1
|
Harris NJ, Jenkins ML, Nam SE, Rathinaswamy MK, Parson MA, Ranga-Prasad H, Dalwadi U, Moeller BE, Sheekey E, Hansen SD, Yip CK, Burke JE. Allosteric activation or inhibition of PI3Kγ mediated through conformational changes in the p110γ helical domain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.12.536585. [PMID: 37090531 PMCID: PMC10120615 DOI: 10.1101/2023.04.12.536585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
PI3Kγ is a critical immune signaling enzyme activated downstream of diverse cell surface molecules, including Ras, PKCβ activated by the IgE receptor, and Gβγ subunits released from activated GPCRs. PI3Kγ can form two distinct complexes, with the p110γ catalytic subunit binding to either a p101 or p84 regulatory subunit, with these complexes being differentially activated by upstream stimuli. Here using a combination of Cryo electron microscopy, HDX-MS, and biochemical assays we have identified novel roles of the helical domain of p110γ in regulating lipid kinase activity of distinct PI3Kγ complexes. We defined the molecular basis for how an allosteric inhibitory nanobody potently inhibits kinase activity through rigidifying the helical domain and regulatory motif of the kinase domain. The nanobody did not block either p110γ membrane recruitment or Ras/Gβγ binding, but instead decreased ATP turnover. We also identified that p110γ can be activated by dual PKCβ helical domain phosphorylation leading to partial unfolding of an N-terminal region of the helical domain. PKCβ phosphorylation is selective for p110γ-p84 compared to p110γ-p101, driven by differential dynamics of the helical domain of these different complexes. Nanobody binding prevented PKCβ mediated phosphorylation. Overall, this works shows an unexpected allosteric regulatory role of the helical domain of p110γ that is distinct between p110γ-p84 and p110γ-p101, and reveals how this can be modulated by either phosphorylation or allosteric inhibitory binding partners. This opens possibilities of future allosteric inhibitor development for therapeutic intervention.
Collapse
|
2
|
Rathinaswamy MK, Jenkins ML, Duewell BR, Zhang X, Harris NJ, Evans JT, Stariha JTB, Dalwadi U, Fleming KD, Ranga-Prasad H, Yip CK, Williams RL, Hansen SD, Burke JE. Molecular basis for differential activation of p101 and p84 complexes of PI3Kγ by Ras and GPCRs. Cell Rep 2023; 42:112172. [PMID: 36842083 PMCID: PMC10068899 DOI: 10.1016/j.celrep.2023.112172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 12/21/2022] [Accepted: 02/13/2023] [Indexed: 02/27/2023] Open
Abstract
Class IB phosphoinositide 3-kinase (PI3Kγ) is activated in immune cells and can form two distinct complexes (p110γ-p84 and p110γ-p101), which are differentially activated by G protein-coupled receptors (GPCRs) and Ras. Using a combination of X-ray crystallography, hydrogen deuterium exchange mass spectrometry (HDX-MS), electron microscopy, molecular modeling, single-molecule imaging, and activity assays, we identify molecular differences between p110γ-p84 and p110γ-p101 that explain their differential membrane recruitment and activation by Ras and GPCRs. The p110γ-p84 complex is dynamic compared with p110γ-p101. While p110γ-p101 is robustly recruited by Gβγ subunits, p110γ-p84 is weakly recruited to membranes by Gβγ subunits alone and requires recruitment by Ras to allow for Gβγ activation. We mapped two distinct Gβγ interfaces on p101 and the p110γ helical domain, with differences in the C-terminal domain of p84 and p101 conferring sensitivity of p110γ-p101 to Gβγ activation. Overall, our work provides key insight into the molecular basis for how PI3Kγ complexes are activated.
Collapse
Affiliation(s)
- Manoj K Rathinaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Meredith L Jenkins
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Benjamin R Duewell
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA
| | - Xuxiao Zhang
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Noah J Harris
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - John T Evans
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Jordan T B Stariha
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Udit Dalwadi
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Harish Ranga-Prasad
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Calvin K Yip
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | | | - Scott D Hansen
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR 97403, USA; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA.
