for Chemotherapy in Glioblastoma. Int J Mol Sci 2018; 19:ijms19123773. [PMID: 30486451 PMCID: PMC6320836 DOI: 10.3390/ijms19123773] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 11/14/2018] [Accepted: 11/21/2018] [Indexed: 01/07/2023] Open
Abstract
Glioblastoma multiforme is the most malignant and aggressive type of brain tumor, with a mean life expectancy of less than 15 months. This is due in part to the high resistance to apoptosis and moderate resistant to autophagic cell death in glioblastoma cells, and to the poor therapeutic response to conventional therapies. Autophagic cell death represents an alternative mechanism to overcome the resistance of glioblastoma to pro-apoptosis-related therapies. Nevertheless, apoptosis induction plays a major conceptual role in several experimental studies to develop novel therapies against brain tumors. In this review, we outline the different components of the apoptotic and autophagic pathways and explore the mechanisms of resistance to these cell death pathways in glioblastoma cells. Finally, we discuss drugs with clinical and preclinical use that interfere with the mechanisms of survival, proliferation, angiogenesis, migration, invasion, and cell death of malignant cells, favoring the induction of apoptosis and autophagy, or the inhibition of the latter leading to cell death, as well as their therapeutic potential in glioma, and examine new perspectives in this promising research field.
Collapse
Affiliation(s)
- Cristina Trejo-Solís
- Departamento de Neuroinmunología, Laboratorio de Neurobiología Molecular y Celular, Laboratorio Experimental de Enfermedades Neurodegenerativas del Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", C.P. 14269 Ciudad de México, Mexico.
| | - Norma Serrano-Garcia
- Departamento de Neuroinmunología, Laboratorio de Neurobiología Molecular y Celular, Laboratorio Experimental de Enfermedades Neurodegenerativas del Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", C.P. 14269 Ciudad de México, Mexico.
| | - Ángel Escamilla-Ramírez
- Departamento de Neuroinmunología, Laboratorio de Neurobiología Molecular y Celular, Laboratorio Experimental de Enfermedades Neurodegenerativas del Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", C.P. 14269 Ciudad de México, Mexico.
- Hospital Regional de Alta Especialidad de Oaxaca, Secretaria de Salud, C.P. 71256 Oaxaca, Mexico.
| | | | - Dolores Jimenez-Farfan
- Laboratorio de Inmunología, División de Estudios de Posgrado e Investigación, Facultad de Odontología, Universidad Nacional Autónoma de México, C.P. 04510 Ciudad de México, Mexico.
| | - Guadalupe Palencia
- Departamento de Neuroinmunología, Laboratorio de Neurobiología Molecular y Celular, Laboratorio Experimental de Enfermedades Neurodegenerativas del Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", C.P. 14269 Ciudad de México, Mexico.
| | - Minerva Calvillo
- Departamento de Neuroinmunología, Laboratorio de Neurobiología Molecular y Celular, Laboratorio Experimental de Enfermedades Neurodegenerativas del Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", C.P. 14269 Ciudad de México, Mexico.
| | - Mayra A Alvarez-Lemus
- División Académica de Ingeniería y Arquitectura, Universidad Juárez Autónoma de Tabasco, C.P. 86040 Tabasco, Mexico.
| | - Athenea Flores-Nájera
- Departamento de Cirugía Experimental, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Secretaria de Salud, 14000 Ciudad de México, Mexico.
| | - Arturo Cruz-Salgado
- Departamento de Neuroinmunología, Laboratorio de Neurobiología Molecular y Celular, Laboratorio Experimental de Enfermedades Neurodegenerativas del Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", C.P. 14269 Ciudad de México, Mexico.
| | - Julio Sotelo
- Departamento de Neuroinmunología, Laboratorio de Neurobiología Molecular y Celular, Laboratorio Experimental de Enfermedades Neurodegenerativas del Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez", C.P. 14269 Ciudad de México, Mexico.
| |
Collapse
|
10
|
Elhassan SAM, Candasamy M, Chan EWL, Bhattamisra SK. Autophagy and GLUT4: The missing pieces. Diabetes Metab Syndr 2018; 12:1109-1116. [PMID: 29843994 DOI: 10.1016/j.dsx.2018.05.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 05/21/2018] [Indexed: 01/22/2023]
Abstract
BACKGROUND Autophagy is a process devoted to degrade and recycle cellular components inside mammalian cells through lysosomal system. It plays a main function in the pathophysiology of several diseases. In type 2 diabetes, works demonstrated the dual functions of autophagy in diabetes biology. Studies had approved the role of autophagy in promoting different routes for movement of integral membrane proteins to the plasma membrane. But its role in regulation of GLUT4 trafficking has not been widely observed. In normal conditions, insulin promotes GLUT4 translocation from intracellular membrane compartments to the plasma membrane, while in type 2 diabetes defects occur in this translocation. METHOD Intriguing evidences discussed the contribution of different intracellular compartments in autophagy membrane formation. Furthermore, autophagy serves to mobilise membranes within cells, thereby promoting cytoplasmic components reorganisation. The intent of this review is to focus on the possibility of autophagy to act as a carrier for GLUT4 through regulating GLUT4 endocytosis, intracellular trafficking in different compartments, and translocation to cell membrane. RESULTS The common themes of autophagy and GLUT4 have been highlighted. The review discussed the overlapping of endocytosis mechanism and intracellular compartments, and has shown that autophagy and GLUT4 utilise similar proteins (SNAREs) which are used for exocytosis. On top of that, PI3K and AMPK also control both autophagy and GLUT4. CONCLUSION The control of GLUT4 trafficking through autophagy could be a promising field for treating type 2 diabetes.
Collapse
Affiliation(s)
- Safa Abdelgadir Mohamed Elhassan
- School of Postgraduate Studies, International Medical University, No 126, Jalan Jalil Perkasa 19, Bukit Jalil 57000, Kuala Lumpur, Malaysia.
| | - Mayuren Candasamy
- Department of Life Sciences, School of Pharmacy, International Medical University, No 126, Jalan Jalil Perkasa 19, Bukit Jalil 57000, Kuala Lumpur, Malaysia.
| | - Elaine Wan Ling Chan
- Institute of Research, Development and Innovation, International Medical University, No 126, Jalan Jalil Perkasa 19, Bukit Jalil 57000, Kuala Lumpur, Malaysia.
| | - Subrat Kumar Bhattamisra
- Department of Life Sciences, School of Pharmacy, International Medical University, No 126, Jalan Jalil Perkasa 19, Bukit Jalil 57000, Kuala Lumpur, Malaysia.
| |
Collapse
|
11
|
Pleet ML, Branscome H, DeMarino C, Pinto DO, Zadeh MA, Rodriguez M, Sariyer IK, El-Hage N, Kashanchi F. Autophagy, EVs, and Infections: A Perfect Question for a Perfect Time. Front Cell Infect Microbiol 2018; 8:362. [PMID: 30406039 PMCID: PMC6201680 DOI: 10.3389/fcimb.2018.00362] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 09/28/2018] [Indexed: 01/07/2023] Open
Abstract
Autophagy, a highly conserved process, serves to maintain cellular homeostasis in response to an extensive variety of internal and external stimuli. The classic, or canonical, pathway of autophagy involves the coordinated degradation and recycling of intracellular components and pathogenic material. Proper regulation of autophagy is critical to maintain cellular health, as alterations in the autophagy pathway have been linked to the progression of a variety of physiological and pathological conditions in humans, namely in aging and in viral infection. In addition to its canonical role as a degradative pathway, a more unconventional and non-degradative role for autophagy has emerged as an area of increasing interest. This process, known as secretory autophagy, is gaining widespread attention as many viruses are believed to use this pathway as a means to release and spread viral particles. Moreover, secretory autophagy has been found to intersect with other intracellular pathways, such as the biogenesis and secretion of extracellular vesicles (EVs). Here, we provide a review of the current landscape surrounding both degradative autophagy and secretory autophagy in relation to both aging and viral infection. We discuss their key features, while describing their interplay with numerous different viruses (i.e. hepatitis B and C viruses, Epstein-Barr virus, SV40, herpesviruses, HIV, chikungunya virus, dengue virus, Zika virus, Ebola virus, HTLV, Rift Valley fever virus, poliovirus, and influenza A virus), and compare secretory autophagy to other pathways of extracellular vesicle release. Lastly, we highlight the need for, and emphasize the importance of, more thorough methods to study the underlying mechanisms of these pathways to better advance our understanding of disease progression.
Collapse
Affiliation(s)
- Michelle L Pleet
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Heather Branscome
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Catherine DeMarino
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Daniel O Pinto
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Mohammad Asad Zadeh
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, United States
| | - Myosotys Rodriguez
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
| | - Ilker Kudret Sariyer
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Nazira El-Hage
- Department of Immunology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
| | - Fatah Kashanchi
- Laboratory of Molecular Virology, School of Systems Biology, George Mason University, Manassas, VA, United States
| |
Collapse
|
12
|
Crosstalk of Autophagy and the Secretory Pathway and Its Role in Diseases. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2018; 337:153-184. [DOI: 10.1016/bs.ircmb.2017.12.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
13
|
The liver protection of propylene glycol alginate sodium sulfate preconditioning against ischemia reperfusion injury: focusing MAPK pathway activity. Sci Rep 2017; 7:15175. [PMID: 29123239 PMCID: PMC5680172 DOI: 10.1038/s41598-017-15521-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/26/2017] [Indexed: 12/21/2022] Open
Abstract
Hepatic ischemia reperfusion (IR) injury contributes to the morbidity and mortality associated with liver surgery. This study investigated the protective function and mechanism of propylene glycol alginate sodium sulfate (PSS), a sulfated polysaccharide, in a mouse hepatic IR injury model. PSS (25 or 50 mg/kg) or saline were injected intraperitoneally to male Balb/c mice 1 h before 45 min of 70% warm hepatic ischemia and 2, 8, and 24 h of reperfusion. Serum and liver tissue samples were collected for evaluation of hepatocellular damage, liver histology, and assay of inflammatory cytokines, apoptosis- and autophagy-related proteins, and proteins in the mitogen-activated protein kinase (MAPKs). Histological injury and release of transaminases, and inflammatory cytokine production were significantly reduced by PSS pretreatment. The expression of apoptosis- and autophagy-related proteins, and the activation of MAPK signal, including jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and P38 were all affected by PSS treatment compared with IR model controls. PSS protected the liver from IR injury by suppressing the MAPK signaling and down-regulating inflammation, apoptosis, and autophagy.
