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Hmeljak J, Hooper KM. Synergistic modelling of human disease. Dis Model Mech 2024; 17:dmm050755. [PMID: 38415825 PMCID: PMC10924228 DOI: 10.1242/dmm.050755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024] Open
Abstract
Living model systems, ranging in complexity from bacterial culture to non-human primates, are a cornerstone in disease biology research. Despite their unquestionable usefulness, the disease modelling community remains acutely aware of the challenges and limitations of any individual model. To describe our collective predicament, we often (mis)use the quote by statistician George Box, ‘All models are wrong, but some are useful’.
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Affiliation(s)
- Julija Hmeljak
- The Company of Biologists, Bidder Building, Station Road, Histon, Cambridge CB24 9LF, UK
| | - Kirsty M. Hooper
- The Company of Biologists, Bidder Building, Station Road, Histon, Cambridge CB24 9LF, UK
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Hooper KM, Hmeljak J. Supporting the translation of multiscale research in rare disease. Dis Model Mech 2023; 16:dmm050495. [PMID: 37737037 PMCID: PMC10538288 DOI: 10.1242/dmm.050495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023] Open
Abstract
Summary: In anticipation of our upcoming Special Issue, ‘Translating Multiscale Research in Rare Disease’, we celebrate the strides taken in rare disease research that are improving patient diagnosis, prognosis and treatment.
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Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists, Bidder Building, Station Road, Histon, Cambridge CB24 9LF, UK
| | - Julija Hmeljak
- The Company of Biologists, Bidder Building, Station Road, Histon, Cambridge CB24 9LF, UK
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Hooper KM. Welcoming new Editors. Dis Model Mech 2023; 16:dmm050368. [PMID: 37462002 PMCID: PMC10387345 DOI: 10.1242/dmm.050368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023] Open
Affiliation(s)
- Kirsty M Hooper
- The Company of Biologists, Bidder Building, Station Road, Histon, Cambridge CB24 9LF, UK
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Hooper KM. New drugs to squash the spread of malaria. Dis Model Mech 2023. [DOI: 10.1242/dmm.050096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists , Bidder Building, Station Road, Histon, Cambridge CB24 9LF , UK
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Hooper KM. Let's talk about sex… obesity and melanoma. Dis Model Mech 2023. [DOI: 10.1242/dmm.050084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists , Bidder Building, Station Road, Histon, Cambridge CB24 9LF , UK
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Hooper KM. COVID-19's next top model. Dis Model Mech 2022. [DOI: 10.1242/dmm.049972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists , Bidder Building, Station Road, Histon, Cambridge CB24 9LF , UK
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Hooper KM. Reducing the shock factor with new anti-epilepsy drugs. Dis Model Mech 2022. [DOI: 10.1242/dmm.049886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists , Bidder Building, Station Road, Cambridge CB24 9LF , UK
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Abstract
The publication of Resource articles is essential for the dissemination of novel, or substantially enhanced, tools, techniques, disease models, datasets and resources. By sharing knowledge and resources in a globally accessible manner, we can support human disease research to accelerate the translation of fundamental discoveries to effective treatments or diagnostics for diverse patient populations. To promote and encourage excellence in Resource articles, Disease Models & Mechanisms (DMM) is launching a new 'Outstanding Resource Paper Prize'. To celebrate this, we highlight recent outstanding DMM Resource articles that have the ultimate goal of benefitting of human health.
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Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists, Bidder Building, Station Road, Histon, Cambridge CB24 9LF, UK
| | - Julija Hmeljak
- The Company of Biologists, Bidder Building, Station Road, Histon, Cambridge CB24 9LF, UK
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Hooper KM, Jacquin E, Li T, Goodwin JM, Brumell JH, Durgan J, Florey O. V-ATPase is a universal regulator of LC3-associated phagocytosis and non-canonical autophagy. J Cell Biol 2022; 221:213194. [PMID: 35511089 PMCID: PMC9082624 DOI: 10.1083/jcb.202105112] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [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] [Received: 05/25/2021] [Revised: 02/04/2022] [Accepted: 04/15/2022] [Indexed: 12/18/2022] Open
Abstract
Non-canonical autophagy is a key cellular pathway in immunity, cancer, and neurodegeneration, characterized by conjugation of ATG8 to endolysosomal single membranes (CASM). CASM is activated by engulfment (endocytosis, phagocytosis), agonists (STING, TRPML1), and infection (influenza), dependent on K490 in the ATG16L1 WD40-domain. However, factors associated with non-canonical ATG16L1 recruitment and CASM induction remain unknown. Here, using pharmacological inhibitors, we investigate a role for V-ATPase during non-canonical autophagy. We report that increased V0–V1 engagement is associated with, and sufficient for, CASM activation. Upon V0–V1 binding, V-ATPase recruits ATG16L1, via K490, during LC3-associated phagocytosis (LAP), STING- and drug-induced CASM, indicating a common mechanism. Furthermore, during LAP, key molecular players, including NADPH oxidase/ROS, converge on V-ATPase. Finally, we show that LAP is sensitive to Salmonella SopF, which disrupts the V-ATPase–ATG16L1 axis and provide evidence that CASM contributes to the Salmonella host response. Together, these data identify V-ATPase as a universal regulator of CASM and indicate that SopF evolved in part to evade non-canonical autophagy.
