1
|
Wang YH, Sheetz MP. When PIP 2 Meets p53: Nuclear Phosphoinositide Signaling in the DNA Damage Response. Front Cell Dev Biol 2022; 10:903994. [PMID: 35646908 PMCID: PMC9136457 DOI: 10.3389/fcell.2022.903994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 04/19/2022] [Indexed: 11/13/2022] Open
Abstract
The mechanisms that maintain genome stability are critical for preventing tumor progression. In the past decades, many strategies were developed for cancer treatment to disrupt the DNA repair machinery or alter repair pathway selection. Evidence indicates that alterations in nuclear phosphoinositide lipids occur rapidly in response to genotoxic stresses. This implies that nuclear phosphoinositides are an upstream element involved in DNA damage signaling. Phosphoinositides constitute a new signaling interface for DNA repair pathway selection and hence a new opportunity for developing cancer treatment strategies. However, our understanding of the underlying mechanisms by which nuclear phosphoinositides regulate DNA damage repair, and particularly the dynamics of those processes, is rather limited. This is partly because there are a limited number of techniques that can monitor changes in the location and/or abundance of nuclear phosphoinositide lipids in real time and in live cells. This review summarizes our current knowledge regarding the roles of nuclear phosphoinositides in DNA damage response with an emphasis on the dynamics of these processes. Based upon recent findings, there is a novel model for p53's role with nuclear phosphoinositides in DNA damage response that provides new targets for synthetic lethality of tumors.
Collapse
Affiliation(s)
| | - Michael P. Sheetz
- Biochemistry and Molecular Biology Dept., University of Texas Medical Branch, Galveston, TX, United States
| |
Collapse
|
2
|
Lacalle-Aurioles M, Trigiani LJ, Bourourou M, Lecrux C, Hamel E. Alzheimer's disease and cerebrovascular pathology alter brain endothelial inward rectifier potassium (K IR 2.1) channels. Br J Pharmacol 2021; 179:2259-2274. [PMID: 34820829 PMCID: PMC9304142 DOI: 10.1111/bph.15751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 11/03/2021] [Accepted: 11/08/2021] [Indexed: 11/27/2022] Open
Abstract
Background and Purpose Inward rectifier potassium (KIR) channels are key effectors of vasodilatation in neurovascular coupling (NVC). KIR channels expressed in cerebral endothelial cells (ECs) have been confirmed as essential modulators of NVC. Alzheimer's disease (AD) and cerebrovascular disease (CVD) impact on EC‐KIR channel function, but whether oxidative stress or inflammation explains this impairment remains elusive. Experimental Approach We evaluated KIR channel function in intact and EC‐denuded pial arteries of wild‐type (WT) and transgenic mice overexpressing a mutated form of the human amyloid precursor protein (APP mice, recapitulating amyloid β‐induced oxidative stress seen in AD) or a constitutively active form of TGF‐β1 (TGF mice, recapitulating inflammation seen in cerebrovascular pathology). The benefits of antioxidant (catalase) or anti‐inflammatory (indomethacin) drugs also were investigated. Vascular and neuronal components of NVC were assessed in vivo. Key Results Our findings show that (i) KIR channel‐mediated maximal vasodilatation in APP and TGF mice reaches only 37% and 10%, respectively, of the response seen in WT mice; (ii) KIR channel dysfunction results from KIR2.1 subunit impairment; (iii) about 50% of K+‐induced artery dilatation is mediated by EC‐KIR channels; (iv) oxidative stress and inflammation impair KIR channel function, which can be restored by antioxidant and anti‐inflammatory drugs; and (v) inflammation induces KIR2.1 overexpression and impairs NVC in TGF mice. Conclusion and Implications Therapies targeting both oxidative stress and inflammation are necessary for full recovery of KIR2.1 channel function in cerebrovascular pathology caused by AD and CVD.