Collapse
|
14
|
Cross-talk between miR-471-5p and autophagy component proteins regulates LC3-associated phagocytosis (LAP) of apoptotic germ cells. Nat Commun 2017; 8:598. [PMID: 28928467 PMCID: PMC5605700 DOI: 10.1038/s41467-017-00590-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 07/12/2017] [Indexed: 12/13/2022] Open
Abstract
Phagocytic clearance of apoptotic germ cells by Sertoli cells is vital for germ cell development and differentiation. Here, using a tissue-specific miRNA transgenic mouse model, we show that interaction between miR-471-5p and autophagy member proteins regulates clearance of apoptotic germ cells via LC3-associated phagocytosis (LAP). Transgenic mice expressing miR-471-5p in Sertoli cells show increased germ cell apoptosis and compromised male fertility. Those effects are due to defective engulfment and impaired LAP-mediated clearance of apoptotic germ cells as miR-471-5p transgenic mice show lower levels of Dock180, LC3, Atg12, Becn1, Rab5 and Rubicon in Sertoli cells. Our results reveal that Dock180 interacts with autophagy member proteins to constitute a functional LC3-dependent phagocytic complex. We find that androgen regulates Sertoli cell phagocytosis by controlling expression of miR-471-5p and its target proteins. These findings suggest that recruitment of autophagy machinery is essential for efficient clearance of apoptotic germ cells by Sertoli cells using LAP. Although phagocytic clearance of apoptotic germ cells by Sertoli cells is essential for spermatogenesis, little of the mechanism is known. Here the authors show that Sertoli cells employ LC3-associated phagocytosis (LAP) by recruiting autophagy member proteins to clear apoptotic germ cells.
Collapse
|
15
|
Yang CL, Chiou SH, Tai WC, Joseph NA, Chow KC. Trivalent chromium induces autophagy by activating sphingomyelin phosphodiesterase 2 and increasing cellular ceramide levels in renal HK2 cells. Mol Carcinog 2017; 56:2424-2433. [DOI: 10.1002/mc.22689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 05/23/2017] [Accepted: 06/01/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Cheng-Lin Yang
- Graduate Institute of Biomedical Sciences; National Chung Hsing University; Taichung Taiwan
| | - Shiow-Her Chiou
- Graduate Institute of Microbiology and Public Health; National Chung Hsing University; Taichung Taiwan
| | - Wei-Chun Tai
- College of Life Science; National Chung Hsing University; Taichung Taiwan
| | - Nithila A. Joseph
- Graduate Institute of Biomedical Sciences; National Chung Hsing University; Taichung Taiwan
| | - Kuan-Chih Chow
- Graduate Institute of Biomedical Sciences; National Chung Hsing University; Taichung Taiwan
| |
Collapse
|
16
|
PI3K-C2α knockdown decreases autophagy and maturation of endocytic vesicles. PLoS One 2017; 12:e0184909. [PMID: 28910396 PMCID: PMC5599018 DOI: 10.1371/journal.pone.0184909] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 09/01/2017] [Indexed: 12/26/2022] Open
Abstract
Phosphoinositide 3-kinase (PI3K) family members are involved in diverse cellular fates including cell growth, proliferation, and survival. While many molecular details are known about the Class I and III PI3Ks, less is known about the Class II PI3Ks. To explore the function of all eight PI3K isoforms in autophagy, we knock down each gene individually and measure autophagy. We find a significant decrease in autophagy following siRNA-mediated PIK3C2A (encoding the Class 2 PI3K, PI3K-C2α) knockdown. This defective autophagy is rescued by exogenous PI3K-C2α, but not kinase-dead PI3K-C2α. Using confocal microscopy, we probe for markers of endocytosis and autophagy, revealing that PI3K-C2α colocalizes with markers of endocytosis. Though endocytic uptake is intact, as demonstrated by transferrin labeling, PIK3C2A knockdown results in vesicle accumulation at the recycling endosome. We isolate distinct membrane sources and observe that PI3K-C2α interacts with markers of endocytosis and autophagy, notably ATG9. Knockdown of either PIK3C2A or ATG9A/B, but not PI3KC3, results in an accumulation of transferrin-positive clathrin coated vesicles and RAB11-positive vesicles at the recycling endosome. Taken together, these results support a role for PI3K-C2α in the proper maturation of endosomes, and suggest that PI3K-C2α may be a critical node connecting the endocytic and autophagic pathways.
Collapse
|
17
|
Perrotta I. The origin of the autophagosomal membrane in human atherosclerotic plaque: a preliminary ultrastructural study. Ultrastruct Pathol 2017; 41:327-334. [PMID: 28796583 DOI: 10.1080/01913123.2017.1349853] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Autophagy is an evolutionarily conserved process that occurs ubiquitously and functions as a primary route for the degradation of damaged organelles and proteins in response to starvation, oxidative stress, and other harmful conditions. The initial event upon autophagy induction is the formation of a membranous cistern called the phagophore or isolation membrane, a cup-shaped structure that elongates, engulfs cytoplasmic "cargo", and fuses at its rims to give rise to the autophagosome within which cytoplasmic material is enclosed. Although thoroughly studied in diverse cell culture systems, few attempts have been made to analyze the membrane dynamics during phagophore biogenesis in tissues. With respect to the cardiovascular system, no structural information is currently available regarding the sources that may contribute to the nucleation and growth of the phagophore membrane. The results presented here demonstrate that in the cells of human atherosclerotic plaque the phagophores are in contact with the endoplasmic reticulum (ER) membranes. Initially, the phagophore appears as a membrane sac that enwraps injured organelles and dysfunctional proteins and then matures into a double-membrane, closed structure often containing portions of the ER. These structural data indicate that the membrane source that elongates the phagophore might probably come from the ER. The topographical relationship between the ER tubules and the phagophore might also favor an efficient mechanism to transfer lipids from their site of synthesis to the nascent membrane, thus promoting its elongation and, ultimately, the formation of the autophagosome.
Collapse
Affiliation(s)
- Ida Perrotta
- a Department of Biology, Ecology and Earth Sciences, Centre for Microscopy and Microanalysis, Transmission Electron Microscopy Laboratory , University of Calabria , Arcavacata di Rende , Cosenza , Italy
| |
Collapse
|
18
|
Interferon regulatory factor-1 activates autophagy to aggravate hepatic ischemia-reperfusion injury via the P38/P62 pathway in mice. Sci Rep 2017; 7:43684. [PMID: 28266555 PMCID: PMC5339805 DOI: 10.1038/srep43684] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 01/30/2017] [Indexed: 01/07/2023] Open
Abstract
Increasing evidence has linked autophagy to a detrimental role in hepatic ischemia- reperfusion (IR) injury (IRI). Here we focus on the role of interferon regulatory factor-1 (IRF-1) in regulating autophagy to aggravate hepatic IRI. We found that IRF-1 was up-regulated during hepatic IRI and was associated with an activation of the autophagic signaling. This increased IRF-1 expression, which was allied with high autophagic activity, amplified liver damage to IR, an effect which was abrogated by IRF-1 depletion. Moreover, IRF-1 contributed to P38 induced autophagic and apoptotic cell death, that can play a key role in liver dysfunction. The levels of P62 mRNA and protein were increased when P38 was activated and decreased when P38 was inhibited by SB203580. We conclude that IRF-1 functioned as a trigger to activate autophagy via P38 activation and that P62 was required for this P38-mediated autophagy. IRF-1 appears to exert a pivotal role in hepatic IRI, by predisposing hepatocytes to activate an autophagic pathway. Such an effect promotes autophagic cell death through the P38/P62 pathway. The identification of this novel pathway, that links expression levels of IRF-1 with autophagy, may provide new insights for the generation of novel protective therapies directed against hepatic IRI.
Collapse
|
19
|
Glioblastoma, hypoxia and autophagy: a survival-prone 'ménage-à-trois'. Cell Death Dis 2016; 7:e2434. [PMID: 27787518 PMCID: PMC5133985 DOI: 10.1038/cddis.2016.318] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 08/24/2016] [Accepted: 09/09/2016] [Indexed: 12/14/2022]
Abstract
Glioblastoma multiforme is the most common and the most aggressive primary brain tumor. It is characterized by a high degree of hypoxia and also by a remarkable resistance to therapy because of its adaptation capabilities that include autophagy. This degradation process allows the recycling of cellular components, leading to the formation of metabolic precursors and production of adenosine triphosphate. Hypoxia can induce autophagy through the activation of several autophagy-related proteins such as BNIP3, AMPK, REDD1, PML, and the unfolded protein response-related transcription factors ATF4 and CHOP. This review summarizes the most recent data about induction of autophagy under hypoxic condition and the role of autophagy in glioblastoma.
