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Korsgen ME, Sun C, Seranova E, Zatyka M, Astuti D, Kataura T, Barrett T, Korolchuk VI, Sarkar S. Analysis of autophagy deficiency and cytotoxicity in autophagy-deficient human embryonic stem cell-derived neurons. STAR Protoc 2023; 4:102529. [PMID: 37624702 PMCID: PMC10474488 DOI: 10.1016/j.xpro.2023.102529] [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: 04/26/2023] [Revised: 06/28/2023] [Accepted: 07/31/2023] [Indexed: 08/27/2023] Open
Abstract
Autophagy, a catabolic process governing cellular and energy homeostasis, is essential for cell survival and human health. Here, we present a protocol for generating autophagy-deficient (ATG5-/-) human neurons from human embryonic stem cell (hESC)-derived neural precursors. We describe steps for analyzing loss of autophagy by immunoblotting. We then detail analysis of cell death by luminescence-based cytotoxicity assay and fluorescence-based TUNEL staining. This hESC-based experimental platform provides a genetic knockout model for undertaking autophagy studies relevant to human biology. For complete details on the use and execution of this protocol, please refer to Sun et al. (2023).1.
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Affiliation(s)
- Miriam E Korsgen
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Congxin Sun
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
| | - Elena Seranova
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Malgorzata Zatyka
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Dewi Astuti
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Tetsushi Kataura
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Timothy Barrett
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; Department of Endocrinology, Birmingham Women's and Children's Hospital, Steelhouse Lane, Birmingham B4 6NH, UK
| | - Viktor I Korolchuk
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
| | - Sovan Sarkar
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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2
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Sporbeck K, Haas ML, Pastor-Maldonado CJ, Schüssele DS, Hunter C, Takacs Z, Diogo de Oliveira AL, Franz-Wachtel M, Charsou C, Pfisterer SG, Gubas A, Haller PK, Knorr RL, Kaulich M, Macek B, Eskelinen EL, Simonsen A, Proikas-Cezanne T. The ABL-MYC axis controls WIPI1-enhanced autophagy in lifespan extension. Commun Biol 2023; 6:872. [PMID: 37620393 PMCID: PMC10449903 DOI: 10.1038/s42003-023-05236-9] [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: 12/22/2022] [Accepted: 08/10/2023] [Indexed: 08/26/2023] Open
Abstract
Human WIPI β-propellers function as PI3P effectors in autophagy, with WIPI4 and WIPI3 being able to link autophagy control by AMPK and TORC1 to the formation of autophagosomes. WIPI1, instead, assists WIPI2 in efficiently recruiting the ATG16L1 complex at the nascent autophagosome, which in turn promotes lipidation of LC3/GABARAP and autophagosome maturation. However, the specific role of WIPI1 and its regulation are unknown. Here, we discovered the ABL-ERK-MYC signalling axis controlling WIPI1. As a result of this signalling, MYC binds to the WIPI1 promoter and represses WIPI1 gene expression. When ABL-ERK-MYC signalling is counteracted, increased WIPI1 gene expression enhances the formation of autophagic membranes capable of migrating through tunnelling nanotubes to neighbouring cells with low autophagic activity. ABL-regulated WIPI1 function is relevant to lifespan control, as ABL deficiency in C. elegans increased gene expression of the WIPI1 orthologue ATG-18 and prolonged lifespan in a manner dependent on ATG-18. We propose that WIPI1 acts as an enhancer of autophagy that is physiologically relevant for regulating the level of autophagic activity over the lifespan.
