1
|
Stoika R, Gudimchuk N, Shcherbata HR, Zaraisky A, Shcheglovitov O, Kozorovitskiy Y, Korolchuk V. The voices of Ukrainian and Russian scientists. Cell 2022; 185:1283-1286. [PMID: 35390273 DOI: 10.1016/j.cell.2022.03.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 03/18/2022] [Accepted: 03/22/2022] [Indexed: 11/25/2022]
Abstract
The brutal attack on Ukraine by the Russian Federation has shocked the world. While the world works to end the violence and help refugees, as a scientific journal, our thoughts are also with those in the scientific community who are directly or indirectly impacted by the war. We have been inspired by and applaud the labs around the world that have opened their doors to displaced scientists and remain committed to supporting scientists, whoever and wherever they are. Because science requires collaboration and trust, we urge the scientific community to continue efforts like this and to remain united, especially in times as difficult as these. In this Voices piece, we feature short comments from scientists from Ukraine and scientists from Russia. This small sampling is far from exhaustive, but our sincere thanks go to those scientists who were willing to share their thoughts on this volatile and emotionally charged situation; the views expressed are those of the contributors alone. We join the world in hoping for a swift resolution to the conflict, for the good of humanity.
Collapse
|
2
|
Georgiou M, Yang C, Atkinson R, Pan K, Buskin A, Molina MM, Collin J, Al‐Aama J, Goertler F, Ludwig SEJ, Davey T, Lührmann R, Nagaraja‐Grellscheid S, Johnson CA, Ali R, Armstrong L, Korolchuk V, Urlaub H, Mozaffari‐Jovin S, Lako M. Activation of autophagy reverses progressive and deleterious protein aggregation in PRPF31 patient-induced pluripotent stem cell-derived retinal pigment epithelium cells. Clin Transl Med 2022; 12:e759. [PMID: 35297555 PMCID: PMC8926896 DOI: 10.1002/ctm2.759] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 01/18/2023] Open
Abstract
INTRODUCTION Mutations in pre-mRNA processing factor 31 (PRPF31), a core protein of the spliceosomal tri-snRNP complex, cause autosomal-dominant retinitis pigmentosa (adRP). It has remained an enigma why mutations in ubiquitously expressed tri-snRNP proteins result in retina-specific disorders, and so far, the underlying mechanism of splicing factors-related RP is poorly understood. METHODS We used the induced pluripotent stem cell (iPSC) technology to generate retinal organoids and RPE models from four patients with severe and very severe PRPF31-adRP, unaffected individuals and a CRISPR/Cas9 isogenic control. RESULTS To fully assess the impacts of PRPF31 mutations, quantitative proteomics analyses of retinal organoids and RPE cells were carried out showing RNA splicing, autophagy and lysosome, unfolded protein response (UPR) and visual cycle-related pathways to be significantly affected. Strikingly, the patient-derived RPE and retinal cells were characterised by the presence of large amounts of cytoplasmic aggregates containing the mutant PRPF31 and misfolded, ubiquitin-conjugated proteins including key visual cycle and other RP-linked tri-snRNP proteins, which accumulated progressively with time. The mutant PRPF31 variant was not incorporated into splicing complexes, but reduction of PRPF31 wild-type levels led to tri-snRNP assembly defects in Cajal bodies of PRPF31 patient retinal cells, altered morphology of nuclear speckles and reduced formation of active spliceosomes giving rise to global splicing dysregulation. Moreover, the impaired waste disposal mechanisms further exacerbated aggregate formation, and targeting these by activating the autophagy pathway using Rapamycin reduced cytoplasmic aggregates, leading to improved cell survival. CONCLUSIONS Our data demonstrate that it is the progressive aggregate accumulation that overburdens the waste disposal machinery rather than direct PRPF31-initiated mis-splicing, and thus relieving the RPE cells from insoluble cytoplasmic aggregates presents a novel therapeutic strategy that can be combined with gene therapy studies to fully restore RPE and retinal cell function in PRPF31-adRP patients.