Collapse
|
20
|
Ito H, Higuchi Y, Shimokawa N. Coarse-grained molecular dynamics simulation of binary charged lipid membranes: Phase separation and morphological dynamics. Phys Rev E 2016; 94:042611. [PMID: 27841477 DOI: 10.1103/physreve.94.042611] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Indexed: 06/06/2023]
Abstract
Biomembranes, which are mainly composed of neutral and charged lipids, exhibit a large variety of functional structures and dynamics. Here, we report a coarse-grained molecular dynamics (MD) simulation of the phase separation and morphological dynamics in charged lipid bilayer vesicles. The screened long-range electrostatic repulsion among charged head groups delays or inhibits the lateral phase separation in charged vesicles compared with neutral vesicles, suggesting the transition of the phase-separation mechanism from spinodal decomposition to nucleation or homogeneous dispersion. Moreover, the electrostatic repulsion causes morphological changes, such as pore formation, and further transformations into disk, string, and bicelle structures, which are spatiotemporally coupled to the lateral segregation of charged lipids. Based on our coarse-grained MD simulation, we propose a plausible mechanism of pore formation at the molecular level. The pore formation in a charged-lipid-rich domain is initiated by the prior disturbance of the local molecular orientation in the domain.
Collapse
Affiliation(s)
- Hiroaki Ito
- Department of Mechanical Engineering, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Yuji Higuchi
- Institute for Materials Research, Tohoku University, Miyagi 980-8577, Japan
| | - Naofumi Shimokawa
- School of Materials Science, Japan Advanced Institute of Science and Technology, Ishikawa 923-1292, Japan
| |
Collapse
|
21
|
Hernández-Tiedra S, Fabriàs G, Dávila D, Salanueva ÍJ, Casas J, Montes LR, Antón Z, García-Taboada E, Salazar-Roa M, Lorente M, Nylandsted J, Armstrong J, López-Valero I, McKee CS, Serrano-Puebla A, García-López R, González-Martínez J, Abad JL, Hanada K, Boya P, Goñi F, Guzmán M, Lovat P, Jäättelä M, Alonso A, Velasco G. Dihydroceramide accumulation mediates cytotoxic autophagy of cancer cells via autolysosome destabilization. Autophagy 2016; 12:2213-2229. [PMID: 27635674 PMCID: PMC5103338 DOI: 10.1080/15548627.2016.1213927] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Autophagy is considered primarily a cell survival process, although it can also lead to cell death. However, the factors that dictate the shift between these 2 opposite outcomes remain largely unknown. In this work, we used Δ9-tetrahydrocannabinol (THC, the main active component of marijuana, a compound that triggers autophagy-mediated cancer cell death) and nutrient deprivation (an autophagic stimulus that triggers cytoprotective autophagy) to investigate the precise molecular mechanisms responsible for the activation of cytotoxic autophagy in cancer cells. By using a wide array of experimental approaches we show that THC (but not nutrient deprivation) increases the dihydroceramide:ceramide ratio in the endoplasmic reticulum of glioma cells, and this alteration is directed to autophagosomes and autolysosomes to promote lysosomal membrane permeabilization, cathepsin release and the subsequent activation of apoptotic cell death. These findings pave the way to clarify the regulatory mechanisms that determine the selective activation of autophagy-mediated cancer cell death.
Collapse
Affiliation(s)
- Sonia Hernández-Tiedra
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,b Instituto de Investigaciones Sanitarias San Carlos (IdISSC) , Madrid , Spain
| | - Gemma Fabriàs
- c Research Unit on BioActive Molecules (RUBAM) , Departments of Biomedicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) , Barcelona , Spain
| | - David Dávila
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,b Instituto de Investigaciones Sanitarias San Carlos (IdISSC) , Madrid , Spain
| | - Íñigo J Salanueva
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain
| | - Josefina Casas
- c Research Unit on BioActive Molecules (RUBAM) , Departments of Biomedicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) , Barcelona , Spain
| | - L Ruth Montes
- d Biofisika Institute (UPV/EHU, CSIC) , and Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n , Leioa , Spain
| | - Zuriñe Antón
- d Biofisika Institute (UPV/EHU, CSIC) , and Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n , Leioa , Spain
| | - Elena García-Taboada
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain
| | - María Salazar-Roa
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain
| | - Mar Lorente
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,b Instituto de Investigaciones Sanitarias San Carlos (IdISSC) , Madrid , Spain
| | - Jesper Nylandsted
- e Unit of Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center (DCRC) , Copenhagen , Denmark
| | - Jane Armstrong
- f Dermatological Sciences , Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne , UK.,g Faculty of Applied Sciences, University of Sunderland , Sunderland , UK
| | - Israel López-Valero
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,b Instituto de Investigaciones Sanitarias San Carlos (IdISSC) , Madrid , Spain
| | - Christopher S McKee
- f Dermatological Sciences , Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne , UK
| | - Ana Serrano-Puebla
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,h Departament of Cellular and Molecular Biology , Centro de Investigaciones Biológicas, CSIC , Madrid , Spain
| | - Roberto García-López
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain
| | - José González-Martínez
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,b Instituto de Investigaciones Sanitarias San Carlos (IdISSC) , Madrid , Spain
| | - José L Abad
- c Research Unit on BioActive Molecules (RUBAM) , Departments of Biomedicinal Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) , Barcelona , Spain
| | - Kentaro Hanada
- i Department of Biochemistry and Cell Biology , National Institute of Infectious Diseases , Shinjuku-ku, Tokyo , Japan
| | - Patricia Boya
- h Departament of Cellular and Molecular Biology , Centro de Investigaciones Biológicas, CSIC , Madrid , Spain
| | - Félix Goñi
- d Biofisika Institute (UPV/EHU, CSIC) , and Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n , Leioa , Spain
| | - Manuel Guzmán
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,j Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas, Instituto Ramón y Cajal de Investigación Sanitaria, Madrid, Spain, Instituto Universitario de Investigación Neuroquímica, Complutense University , Madrid , Spain
| | - Penny Lovat
- f Dermatological Sciences , Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne , UK
| | - Marja Jäättelä
- e Unit of Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center (DCRC) , Copenhagen , Denmark
| | - Alicia Alonso
- d Biofisika Institute (UPV/EHU, CSIC) , and Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n , Leioa , Spain
| | - Guillermo Velasco
- a Department of Biochemistry and Molecular Biology I , School of Biology, Complutense University , Madrid , Spain.,b Instituto de Investigaciones Sanitarias San Carlos (IdISSC) , Madrid , Spain
| |
Collapse
|
22
|
Liu Y, Yan J, Santangelo PJ, Prausnitz MR. DNA uptake, intracellular trafficking and gene transfection after ultrasound exposure. J Control Release 2016; 234:1-9. [PMID: 27165808 DOI: 10.1016/j.jconrel.2016.05.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 04/26/2016] [Accepted: 05/06/2016] [Indexed: 11/17/2022]
Abstract
Ultrasound has been studied as a promising tool for intracellular gene delivery. In this work, we studied gene transfection of a human prostate cancer cell line exposed to megahertz pulsed ultrasound in the presence of contrast agent and assessed the efficiency of fluorescently labelled DNA delivery into cell nuclei, which is necessary for gene transfection. At the sonication conditions studied, ~30% of cells showed DNA uptake 30min after sonication, but that fraction decreased over time to ~10% of cells after 24h. Most cells containing DNA had DNA in their nuclei, but the amount varied significantly. Transfection efficiency peaked at ~10% at 8h post sonication. Among those cells containing DNA, ~30% of DNA was localized in the cell nuclei, ~30% was in autophagosomes/autophagolysosomes and the remainder was "free" in the cytoplasm 30min after sonication. At later times up to 24h, ~30% of DNA continued to be found in the nuclei and most or all of the rest of the DNA was in autophagosomes/autophagolysosomes. These results demonstrate that ultrasound can deliver DNA into cell nuclei shortly after sonication and that the rest of the DNA can be cleared by autophagosomes/autophagolysosomes.
Collapse
Affiliation(s)
- Ying Liu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Jing Yan
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA
| | - Philip J Santangelo
- Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Mark R Prausnitz
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA; Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| |
Collapse
|
23
|
Biazik J, Ylä-Anttila P, Vihinen H, Jokitalo E, Eskelinen EL. Ultrastructural relationship of the phagophore with surrounding organelles. Autophagy 2016; 11:439-51. [PMID: 25714487 DOI: 10.1080/15548627.2015.1017178] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Phagophore nucleates from a subdomain of the endoplasmic reticulum (ER) termed the omegasome and also makes contact with other organelles such as mitochondria, Golgi complex, plasma membrane and recycling endosomes during its formation. We have used serial block face scanning electron microscopy (SB-EM) and electron tomography (ET) to image phagophore biogenesis in 3 dimensions and to determine the relationship between the phagophore and surrounding organelles at high resolution. ET was performed to confirm whether membrane contact sites (MCSs) are evident between the phagophore and those surrounding organelles. In addition to the known contacts with the ER, we identified MCSs between the phagophore and membranes from putative ER exit sites, late endosomes or lysosomes, the Golgi complex and mitochondria. We also show that one phagophore can have simultaneous MCSs with more than one organelle. Future membrane flux experiments are needed to determine whether membrane contacts also signify lipid translocation.