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Affiliation(s)
| | - Elise Jacquin
- Signalling Programme, Babraham Institute, Cambridge, UK.,Institut national de la santé et de la recherche médicale UMR-S 1193, Université Paris-Saclay, Châtenay-Malabry, France
| | - Taoyingnan Li
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.,Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - John H Brumell
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.,Cell Biology Program, Hospital for Sick Children, Toronto, Ontario, Canada.,Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,SickKids Inflammatory Bowel Disease Centre, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Joanne Durgan
- Signalling Programme, Babraham Institute, Cambridge, UK
| | - Oliver Florey
- Signalling Programme, Babraham Institute, Cambridge, UK
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Lek M, Hmeljak J, Hooper KM. Genetic variance in human disease - modelling the future of genomic medicine. Dis Model Mech 2022; 15:275862. [PMID: 35771631 PMCID: PMC9254226 DOI: 10.1242/dmm.049700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Summary: DMM is launching a new Subject Focus on genetic variance in human disease. Here, we discuss this ongoing series of invited articles and reflect on advances in understanding the genotype–phenotype complexities in disease.
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Affiliation(s)
- Monkol Lek
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Julija Hmeljak
- The Company of Biologists, Bidder Building, Station Road, Cambridge CB24 9LF, UK
| | - Kirsty M Hooper
- The Company of Biologists, Bidder Building, Station Road, Cambridge CB24 9LF, UK
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Hooper KM. What lies beyond 100 years of insulin. Dis Model Mech 2021; 14:dmm049361. [PMID: 34752619 PMCID: PMC8592014 DOI: 10.1242/dmm.049361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It has been 100 years since the discovery of insulin. This revolutionary treatment saves the lives of millions of people living with diabetes, but much remains to be understood of its mechanisms and roles in homeostasis and disease. To celebrate this centenary, we explore areas of ongoing insulin research in diabetes, metabolic syndrome and beyond. Disease Models & Mechanisms aims to publish high-quality basic and pre-clinical research that advances our understanding of these conditions to facilitate clinical and public health impact.
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Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists, Bidder Building, Station Road, Cambridge CB24 9LF, UK
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Hooper KM, Justice MJ, Patton EE. Developmental disorders Journal Meeting: a collaboration between Development and Disease Models & Mechanisms. Dis Model Mech 2021; 14:272141. [PMID: 34515289 DOI: 10.1242/dmm.049268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Kirsty M Hooper
- The Company of Biologists, Station Road, Histon, Cambridge CB24 9LF, UK
| | - Monica J Justice
- Program in Genetics and Genome Biology, The Hospital for Sick Children, and Department of Molecular Genetics, The University of Toronto, Toronto, Ontario M5G 0A4, Canada
| | - E Elizabeth Patton
- MRC Human Genetics Unit and Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Cancer, The University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK
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Hooper KM, Patton EE. Models and Mechanisms for COVID-19 Research. Dis Model Mech 2021; 14:dmm049163. [PMID: 34165549 PMCID: PMC8246271 DOI: 10.1242/dmm.049163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Kirsty M. Hooper
- The Company of Biologists, Station Road, Histon, Cambridge CB24 9LF, UK
| | - E. Elizabeth Patton
- MRC Human Genetics Unit and Cancer Research UK Edinburgh Centre, MRC Institute of Genetics and Cancer, The University of Edinburgh, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK
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Hooper KM, Casanova V, Kemp S, Staines KA, Satsangi J, Barlow PG, Henderson P, Stevens C. The Inflammatory Bowel Disease Drug Azathioprine Induces Autophagy via mTORC1 and the Unfolded Protein Response Sensor PERK. Inflamm Bowel Dis 2019; 25:1481-1496. [PMID: 30889246 DOI: 10.1093/ibd/izz039] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 01/26/2019] [Accepted: 02/22/2019] [Indexed: 02/05/2023]
Abstract