Collapse
Affiliation(s)
- María Lacalle-Aurioles
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Lianne J Trigiani
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Miled Bourourou
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Clotilde Lecrux
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Edith Hamel
- Laboratory of Cerebrovascular Research, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| |
Collapse
|
3
|
Hans S, Fatima Z, Hameed S. Mass spectrometry-based untargeted lipidomics reveals new compositional insights into membrane dynamics of Candida albicans under magnesium deprivation. J Appl Microbiol 2021; 132:978-993. [PMID: 34424599 DOI: 10.1111/jam.15265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/16/2021] [Accepted: 08/18/2021] [Indexed: 11/29/2022]
Abstract
AIMS There is growing appreciation in adopting new approaches to disrupt multidrug resistance in human fungal pathogen, Candida albicans. The plasma membrane of C. albicans comprises potential lipid moieties that contribute towards the survival of pathogen and could be utilized as antifungal targets. Considering promising applications of developments in mass spectrometry (MS)-based lipidomics technology, the aim of the study was to analyse lipidome profile and expose lipid-dependent changes in response to Mg deprivation. METHODS AND RESULTS We found that both phosphatidylcholine (PC) and lysophosphatidylcholine (LysoPC) were decreased. Increased flip (inward translocation) in the fluorophore labelled NBD-PC was ascribed to enhanced PC-specific flippase activity. Furthermore, a decrease in phosphatidylethanolamine (PE) leading to altered membrane fluidity and loss of cellular material was prominent. Additionally, we observed decreased phosphatidylglycerol (PG) and phosphatidylinositol (PI) leading to genotoxic stress. Besides, we could detect enhanced levels of phosphatidylserine (PS), diacylglycerol (DAG) and triacylglycerides (TAG). The altered gene expressions of lipid biosynthetic pathway by RT-PCR correlated with the lipidome profile. Lastly, we explored abrogated ionic (Na+ and K+ ) transport across the plasma membrane. CONCLUSIONS We propose that C. albicans exposed to Mg deprivation could reorganize plasma membrane (lipid species, membrane fluidity and ionic transport), and possibly redirected carbon flux to store energy in TAGs as an adaptive stress response. This work unravels several vulnerable targets governing lipid metabolism in C. albicans and pave way for better antifungal strategies. SIGNIFICANCE AND IMPACT OF THE STUDY This study demonstrates that magnesium availability is important when one considers dissecting drug resistance mechanisms in Candida albicans. Through mass spectrometry (MS)-based lipidomics technology, the study analyses lipidome profile and exposes lipid-dependent changes that are vulnerable to magnesium availability and presents an opportunity to employ this new information in improving treatment strategies.
Collapse
Affiliation(s)
- Sandeep Hans
- Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurugram, India
| | - Zeeshan Fatima
- Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurugram, India
| | - Saif Hameed
- Amity Institute of Biotechnology, Amity University Haryana, Manesar, Gurugram, India
| |
Collapse
|
4
|
Bousquet J, Czarlewski W, Zuberbier T, Mullol J, Blain H, Cristol JP, De La Torre R, Pizarro Lozano N, Le Moing V, Bedbrook A, Agache I, Akdis CA, Canonica GW, Cruz AA, Fiocchi A, Fonseca JA, Fonseca S, Gemicioğlu B, Haahtela T, Iaccarino G, Ivancevich JC, Jutel M, Klimek L, Kraxner H, Kuna P, Larenas-Linnemann DE, Martineau A, Melén E, Okamoto Y, Papadopoulos NG, Pfaar O, Regateiro FS, Reynes J, Rolland Y, Rouadi PW, Samolinski B, Sheikh A, Toppila-Salmi S, Valiulis A, Choi HJ, Kim HJ, Anto JM. Potential Interplay between Nrf2, TRPA1, and TRPV1 in Nutrients for the Control of COVID-19. Int Arch Allergy Immunol 2021; 182:324-338. [PMID: 33567446 PMCID: PMC8018185 DOI: 10.1159/000514204] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 12/15/2020] [Indexed: 12/16/2022] Open
Abstract
In this article, we propose that differences in COVID-19 morbidity may be associated with transient receptor potential ankyrin 1 (TRPA1) and/or transient receptor potential vanilloid 1 (TRPV1) activation as well as desensitization. TRPA1 and TRPV1 induce inflammation and play a key role in the physiology of almost all organs. They may augment sensory or vagal nerve discharges to evoke pain and several symptoms of COVID-19, including cough, nasal obstruction, vomiting, diarrhea, and, at least partly, sudden and severe loss of smell and taste. TRPA1 can be activated by reactive oxygen species and may therefore be up-regulated in COVID-19. TRPA1 and TRPV1 channels can be activated by pungent compounds including many nuclear factor (erythroid-derived 2) (Nrf2)-interacting foods leading to channel desensitization. Interactions between Nrf2-associated nutrients and TRPA1/TRPV1 may be partly responsible for the severity of some of the COVID-19 symptoms. The regulation by Nrf2 of TRPA1/TRPV1 is still unclear, but suggested from very limited clinical evidence. In COVID-19, it is proposed that rapid desensitization of TRAP1/TRPV1 by some ingredients in foods could reduce symptom severity and provide new therapeutic strategies.