Collapse
Key Words
- 3D, 3 dimensional
- ATG, autophagy-related
- BSA, bovine serum albumin
- COPII, coat protein II
- ER, endoplasmic reticulum
- ET, electron tomography
- GOLGA2/GM130, golgin A2
- Golgi complex
- LAMP1, lysosomal-associated membrane protein 1
- MAP1LC3/LC3, microtubule-associated protein 1 light chain 3
- MCS, membrane contact site
- PBS, phosphate-buffered saline
- SB-EM, serial block-face scanning electron microscopy
- SEC31A, SEC31 homolog A (S. cerevisiae)
- TFRC, transferrin receptor
- WIPI2, WD repeat domain, phosphoinositide interacting 2
- autophagy
- electron tomography
- immunoEM
- immunoEM, immuno electron microscopy
- lysosome
- mitochondrion
- serial block face scanning electron microscopy
- three dimensional
Collapse
Affiliation(s)
- Joanna Biazik
- a Department of Biosciences ; Division of Biochemistry and Biotechnology; University of Helsinki ; Helsinki , Finland
| | | | | | | | | |
Collapse
|
24
|
Cosway B, Lovat P. The role of autophagy in squamous cell carcinoma of the head and neck. Oral Oncol 2016; 54:1-6. [PMID: 26774913 DOI: 10.1016/j.oraloncology.2015.12.007] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 12/01/2015] [Accepted: 12/19/2015] [Indexed: 01/07/2023]
Abstract
Half a million new head and neck cancers are diagnosed each year worldwide. Although traditionally thought to be triggered by alcohol and smoking abuse, there is a growing subset of oropharyngeal cancers driven by the oncogenic human papilloma virus (HPV). Despite advances in both surgical and non-surgical treatment strategies, survival rates have remained relatively static emphasising the need for novel therapeutic approaches. Autophagy, the principal catabolic process for the lysosomal--mediated breakdown of cellular products is a hot topic in cancer medicine. Increasing evidence points towards the prognostic significance of autophagy biomarkers in solid tumours as well as strategies through which to harness autophagy modulation to promote tumour cell death. However, the role of autophagy in head and neck cancers is less well defined. In the present review, we summarise the current understanding of autophagy in head and neck cancers, revealing key areas for future translational research.
Collapse
Affiliation(s)
- Benjamin Cosway
- Institute for Cellular Medicine, Newcastle University, United Kingdom.
| | - Penny Lovat
- Institute for Cellular Medicine, Newcastle University, United Kingdom
| |
Collapse
|
25
|
Wen X, Klionsky DJ. An overview of macroautophagy in yeast. J Mol Biol 2016; 428:1681-99. [PMID: 26908221 DOI: 10.1016/j.jmb.2016.02.021] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 02/15/2016] [Accepted: 02/16/2016] [Indexed: 12/19/2022]
Abstract
Macroautophagy is an evolutionarily conserved dynamic pathway that functions primarily in a degradative manner. A basal level of macroautophagy occurs constitutively, but this process can be further induced in response to various types of stress including starvation, hypoxia and hormonal stimuli. The general principle behind macroautophagy is that cytoplasmic contents can be sequestered within a transient double-membrane organelle, an autophagosome, which subsequently fuses with a lysosome or vacuole (in mammals, or yeast and plants, respectively), allowing for degradation of the cargo followed by recycling of the resulting macromolecules. Through this basic mechanism, macroautophagy has a critical role in cellular homeostasis; however, either insufficient or excessive macroautophagy can seriously compromise cell physiology, and thus, it needs to be properly regulated. In fact, a wide range of diseases are associated with dysregulation of macroautophagy. There has been substantial progress in understanding the regulation and molecular mechanisms of macroautophagy in different organisms; however, many questions concerning some of the most fundamental aspects of macroautophagy remain unresolved. In this review, we summarize current knowledge about macroautophagy mainly in yeast, including the mechanism of autophagosome biogenesis, the function of the core macroautophagic machinery, the regulation of macroautophagy and the process of cargo recognition in selective macroautophagy, with the goal of providing insights into some of the key unanswered questions in this field.
Collapse
Affiliation(s)
- Xin Wen
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Daniel J Klionsky
- Life Sciences Institute and Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
| |
Collapse
|
26
|
Bento CF, Renna M, Ghislat G, Puri C, Ashkenazi A, Vicinanza M, Menzies FM, Rubinsztein DC. Mammalian Autophagy: How Does It Work? Annu Rev Biochem 2016; 85:685-713. [PMID: 26865532 DOI: 10.1146/annurev-biochem-060815-014556] [Citation(s) in RCA: 494] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autophagy is a conserved intracellular pathway that delivers cytoplasmic contents to lysosomes for degradation via double-membrane autophagosomes. Autophagy substrates include organelles such as mitochondria, aggregate-prone proteins that cause neurodegeneration and various pathogens. Thus, this pathway appears to be relevant to the pathogenesis of diverse diseases, and its modulation may have therapeutic value. Here, we focus on the cell and molecular biology of mammalian autophagy and review the key proteins that regulate the process by discussing their roles and how these may be modulated by posttranslational modifications. We consider the membrane-trafficking events that impact autophagy and the questions relating to the sources of autophagosome membrane(s). Finally, we discuss data from structural studies and some of the insights these have provided.
Collapse
Affiliation(s)
- Carla F Bento
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Maurizio Renna
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Ghita Ghislat
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Claudia Puri
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Avraham Ashkenazi
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Mariella Vicinanza
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - Fiona M Menzies
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| | - David C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research, University of Cambridge, Wellcome Trust/MRC Building, Cambridge Biomedical Campus, Cambridge CB2 0XY, United Kingdom;
| |
Collapse
|
27
|
Abstract
During the intracellular process of macroautophagy (hereafter autophagy), a membrane-bound organelle, the autophagosome, is generated de novo. The remodeling of the autophagic membrane during the life cycle of the organelle is a complex multistep process and involves several changes in the topology of the autophagic membrane. Here, we focus on the final step of autophagosome formation, the closure of the phagophore, during which the inner and outer autophagic membranes become separate entities. We argue that this topological membrane transformation is a membrane scission event. Surprisingly, not a single recent review describes this substep as membrane scission (or membrane fission). In contrast, a number of publications imply that membrane fusion is involved. We discuss the potential sources for misinterpretation and recommend to consistent use of the unambiguous term "membrane scission."
Collapse
Affiliation(s)
- Roland L Knorr
- a Max Planck Institute of Colloids and Interfaces; Science Park Golm ; Potsdam , Germany
| | - Reinhard Lipowsky
- a Max Planck Institute of Colloids and Interfaces; Science Park Golm ; Potsdam , Germany
| | - Rumiana Dimova
- a Max Planck Institute of Colloids and Interfaces; Science Park Golm ; Potsdam , Germany
| |
Collapse
|
28
|
Himeno H, Ito H, Higuchi Y, Hamada T, Shimokawa N, Takagi M. Coupling between pore formation and phase separation in charged lipid membranes. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:062713. [PMID: 26764733 DOI: 10.1103/physreve.92.062713] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Indexed: 06/05/2023]
Abstract
We investigated the effect of charge on the membrane morphology of giant unilamellar vesicles (GUVs) composed of various mixtures containing charged lipids. We observed the membrane morphologies by fluorescent and confocal laser microscopy in lipid mixtures consisting of a neutral unsaturated lipid [dioleoylphosphatidylcholine (DOPC)], a neutral saturated lipid [dipalmitoylphosphatidylcholine (DPPC)], a charged unsaturated lipid [dioleoylphosphatidylglycerol (DOPG((-)))], a charged saturated lipid [dipalmitoylphosphatidylglycerol (DPPG((-)))], and cholesterol (Chol). In binary mixtures of neutral DOPC-DPPC and charged DOPC-DPPG((-))), spherical vesicles were formed. On the other hand, pore formation was often observed with GUVs consisting of DOPG((-))) and DPPC. In a DPPC-DPPG((-)))-Chol ternary mixture, pore-formed vesicles were also frequently observed. The percentage of pore-formed vesicles increased with the DPPG((-))) concentration. Moreover, when the head group charges of charged lipids were screened by the addition of salt, pore-formed vesicles were suppressed in both the binary and ternary charged lipid mixtures. We discuss the mechanisms of pore formation in charged lipid mixtures and the relationship between phase separation and the membrane morphology. Finally, we reproduce the results seen in experimental systems by using coarse-grained molecular dynamics simulations.
Collapse
Affiliation(s)
- Hiroki Himeno
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
- Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu 761-0395, Japan
| | - Hiroaki Ito
- Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan
| | - Yuji Higuchi
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
| | - Tsutomu Hamada
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Naofumi Shimokawa
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| | - Masahiro Takagi
- School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan
| |
Collapse
|
29
|
Yeast and mammalian autophagosomes exhibit distinct phosphatidylinositol 3-phosphate asymmetries. Nat Commun 2015; 5:3207. [PMID: 24492518 DOI: 10.1038/ncomms4207] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 01/07/2014] [Indexed: 01/05/2023] Open
Abstract
Phosphatidylinositol 3-kinase is indispensable for autophagy but it is not well understood how its product, phosphatidylinositol 3-phosphate (PtdIns(3)P), participates in the biogenesis of autophagic membranes. Here, by using quick-freezing and freeze-fracture replica labelling, which enables determination of the nanoscale distributions of membrane lipids, we show that PtdIns(3)P in yeast autophagosomes is more abundant in the luminal leaflet (the leaflet facing the closed space between the outer and inner autophagosomal membranes) than in the cytoplasmic leaflet. This distribution is drastically different from that of the mammalian autophagosome in which PtdIns(3)P is confined to the cytoplasmic leaflet. In mutant yeast lacking two cytoplasmic phosphatases, ymr1Δ and sjl3Δ, PtdIns(3)P in the autophagosome is equally abundant in the two membrane leaflets, suggesting that the PtdIns(3)P asymmetry in wild-type yeast is generated by unilateral hydrolysis. The observed differences in PtdIns(3)P distribution suggest that autophagy in yeast and mammals may involve substantially different processes.