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Affiliation(s)
- Katharina Sporbeck
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
- International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Biology and Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Maximilian L Haas
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Carmen J Pastor-Maldonado
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - David S Schüssele
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Catherine Hunter
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
- International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Biology and Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Zsuzsanna Takacs
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
- International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Biology and Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
- Institute of Molecular Biotechnology, A-1030, Vienna, Austria
| | - Ana L Diogo de Oliveira
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Mirita Franz-Wachtel
- Proteome Center Tübingen, Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Chara Charsou
- Institute of Basic Medical Sciences, University of Oslo, 0372, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0316, Oslo, Norway
| | - Simon G Pfisterer
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
- Department of Anatomy, Faculty of Medicine, University of Helsinki, FI-00290, Helsinki, Finland
| | - Andrea Gubas
- Institute of Biochemistry II, Frankfurt Cancer Institute, Goethe University Medical School, D-60590, Frankfurt, Germany
| | - Patricia K Haller
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
- International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Biology and Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Roland L Knorr
- Humboldt University of Berlin, Institute of Biology, D-10115, Berlin, Germany
- Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
- International Research Frontiers Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226-8503, Japan
| | - Manuel Kaulich
- Institute of Biochemistry II, Frankfurt Cancer Institute, Goethe University Medical School, D-60590, Frankfurt, Germany
| | - Boris Macek
- International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Biology and Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
- Proteome Center Tübingen, Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany
| | - Eeva-Liisa Eskelinen
- Department of Biosciences, University of Helsinki, Fl-00790, Helsinki, Finland
- Institute of Biomedicine, University of Turku, FI-20520, Turku, Finland
| | - Anne Simonsen
- Institute of Basic Medical Sciences, University of Oslo, 0372, Oslo, Norway
- Centre for Cancer Cell Reprogramming, Institute of Clinical Medicine, University of Oslo, 0316, Oslo, Norway
| | - Tassula Proikas-Cezanne
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076, Tübingen, Germany.
- International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Biology and Eberhard Karls University Tübingen, D-72076, Tübingen, Germany.
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3
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Schüssele DS, Haller PK, Haas ML, Hunter C, Sporbeck K, Proikas-Cezanne T. Autophagy profiling in single cells with open source CellProfiler-based image analysis. Autophagy 2023; 19:338-351. [PMID: 35435815 PMCID: PMC9809960 DOI: 10.1080/15548627.2022.2065617] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Single cell-based analysis of macroautophagy/autophagy is largely achieved through the use of fluorescence microscopy to detect autophagy-related proteins that associate with autophagic membranes and therefore can be quantified as fluorescent puncta. In this context, an automated analysis of the number and size of recognized puncta is preferable to a manual count, because more reliable results can be generated in a short time. Here we present a method for open source CellProfiler software-based analysis for quantitative autophagy assessments using GFP-tagged WIPI1 (WD repeat domain, phosphoinositide interacting 1) images acquired with Airyscan or confocal laser-scanning microscopy. The CellProfiler protocol is provided as a ready-to-use software pipeline, and the creation of this pipeline is detailed in both text and video formats. In addition, we provide CellProfiler pipelines for endogenous SQSTM1/p62 (sequestosome 1) or intracellular lipid droplet (LD) analysis, suitable to assess forms of selective autophagy. All protocols and software pipelines can be quickly and easily adapted for the use of alternative autophagy markers or cell types, and can also be used for high-throughput purposes.Abbreviations: AF Alexa Fluor ATG autophagy related BafA1 bafilomycin A1 BSA bovine serum albumin DAPI 4,6-diamidino-2-phenylindole DMEM Dulbecco's modified Eagle's medium DMSO dimethyl sulfoxide EDTA ethylenediaminetetraacetic acid EBSS Earle's balanced salt solution FBS fetal bovine serum GFP green fluorescent protein LD lipid droplet LSM laser scanning microscope MAP1LC3B microtubule associated protein 1 light chain 3 beta MTOR mechanistic target of rapamycin kinase PBS phosphate-buffered saline PIK3C3/VPS34 phosphatidylinositol 3-kinase catalytic subunit type 3 SQSTM1 sequestosome 1 TIFF tagged image file format U2OS U-2 OS cell line WIPI WD repeat domain, phosphoinositide interacting.