Collapse
Affiliation(s)
- Jean Bousquet
- Department of Dermatology and Allergy, Comprehensive Allergy Center, Charité, and Berlin Institute of Health, Comprehensive Allergy Center, Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany, .,University Hospital and MACVIA France, Montpellier, France,
| | | | - Torsten Zuberbier
- Department of Dermatology and Allergy, Comprehensive Allergy Center, Charité, and Berlin Institute of Health, Comprehensive Allergy Center, Universitätsmedizin Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Joaquim Mullol
- Rhinology Unit & Smell Clinic, ENT Department, Hospital Clinic - Clinical & Experimental Respiratory Immunoallergy, IDIBAPS, CIBERES, Universitat de Barcelona, Barcelona, Spain
| | - Hubert Blain
- Department of Geriatrics, Montpellier University Hospital, Montpellier, France
| | - Jean-Paul Cristol
- Laboratoire de Biochimie et Hormonologie, PhyMedExp, Université de Montpellier, INSERM, CNRS, CHU de, Montpellier, France
| | - Rafael De La Torre
- CIBER Fisiopatologia de la Obesidad y Nutrición (CIBEROBN), Madrid, Spain.,IMIM (Hospital del Mar Research Institute), Barcelona, Spain.,Departament de Ciències Experimentals i de la Salut Toxicologia, Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | | | | | - Anna Bedbrook
- University Hospital and MACVIA France, Montpellier, France.,MASK-air, Montpellier, France
| | - Ioana Agache
- Faculty of Medicine, Transylvania University, Brasov, Romania
| | - Cezmi A Akdis
- Christine Kühne - Center for Allergy Research and Education (CK-CARE), Swiss Institute of Allergy and Asthma Research (SIAF), University of Zurich, Zurich, Switzerland
| | - G Walter Canonica
- Personalized Medicine, Asthma and Allergy, Humanitas Clinical and Research Center IRCCS and Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy
| | - Alvaro A Cruz
- Fundação ProAR, Federal University of Bahia and GARD/WHO Planning Group, Salvador, Brazil
| | - Alessandro Fiocchi
- Division of Allergy, The Bambino Gesù Children's Research Hospital IRCCS, Rome, Italy
| | - Joao A Fonseca
- CINTESIS, Center for Research in Health Technologies and Information Systems, Faculdade de Medicina da Universidade do Porto, Porto, Portugal.,MEDIDA, Lda, Porto, Portugal
| | - Susana Fonseca
- GreenUPorto - Sustainable Agrifood Production Research Centre, DGAOT, Faculty of Sciences, University of Porto, Vila do Conde, Portugal
| | - Bilun Gemicioğlu
- Department of Pulmonary Diseases, Istanbul University-Cerrahpasa, Cerrahpasa Faculty of Medicine, Istanbul, Turkey
| | - Tari Haahtela
- Skin and Allergy Hospital, Helsinki University Hospital, and University of Helsinki, Helsinki, Finland
| | - Guido Iaccarino
- Interdepartmental Center of Research on Hypertension and Related Conditions CIRIAPA, Federico II University, Napoli, Italy
| | | | - Marek Jutel
- Department of Clinical Immunology, Wrocław Medical University and ALL-MED Medical Research Institute, Wrocław, Poland
| | - Ludger Klimek
- Center for Rhinology and Allergology, Wiesbaden, Germany
| | - Helga Kraxner
- Department of Otorhinolaryngology, Head and Neck Surgery, Semmelweis University, Budapest, Hungary
| | - Piotr Kuna
- Division of Internal Medicine, Asthma and Allergy, Barlicki University Hospital, Medical University of Lodz, Lodz, Poland
| | - Désirée E Larenas-Linnemann
- Center of Excellence in Asthma and Allergy, Médica Sur Clinical Foundation and Hospital, Mexico City, Mexico
| | - Adrian Martineau
- Institute for Population Health Sciences, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, United Kingdom
| | - Erik Melén
- Institute of Environmental Medicine, Karolinska Institutet and Sachs' Children's Hospital, Stockholm, Sweden
| | - Yoshitaka Okamoto
- Department of Otorhinolaryngology, Chiba University Hospital, Chiba, Japan
| | - Nikolaos G Papadopoulos
- Division of Infection, Immunity & Respiratory Medicine, Royal Manchester Children's Hospital, University of Manchester, Manchester, United Kingdom.,Allergy Department, 2nd Pediatric Clinic, Athens General Children's Hospital "P&A Kyriakou," University of Athens, Athens, Greece
| | - Oliver Pfaar
- Section of Rhinology and Allergy, Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Marburg, Philipps-Universität Marburg, Marburg, Germany
| | - Frederico S Regateiro
- Allergy and Clinical Immunology Unit, Centro Hospitalar e Universitário de Coimbra, Faculty of Medicine, Institute of Immunology, University of Coimbra, Coimbra, Portugal.,Faculty of Medicine, ICBR - Institute for Clinical and Biomedical Research, CIBB, University of Coimbra, Coimbra, Portugal
| | - Jacques Reynes
- Maladies Infectieuses et Tropicales, CHU, Montpellier, France
| | | | - Philip W Rouadi
- Department of Otolaryngology-Head and Neck Surgery, Eye and Ear University Hospital, Beirut, Lebanon
| | - Boleslaw Samolinski
- Department of Prevention of Environmental Hazards and Allergology, Medical University of Warsaw, Warsaw, Poland