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC V8W 2Y2, Canada; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
| |
Collapse
|
3
|
Lanahan SM, Wymann MP, Lucas CL. The role of PI3Kγ in the immune system: new insights and translational implications. Nat Rev Immunol 2022; 22:687-700. [PMID: 35322259 PMCID: PMC9922156 DOI: 10.1038/s41577-022-00701-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2022] [Indexed: 12/27/2022]
Abstract
Over the past two decades, new insights have positioned phosphoinositide 3-kinase-γ (PI3Kγ) as a context-dependent modulator of immunity and inflammation. Recent advances in protein structure determination and drug development have allowed for generation of highly specific PI3Kγ inhibitors, with the first now in clinical trials for several oncology indications. Recently, a monogenic immune disorder caused by PI3Kγ deficiency was discovered in humans and modelled in mice. Human inactivated PI3Kγ syndrome confirms the immunomodulatory roles of PI3Kγ and strengthens newly defined roles of this molecule in modulating inflammatory cytokine release in macrophages. Here, we review the functions of PI3Kγ in the immune system and discuss how our understanding of its potential as a therapeutic target has evolved.
Collapse
Affiliation(s)
- Stephen M Lanahan
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | | | - Carrie L Lucas
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA.
| |
Collapse
|
4
|
PI3K and AKT at the Interface of Signaling and Metabolism. Curr Top Microbiol Immunol 2022; 436:311-336. [DOI: 10.1007/978-3-031-06566-8_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
5
|
Class I PI3K Biology. Curr Top Microbiol Immunol 2022; 436:3-49. [DOI: 10.1007/978-3-031-06566-8_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
6
|
Rathinaswamy MK, Dalwadi U, Fleming KD, Adams C, Stariha JTB, Pardon E, Baek M, Vadas O, DiMaio F, Steyaert J, Hansen SD, Yip CK, Burke JE. Structure of the phosphoinositide 3-kinase (PI3K) p110γ-p101 complex reveals molecular mechanism of GPCR activation. SCIENCE ADVANCES 2021; 7:7/35/eabj4282. [PMID: 34452907 PMCID: PMC8397274 DOI: 10.1126/sciadv.abj4282] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 07/06/2021] [Indexed: 05/04/2023]
Abstract
The class IB phosphoinositide 3-kinase (PI3K), PI3Kγ, is a master regulator of immune cell function and a promising drug target for both cancer and inflammatory diseases. Critical to PI3Kγ function is the association of the p110γ catalytic subunit to either a p101 or p84 regulatory subunit, which mediates activation by G protein-coupled receptors. Here, we report the cryo-electron microscopy structure of a heterodimeric PI3Kγ complex, p110γ-p101. This structure reveals a unique assembly of catalytic and regulatory subunits that is distinct from other class I PI3K complexes. p101 mediates activation through its Gβγ-binding domain, recruiting the heterodimer to the membrane and allowing for engagement of a secondary Gβγ-binding site in p110γ. Mutations at the p110γ-p101 and p110γ-adaptor binding domain interfaces enhanced Gβγ activation. A nanobody that specifically binds to the p101-Gβγ interface blocks activation, providing a novel tool to study and target p110γ-p101-specific signaling events in vivo.
Collapse
Affiliation(s)
- Manoj K Rathinaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Udit Dalwadi
- Life Sciences Institute, Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Carson Adams
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Jordan T B Stariha
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Minkyung Baek
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Oscar Vadas
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Frank DiMaio
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Scott D Hansen
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA
| | - Calvin K Yip
- Life Sciences Institute, Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada.