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Affiliation(s)
- David S. Schüssele
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Patricia K. Haller
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany,International Max Planck Research School ‘From Molecules to Organisms’, Max Planck Institute for Developmental Biology and Eberhard Karls University Tübingen, Tübingen, Germany
| | - Maximilian L. Haas
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Catherine Hunter
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany,International Max Planck Research School ‘From Molecules to Organisms’, Max Planck Institute for Developmental Biology and Eberhard Karls University Tübingen, Tübingen, Germany
| | - Katharina Sporbeck
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany,International Max Planck Research School ‘From Molecules to Organisms’, Max Planck Institute for Developmental Biology and Eberhard Karls University Tübingen, Tübingen, Germany
| | - Tassula Proikas-Cezanne
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, Tübingen, Germany,International Max Planck Research School ‘From Molecules to Organisms’, Max Planck Institute for Developmental Biology and Eberhard Karls University Tübingen, Tübingen, Germany,CONTACT Tassula Proikas-Cezanne Interfaculty Institute of Cell Biology, Eberhard Karls University Tübingen, D-72076Tübingen, Germany
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4
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Sun C, Rosenstock TR, Cohen MA, Sarkar S. Autophagy Dysfunction as a Phenotypic Readout in hiPSC-Derived Neuronal Cell Models of Neurodegenerative Diseases. Methods Mol Biol 2022; 2549:103-136. [PMID: 34490597 DOI: 10.1007/7651_2021_420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Autophagy is an evolutionarily conserved catabolic pathway for the degradation of cytoplasmic constituents in eukaryotic cells. It is the primary disposal route for selective removal of undesirable cellular materials like aggregation-prone proteins and damaged organelles for maintaining cellular homeostasis, and for bulk degradation of intracellular macromolecules and recycling the breakdown products for providing energy homeostasis during starvation. These functions of autophagy are attributed to cellular survival and thus pertinent for human health; however, malfunction of this process is detrimental to the cells, particularly for post-mitotic neurons. Thus, basal autophagy is vital for maintaining neuronal homeostasis, whereas autophagy dysfunction contributes to neurodegeneration. Defective autophagy has been demonstrated in several neurodegenerative diseases wherein pharmacological induction of autophagy is beneficial in many of these disease models. Elucidating the mechanisms underlying defective autophagy is imperative for the development of therapies targeting this process. Disease-affected human neuronal cells can be established from patient-derived human induced pluripotent stem cells (hiPSCs) that provide a clinically relevant platform for studying disease mechanisms and drug discovery. Thus, modeling autophagy dysfunction as a phenotypic readout in patient-derived neurons provides a more direct platform for investigating the mechanisms underlying defective autophagy and evaluating the therapeutic efficacy of autophagy inducers. Toward this, several hiPSC-derived neuronal cell models of neurodegenerative diseases have been employed. In this review, we highlight the key methodologies pertaining to hiPSC maintenance and neuronal differentiation, and studying autophagy at an endogenous level in hiPSC-derived neuronal cells.
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Affiliation(s)
- Congxin Sun
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Tatiana R Rosenstock
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- Department of Pharmacology, University of São Paulo, São Paulo, Brazil
| | - Malkiel A Cohen
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA
| | - Sovan Sarkar
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
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5
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Abstract
Autophagy is an adaptive catabolic process functioning to promote cell survival in the event of inappropriate living conditions such as nutrient shortage and to cope with diverse cytotoxic insults. It is regarded as one of the key survival mechanisms of living organisms. Cells undergo autophagy to accomplish the lysosomal digestion of intracellular materials including damaged proteins, organelles, and foreign bodies, in a bulk, non-selective or a cargo-specific manner. Studies in the past decades have shed light on the association of autophagy pathways with various diseases and also highlighted the therapeutic value of autophagy modulation. Hence, it is crucial to develop effective approaches for monitoring intracellular autophagy dynamics, as a comprehensive account of methodology establishment is far from complete. In this review, we aim to provide an overview of the major current fluorescence-based techniques utilized for visualizing, sensing or measuring autophagic activities in cells or tissues, which are categorized firstly by targets detected and further by the types of fluorescence tools. We will mainly focus on the working mechanisms of these techniques, put emphasis on the insight into their roles in biomedical science and provide perspectives on the challenges and future opportunities in this field.
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Affiliation(s)
- Siyang Ding
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne Victoria 3086, Australia.
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6
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Modulation of proliferation factors in lung adenocarcinoma with an analysis of the transcriptional consequences of genomic EGFR activation. Oncotarget 2019; 10:6913-6933. [PMID: 31857847 PMCID: PMC6916753 DOI: 10.18632/oncotarget.27316] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 10/26/2019] [Indexed: 11/25/2022] Open
Abstract
Genes of the pre-replication, pre-initiation and replisome complexes duplicate the genome from many sites once in a normal cell cycle. This study examines complex components in lung adenocarcinoma (LUAD) closely, correlating changes in the genome and transcriptome with proliferation and overall survival. Molecular subtypes (The Cancer Genome Atlas (TCGA), 2014) based on copy number, DNA methylation, and mRNA expression had variable proliferation levels, the highest correlating with decreased survival. A pattern of increased expression typified by POLE2 and POLQ was found for multiple replication factors over thirty-seven tumor types. EGFR altered cases unanticipatedly inversely correlated with proliferation factor expression in LUAD, Colon adenocarcinoma, and Cancer Cell Line Encyclopedia cell lines, but not in glioblastoma or breast cancer. Activation mutations did not uniformly correlate with proliferation, most cases were pre-metastatic. A gene expression profile was identified, and pathway involvement considered. Significantly, results suggest EGFR over expression and activation are early alterations that likely stall the replication complex through PCNA phosphorylation creating replication stress responsible for DNA damage response and further mutation, but does not promote increased proliferation itself. An argument is presented that the mechanism driving lethality in this tumor cohort could differ from over proliferation seen in other LUAD.