| | - Aziz Sheikh
- Usher Institute, The University of Edinburgh, Edinburgh, United Kingdom
| | - Sanna Toppila-Salmi
- Skin and Allergy Hospital, Helsinki University Hospital, and University of Helsinki, Helsinki, Finland
| | - Arunas Valiulis
- Vilnius University Faculty of Medicine, Institute of Clinical Medicine & Institute of Health Sciences, Vilnius, Lithuania
| | - Hak-Jong Choi
- Research and Development Division, Microbiology and Functionality Research Group, World Institute of Kimchi, Gwangju, Republic of Korea
| | - Hyun Ju Kim
- Strategy and Planning Division, SME Service Department, World Institute of Kimchi, Gwangju, Republic of Korea
| | - Josep M Anto
- IMIM (Hospital del Mar Research Institute), Barcelona, Spain.,Departament de Ciències Experimentals i de la Salut Toxicologia, Universitat Pompeu Fabra (UPF), Barcelona, Spain.,CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.,ISGlobAL, Barcelona, Centre for Research in Environmental Epidemiology, Barcelona, Spain
| |
Collapse
|
5
|
Baruah TJ, Kma L. Vicenin-2 acts as a radiosensitizer of the non-small cell lung cancer by lowering Akt expression. Biofactors 2019; 45:200-210. [PMID: 30496626 DOI: 10.1002/biof.1472] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/28/2018] [Accepted: 10/04/2018] [Indexed: 12/27/2022]
Abstract
Non-small cell lung cancer (NSCLC) has a very high rate of incidence and is resistant to chemo- and radiotherapy. Vicenin-2 (VCN-2) is a flavonoid obtained from Ocimum sanctum L. and it has been reported to have radioprotective, anticancer, and radiosensitizing properties. We have conducted this study to check the effect of VCN-2 on the cell viability and the effect on PTEN (Phosphatase and tensin homolog), PI3KCA (Phosphatidylinositol 4, 5-biphosphate 3-kinase catalytic subunit alpha isoform/PI3K 110α subunit), and Akt1 when VCN-2 was used alone and in combination with radiation in the NSCLC cell line NCI-H23 (H23). We have also checked the effect of VCN-2 on various pro- and anti-apoptotic genes and the ultra-morphological changes that occurred in the cells when VCN-2 is used alone and in combination with radiation. VCN-2 was able to lower cancer cell survival and phosphorylated Akt while promoting the expression of pro-apoptotic genes and down-regulating anti-apoptotic genes. We also observed the apoptosis-associated ultra-morphological changes in the VCN-2-treated cells. Our study have demonstrated that VCN-2 can be a potential chemotherapeutic and radiosensitizing agent in NSCLC. © 2018 BioFactors, 45(2):200-210, 2019.
Collapse
Affiliation(s)
- Taranga Jyoti Baruah
- Cancer and Radiation Countermeasures Unit, Department of Biochemistry, North-Eastern Hill University, Shillong, India
| | - Lakhon Kma
- Cancer and Radiation Countermeasures Unit, Department of Biochemistry, North-Eastern Hill University, Shillong, India
| |
Collapse
|
6
|
Kaplan HM, Şingirik E, Erdoğan KE, Doran F. Protective effect of alpha-linolenic acid on gentamicin-induced ototoxicity in mice. Somatosens Mot Res 2017; 34:145-150. [DOI: 10.1080/08990220.2017.1356283] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Halil Mahir Kaplan
- Department of Pharmacology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | - Ergin Şingirik
- Department of Pharmacology, Faculty of Medicine, Cukurova University, Adana, Turkey
| | | | - Figen Doran
- Department of Pathology, Faculty of Medicine, Cukurova University, Adana, Turkey
| |
Collapse
|
7
|
Abstract
The Atg8 autophagy proteins are essential for autophagosome biogenesis and maturation. The γ-aminobutyric acid receptor-associated protein (GABARAP) Atg8 family is much less understood than the LC3 Atg8 family, and the relationship between the GABARAPs' previously identified roles as modulators of transmembrane protein trafficking and autophagy is not known. Here we report that GABARAPs recruit palmitoylated PI4KIIα, a lipid kinase that generates phosphatidylinositol 4-phosphate (PI4P) and binds GABARAPs, from the perinuclear Golgi region to autophagosomes to generate PI4P in situ. Depletion of either GABARAP or PI4KIIα, or overexpression of a dominant-negative kinase-dead PI4KIIα mutant, decreases autophagy flux by blocking autophagsome:lysosome fusion, resulting in the accumulation of abnormally large autophagosomes. The autophagosome defects are rescued by overexpressing PI4KIIα or by restoring intracellular PI4P through "PI4P shuttling." Importantly, PI4KIIα's role in autophagy is distinct from that of PI4KIIIβ and is independent of subsequent phosphatidylinositol 4,5 biphosphate (PIP2) generation. Thus, GABARAPs recruit PI4KIIα to autophagosomes, and PI4P generation on autophagosomes is critically important for fusion with lysosomes. Our results establish that PI4KIIα and PI4P are essential effectors of the GABARAP interactome's fusion machinery.