Collapse
Affiliation(s)
- Maria Georgiou
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| | - Chunbo Yang
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| | - Robert Atkinson
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| | - Kuan‐Ting Pan
- Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Adriana Buskin
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| | | | - Joseph Collin
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| | - Jumana Al‐Aama
- Faculty of MedicineKing Abdulaziz UniversitySaudi Arabia
| | | | | | - Tracey Davey
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| | | | | | | | | | - Lyle Armstrong
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| | | | - Henning Urlaub
- Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
- Bioanalytics, Department of Clinical ChemistryUniversity Medical CenterGoettingenGermany
| | - Sina Mozaffari‐Jovin
- Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
- Medical Genetics Research CenterMashhad University of Medical SciencesMashhadIran
- Department of Medical Genetics, Faculty of MedicineMashhad University of Medical SciencesMashhadIran
| | - Majlinda Lako
- Newcastle University Biosciences InstituteNewcastle upon TyneUK
| |
Collapse
|
3
|
Hallam D, Collin J, Bojic S, Chichagova V, Buskin A, Xu Y, Lafage L, Otten EG, Anyfantis G, Mellough C, Przyborski S, Alharthi S, Korolchuk V, Lotery A, Saretzki G, McKibbin M, Armstrong L, Steel D, Kavanagh D, Lako M. An Induced Pluripotent Stem Cell Patient Specific Model of Complement Factor H (Y402H) Polymorphism Displays Characteristic Features of Age-Related Macular Degeneration and Indicates a Beneficial Role for UV Light Exposure. Stem Cells 2017; 35:2305-2320. [PMID: 28913923 PMCID: PMC5698780 DOI: 10.1002/stem.2708] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/21/2017] [Accepted: 09/07/2017] [Indexed: 11/11/2022]
Abstract
Age-related macular degeneration (AMD) is the most common cause of blindness, accounting for 8.7% of all blindness globally. Vision loss is caused ultimately by apoptosis of the retinal pigment epithelium (RPE) and overlying photoreceptors. Treatments are evolving for the wet form of the disease; however, these do not exist for the dry form. Complement factor H polymorphism in exon 9 (Y402H) has shown a strong association with susceptibility to AMD resulting in complement activation, recruitment of phagocytes, RPE damage, and visual decline. We have derived and characterized induced pluripotent stem cell (iPSC) lines from two subjects without AMD and low-risk genotype and two patients with advanced AMD and high-risk genotype and generated RPE cells that show local secretion of several proteins involved in the complement pathway including factor H, factor I, and factor H-like protein 1. The iPSC RPE cells derived from high-risk patients mimic several key features of AMD including increased inflammation and cellular stress, accumulation of lipid droplets, impaired autophagy, and deposition of "drüsen"-like deposits. The low- and high-risk RPE cells respond differently to intermittent exposure to UV light, which leads to an improvement in cellular and functional phenotype only in the high-risk AMD-RPE cells. Taken together, our data indicate that the patient specific iPSC model provides a robust platform for understanding the role of complement activation in AMD, evaluating new therapies based on complement modulation and drug testing. Stem Cells 2017;35:2305-2320.
Collapse
Affiliation(s)
- Dean Hallam
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Joseph Collin
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Sanja Bojic
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Valeria Chichagova
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Adriana Buskin
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Yaobo Xu
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Lucia Lafage
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Elsje G Otten
- Campus for Ageing and Vitality, Institute for Cell and Molecular Biosciences and Institute for Ageing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - George Anyfantis
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Carla Mellough
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Stefan Przyborski
- Department of Biosciences, Durham University, Durham, United Kingdom
| | - Sameer Alharthi
- Princess Al Jawhara Al-Brahim Centre of Excellence in Research of Hereditary Disorders, King Abdulaziz University, Saudi Arabia
| | - Viktor Korolchuk
- Campus for Ageing and Vitality, Institute for Cell and Molecular Biosciences and Institute for Ageing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Andrew Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Gabriele Saretzki
- Campus for Ageing and Vitality, Institute for Cell and Molecular Biosciences and Institute for Ageing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Lyle Armstrong
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - David Steel
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - David Kavanagh
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| | - Majlinda Lako
- Institute of Genetic Medicine, International Centre for Life, United Kingdom
| |
Collapse
|
4
|
Jurk D, Wang C, Miwa S, Maddick M, Korolchuk V, Tsolou A, Gonos ES, Thrasivoulou C, Jill Saffrey M, Cameron K, von Zglinicki T. Postmitotic neurons develop a p21-dependent senescence-like phenotype driven by a DNA damage response. Aging Cell 2012; 11:996-1004. [PMID: 22882466 PMCID: PMC3533793 DOI: 10.1111/j.1474-9726.2012.00870.x] [Citation(s) in RCA: 362] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In senescent cells, a DNA damage response drives not only irreversible loss of replicative capacity but also production and secretion of reactive oxygen species (ROS) and bioactive peptides including pro-inflammatory cytokines. This makes senescent cells a potential cause of tissue functional decline in aging. To our knowledge, we show here for the first time evidence suggesting that DNA damage induces a senescence-like state in mature postmitotic neurons in vivo. About 40–80% of Purkinje neurons and 20–40% of cortical, hippocampal and peripheral neurons in the myenteric plexus from old C57Bl/6 mice showed severe DNA damage, activated p38MAPkinase, high ROS production and oxidative damage, interleukin IL-6 production, heterochromatinization and senescence-associated β-galactosidase activity. Frequencies of these senescence-like neurons increased with age. Short-term caloric restriction tended to decrease frequencies of positive cells. The phenotype was aggravated in brains of late-generation TERC−/− mice with dysfunctional telomeres. It was fully rescued by loss of p21(CDKN1A) function in late-generation TERC−/−CDKN1A−/− mice, indicating p21 as the necessary signal transducer between DNA damage response and senescence-like phenotype in neurons, as in senescing fibroblasts and other proliferation-competent cells. We conclude that a senescence-like phenotype is possibly not restricted to proliferation-competent cells. Rather, dysfunctional telomeres and/or accumulated DNA damage can induce a DNA damage response leading to a phenotype in postmitotic neurons that resembles cell senescence in multiple features. Senescence-like neurons might be a source of oxidative and inflammatory stress and a contributor to brain aging.