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
- Life Sciences Institute, Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
7
|
Rathinaswamy MK, Fleming KD, Dalwadi U, Pardon E, Harris NJ, Yip CK, Steyaert J, Burke JE. HDX-MS-optimized approach to characterize nanobodies as tools for biochemical and structural studies of class IB phosphoinositide 3-kinases. Structure 2021; 29:1371-1381.e6. [PMID: 34348129 DOI: 10.1016/j.str.2021.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/07/2021] [Accepted: 07/15/2021] [Indexed: 10/20/2022]
Abstract
There is considerable interest in developing antibodies as modulators of signaling pathways. One of the most important signaling pathways in higher eukaryotes is the phosphoinositide 3-kinase (PI3K) pathway, which plays fundamental roles in growth, metabolism, and immunity. The class IB PI3K, PI3Kγ, is a heterodimeric complex composed of a catalytic p110γ subunit bound to a p101 or p84 regulatory subunit. PI3Kγ is a critical component in multiple immune signaling processes and is dependent on activation by Ras and G protein-coupled receptors (GPCRs) to mediate its cellular roles. Here we describe the rapid and efficient characterization of multiple PI3Kγ binding single-chain camelid nanobodies using hydrogen-deuterium exchange (HDX) mass spectrometry (MS) for structural and biochemical studies. We identify nanobodies that stimulated lipid kinase activity, block Ras activation, and specifically inhibited p101-mediated GPCR activation. Overall, our work reveals insight into PI3Kγ regulation and identifies sites that may be exploited for therapeutic development.
Collapse
Affiliation(s)
- Manoj K Rathinaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
| | - Udit Dalwadi
- Life Sciences Institute, Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Noah J Harris
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
| | - Calvin K Yip
- Life Sciences Institute, Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium; VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada; Life Sciences Institute, Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
| |
Collapse
|
8
|
Rathinaswamy MK, Gaieb Z, Fleming KD, Borsari C, Harris NJ, Moeller BE, Wymann MP, Amaro RE, Burke JE. Disease-related mutations in PI3Kγ disrupt regulatory C-terminal dynamics and reveal a path to selective inhibitors. eLife 2021; 10:e64691. [PMID: 33661099 PMCID: PMC7955810 DOI: 10.7554/elife.64691] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 03/03/2021] [Indexed: 12/11/2022] Open
Abstract
Class I Phosphoinositide 3-kinases (PI3Ks) are master regulators of cellular functions, with the class IB PI3K catalytic subunit (p110γ) playing key roles in immune signalling. p110γ is a key factor in inflammatory diseases and has been identified as a therapeutic target for cancers due to its immunomodulatory role. Using a combined biochemical/biophysical approach, we have revealed insight into regulation of kinase activity, specifically defining how immunodeficiency and oncogenic mutations of R1021 in the C-terminus can inactivate or activate enzyme activity. Screening of inhibitors using HDX-MS revealed that activation loop-binding inhibitors induce allosteric conformational changes that mimic those in the R1021C mutant. Structural analysis of advanced PI3K inhibitors in clinical development revealed novel binding pockets that can be exploited for further therapeutic development. Overall, this work provides unique insights into regulatory mechanisms that control PI3Kγ kinase activity and shows a framework for the design of PI3K isoform and mutant selective inhibitors.