Collapse
|
8
|
Lacalle RA, de Karam JC, Martínez-Muñoz L, Artetxe I, Peregil RM, Sot J, Rojas AM, Goñi FM, Mellado M, Mañes S. Type I phosphatidylinositol 4-phosphate 5-kinase homo- and heterodimerization determines its membrane localization and activity. FASEB J 2015; 29:2371-85. [PMID: 25713054 DOI: 10.1096/fj.14-264606] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 02/03/2015] [Indexed: 11/11/2022]
Abstract
Type I phosphatidylinositol 4-phosphate 5-kinases (PIP5KIs; α, β, and γ) are a family of isoenzymes that produce phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] using phosphatidylinositol 4-phosphate as substrate. Their structural homology with the class II lipid kinases [type II phosphatidylinositol 5-phosphate 4-kinase (PIP4KII)] suggests that PIP5KI dimerizes, although this has not been formally demonstrated. Neither the hypothetical structural dimerization determinants nor the functional consequences of dimerization have been studied. Here, we used Förster resonance energy transfer, coprecipitation, and ELISA to show that PIP5KIβ forms homo- and heterodimers with PIP5KIγ_i2 in vitro and in live human cells. Dimerization appears to be a general phenomenon for PIP5KI isoenzymes because PIP5KIβ/PIP5KIα heterodimers were also detected by mass spectrometry. Dimerization was independent of actin cytoskeleton remodeling and was also observed using purified proteins. Mutagenesis studies of PIP5KIβ located the dimerization motif at the N terminus, in a region homologous to that implicated in PIP4KII dimerization. PIP5KIβ mutants whose dimerization was impaired showed a severe decrease in PI(4,5)P2 production and plasma membrane delocalization, although their association to lipid monolayers was unaltered. Our results identify dimerization as an integral feature of PIP5K proteins and a central determinant of their enzyme activity.
Collapse
Affiliation(s)
- Rosa Ana Lacalle
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Juan C de Karam
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Laura Martínez-Muñoz
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Ibai Artetxe
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Rosa M Peregil
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Jesús Sot
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Ana M Rojas
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Félix M Goñi
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Mario Mellado
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| | - Santos Mañes
- *Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid, Spain; Unidad de Biofísica Consejo Superior de Investigaciones Científicas, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Campus de Leioa, Barrio Sarriena s/n, Leioa, Bizkaia, Spain; and Computational Biology and Bioinformatics Group, Instituto de Biomedicina de Sevilla-Hospital Universitario Virgen del Rocío-Consejo Superior de Investigaciones Científicas, Manuel Siurot s/n, Seville, Spain
| |
Collapse
|
9
|
Inoue H, Murayama T, Tashiro M, Sakurai T, Konishi M. Mg(2+)- and ATP-dependent inhibition of transient receptor potential melastatin 7 by oxidative stress. Free Radic Biol Med 2014; 72:257-66. [PMID: 24747489 DOI: 10.1016/j.freeradbiomed.2014.04.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 11/25/2022]
Abstract
Transient receptor potential melastatin 7 (TRPM7) is a Ca(2+)- and Mg(2+)-permeable nonselective cation channel that contains a unique carboxyl-terminal serine/threonine protein kinase domain. It has been reported that reactive oxygen species associated with hypoxia or ischemia activate TRPM7 current and then induce Ca(2+) overload resulting in neuronal cell death in the brain. In this study, we aimed to investigate the molecular mechanisms of TRPM7 regulation by hydrogen peroxide (H2O2) using murine TRPM7 expressed in HEK293 cells. Using the whole-cell patch-clamp technique, it was revealed that the TRPM7 current was inhibited, not activated, by the application of H2O2 to the extracellular solution. This inhibition was not reversed after washout or treatment with dithiothreitol, suggesting irreversible oxidation of TRPM7 or its regulatory factors by H2O2 under whole-cell recording. Application of an electrophile, N-methylmaleimide (NMM), which covalently modifies cysteine residues in proteins, also inhibited TRPM7 current irreversibly. The effects of H2O2 and NMM were dependent on free [Mg(2+)]i; the inhibition was stronger when cells were perfused with higher free [Mg(2+)]i solutions via pipette. In addition, TRPM7 current was not inhibited by H2O2 when millimolar ATP was included in the intracellular solution, even in the presence of substantial free [Mg(2+)]i, which is sufficient for TRPM7 inhibition by H2O2 in the absence of ATP. Moreover, a kinase-deficient mutant of TRPM7 (K1645R) was similarly inhibited by H2O2 just like the wild-type TRPM7 in a [Mg(2+)]i- and [ATP]i-dependent manner, indicating no involvement of the kinase activity of TRPM7. Thus, these data suggest that oxidative stress inhibits TRPM7 current under pathological conditions that accompany intracellular ATP depletion and free [Mg(2+)]i elevation.