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7
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Mueller AJ, Proikas-Cezanne T. Automated Detection of Autophagy Response Using Single Cell-Based Microscopy Assays. Methods Mol Biol 2019; 1880:429-445. [PMID: 30610713 DOI: 10.1007/978-1-4939-8873-0_27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The fluorescence microscopy-based detection of intracellular LC3, p62, and/or WIPI punctate structures is a robust tool to monitor and assess macroautophagy/autophagy in single cells. This method was established for automated high-throughput/content analysis to reliably detect narrow differences in autophagy activity/capacity and to provide screening opportunities for biological and chemical libraries.
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Affiliation(s)
- Amelie J Mueller
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Tübingen, Germany.,International Max Planck Research School "From Molecules to Organisms", Tübingen, Germany
| | - Tassula Proikas-Cezanne
- Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Tübingen, Germany. .,International Max Planck Research School "From Molecules to Organisms", Tübingen, Germany.
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8
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Corona Velazquez AF, Jackson WT. So Many Roads: the Multifaceted Regulation of Autophagy Induction. Mol Cell Biol 2018; 38:e00303-18. [PMID: 30126896 PMCID: PMC6189458 DOI: 10.1128/mcb.00303-18] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Autophagy is an evolutionary conserved, degradative process from single-cell eukaryotes, such as Saccharomyces cerevisiae, to higher mammals, such as humans. The regulation of autophagy has been elucidated through the combined study of yeast, Caenorhabditis elegans, mice, Drosophila melanogaster, and humans. MTOR, the major negative regulator of autophagy, and activating nutrient kinases, such as 5'-AMP-activated protein kinase (AMPK), interact with the autophagy regulatory complex: ULK1/2, RB1CC1, ATG13, and ATG101. The ULK1/2 complex induces autophagy by phosphorylating downstream autophagy complexes, such as the BECN1 PIK3 signaling complex that leads to the creation of LC3+ autophagosomes. We highlight in this review various reports of autophagy induction that are independent of these regulators. We discuss reports of MTOR-independent, AMPK-independent, ULK1/2-independent, and BECN1-PIK3C3-independent autophagy. We illustrate that autophagy induction and the components required vary by the nature of the induction signal and type of cell and do not always require canonical members of the autophagy signaling pathway. We illustrate that rather than thinking of autophagy as a linear pathway, it is better to think of autophagy induction as an interconnecting web of key regulators, many of which can induce autophagy through different requirements depending on the type and length of induction signals.