BACKGROUND Genetic studies have strongly linked autophagy to Crohn's disease (CD), and stimulating autophagy in CD patients may be therapeutically beneficial. The aim of this study was to evaluate the effect of current inflammatory bowel disease (IBD) drugs on autophagy and investigate molecular mechanisms of action and functional outcomes in relation to this cellular process. METHODS Autophagy marker LC3 was evaluated by confocal fluorescence microscopy and flow cytometry. Drug mechanism of action was investigated by polymerase chain reaction (PCR) array with changes in signaling pathways examined by immunoblot and quantitative reverse transcription PCR (RT-qPCR). Clearance of adherent-invasive Escherichia coli (AIEC) and levels of pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) were evaluated by gentamicin protection assays and RT-qPCR, respectively. The marker LC3 was analyzed in peripheral blood mononuclear cells (PBMCs) from pediatric patients by flow cytometry. RESULTS Azathioprine induces autophagy via mechanisms involving modulation of mechanistic target of rapamycin (mTORC1) signaling and stimulation of the unfolded protein response (UPR) sensor PERK. Induction of autophagy with azathioprine correlated with the enhanced clearance of AIEC and dampened AIEC-induced increases in TNFα. Azathioprine induced significant increase in autophagosome bound LC3-II in PBMC populations ex vivo, supporting in vitro findings. In patients, the CD-associated ATG16L1 T300A single-nucleotide polymorphism did not attenuate azathioprine induction of autophagy. CONCLUSIONS Modulation of autophagy via mTORC1 and the UPR may contribute to the therapeutic efficacy of azathioprine in IBD.
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Affiliation(s)
- Kirsty M Hooper
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, Scotland
| | - Victor Casanova
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, Scotland
| | - Sadie Kemp
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, Scotland
| | - Katherine A Staines
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, Scotland
| | - Jack Satsangi
- Centre for Genomic & Experimental Medicine, University of Edinburgh, Western General Hospital Campus, Crewe Road, Edinburgh Scotland.,Translational Gastroenterology Unit, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, England
| | - Peter G Barlow
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, Scotland
| | - Paul Henderson
- Child Life and Health, University of Edinburgh, Edinburgh, Scotland.,Department of Pediatric Gastroenterology and Nutrition, Royal Hospital for Sick Children, Edinburgh, Scotland
| | - Craig Stevens
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, Scotland
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Hooper KM, Barlow PG, Henderson P, Stevens C. Interactions Between Autophagy and the Unfolded Protein Response: Implications for Inflammatory Bowel Disease. Inflamm Bowel Dis 2019; 25:661-671. [PMID: 30590697 DOI: 10.1093/ibd/izy380] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Indexed: 02/06/2023]
Abstract
Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis, is characterized by chronic inflammation of the gastrointestinal tract. The etiology involves a combination of genetic and environmental factors resulting in abnormal immune responses to intestinal microbiota. Genetic studies have strongly linked genes involved in autophagy to CD, and genes involved in the unfolded protein response (UPR) to IBD. The UPR is triggered in response to accumulation of misfolded proteins in the endoplasmic reticulum (ER), and autophagy plays a key role in relieving ER stress and restoring homeostasis. This review summarizes the known interactions between autophagy and the UPR and discusses the impact of these converging pathways on IBD pathogenesis. With a paucity of effective long-term treatments for IBD, targeting of synergistic pathways may provide novel and more effective therapeutic options.
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Affiliation(s)
- Kirsty M Hooper
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, United Kingdom
| | - Peter G Barlow
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, United Kingdom
| | - Paul Henderson
- Child Life and Health, University of Edinburgh, Edinburgh, United Kingdom.,Department of Paediatric Gastroenterology and Nutrition, Royal Hospital for Sick Children, Edinburgh, United Kingdom
| | - Craig Stevens
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, United Kingdom
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Biskou O, Casanova V, Hooper KM, Kemp S, Wright GP, Satsangi J, Barlow PG, Stevens C. The type III intermediate filament vimentin regulates organelle distribution and modulates autophagy. PLoS One 2019; 14:e0209665. [PMID: 30699149 PMCID: PMC6353089 DOI: 10.1371/journal.pone.0209665] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 12/10/2018] [Indexed: 12/21/2022] Open
Abstract
The cytoskeletal protein vimentin plays a key role in positioning of organelles within the cytosol and has been linked to the regulation of numerous cellular processes including autophagy, however, how vimentin regulates autophagy remains relatively unexplored. Here we report that inhibition of vimentin using the steroidal lactone Withaferin A (WFA) causes vimentin to aggregate, and this is associated with the relocalisation of organelles including autophagosomes and lysosomes from the cytosol to a juxtanuclear location. Vimentin inhibition causes autophagosomes to accumulate, and we demonstrate this results from modulation of mechanistic target of rapamycin (mTORC1) activity, and disruption of autophagosome-lysosome fusion. We suggest that vimentin plays a physiological role in autophagosome and lysosome positioning, thus identifying vimentin as a key factor in the regulation of mTORC1 and autophagy.