Collapse
Affiliation(s)
- Hana Inoue
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan.
| | - Takashi Murayama
- Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Michiko Tashiro
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan
| | - Takashi Sakurai
- Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Masato Konishi
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan
| |
Collapse
|
10
|
Mittal M, Siddiqui MR, Tran K, Reddy SP, Malik AB. Reactive oxygen species in inflammation and tissue injury. Antioxid Redox Signal 2014; 20:1126-67. [PMID: 23991888 PMCID: PMC3929010 DOI: 10.1089/ars.2012.5149] [Citation(s) in RCA: 2788] [Impact Index Per Article: 278.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Abstract Reactive oxygen species (ROS) are key signaling molecules that play an important role in the progression of inflammatory disorders. An enhanced ROS generation by polymorphonuclear neutrophils (PMNs) at the site of inflammation causes endothelial dysfunction and tissue injury. The vascular endothelium plays an important role in passage of macromolecules and inflammatory cells from the blood to tissue. Under the inflammatory conditions, oxidative stress produced by PMNs leads to the opening of inter-endothelial junctions and promotes the migration of inflammatory cells across the endothelial barrier. The migrated inflammatory cells not only help in the clearance of pathogens and foreign particles but also lead to tissue injury. The current review compiles the past and current research in the area of inflammation with particular emphasis on oxidative stress-mediated signaling mechanisms that are involved in inflammation and tissue injury.
Collapse
Affiliation(s)
- Manish Mittal
- 1 Department of Pharmacology, Center for Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, Illinois
| | | | | | | | | |
Collapse
|
11
|
Collaboration of AMPK and PKC to induce phosphorylation of Ser413 on PIP5K1B resulting in decreased kinase activity and reduced PtdIns(4,5)P2 synthesis in response to oxidative stress and energy restriction. Biochem J 2014; 455:347-58. [PMID: 23909401 DOI: 10.1042/bj20130259] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The spatial and temporal regulation of the second messenger PtdIns(4,5)P2 has been shown to be crucial for regulating numerous processes in the cytoplasm and in the nucleus. Three isoforms of PIP5K1 (phosphatidylinositol 4-phosphate 5-kinase), A, B and C, are responsible for the regulation of the major pools of cellular PtdIns(4,5)P2. PIP5K1B is negatively regulated in response to oxidative stress although it remains unclear which pathways regulate its activity. In the present study, we have investigated the regulation of PIP5K1B by protein phosphorylation. Using MS analysis, we identified 12 phosphorylation sites on PIP5K1B. We developed a phospho-specific antibody against Ser413 and showed that its phosphorylation was increased in response to treatment of cells with phorbol ester, H2O2 or energy restriction. Using inhibitors, we define a stress-dependent pathway that requires the activity of the cellular energy sensor AMPK (AMP-activated protein kinase) and PKC (protein kinase C) to regulate Ser413 phosphorylation. Furthermore, we demonstrate that PKC can directly phosphorylate Ser413 in vitro. Mutation of Ser413 to aspartate to mimic serine phosphorylation decreased both PIP5K1B activity in vitro and PtdIns(4,5)P2 synthesis in vivo. Our studies show that collaboration between AMPK and PKC dictates the extent of Ser413 phosphorylation on PIP5K1B and regulates PtdIns(4,5)P2 synthesis.
Collapse
|
12
|
Abstract
Phosphoinositides (PIs) make up only a small fraction of cellular phospholipids, yet they control almost all aspects of a cell's life and death. These lipids gained tremendous research interest as plasma membrane signaling molecules when discovered in the 1970s and 1980s. Research in the last 15 years has added a wide range of biological processes regulated by PIs, turning these lipids into one of the most universal signaling entities in eukaryotic cells. PIs control organelle biology by regulating vesicular trafficking, but they also modulate lipid distribution and metabolism via their close relationship with lipid transfer proteins. PIs regulate ion channels, pumps, and transporters and control both endocytic and exocytic processes. The nuclear phosphoinositides have grown from being an epiphenomenon to a research area of its own. As expected from such pleiotropic regulators, derangements of phosphoinositide metabolism are responsible for a number of human diseases ranging from rare genetic disorders to the most common ones such as cancer, obesity, and diabetes. Moreover, it is increasingly evident that a number of infectious agents hijack the PI regulatory systems of host cells for their intracellular movements, replication, and assembly. As a result, PI converting enzymes began to be noticed by pharmaceutical companies as potential therapeutic targets. This review is an attempt to give an overview of this enormous research field focusing on major developments in diverse areas of basic science linked to cellular physiology and disease.