Collapse
Affiliation(s)
- Manoj K Rathinaswamy
- Department of Biochemistry and Microbiology, University of VictoriaVictoriaCanada
| | - Zied Gaieb
- Department of Chemistry and Biochemistry, University of California San DiegoSan DiegoUnited States
| | - Kaelin D Fleming
- Department of Biochemistry and Microbiology, University of VictoriaVictoriaCanada
| | - Chiara Borsari
- University of Basel, Department of BiomedicineBaselSwitzerland
| | - Noah J Harris
- Department of Biochemistry and Microbiology, University of VictoriaVictoriaCanada
| | - Brandon E Moeller
- Department of Biochemistry and Microbiology, University of VictoriaVictoriaCanada
| | | | - Rommie E Amaro
- Department of Chemistry and Biochemistry, University of California San DiegoSan DiegoUnited States
| | - John E Burke
- Department of Biochemistry and Microbiology, University of VictoriaVictoriaCanada
- Department of Biochemistry and Molecular Biology, The University of British ColumbiaVancouverCanada
| |
Collapse
|
9
|
An C, Wen J, Hu Z, Mitch WE, Wang Y. Phosphoinositide 3-kinase γ deficiency attenuates kidney injury and fibrosis in angiotensin II-induced hypertension. Nephrol Dial Transplant 2021; 35:1491-1500. [PMID: 32500132 DOI: 10.1093/ndt/gfaa062] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 03/04/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND We have shown that the CXCL16/CXCR6 axis plays a critical role in recruiting inflammatory cells and bone marrow-derived fibroblasts into the kidney leading to renal injury and fibrosis. However, the underlying signaling mechanisms are not known. METHODS In the present study, we examined the role of phosphoinositide-3 kinase γ (PI3Kγ) signaling in the recruitment of inflammatory cells and bone marrow-derived fibroblasts into the kidney and development of renal injury and fibrosis in an experimental model of hypertension induced by angiotensin II. RESULTS Blood pressure was comparable between wild-type (WT) and PI3Kγ knockout (KO) mice at baseline. Angiotensin II treatment led to an increase in blood pressure that was similar between WT and PI3Kγ KO mice. Compared with WT mice, PI3Kγ KO mice were protected from angiotensin II-induced renal dysfunction and injury and developed less proteinuria. PI3Kγ deficiency suppressed bone marrow-derived fibroblast accumulation and myofibroblast formation in the kidney and inhibited total collagen deposition and extracellular matrix protein production in the kidney in response to angiotensin II. PI3Kγ deficiency inhibited the infiltration of F4/80+ macrophages and CD3+ T cells into the kidney and reduced gene expression levels of pro-inflammatory cytokines in the kidney following angiotensin II treatment. Finally, inhibition of PI3Kγ suppressed CXCL16-induced monocyte migration in vitro. CONCLUSION These results indicate that PI3Kγ mediates the influx of macrophages, T cells and bone marrow-derived fibroblasts into the kidney resulting in kidney injury and fibrosis.
Collapse
Affiliation(s)
- Changlong An
- Division of Nephrology, Department of Medicine, University of Connecticut Health Center, Farmington, CT, USA
| | - Jia Wen
- Division of Nephrology, Department of Medicine, University of Connecticut Health Center, Farmington, CT, USA
| | - Zhaoyong Hu
- Section of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - William E Mitch
- Section of Nephrology, Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Yanlin Wang
- Division of Nephrology, Department of Medicine, University of Connecticut Health Center, Farmington, CT, USA.,Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA.,Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT, USA.,Renal Section, Veterans Affairs Connecticut Healthcare System, West Haven, CT, USA
| |
Collapse
|
10
|
Borsari C, Keles E, Rageot D, Treyer A, Bohnacker T, Bissegger L, De Pascale M, Melone A, Sriramaratnam R, Beaufils F, Hamburger M, Hebeisen P, Löscher W, Fabbro D, Hillmann P, Wymann MP. 4-(Difluoromethyl)-5-(4-((3 R,5 S)-3,5-dimethylmorpholino)-6-(( R)-3-methylmorpholino)-1,3,5-triazin-2-yl)pyridin-2-amine (PQR626), a Potent, Orally Available, and Brain-Penetrant mTOR Inhibitor for the Treatment of Neurological Disorders. J Med Chem 2020; 63:13595-13617. [PMID: 33166139 DOI: 10.1021/acs.jmedchem.0c00620] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The mechanistic target of rapamycin (mTOR) pathway is hyperactivated in cancer and neurological disorders. Rapalogs and mTOR kinase inhibitors (TORKi) have recently been applied to alleviate epileptic seizures in tuberous sclerosis complex (TSC). Herein, we describe a pharmacophore exploration to identify a highly potent, selective, brain penetrant TORKi. An extensive investigation of the morpholine ring engaging the mTOR solvent exposed region led to the discovery of PQR626 (8). 8 displayed excellent brain penetration and was well-tolerated in mice. In mice with a conditionally inactivated Tsc1 gene in glia, 8 significantly reduced the loss of Tsc1-induced mortality at 50 mg/kg p.o. twice a day. 8 overcomes the metabolic liabilities of PQR620 (52), the first-in-class brain penetrant TORKi showing efficacy in a TSC mouse model. The improved stability in human hepatocytes, excellent brain penetration, and efficacy in Tsc1GFAPCKO mice qualify 8 as a potential therapeutic candidate for the treatment of neurological disorders.