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Affiliation(s)
- Angel F Corona Velazquez
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - William T Jackson
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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9
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SGK1 Inhibits Autophagy in Murine Muscle Tissue. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:4043726. [PMID: 29849891 PMCID: PMC5937381 DOI: 10.1155/2018/4043726] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/20/2018] [Accepted: 02/20/2018] [Indexed: 11/17/2022]
Abstract
Background/Aims As autophagy is linked to several pathological conditions, like cancer and neurodegenerative diseases, it is crucial to understand its regulatory signaling network. In this study, we investigated the role of the serum- and glucocorticoid-induced protein kinase 1 (SGK1) in the control of autophagy. Methods To measure autophagic activity in vivo, we quantified the abundance of the autophagy conjugates LC3-PE (phosphatidylethanolamine) and ATG12-ATG5 in tissue extracts of SGK1 wild-type (Sgk1+/+) and knockout (Sgk1-/-) mice that were either fed or starved for 24 h prior sacrifice. In vitro, we targeted SGK1 by RNAi using GFP-WIPI1 expressing U-2 OS cells to quantify the numbers of cells displaying newly formed autophagosomes. In parallel, these cells were also assessed with regard to LC3 and ULK1 by quantitative Western blotting. Results The abundance of both LC3-PE (LC3-II) and ATG12-ATG5 was significantly increased in red muscle tissues of SGK1 knockout mice. This was found in particular in fed conditions, suggesting that SGK1 may keep basal autophagy under control in red muscle in vivo. Under starved conditions, significant differences were observed in SGK1-deficient white muscle tissue and, under fed conditions, also in the liver. In vitro, we found that SGK1 silencing provoked a significant increase of cells displaying WIPI1-positive autophagosomes and autophagosomal LC3 (LC3-II). Moreover, autophagic flux assessments revealed that autophagic degradation significantly increased in the absence of SGK1, strongly suggesting that SGK1 inhibits both autophagosome formation and autophagic degradation in vitro. In addition, more ULK1 protein lacking the inhibitory, TORC1-specific phosphorylation at serine 758 was detected in the absence of SGK1. Conclusions Combined, our data strongly support the idea that SGK1 inhibits the process of autophagy. Mechanistically, our data suggest that SGK1 should act upstream of ULK1 in regulating autophagy, and we hypothesize that SGK1 contributes to the regulation of ULK1 gene expression.
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10
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Nguyen HM, Liu S, Daher W, Tan F, Besteiro S. Characterisation of two Toxoplasma PROPPINs homologous to Atg18/WIPI suggests they have evolved distinct specialised functions. PLoS One 2018; 13:e0195921. [PMID: 29659619 PMCID: PMC5901921 DOI: 10.1371/journal.pone.0195921] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/02/2018] [Indexed: 01/20/2023] Open
Abstract
Toxoplasma gondii is a parasitic protist possessing a limited set of proteins involved in the autophagy pathway, a self-degradative machinery for protein and organelle recycling. This distant eukaryote has even repurposed part of this machinery, centered on protein ATG8, for a non-degradative function related to the maintenance of the apicoplast, a parasite-specific organelle. However, some evidence also suggest Toxoplasma is able to generate autophagic vesicles upon stress, and that some autophagy-related proteins, such as ATG9, might be involved solely in the canonical autophagy function. Here, we have characterised TgPROP1 and TgPROP2, two Toxoplasma proteins containing WD-40 repeat that can bind lipids for their recruitment to vesicular structures upon stress. They belong to the PROPPIN family and are homologues to ATG18/WIPI, which are known to be important for the autophagic process. We conducted a functional analysis of these two Toxoplasma PROPPINs. One of them is dispensable for normal in vitro growth, although it may play a role for parasite survival in specific stress conditions or for parasite fitness in the host, through a canonical autophagy-related function. The other, however, seems important for parasite viability in normal growth conditions and could be primarily involved in a non-canonical function. These divergent roles for two proteins from the same family illustrate the functional versatility of the autophagy-related machinery in Toxoplasma.
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Affiliation(s)
- Hoa Mai Nguyen
- DIMNP, UMR5235 CNRS - Université de Montpellier, Montpellier, France
| | - Shuxian Liu
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China
| | - Wassim Daher
- DIMNP, UMR5235 CNRS - Université de Montpellier, Montpellier, France
| | - Feng Tan
- Department of Parasitology, School of Basic Medical Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China
- * E-mail: (FT); (SB)
| | - Sébastien Besteiro
- DIMNP, UMR5235 CNRS - Université de Montpellier, Montpellier, France
- * E-mail: (FT); (SB)
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11
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Das K, Beyene BB, Datta A, Garribba E, Roma-Rodrigues C, Silva A, Fernandes AR, Hung CH. EPR and electrochemical interpretation of bispyrazolylacetate anchored Ni(ii) and Mn(ii) complexes: cytotoxicity and anti-proliferative activity towards human cancer cell lines. NEW J CHEM 2018. [DOI: 10.1039/c8nj01033a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The cytotoxicity and antiproliferative activity are carried out along with EPR and redox interpretation.