Collapse
|
30
|
LAPTM4B is associated with poor prognosis in NSCLC and promotes the NRF2-mediated stress response pathway in lung cancer cells. Sci Rep 2015; 5:13846. [PMID: 26343532 PMCID: PMC4561374 DOI: 10.1038/srep13846] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 08/11/2015] [Indexed: 01/16/2023] Open
Abstract
We recently demonstrated that lysosomal protein transmembrane 4 beta (LAPTM4B) is elevated in non-small cell lung cancers (NSCLCs) and in the surrounding premalignant airway field of cancerization. In the present study, we sought to begin to understand the relevance of LAPTM4B expression and signaling to NSCLC pathogenesis. In situ hybridization analysis of LAPTM4B transcript in tissue microarrays comprised of 368 NSCLCs demonstrated that LAPTM4B expression was significantly increased in smoker compared to non-smoker lung adenocarcinoma tumors (P < 0.001) and was significantly associated with poor overall survival (P < 0.05) in adenocarcinoma patients. Knockdown of LAPTM4B expression inhibited cell growth, induced cellular apoptosis and decreased cellular autophagy in serum starved lung cancer cells. Expression profiling coupled with pathways analysis revealed decreased activation of the nuclear factor erythroid 2-like 2 (NRF2) stress response pathway following LAPTM4B knockdown. Further analysis demonstrated that LAPTM4B augmented the expression and nuclear translocation of the NRF2 transcription factor following serum deprivation as well as increased the expression of NRF2 target genes such as heme oxygenase 1/HMOX1). Our study points to the relevance of LAPTM4B expression to NSCLC pathogenesis as well as to the probable role of LAPTM4B/NRF2 signaling in promoting lung cancer cell survival.
Collapse
|
31
|
Autophagy Activated by Bluetongue Virus Infection Plays a Positive Role in Its Replication. Viruses 2015; 7:4657-75. [PMID: 26287233 PMCID: PMC4576199 DOI: 10.3390/v7082838] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/27/2015] [Accepted: 07/30/2015] [Indexed: 01/19/2023] Open
Abstract
Bluetongue virus (BTV) is an important pathogen of wild and domestic ruminants. Despite extensive study in recent decades, the interplay between BTV and host cells is not clearly understood. Autophagy as a cellular adaptive response plays a part in many viral infections. In our study, we found that BTV1 infection triggers the complete autophagic process in host cells, as demonstrated by the appearance of obvious double-membrane autophagosome-like vesicles, GFP-LC3 dots accumulation, the conversion of LC3-I to LC3-II and increased levels of autophagic flux in BSR cells (baby hamster kidney cell clones) and primary lamb lingual epithelial cells upon BTV1 infection. Moreover, the results of a UV-inactivated BTV1 infection assay suggested that the induction of autophagy was dependent on BTV1 replication. Therefore, we investigated the role of autophagy in BTV1 replication. The inhibition of autophagy by pharmacological inhibitors (3-MA, CQ) and RNA interference (siBeclin1) significantly decreased viral protein synthesis and virus yields. In contrast, treating BSR cells with rapamycin, an inducer of autophagy, promoted viral protein expression and the production of infectious BTV1. These findings lead us to conclude that autophagy is activated by BTV1 and contributes to its replication, and provide novel insights into BTV-host interactions.
Collapse
|
32
|
El-Mashed S, O'Donovan TR, Kay EW, Abdallah AR, Cathcart MC, O'Sullivan J, O'Grady A, Reynolds J, O'Reilly S, O'Sullivan GC, McKenna SL. LC3B globular structures correlate with survival in esophageal adenocarcinoma. BMC Cancer 2015; 15:582. [PMID: 26265176 PMCID: PMC4533787 DOI: 10.1186/s12885-015-1574-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 07/27/2015] [Indexed: 12/16/2022] Open
Abstract
Background Esophageal adenocarcinoma has the fastest growing incidence of any solid tumor in the Western world. Prognosis remains poor with overall five-year survival rates under 25 %. Only a limited number of patients benefit from chemotherapy and there are no biomarkers that can predict outcome. Previous studies have indicated that induction of autophagy can influence various aspects of tumor cell biology, including chemosensitivity. The objective of this study was to assess whether expression of the autophagy marker (LC3B) correlated with patient outcome. Methods Esophageal adenocarcinoma tumor tissue from two independent sites, was examined retrospectively. Tumors from 104 neoadjuvant naïve patients and 48 patients post neoadjuvant therapy were assembled into tissue microarrays prior to immunohistochemical analysis. Kaplan-Meier survival curves and log-rank tests were used to assess impact of LC3B expression on survival. Cox regression was used to examine association with clinical risk factors. Results A distinct globular pattern of LC3B expression was found to be predictive of outcome in both patient groups, irrespective of treatment (p < 0.001). Multivariate analysis found that this was a strong independent predictor of poor prognosis (p < 0.001). Conclusions This distinctive staining pattern of LC3B represents a novel prognostic marker for resectable esophageal adenocarcinoma. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1574-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Shereen El-Mashed
- Leslie C. Quick Laboratory, Cork Cancer Research Centre, BioSciences Institute, University College, Cork, Ireland
| | - Tracey R O'Donovan
- Leslie C. Quick Laboratory, Cork Cancer Research Centre, BioSciences Institute, University College, Cork, Ireland
| | - Elaine W Kay
- Department of Pathology, Royal College of Surgeons Ireland (RCSI), Beaumont Hospital, Dublin, Ireland
| | - Ayat R Abdallah
- National Liver Institute, Menoufiya University, Shebin El Kom, Egypt
| | - Mary-Clare Cathcart
- Department of Surgery & Trinity Centre for Health Sciences, St James Hospital, Dublin, Ireland
| | - Jacintha O'Sullivan
- Department of Surgery & Trinity Centre for Health Sciences, St James Hospital, Dublin, Ireland
| | - Anthony O'Grady
- Department of Pathology, Royal College of Surgeons Ireland (RCSI), Beaumont Hospital, Dublin, Ireland
| | - John Reynolds
- Department of Surgery & Trinity Centre for Health Sciences, St James Hospital, Dublin, Ireland
| | - Seamus O'Reilly
- Department of Oncology, Cork University Hospital, Cork, Ireland
| | - Gerald C O'Sullivan
- Leslie C. Quick Laboratory, Cork Cancer Research Centre, BioSciences Institute, University College, Cork, Ireland
| | - Sharon L McKenna
- Leslie C. Quick Laboratory, Cork Cancer Research Centre, BioSciences Institute, University College, Cork, Ireland.
| |
Collapse
|
33
|
Müller AJ, Proikas-Cezanne T. Function of human WIPI proteins in autophagosomal rejuvenation of endomembranes? FEBS Lett 2015; 589:1546-51. [PMID: 25980605 DOI: 10.1016/j.febslet.2015.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 04/30/2015] [Accepted: 05/05/2015] [Indexed: 12/28/2022]
Abstract
Despite the availability of a large pool of experimental approaches and hypothetical considerations, the hunt for the enigmatic membrane origin of autophagosomes is still on. In mammalian cells proposed scenarios for the formation of the autophagosomal membrane include both de novo assembly, and rearrangements plus maturation of pre-existing membrane sections from the endoplasmic reticulum (ER), plasma membrane, Golgi or mitochondria. Earlier, we identified the human WD-repeat protein interacting with phosphoinositides (WIPI) family and showed that WIPI proteins function as essential phosphatidylinositol 3-phosphate (PtdIns3P) effectors at the nascent autophagosome. Interestingly, WIPI proteins localize to both pre-existing endomembranes and nascent autophagosomes. In this context, and on the basis of historical records on the formation of autophagosomes, we discuss with appropriate modesty an alternative perspective on the membrane origin of autophagosomes.
Collapse
Affiliation(s)
- Amelie Johanna Müller
- Autophagy Laboratory, Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Tassula Proikas-Cezanne
- Autophagy Laboratory, Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany.
| |
Collapse
|
34
|
Girolamo F, Lia A, Amati A, Strippoli M, Coppola C, Virgintino D, Roncali L, Toscano A, Serlenga L, Trojano M. Overexpression of autophagic proteins in the skeletal muscle of sporadic inclusion body myositis. Neuropathol Appl Neurobiol 2014; 39:736-49. [PMID: 23452291 DOI: 10.1111/nan.12040] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2012] [Accepted: 02/22/2013] [Indexed: 01/01/2023]
Abstract
AIMS Sporadic inclusion body myositis (s-IBM) is characterized by rimmed vacuole formation and misfolded protein accumulation. Intracellular protein aggregates are cleared by autophagy. When autophagy is blocked aggregates accumulate, resulting in abnormal rimmed vacuole formation. This study investigated the autophagy-lysosome pathway contribution to rimmed vacuole accumulation. METHODS Autophagy was studied in muscle biopsy specimens obtained from eleven s-IBM patients, one suspected hereditary IBM patient, nine patients with other inflammatory myopathies and nine non-myopathic patients as controls. The analysis employed morphometric methods applied to immunohistochemistry using the endosome marker Clathrin, essential proteins of the autophagic cascade such as AuTophaGy-related protein ATG5, splicing variants of microtubule-associated protein light chain 3a (LC3a) and LC3b, compared with Beclin 1, the major autophagy regulator of both the initiation phase and late endosome/lysosome fusion of the autophagy-lysosome pathway. RESULTS In muscle biopsies of s-IBM patients, an increased expression of Clathrin, ATG5, LC3a, LC3b and Beclin 1 was shown. Moreover, the inflammatory components of the disease, essentially lymphocytes, were preferentially distributed around the Beclin 1(+) myofibres. These affected myofibres also showed a moderate sarcoplasmic accumulation of SMI-31(+) phospho-tau paired helical filaments. CONCLUSION The overexpression of autophagy markers linked to the decreased clearance of misfolded proteins, including SMI-31, and rimmed vacuoles accumulation may exhaust cellular resources and lead to cell death.