Collapse
Affiliation(s)
- Diana Jurk
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Chunfang Wang
- Department of Life Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - Satomi Miwa
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Mandy Maddick
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Viktor Korolchuk
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Avgi Tsolou
- National Hellenic Research Foundation, Institute of Biological Research and Biotechnology, Athens, Greece
| | - Efstathios S. Gonos
- National Hellenic Research Foundation, Institute of Biological Research and Biotechnology, Athens, Greece
| | | | - M. Jill Saffrey
- Department of Life Sciences, The Open University, Milton Keynes MK7 6AA, UK
| | - Kerry Cameron
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| | - Thomas von Zglinicki
- Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne NE4 5PL, UK
| |
Collapse
|
5
|
Rubinsztein DC, Cuervo AM, Ravikumar B, Sarkar S, Korolchuk V, Kaushik S, Klionsky DJ. In search of an "autophagomometer". Autophagy 2009; 5:585-9. [PMID: 19411822 DOI: 10.4161/auto.5.5.8823] [Citation(s) in RCA: 445] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Recent years have seen the realization that macroautophagy (which we will call autophagy) is not only important in yeast but is necessary for diverse functions in plants and animals. Importantly, autophagy can have an impact on human pathologies including infectious diseases, cancers, and neurodegenerative conditions. Thus, we need to be able to measure autophagy accurately in order to understand how it can be regulated physiologically and with exogenous agents.
Collapse
|
6
|
Rollason R, Korolchuk V, Hamilton C, Jepson M, Banting G. A CD317/tetherin-RICH2 complex plays a critical role in the organization of the subapical actin cytoskeleton in polarized epithelial cells. ACTA ACUST UNITED AC 2009; 184:721-36. [PMID: 19273615 PMCID: PMC2686410 DOI: 10.1083/jcb.200804154] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
CD317/tetherin is a lipid raft–associated integral membrane protein with a novel topology. It has a short N-terminal cytosolic domain, a conventional transmembrane domain, and a C-terminal glycosyl-phosphatidylinositol anchor. We now show that CD317 is expressed at the apical surface of polarized epithelial cells, where it interacts indirectly with the underlying actin cytoskeleton. CD317 is linked to the apical actin network via the proteins RICH2, EBP50, and ezrin. Knocking down expression of either CD317 or RICH2 gives rise to the same phenotype: a loss of the apical actin network with concomitant loss of apical microvilli, an increase in actin bundles at the basal surface, and a reduction in cell height without any loss of tight junctions, transepithelial resistance, or the polarized targeting of apical and basolateral membrane proteins. Thus, CD317 provides a physical link between lipid rafts and the apical actin network in polarized epithelial cells and is crucial for the maintenance of microvilli in such cells.
Collapse
Affiliation(s)
- Ruth Rollason
- Department of Biochemistry, University of Bristol, Bristol BS8 1TD, England, UK
| | | | | | | | | |
Collapse
|
7
|
Sarkar S, Korolchuk V, Renna M, Winslow A, Rubinsztein DC. Methodological considerations for assessing autophagy modulators: a study with calcium phosphate precipitates. Autophagy 2009; 5:307-13. [PMID: 19182529 DOI: 10.4161/auto.5.3.7664] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Autophagy has been implicated in various physiological and disease conditions in recent years. A number of small molecule modulators have been identified, both as tools and as potential therapeutics. Despite extensive characterization of autophagy in yeast, mammalian autophagy pathways are not fully understood. Recently, calcium phosphate precipitates (CPP), which are used to transfect DNA into cells, were reported to induce autophagy, when assayed up to 6 h after treatment. Because of the widespread use of this reagent, we attempted to confirm these findings. Consistent with the previous study, we showed that CPP induces autophagosome synthesis at early time points, such as 4 h and 6 h. However, at 24 h after treatment, we were surprised to see that autophagy flux was reduced, due to impaired autophagosome-lysosome fusion. At this time point, there was an accumulation of autophagy substrates and the formation of abnormally large autophagosomes. Thus, one may need to consider assaying autophagy modulators at different time points with a range of assays in order to understand their effects. Finally, the complex consequences of CPP on autophagy suggest that it is best avoided as a transfection reagent in studies aiming to analyze autophagy itself, or processes that are modulated by autophagy, like apoptosis.