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Affiliation(s)
- Kuheli Das
- Institute of Chemistry
- Academia Sinica
- Nankang
- Taipei – 115
- Taiwan
| | | | - Amitabha Datta
- Institute of Chemistry
- Academia Sinica
- Nankang
- Taipei – 115
- Taiwan
| | - Eugenio Garribba
- Dipartimento di Chimica e Farmacia
- Università di Sassari
- I-07100 Sassari
- Italy
| | | | - Ana Silva
- UCIBIO
- DCV
- Faculdade de Ciências e Tecnologia
- Universidade Nova de Lisboa
- 2829-516 Caparica
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12
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Bakula D, Müller AJ, Zuleger T, Takacs Z, Franz-Wachtel M, Thost AK, Brigger D, Tschan MP, Frickey T, Robenek H, Macek B, Proikas-Cezanne T. WIPI3 and WIPI4 β-propellers are scaffolds for LKB1-AMPK-TSC signalling circuits in the control of autophagy. Nat Commun 2017; 8:15637. [PMID: 28561066 PMCID: PMC5460038 DOI: 10.1038/ncomms15637] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 04/13/2017] [Indexed: 12/31/2022] Open
Abstract
Autophagy is controlled by AMPK and mTOR, both of which associate with ULK1 and control the production of phosphatidylinositol 3-phosphate (PtdIns3P), a prerequisite for autophagosome formation. Here we report that WIPI3 and WIPI4 scaffold the signal control of autophagy upstream of PtdIns3P production and have a role in the PtdIns3P effector function of WIPI1-WIPI2 at nascent autophagosomes. In response to LKB1-mediated AMPK stimulation, WIPI4-ATG2 is released from a WIPI4-ATG2/AMPK-ULK1 complex and translocates to nascent autophagosomes, controlling their size, to which WIPI3, in complex with FIP200, also contributes. Upstream, WIPI3 associates with AMPK-activated TSC complex at lysosomes, regulating mTOR. Our WIPI interactome analysis reveals the scaffold functions of WIPI proteins interconnecting autophagy signal control and autophagosome formation. Our functional kinase screen uncovers a novel regulatory link between LKB1-mediated AMPK stimulation that produces a direct signal via WIPI4, and we show that the AMPK-related kinases NUAK2 and BRSK2 regulate autophagy through WIPI4. During autophagy, AMPK and mTOR associate with ULK1 and regulate phosphatidylinositol 3-phosphate (PtdIns3P) production that mediates autophagosome formation via WIPI proteins. Here the authors show WIPI3 and WIPI4 have a scaffolding function upstream of PtdIns3P production and have a role in the PtdIns3P effector function of WIPI1-WIPI2 at nascent autophagosomes.
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Affiliation(s)
- Daniela Bakula
- Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany.,International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
| | - Amelie J Müller
- Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany.,International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
| | - Theresia Zuleger
- Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
| | - Zsuzsanna Takacs
- Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany.,International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
| | - Mirita Franz-Wachtel
- Proteome Center Tuebingen, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
| | - Ann-Katrin Thost
- Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
| | - Daniel Brigger
- Division of Experimental Pathology, Institute of Pathology, University of Bern, CH-3008 Bern, Switzerland
| | - Mario P Tschan
- Division of Experimental Pathology, Institute of Pathology, University of Bern, CH-3008 Bern, Switzerland
| | - Tancred Frickey
- Department of Biology, Applied Bioinformatics, Konstanz University, D-78457 Konstanz, Germany
| | - Horst Robenek
- Institute of Experimental Musculoskeletal Medicine, University Hospital Muenster, D-48149 Muenster, Germany
| | - Boris Macek
- International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany.,Proteome Center Tuebingen, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
| | - Tassula Proikas-Cezanne
- Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany.,International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, D-72076 Tuebingen, Germany
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Walter C, Clemens LE, Müller AJ, Fallier-Becker P, Proikas-Cezanne T, Riess O, Metzger S, Nguyen HP. Activation of AMPK-induced autophagy ameliorates Huntington disease pathology in vitro. Neuropharmacology 2016; 108:24-38. [DOI: 10.1016/j.neuropharm.2016.04.041] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 01/11/2023]
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14
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Reggiori F, Codogno P. Assessing the progression of autophagy pathways in different organisms and tissues. Methods 2015; 75:1-2. [PMID: 25747287 DOI: 10.1016/j.ymeth.2015.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Fulvio Reggiori
- Department of Cell Biology, University Medical Center Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
| | - Patrice Codogno
- Institut Necker Enfants-Malades (INEM), INSERM U1151-CNRS UMR 8253, Université Paris Descartes-Sorbonne Paris Cité, rue Maria Helena Vieira Da Silva 14, 75993 Paris cedex 14, France.
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