Collapse
Affiliation(s)
- F Girolamo
- Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari School of Medicine, Bari, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Ogasawara Y, Itakura E, Kono N, Mizushima N, Arai H, Nara A, Mizukami T, Yamamoto A. Stearoyl-CoA desaturase 1 activity is required for autophagosome formation. J Biol Chem 2014; 289:23938-50. [PMID: 25023287 DOI: 10.1074/jbc.m114.591065] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Autophagy is one of the major degradation pathways for cytoplasmic components. The autophagic isolation membrane is a unique membrane whose content of unsaturated fatty acids is very high. However, the molecular mechanisms underlying formation of this membrane, including the roles of unsaturated fatty acids, remain to be elucidated. From a chemical library consisting of structurally diverse compounds, we screened for novel inhibitors of starvation-induced autophagy by measuring LC3 puncta formation in mouse embryonic fibroblasts stably expressing GFP-LC3. One of the inhibitors we identified, 2,5-pyridinedicarboxamide, N2,N5-bis[5-[(dimethylamino)carbonyl]-4-methyl-2-thiazolyl], has a molecular structure similar to that of a known stearoyl-CoA desaturase (SCD) 1 inhibitor. To determine whether SCD1 inhibition influences autophagy, we examined the effects of the SCD1 inhibitor 28c. This compound strongly inhibited starvation-induced autophagy, as determined by LC3 puncta formation, immunoblot analyses of LC3, electron microscopic observations, and p62/SQSTM1 accumulation. Overexpression of SCD1 or supplementation with oleic acid, which is a catalytic product of SCD1 abolished the inhibition of autophagy by 28c. Furthermore, 28c suppressed starvation-induced autophagy without affecting mammalian target of rapamycin activity, and also inhibited rapamycin-induced autophagy. In addition to inhibiting formation of LC3 puncta, 28c also inhibited formation of ULK1, WIPI1, Atg16L, and p62/SQSTM1 puncta. These results suggest that SCD1 activity is required for the earliest step of autophagosome formation.
Collapse
Affiliation(s)
- Yuta Ogasawara
- From the Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829
| | - Eisuke Itakura
- the Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Tokyo 113-8519, and
| | - Nozomu Kono
- the Graduate School of Pharmaceutical Sciences and
| | - Noboru Mizushima
- the Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Tokyo 113-8519, and Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | | | - Atsuki Nara
- From the Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829
| | - Tamio Mizukami
- From the Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829
| | - Akitsugu Yamamoto
- From the Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829,
| |
Collapse
|
36
|
Xia P, Wang S, Huang G, Du Y, Zhu P, Li M, Fan Z. RNF2 is recruited by WASH to ubiquitinate AMBRA1 leading to downregulation of autophagy. Cell Res 2014; 24:943-58. [PMID: 24980959 PMCID: PMC4123297 DOI: 10.1038/cr.2014.85] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/01/2014] [Accepted: 05/26/2014] [Indexed: 12/17/2022] Open
Abstract
WASH (Wiskott-Aldrich syndrome protein (WASP) and SCAR homolog) was identified to function in endosomal sorting via Arp2/3 activation. We previously demonstrated that WASH is a new interactor of BECN1 and present in the BECN1-PIK3C3 complex with AMBRA1. The AMBRA1-DDB1-CUL4A complex is an E3 ligase for K63-linked ubiquitination of BECN1, which is required for starvation-induced autophagy. WASH suppresses autophagy by inhibition of BECN1 ubiquitination. However, how AMBRA1 is regulated during autophagy remains elusive. Here, we found that RNF2 associates with AMBRA1 to act as an E3 ligase to ubiquitinate AMBRA1 via K48 linkage. RNF2 mediates ubiquitination of AMBRA1 at lysine 45. Notably, RNF2 deficiency enhances autophagy induction. Upon autophagy induction, RNF2 potentiates AMBRA1 degradation with the help of WASH. WASH deficiency impairs the association of RNF2 with AMBRA1 to impede AMBRA1 degradation. Our findings reveal another novel layer of regulation of autophagy through WASH recruitment of RNF2 for AMBRA1 degradation leading to downregulation of autophagy.
Collapse
Affiliation(s)
- Pengyan Xia
- 1] Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuo Wang
- Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Guanling Huang
- 1] Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying Du
- Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Pingping Zhu
- Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Man Li
- 1] Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China [2] University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zusen Fan
- Key Laboratory of Infection and Immunity of CAS, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|
37
|
Xu L, Wang ZH, Xu D, Lin G, Li DR, Wan T, Guo SL. Expression of Derlin-1 and its effect on expression of autophagy marker genes under endoplasmic reticulum stress in lung cancer cells. Cancer Cell Int 2014; 14:50. [PMID: 24944523 PMCID: PMC4061450 DOI: 10.1186/1475-2867-14-50] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Accepted: 06/05/2014] [Indexed: 12/05/2022] Open
Abstract
Background Recent findings indicated that Derlin-1 has an important function in tumour progression. In this study, we aimed to determine whether Derlin-1 has an oncogene function as a cross-talk molecule with autophagy. Methods Cancer cells were treated with tunicamycin (TM) for 8 and 24 h. The expression of Derlin-1 and autophagy-related genes was determined by western blot. Autophagy was analysed by fluorescence microscopy after staining the cancer cells with monodansylcadaverine. The interaction between Derlin-1 and other proteins was identified using co-immunoprecipitation assay. Results Our study demonstrated high Derlin-1 expression levels in most non-small lung cancer cell lines. Derlin-1 expression was enhanced under endoplasmic reticulum (ER) stress. Previous studies revealed that TM triggers the initiation of autophagy by activating Beclin 1, converting LC3I to LC3II and degrading p62. Knockdown of Derlin-1 did not affect Beclin 1 and LC3II expression but disrupted the degradation of p62 under ER stress, which resulted in the blockage of autophagy flux. Furthermore, Derlin-1 and p62 were observed to interact under ER stress. Conclusion This study is the first report about the interaction between Derlin-1 and p62. Derlin-1 may function in tumour progression partially by interacting with p62.
Collapse
Affiliation(s)
- Li Xu
- Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Zan-Hong Wang
- Department of Obstetrics and Gynecology, The Shanxi Da Yi Hospital, Taiyuan 030001, P.R. China
| | - Dong Xu
- Center for Disease Control and Prevention, Gaoxin/Xinshi, District of Urumqi, Xinjiang Province, P.R. China
| | - Gang Lin
- Center for Disease Control and Prevention, Gaoxin/Xinshi, District of Urumqi, Xinjiang Province, P.R. China
| | - Dai-Rong Li
- Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Tao Wan
- Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Shu-Liang Guo
- Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| |
Collapse
|
38
|
Mulakkal NC, Nagy P, Takats S, Tusco R, Juhász G, Nezis IP. Autophagy in Drosophila: from historical studies to current knowledge. BIOMED RESEARCH INTERNATIONAL 2014; 2014:273473. [PMID: 24949430 PMCID: PMC4052151 DOI: 10.1155/2014/273473] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/17/2014] [Indexed: 12/17/2022]
Abstract
The discovery of evolutionarily conserved Atg genes required for autophagy in yeast truly revolutionized this research field and made it possible to carry out functional studies on model organisms. Insects including Drosophila are classical and still popular models to study autophagy, starting from the 1960s. This review aims to summarize past achievements and our current knowledge about the role and regulation of autophagy in Drosophila, with an outlook to yeast and mammals. The basic mechanisms of autophagy in fruit fly cells appear to be quite similar to other eukaryotes, and the role that this lysosomal self-degradation process plays in Drosophila models of various diseases already made it possible to recognize certain aspects of human pathologies. Future studies in this complete animal hold great promise for the better understanding of such processes and may also help finding new research avenues for the treatment of disorders with misregulated autophagy.
Collapse
Affiliation(s)
- Nitha C. Mulakkal
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Peter Nagy
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Szabolcs Takats
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Radu Tusco
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Gábor Juhász
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Budapest H-1117, Hungary
| | - Ioannis P. Nezis
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| |
Collapse
|
39
|
Bouley SJ, Maginnis MS, Derdowski A, Gee GV, O'Hara BA, Nelson CD, Bara AM, Atwood WJ, Dugan AS. Host cell autophagy promotes BK virus infection. Virology 2014; 456-457:87-95. [PMID: 24889228 PMCID: PMC7112032 DOI: 10.1016/j.virol.2014.03.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 11/27/2013] [Accepted: 03/10/2014] [Indexed: 12/16/2022]
Abstract
Autophagy is important for a variety for virus life cycles. We sought to determine the role of autophagy in human BK polyomavirus (BKPyV) infection. The addition excess amino acids during viral infection reduced BKPyV infection. Perturbing autophagy levels using inhibitors, 3-MA, bafilomycin A1, and spautin-1, also reduced infection, while rapamycin treatment of host cells increased infection. siRNA knockdown of autophagy genes, ATG7 and Beclin-1, corresponded to a decrease in BKPyV infection. BKPyV infection not only correlated with autophagosome formation, but also virus particles localized to autophagy-specific compartments early in infection. These data support a novel role for autophagy in the promotion of BKPyV infection. Amino acid supplementation decreases BKPyV infection. Autophagy inhibitors, 3-MA, bafilomycin A, and spautin-1, decrease BKPyV infection, while rapamycin increases infection. Inhibitors are most effective when added early in viral life cycle. Knockdown of autophagy genes, Beclin-1 and ATG7, in host cells decreases BKPyV infection levels. BKPyV localizes to LC3+ autophagosome 3 h post infection.