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Affiliation(s)
- Olga Biskou
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, United Kingdom
| | - Victor Casanova
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, United Kingdom
| | - Kirsty M. Hooper
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, United Kingdom
| | - Sadie Kemp
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, United Kingdom
| | - Graham P. Wright
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, United Kingdom
| | - Jack Satsangi
- Centre for Genomic & Experimental Medicine, University of Edinburgh, Western General Hospital Campus, Crewe Road, Edinburgh, United Kingdom
- Translational Gastroenterology Unit, Nuffield Department of Medicine, John Radcliffe Hospital, Oxford, United Kingdom
| | - Peter G. Barlow
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, United Kingdom
| | - Craig Stevens
- School of Applied Sciences, Edinburgh Napier University, Sighthill Campus, Sighthill Court, Edinburgh, United Kingdom
- * E-mail:
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Abstract
Inflammatory bowel disease [IBD] is characterized by chronic inflammation of the gastrointestinal tract. Medications such as corticosteroids, thiopurines, immunomodulators and biologic agents are used to induce and maintain remission; however, response to these drugs is variable and can diminish over time. Defective autophagy has been strongly linked to IBD pathogenesis, with evidence showing that enhancing autophagy may be therapeutically beneficial by regulating inflammation and clearing intestinal pathogens. It is plausible that the therapeutic effects of some IBD drugs are mediated in part through modulation of the autophagy pathway, with studies investigating a wide range of diseases and cell types demonstrating autophagy pathway regulation by these agents. This review will highlight the current evidence, both in vitro and in vivo, for the modulation of autophagy by drugs routinely used in IBD. A clearer understanding of their mechanisms of action will be invaluable to utilize these drugs in a more targeted and personalized manner in this diverse and often complex group of patients.
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Affiliation(s)
- Kirsty M. Hooper
- School of Life, Sport & Social Sciences, Edinburgh Napier University, Edinburgh, UK
| | - Peter G. Barlow
- School of Life, Sport & Social Sciences, Edinburgh Napier University, Edinburgh, UK
| | - Craig Stevens
- School of Life, Sport & Social Sciences, Edinburgh Napier University, Edinburgh, UK
| | - Paul Henderson
- Child Life and Health, University of Edinburgh, Edinburgh, UK,Department of Paediatric Gastroenterology and Nutrition, Royal Hospital for Sick Children, Edinburgh, UK
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Hooper KM, Boletta A, Germino GG, Hu Q, Ziegelstein RC, Sutters M. Expression of polycystin-1 enhances endoplasmic reticulum calcium uptake and decreases capacitative calcium entry in ATP-stimulated MDCK cells. Am J Physiol Renal Physiol 2005; 289:F521-30. [PMID: 15870383 DOI: 10.1152/ajprenal.00355.2004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Autosomal dominant polycystic kidney disease (ADPKD) types 1 and 2 arise as a consequence of mutations in the PKD1 or PKD2 genes, encoding polycystins-1 and -2. Because loss of function of either of the polycystins leads to a very similar phenotype and the two proteins are known to interact, polycystins-1 and -2 are probably active in the same pathway. The way in which loss of either polycystin leads to the development of ADPKD remains to be established, but disturbances of cell calcium regulation are likely to play an important role. Here, we demonstrate that polycystin-1, heterologously expressed in Madin-Darby canine kidney cells, had a pronounced effect on intracellular calcium homeostasis. ATP-induced calcium responses in transfection control cells exhibited a double peak and relatively gradual return to baseline. By contrast, cells expressing heterologous polycystin-1 showed a brief, uniphasic peak and an accelerated rate of decay. Heterologously expressed polycystin-1 accelerated endoplasmic reticulum (ER) calcium reuptake and inhibited capacitative calcium entry; we found no effect of the protein on mitochondrial calcium buffering or plasma membrane calcium extrusion. We therefore propose that polycystin-1 accelerated the decay of the cell calcium response to ATP by upregulation of ER calcium reuptake and consequent minimization of the stimulus for capacitative calcium entry. It is possible that cellular dedifferentiation, fluid secretion, and proliferation might therefore arise in ADPKD as a consequence of disturbances in cytoplasmic and ER calcium homeostasis and aberrant capacitative calcium entry.
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Affiliation(s)
- K M Hooper
- Div. of Renal Medicine, Johns Hopkins Bayview Medical Ctr., 4940 Eastern Ave., Baltimore, MD 21224, USA
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