Collapse
Affiliation(s)
- Sovan Sarkar
- Department of Medical Genetics, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, UK
| | | | | | | | | |
Collapse
|
8
|
Rollason R, Korolchuk V, Hamilton C, Schu P, Banting G. Clathrin-mediated endocytosis of a lipid-raft-associated protein is mediated through a dual tyrosine motif. J Cell Sci 2007; 120:3850-8. [DOI: 10.1242/jcs.003343] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
We have previously shown that the integral membrane protein CD317 has both a conventional transmembrane domain near its N-terminus and a C-terminal glycosyl-phosphatidylinositol (GPI) anchor. With the possible exception of a minor topological variant of the prion protein, there remain no other convincing examples of a mammalian protein with such a topology. CD317 is localised to cholesterol-rich lipid microdomains (`lipid rafts') in the plasma membrane and is internalised from the cell surface for delivery to a juxta-nuclear compartment (most probably the TGN). We have now investigated the mechanism by which CD317 is internalised and find that this raft-associated integral membrane protein is internalised through a clathrin-dependent pathway, internalisation is dependent upon a novel dual-tyrosine-based motif in the cytosolic domain of CD317, the cytosolic domain of CD317 can interact with the μ subunits of the AP2 and AP1 adaptor complexes, interaction with AP1 is required for delivery of CD317 back to the TGN, and removal of the GPI anchor from CD317 reduces the efficiency of CD317 internalisation. Collectively, these data indicate that CD317 is internalised and delivered back to the TGN by the sequential action of AP2 and AP1 adaptor complexes and that, surprisingly, the clathrin-mediated internalisation of CD317 occurs more efficiently if CD317 is localised to lipid rafts.
Collapse
Affiliation(s)
- Ruth Rollason
- Department of Biochemistry, University of Bristol, Bristol, BS8 1T, UK
| | - Viktor Korolchuk
- Department of Biochemistry, University of Bristol, Bristol, BS8 1T, UK
| | - Clare Hamilton
- Department of Biochemistry, University of Bristol, Bristol, BS8 1T, UK
| | - Peter Schu
- Zentrum für Biochemie und Molekulare Zellbiologie, Universität Goettingen, Germany
| | - George Banting
- Department of Biochemistry, University of Bristol, Bristol, BS8 1T, UK
| |
Collapse
|
9
|
Abstract
An expression screen of a rat cDNA library for sequences encoding Golgi-localized integral membrane proteins identified a protein with an apparent novel topology, i.e. with both an N-terminal transmembrane domain and a C-terminal glycosyl-phosphatidylinositol (GPI) anchor. Our data are consistent with this. Thus, the protein would have a topology that, in mammalian cells, is shared only by a minor, but pathologically important, topological isoform of the prion protein (PrP). The human orthologue of this protein has been described previously (BST-2 or HM1.24 antigen) as a cell surface molecule that appears to be involved in early pre-B-cell development and which is present at elevated levels at the surface of myeloma cells. We show that rat BST-2/HM1.24 has both a cell surface and an intracellular (juxtanuclear) location and is efficiently internalized from the cell surface. We also show that the cell surface pool of BST-2/HM1.24 is predominantly present in the apical plasma membrane of polarized cells. The fact that rat BST-2/HM1.24 apparently possesses a GPI anchor led us to speculate that it might exist in cholesterol-rich lipid microdomains (lipid rafts) at the plasma membrane. Data from several experiments are consistent with this localization. We present a model in which BST-2/HM1.24 serves to link adjacent lipid rafts within the plasma membrane.
Collapse
Affiliation(s)
- Sabine Kupzig
- Department of Biochemistry, University of Bristol, Bristol BS8 1TD, UK
| | | | | | | | | | | |
Collapse
|
10
|
Abstract
The process of clathrin-coated vesicle (CCV) formation/disassembly has been studied intensively, and numerous proteins have been identified which aid this process. We have learnt a great deal about individual components of the CCV machinery, and now the ultimate aim is to elucidate the mechanisms regulating clathrin-mediated trafficking. One of the fundamental processes governing the complicated network of interactions is phosphorylation. It has been known for some time that several proteins associated with clathrin-coated vesicles are substrates for protein kinases. These proteins include clathrin, three of the four adaptor complex subunits, dynamin 1, synaptojanin 1 and the amphiphysins. However, the identities of the kinases involved in this process remained largely unknown until recently. This short review discusses advances in our knowledge of how CCV formation/disassembly is regulated by the phosphorylation/dephosphorylation cycle and the role played by specific protein kinases in that process.
Collapse
Affiliation(s)
- V Korolchuk
- Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | | |
Collapse
|