Collapse
Affiliation(s)
- Stephanie J Bouley
- Department of Natural Sciences, Assumption College, Worcester, MA 01609, United States
| | - Melissa S Maginnis
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI 02912, United States
| | - Aaron Derdowski
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI 02912, United States
| | - Gretchen V Gee
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI 02912, United States
| | - Bethany A O'Hara
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI 02912, United States
| | - Christian D Nelson
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI 02912, United States
| | - Anne M Bara
- Department of Natural Sciences, Assumption College, Worcester, MA 01609, United States
| | - Walter J Atwood
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI 02912, United States
| | - Aisling S Dugan
- Department of Natural Sciences, Assumption College, Worcester, MA 01609, United States.
| |
Collapse
|
40
|
Venter E, van der Merwe CF, Buys AV, Huismans H, van Staden V. Comparative ultrastructural characterization of African horse sickness virus-infected mammalian and insect cells reveals a novel potential virus release mechanism from insect cells. J Gen Virol 2014; 95:642-651. [PMID: 24347494 DOI: 10.1099/vir.0.060400-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
African horse sickness virus (AHSV) is an arbovirus capable of successfully replicating in both its mammalian host and insect vector. Where mammalian cells show a severe cytopathic effect (CPE) following AHSV infection, insect cells display no CPE. These differences in cell death could be linked to the method of viral release, i.e. lytic or non-lytic, that predominates in a specific cell type. Active release of AHSV, or any related orbivirus, has, however, not yet been documented from insect cells. We applied an integrated microscopy approach to compare the nanomechanical and morphological response of mammalian and insect cells to AHSV infection. Atomic force microscopy revealed plasma membrane destabilization, integrity loss and structural deformation of the entire surface of infected mammalian cells. Infected insect cells, in contrast, showed no morphological differences from mock-infected cells other than an increased incidence of circular cavities present on the cell surface. Transmission electron microscopy imaging identified a novel large vesicle-like compartment within infected insect cells, not present in mammalian cells, containing viral proteins and virus particles. Extracellular clusters of aggregated virus particles were visualized adjacent to infected insect cells with intact plasma membranes. We propose that foreign material is accumulated within these vesicles and that their subsequent fusion with the cell membrane releases entrapped viruses, thereby facilitating a non-lytic virus release mechanism different from the budding previously observed in mammalian cells. This insect cell-specific defence mechanism contributes to the lack of cell damage observed in AHSV-infected insect cells.
Collapse
Affiliation(s)
- E. Venter
- Department of Genetics, University of Pretoria, Pretoria 0002, South Africa
| | - C. F. van der Merwe
- Laboratory for Microscopy and Microanalysis, University of Pretoria, South Africa
| | - A. V. Buys
- Laboratory for Microscopy and Microanalysis, University of Pretoria, South Africa
| | - H. Huismans
- Department of Genetics, University of Pretoria, Pretoria 0002, South Africa
| | - V. van Staden
- Department of Genetics, University of Pretoria, Pretoria 0002, South Africa
| |
Collapse
|
41
|
Dodson M, Darley-Usmar V, Zhang J. Cellular metabolic and autophagic pathways: traffic control by redox signaling. Free Radic Biol Med 2013; 63:207-21. [PMID: 23702245 PMCID: PMC3729625 DOI: 10.1016/j.freeradbiomed.2013.05.014] [Citation(s) in RCA: 437] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 05/08/2013] [Accepted: 05/09/2013] [Indexed: 11/16/2022]
Abstract
It has been established that the key metabolic pathways of glycolysis and oxidative phosphorylation are intimately related to redox biology through control of cell signaling. Under physiological conditions glucose metabolism is linked to control of the NADH/NAD redox couple, as well as providing the major reductant, NADPH, for thiol-dependent antioxidant defenses. Retrograde signaling from the mitochondrion to the nucleus or cytosol controls cell growth and differentiation. Under pathological conditions mitochondria are targets for reactive oxygen and nitrogen species and are critical in controlling apoptotic cell death. At the interface of these metabolic pathways, the autophagy-lysosomal pathway functions to maintain mitochondrial quality and generally serves an important cytoprotective function. In this review we will discuss the autophagic response to reactive oxygen and nitrogen species that are generated from perturbations of cellular glucose metabolism and bioenergetic function.
Collapse
Affiliation(s)
- Matthew Dodson
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Victor Darley-Usmar
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Jianhua Zhang
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
- Department of Veterans Affairs, Birmingham VA Medical Center
| |
Collapse
|
42
|
Choy A, Roy CR. Autophagy and bacterial infection: an evolving arms race. Trends Microbiol 2013; 21:451-6. [PMID: 23880062 DOI: 10.1016/j.tim.2013.06.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 06/17/2013] [Accepted: 06/21/2013] [Indexed: 12/31/2022]
Abstract
Autophagy is an important membrane transport pathway that is conserved among eukaryotic cells. Although first described as an intracellular catabolic pathway used to break down self-components, autophagy has been found to play an important role in the elimination of intracellular pathogens. A variety of host mechanisms exist for recognizing and targeting intracellular bacteria to autophagosomes. Several intracellular bacteria have evolved ways to manipulate, inhibit, or avoid autophagy in order to survive in the cell. Thus, the autophagy pathway can be viewed as an evolutionarily conserved host response to infection.
Collapse
Affiliation(s)
- Augustine Choy
- Department of Microbial Pathogenesis, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA
| | | |
Collapse
|
43
|
Lőw P, Varga Á, Pircs K, Nagy P, Szatmári Z, Sass M, Juhász G. Impaired proteasomal degradation enhances autophagy via hypoxia signaling in Drosophila. BMC Cell Biol 2013; 14:29. [PMID: 23800266 PMCID: PMC3700814 DOI: 10.1186/1471-2121-14-29] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 06/21/2013] [Indexed: 01/04/2023] Open
Abstract
Background Two pathways are responsible for the majority of regulated protein catabolism in eukaryotic cells: the ubiquitin-proteasome system (UPS) and lysosomal self-degradation through autophagy. Both processes are necessary for cellular homeostasis by ensuring continuous turnover and quality control of most intracellular proteins. Recent studies established that both UPS and autophagy are capable of selectively eliminating ubiquitinated proteins and that autophagy may partially compensate for the lack of proteasomal degradation, but the molecular links between these pathways are poorly characterized. Results Here we show that autophagy is enhanced by the silencing of genes encoding various proteasome subunits (α, β or regulatory) in larval fat body cells. Proteasome inactivation induces canonical autophagy, as it depends on core autophagy genes Atg1, Vps34, Atg9, Atg4 and Atg12. Large-scale accumulation of aggregates containing p62 and ubiquitinated proteins is observed in proteasome RNAi cells. Importantly, overexpressed Atg8a reporters are captured into the cytoplasmic aggregates, but these do not represent autophagosomes. Loss of p62 does not block autophagy upregulation upon proteasome impairment, suggesting that compensatory autophagy is not simply due to the buildup of excess cargo. One of the best characterized substrates of UPS is the α subunit of hypoxia-inducible transcription factor 1 (HIF-1α), which is continuously degraded by the proteasome during normoxic conditions. Hypoxia is a known trigger of autophagy in mammalian cells, and we show that genetic activation of hypoxia signaling also induces autophagy in Drosophila. Moreover, we find that proteasome inactivation-induced autophagy requires sima, the Drosophila ortholog of HIF-1α. Conclusions We have characterized proteasome inactivation- and hypoxia signaling-induced autophagy in the commonly used larval Drosophila fat body model. Activation of both autophagy and hypoxia signaling was implicated in various cancers, and mutations affecting genes encoding UPS enzymes have recently been suggested to cause renal cancer. Our studies identify a novel genetic link that may play an important role in that context, as HIF-1α/sima may contribute to upregulation of autophagy by impaired proteasomal activity.
Collapse
Affiliation(s)
- Péter Lőw
- Department of Anatomy, Cell and Developmental Biology, Eötvös Loránd University, Pázmány P. s. 1/C, H-1117, Budapest, Hungary
| | | | | | | | | | | | | |
Collapse
|
44
|
Yefimova MG, Messaddeq N, Harnois T, Meunier AC, Clarhaut J, Noblanc A, Weickert JL, Cantereau A, Philippe M, Bourmeyster N, Benzakour O. A chimerical phagocytosis model reveals the recruitment by Sertoli cells of autophagy for the degradation of ingested illegitimate substrates. Autophagy 2013; 9:653-66. [PMID: 23439251 PMCID: PMC3669177 DOI: 10.4161/auto.23839] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Phagocytosis and autophagy are typically dedicated to degradation of substrates of extrinsic and intrinsic origins respectively. Although overlaps between phagocytosis and autophagy were reported, the use of autophagy for ingested substrate degradation by nonprofessional phagocytes has not been described. Blood-separated tissues use their tissue-specific nonprofessional phagocytes for homeostatic phagocytosis. In the testis, Sertoli cells phagocytose spermatid residual bodies produced during germ cell differentiation. In the retina, pigmented epithelium phagocytoses shed photoreceptor tips produced during photoreceptor renewal. Spermatid residual bodies and shed photoreceptor tips are phosphatidylserine-exposing substrates. Activation of the tyrosine kinase receptor MERTK, which is implicated in phagocytosis of phosphatidylserine-exposing substrates, is a common feature of Sertoli and retinal pigmented epithelial cell phagocytosis. The major aim of our study was to investigate to what extent phagocytosis by Sertoli cells may be tissue specific. We analyzed in Sertoli cell cultures that were exposed to either spermatid residual bodies (legitimate substrates) or retina photoreceptor outer segments (illegitimate substrates) the course of the main phagocytosis stages. We show that whereas substrate binding and ingestion stages occur similarly for legitimate or illegitimate substrates, the degradation of illegitimate but not of legitimate substrates triggers autophagy as evidenced by the formation of double-membrane wrapping, MAP1LC3A-II/LC3-II clustering, SQSTM1/p62 degradation, and by marked changes in ATG5, ATG9 and BECN1/Beclin 1 protein expression profiles. The recruitment by nonprofessional phagocytes of autophagy for the degradation of ingested cell-derived substrates is a novel feature that may be of major importance for fundamentals of both apoptotic substrate clearance and tissue homeostasis.