Collapse
Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Program for Developmental Neuroscience, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
| |
Collapse
|
13
|
Shulga YV, Anderson RA, Topham MK, Epand RM. Phosphatidylinositol-4-phosphate 5-kinase isoforms exhibit acyl chain selectivity for both substrate and lipid activator. J Biol Chem 2012; 287:35953-63. [PMID: 22942276 DOI: 10.1074/jbc.m112.370155] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Phosphatidylinositol 4,5-bisphosphate is mostly produced in the cell by phosphatidylinositol-4-phosphate 5-kinases (PIP5K) and has a crucial role in numerous signaling events. Here we demonstrate that in vitro all three isoforms of PIP5K, α, β, and γ, discriminate among substrates with different acyl chains for both the substrates phosphatidylinositol 4-phosphate (PtdIns4P) and phosphatidylinositol (PtdIns) although to different extents, with isoform γ being the most selective. Fully saturated dipalmitoyl-PtdIns4P was a poor substrate for all three isoforms, but both the 1-stearoyl-2-arachidonoyl and the 1-stearoyl-2-oleoyl forms of PtdIns4P were good substrates. V(max) was greater for the 1-stearoyl-2-arachidonoyl form compared with the 1-stearoyl-2-oleoyl form, although for PIP5Kβ the difference was small. For the α and γ isoforms, K(m) was much lower for 1-stearoyl-2-oleoyl PtdIns4P, making this lipid the better substrate of the two under most conditions. Activation of PIP5K by phosphatidic acid is also acyl chain-dependent. Species of phosphatidic acid with two unsaturated acyl chains are much better activators of PIP5K than those containing one saturated and one unsaturated acyl chain. PtdIns is a poor substrate for PIP5K, but it also shows acyl chain selectivity. Curiously, there is no acyl chain discrimination among species of phosphatidic acid in the activation of the phosphorylation of PtdIns. Together, our findings indicate that PIP5K isoforms α, β, and γ act selectively on substrates and activators with different acyl chains. This could be a tightly regulated mechanism of producing physiologically active unsaturated phosphatidylinositol 4,5-bisphosphate species in the cell.
Collapse
Affiliation(s)
- Yulia V Shulga
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | | | | | | |
Collapse
|
14
|
Zhang L, Mao YS, Janmey PA, Yin HL. Phosphatidylinositol 4, 5 bisphosphate and the actin cytoskeleton. Subcell Biochem 2012; 59:177-215. [PMID: 22374091 DOI: 10.1007/978-94-007-3015-1_6] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Dynamic changes in PM PIP(2) have been implicated in the regulation of many processes that are dependent on actin polymerization and remodeling. PIP(2) is synthesized primarily by the type I phosphatidylinositol 4 phosphate 5 kinases (PIP5Ks), and there are three major isoforms, called a, b and g. There is emerging evidence that these PIP5Ks have unique as well as overlapping functions. This review will focus on the isoform-specific roles of individual PIP5K as they relate to the regulation of the actin cytoskeleton. We will review recent advances that establish PIP(2) as a critical regulator of actin polymerization and cytoskeleton/membrane linkages, and show how binding of cytoskeletal proteins to membrane PIP(2) might alter lateral or transverse movement of lipids to affect raft formation or lipid asymmetry. The mechanisms for specifying localized increase in PIP(2) to regulate dynamic actin remodeling will also be discussed.
Collapse
Affiliation(s)
- Li Zhang
- Department of Physiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, 75390-9040, Dallas, TX, USA
| | | | | | | |
Collapse
|
15
|
Martelli AM, Ognibene A, Buontempo F, Fini M, Bressanin D, Goto K, McCubrey JA, Cocco L, Evangelisti C. Nuclear phosphoinositides and their roles in cell biology and disease. Crit Rev Biochem Mol Biol 2011; 46:436-57. [DOI: 10.3109/10409238.2011.609530] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
16
|
Funakoshi Y, Hasegawa H, Kanaho Y. Regulation of PIP5K activity by Arf6 and its physiological significance. J Cell Physiol 2011; 226:888-95. [PMID: 20945365 DOI: 10.1002/jcp.22482] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The phospholipid kinase phosphatidylinositol 4-phosphate 5-kinase (PIP5K) catalyzes the phosphorylation of the membrane phospholipid phosphatidylinositol 4-phosphate to generate the pleiotropic phospholipid phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2) ]. To date, three mammalian PIP5K isozymes, α, β, and γ, and several splicing variants of the γ isozyme have been identified. These PIP5K isozymes and PIP5Kγ variants play critical roles in various cellular functions through their product PI(4,5)P(2) . The small GTPase Arf6 is one of the key activators of PIP5K. Increasing evidence suggests that PIP5K functions as a downstream effector of Arf6 to regulate a wide variety of cellular functions, such as exocytosis, endocytosis, endosomal recycling, membrane ruffle formation, immune response, and bacterial invasion. In this review, we place our focus on the recent advances in Arf6/PIP5K signaling and its linkage to cellular functions.
Collapse
Affiliation(s)
- Yuji Funakoshi
- Department of Physiological Chemistry, Graduate School of Comprehensive Human Sciences and Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba, Japan
| | | | | |
Collapse
|
17
|
Kwiatkowska K. One lipid, multiple functions: how various pools of PI(4,5)P(2) are created in the plasma membrane. Cell Mol Life Sci 2010; 67:3927-46. [PMID: 20559679 PMCID: PMC11115911 DOI: 10.1007/s00018-010-0432-5] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Revised: 06/01/2010] [Accepted: 06/02/2010] [Indexed: 01/25/2023]
Abstract
Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)] is a minor lipid of the inner leaflet of the plasma membrane that controls the activity of numerous proteins and serves as a source of second messengers. This multifunctionality of PI(4,5)P(2) relies on mechanisms ensuring transient appearance of PI(4,5)P(2) clusters in the plasma membrane. One such mechanism involves phosphorylation of PI(4)P to PI(4,5)P(2) by the type I phosphatidylinositol-4-phosphate 5-kinases (PIP5KI) at discrete membrane locations coupled with PI(4)P delivery/synthesis at the plasma membrane. Simultaneously, both PI(4)P and PI(4,5)P(2) participate in anchoring PIP5KI at the plasma membrane via electrostatic bonds. PIP5KI isoforms are also selectively recruited and activated at the plasma membrane by Rac1, talin, or AP-2 to generate PI(4,5)P(2) in ruffles and lamellipodia, focal contacts, and clathrin-coated pits. In addition, PI(4,5)P(2) can accumulate at sphingolipid/cholesterol-based rafts following activation of distinct membrane receptors or be sequestered in a reversible manner due to electrostatic constrains posed by proteins like MARCKS.