Collapse
Affiliation(s)
- Marina G Yefimova
- Institut de Physiologie et Biologie Cellulaires, CNRS-FRE 3511, Université de Poitiers, Poitiers, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Kim SH, Hwang SY, Min KS, Yoon JT. Molecular cloning and expression analyses of porcine MAP1LC3A in the granulosa cells of normal and miniature pig. Reprod Biol Endocrinol 2013; 11:8. [PMID: 23402365 PMCID: PMC3579721 DOI: 10.1186/1477-7827-11-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 12/08/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The members of the microtubule-associated protein 1 light chain (MAP1LC) family, especially those of the LC3 family (MAP1LC3A, B, C), are known to induce autophagy upon localization onto the autophagosomal membrane. In this regard, LC3 can be utilized as a marker for the formation of autophagosomes during the process of autophagy. The aims of this study are to clone porcine MAP1LC3A, and analyze the pattern of its expression in the ovarian tissues of normal and miniature pig ovary in an attempt to understand the distinct mode of apoptosis between two strains. METHODS Rapid amplification of cDNA ends (RACE) were used to obtain the 5' and 3' ends of the porcine MAP1LC3A full length cDNA. Reverse-transcriptase-PCR (RT-PCR), real-time PCR, and western blot analysis were performed to examine the expression of porcine MAP1LC3A. The localization of MAP1LC3A in the ovary was determined by In situ Hybridization and Immunohistochemical staining. RESULTS We cloned the full-length cDNA of porcine MAP1LC3A and identified an open reading frame of 980 bp encoding 121 amino acids. Based on its homology to known mammalian proteins (98%) this novel cDNA was designated as porcine MAP1LC3A and registered to the GenBank (Accession No. GU272221). We compared the expression of MAP1LC3A in the Graafian follicles of normal and miniature pigs by in situ hybridization at day 15 of the estrus cycle. While normal pigs showed a stronger expression of MAP1LC3A mRNA than miniature pigs in the theca cell area, the expression was lower in the granulosa cells. Immunofluorescence analysis of the MAP1LC3A fusion reporter protein showed the subcellular localization of porcine MAP1LC3A and ATG5 as a punctate pattern in the cytoplasm of porcine granulosa cells under stress conditions. In addition, the expressions of MAP1LC3A and ATG5 were higher in normal pigs than in miniature pigs both in the presence and absence of rapamycin. CONCLUSIONS The newly cloned porcine MAP1LC3A provides a novel autophagosomal marker in both normal and miniature pig. We demonstrated that the expression of MAP1LC3A in graafian follicle is distinct in normal and miniature pig, which may explain the unique folliculogenesis of miniature pigs.
Collapse
Affiliation(s)
- Sang H Kim
- Institute of Genetic Engineering, Hankyong National University, Ansung, 456-749, Korea
| | - Sue Y Hwang
- Graduate School of Bio & Information Technology, Hankyong National University, Ansung, 456-749, Korea
| | - Kwan S Min
- Graduate School of Bio & Information Technology, Hankyong National University, Ansung, 456-749, Korea
| | - Jong T Yoon
- Department of Animal Life Science, Hankyong National University, Ansung, 456-749, Korea
| |
Collapse
|
46
|
Abstract
Macroautophagy (autophagy) is a conserved catabolic process that targets cytoplasmic components to lysosomes for degradation. Autophagy is required for cellular homeostasis and cell survival in response to starvation and stress, and paradoxically, it also plays a role in programmed cell death during development. The mechanisms that regulate the relationship between autophagy, cell survival, and cell death are poorly understood. Here we review research in Drosophila that has provided insights into the regulation of autophagy by steroid hormones and nutrient restriction and discuss how autophagy influences cell growth, nutrient utilization, cell survival, and cell death.
Collapse
|
47
|
Palumbo S, Comincini S. Autophagy and ionizing radiation in tumors: the "survive or not survive" dilemma. J Cell Physiol 2012; 228:1-8. [PMID: 22585676 DOI: 10.1002/jcp.24118] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autophagy is a so-called "self-eating" system responsible for degrading long-lived proteins and cytoplasmic organelles, whose products are recycled to maintain cellular homeostasis. This ability makes autophagy a good candidate for a survival mechanism in response to several stresses, including the tumor cell transformation. In particular, recent studies suggested that autophagy functions as a pro-death mechanism within different tumor contexts. It is, however, widely reported that autophagy represents both a survival mechanism or contributes directly to cell death fate. This interplay of the autophagy functions has been observed in many types of cancers and, in some cases, autophagy has been demonstrated to both promote and inhibit antitumor drug resistance. From a therapeutical point of view, the effects of the modulation of the tumor cell autophagic status, in response to ionizing radiations, are presently of particular relevance in oncology. Accordingly, this review also provides a perspective view on future works for exploring the modulation of autophagic indices in tumor cells as a novel molecular-based adjuvant strategy, in order to improve radiotherapy and chemotherapy effects in cancer patients.
Collapse
Affiliation(s)
- Silvia Palumbo
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy.
| | | |
Collapse
|
48
|
Abstract
Autophagy is an essential process for the maintenance of cellular homeostasis in the heart under both normal and stress conditions. Autophagy is a key degradation pathway and acts as a quality control sensor. It protects myocytes from cytotoxic protein aggregates and dysfunctional organelles by quickly clearing them from the cell. It also responds to changes in energy demand and mechanical stressors to maintain contractile function. The autophagic-lysosomal pathway responds to serum starvation to ensure that the cell maintains its metabolism and energy levels when nutrients run low. In contrast, excessive activation of autophagy is detrimental to cells and contributes to the development of pathological conditions. A number of signaling pathways and proteins regulate autophagy. These include the 5'-AMP-activated protein kinase/mammalian target of rapamycin pathway, FoxO transcription factors, Sirtuin 1, oxidative stress, Bcl-2 family proteins, and the E3 ubiquitin ligase Parkin. In this review, we will discuss how this diverse cast of characters regulates the important autophagic process in the myocardium.
Collapse
|
49
|
Pehar M, Puglielli L. Lysine acetylation in the lumen of the ER: a novel and essential function under the control of the UPR. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:686-97. [PMID: 23247107 DOI: 10.1016/j.bbamcr.2012.12.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/03/2012] [Accepted: 12/05/2012] [Indexed: 01/15/2023]
Abstract
The N(ε)-amino group of lysine residues can be transiently modified by the addition of an acetyl group. Recognized functions of N(ε)-lysine acetylation include regulation of activity, molecular stabilization and conformational assembly of a protein. For more than forty years lysine acetylation was thought to occur only in the cytosol and nucleus. Targets included cytoskeletal-associated proteins as well as transcription factors, histone proteins and proteins involved in DNA recombination and repair. However, in 2007 we reported that a type I membrane protein involved in the pathogenesis of Alzheimer's disease was transiently acetylated on the ε amino group of seven lysine residues while transiting along the secretory pathway. Surprisingly, the acetylation occurred in the lumen of the endoplasmic reticulum (ER) forcing us to reconsider old paradigms. Indeed, if lysine acetylation can occur in the lumen of the ER, then all the essential biochemical elements of the reaction must be available in the lumen of the organelle. Follow-up studies revealed the existence of ER-based acetyl-CoA:lysine acetyltransferases as well as a membrane transporter that translocates acetyl-CoA from the cytosol into the ER lumen. Large-scale proteomics showed that the list of substrates of the ER-based acetylation machinery includes both transiting and resident proteins. Finally, genetic studies revealed that this machinery is tightly linked to human diseases. Here, we describe these exciting findings as well as recent biochemical and cellular advances, and discuss possible impact on both human physiology and pathology.
Collapse
Affiliation(s)
- Mariana Pehar
- Department of Medicine, University of Wisconsin-Madison, VA Medical Center, Madison, WI 53705, USA
| | | |
Collapse
|
50
|
Faas FG, Avramut MC, M. van den Berg B, Mommaas AM, Koster AJ, Ravelli RB. Virtual nanoscopy: generation of ultra-large high resolution electron microscopy maps. J Cell Biol 2012; 198:457-69. [PMID: 22869601 PMCID: PMC3413355 DOI: 10.1083/jcb.201201140] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Accepted: 06/27/2012] [Indexed: 12/23/2022] Open
Abstract
A key obstacle in uncovering the orchestration between molecular and cellular events is the vastly different length scales on which they occur. We describe here a methodology for ultrastructurally mapping regions of cells and tissue as large as 1 mm(2) at nanometer resolution. Our approach employs standard transmission electron microscopy, rapid automated data collection, and stitching to create large virtual slides. It greatly facilitates correlative light-electron microscopy studies to relate structure and function and provides a genuine representation of ultrastructural events. The method is scalable as illustrated by slides up to 281 gigapixels in size. Here, we applied virtual nanoscopy in a correlative light-electron microscopy study to address the role of the endothelial glycocalyx in protein leakage over the glomerular filtration barrier, in an immunogold labeling study of internalization of oncolytic reovirus in human dendritic cells, in a cryo-electron microscopy study of intact vitrified mouse embryonic cells, and in an ultrastructural mapping of a complete zebrafish embryo slice.
Collapse
Affiliation(s)
- Frank G.A. Faas
- Department of Molecular Cell Biology and Department of Nephrology, Leiden University Medical Center (LUMC), 2300 RC Leiden, Netherlands
| | - M. Cristina Avramut
- Department of Molecular Cell Biology and Department of Nephrology, Leiden University Medical Center (LUMC), 2300 RC Leiden, Netherlands
| | - Bernard M. van den Berg
- Department of Molecular Cell Biology and Department of Nephrology, Leiden University Medical Center (LUMC), 2300 RC Leiden, Netherlands
| | - A. Mieke Mommaas
- Department of Molecular Cell Biology and Department of Nephrology, Leiden University Medical Center (LUMC), 2300 RC Leiden, Netherlands
| | - Abraham J. Koster
- Department of Molecular Cell Biology and Department of Nephrology, Leiden University Medical Center (LUMC), 2300 RC Leiden, Netherlands
| | - Raimond B.G. Ravelli
- Department of Molecular Cell Biology and Department of Nephrology, Leiden University Medical Center (LUMC), 2300 RC Leiden, Netherlands
| |
Collapse
|