Collapse
Affiliation(s)
- Katarzyna Kwiatkowska
- Laboratory of Plasma Membrane Receptors, Nencki Institute of Experimental Biology, 3 Pasteur St., 02-093 Warsaw, Poland.
| |
Collapse
|
18
|
Mañes S, Fuentes G, Peregil RM, Rojas AM, Lacalle RA. An isoform-specific PDZ-binding motif targets type I PIP5 kinase beta to the uropod and controls polarization of neutrophil-like HL60 cells. FASEB J 2010; 24:3381-92. [PMID: 20442317 DOI: 10.1096/fj.09-153106] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Type I phosphatidylinositol 4-phosphate 5-kinase (PIP5KI)-beta participates in establishing polarity during leukocyte chemotaxis. Its final 83 amino acids localize PIP5KIbeta to the uropod of chemotaxing neutrophils and T cells, and interact with ezrin-radixin-moesin (ERM) proteins and EBP50 (4.1-ERM-binding phosphoprotein 50), a scaffold protein with 2 PDZ (PSD-95, disc large, ZO-1) domains. The structural motifs at the PIP5KIbeta C terminus that confer signaling specificity are, nonetheless, unknown. We show that the last 4 residues of PIP5KIbeta constitute an atypical PDZ-binding motif, which steers PIP5KIbeta to the uropod by binding to both EBP50 PDZ domains. Molecular modeling and mutagenesis indicated that PDZ-binding motif is necessary for PIP5KIbeta localization and for chemoattractant-induced neutrophil polarization. Polarity in cells that express PIP5KIbeta mutants lacking the PDZ-binding motif was restored by overexpression of PIP5KIbeta, but not of PIP5KIgamma_i2, another isoform that localizes to the neutrophil uropod. Our results identify an isoform-specific PDZ-binding motif in PIP5KIbeta, which confers specificity for PIP5KIbeta signaling at the uropod during leukocyte chemotaxis.
Collapse
Affiliation(s)
- Santos Mañes
- Department of Immunology and Oncology, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Darwin 3, Campus de Cantoblanco, Madrid E-28049, Spain
| | | | | | | | | |
Collapse
|
19
|
Terhzaz S, Finlayson AJ, Stirrat L, Yang J, Tricoire H, Woods DJ, Dow JAT, Davies SA. Cell-specific inositol 1,4,5 trisphosphate 3-kinase mediates epithelial cell apoptosis in response to oxidative stress in Drosophila. Cell Signal 2010; 22:737-48. [PMID: 20060894 DOI: 10.1016/j.cellsig.2009.12.009] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 12/24/2009] [Indexed: 11/18/2022]
Abstract
Organismal stress responses to oxidative stress are relevant to ageing and disease and involve key cell-/tissue-specific signal transduction mechanisms. Using Drosophila, an established in vivo model for stress studies, we show that cell-specific inositol phosphate signalling specifically via inositol 1,4,5 trisphosphate 3-kinase (InsP(3) 3-K, IP(3)K), negatively regulates organismal responses to oxidative stress. We demonstrate that the Drosophila Malpighian tubule (equivalent to vertebrate kidney and liver) is a key epithelial sensor for organismal oxidative stress responses: precise targeting of either gain-of-function constructs of Drosophila IP(3)Ks (IP(3)K-1 and IP(3)K-2), or loss-of-function (RNAi) constructs to only one cell type in tubule reversibly modulates survival of stress-challenged adult flies. In vivo, targeted IP(3)K-1 directly increases H(2)O(2) production, pro-apoptotic caspase-9 activity and mitochondrial membrane potential. The mitochondrial calcium load in tubule principal cells-assessed by luminescent and fluorescent genetically-encoded mitochondrial calcium reporters-is significantly increased by IP(3)K-1 under oxidative stress conditions, leading to apoptosis. The Drosophila orthologues of human apoptotic bcl-2 genes include debcl and buffy. Oxidative stress challenge does not modulate gene expression of either debcl or buffy in tubules; and altered debcl expression does not influence survival rates under oxidative stress challenge. Finally, targeted over-expression of either debcl or buffy to tubule principal cells does not impact on tubule caspase-9 activity. Thus, IP(3)K-1 modulates epithelial cell apoptosis without involvement of bcl-2-type proteins.
Collapse
|