Collapse
Affiliation(s)
- Chiara Borsari
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Erhan Keles
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Denise Rageot
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Andrea Treyer
- Pharmaceutical Biology, Pharmacenter, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Thomas Bohnacker
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Lukas Bissegger
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Martina De Pascale
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Anna Melone
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Rohitha Sriramaratnam
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Florent Beaufils
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Matthias Hamburger
- Pharmaceutical Biology, Pharmacenter, University of Basel, Klingelbergstrasse 50, 4056 Basel, Switzerland
| | - Paul Hebeisen
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, 30559 Hannover, Germany.,Center for Systems Neuroscience, University of Veterinary Medicine, 30559 Hannover, Germany
| | - Doriano Fabbro
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Petra Hillmann
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Matthias P Wymann
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| |
Collapse
|
11
|
Rynkiewicz NK, Anderson KE, Suire S, Collins DM, Karanasios E, Vadas O, Williams R, Oxley D, Clark J, Stephens LR, Hawkins PT. Gβγ is a direct regulator of endogenous p101/p110γ and p84/p110γ PI3Kγ complexes in mouse neutrophils. Sci Signal 2020; 13:13/656/eaaz4003. [PMID: 33144519 DOI: 10.1126/scisignal.aaz4003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The PI3Kγ isoform is activated by Gi-coupled GPCRs in myeloid cells, but the extent to which the two endogenous complexes of PI3Kγ, p101/p110γ and p84/p110γ, receive direct regulation through Gβγ or indirect regulation through RAS and the sufficiency of those inputs is controversial or unclear. We generated mice with point mutations that prevent Gβγ binding to p110γ (RK552DD) or to p101 (VVKR777AAAA) and investigated the effects of these mutations in primary neutrophils and in mouse models of neutrophilic inflammation. Loss of Gβγ binding to p110γ substantially reduced the activation of both p101/p110γ and p84/p110γ in neutrophils by various GPCR agonists. Loss of Gβγ binding to p101 caused more variable effects, depending on both the agonist and cellular response, with the biggest reductions seen in PIP3 production by primary neutrophils in response to LTB4 and MIP-2 and in the migration of neutrophils during thioglycolate-induced peritonitis or MIP2-induced ear pouch inflammation. We also observed that p101VVKR777AAAA neutrophils showed enhanced p84-dependent ROS responses to fMLP and C5a, suggesting that competition may exist between p101/p110γ and p84/p110γ for Gβγ subunits downstream of GPCR activation. GPCRs did not activate p110γ in neutrophils from mice lacking both the p101 and p84 regulatory subunits, indicating that RAS binding to p110γ is insufficient to support GPCR activation in this cell type. These findings define a direct role for Gβγ subunits in activating both of the endogenous PI3Kγ complexes and indicate that the regulatory PI3Kγ subunit biases activation toward different GPCRs.
Collapse
Affiliation(s)
- Natalie K Rynkiewicz
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Karen E Anderson
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Sabine Suire
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Daniel M Collins
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Eleftherios Karanasios
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Oscar Vadas
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Roger Williams
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - David Oxley
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Jonathan Clark
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK
| | - Len R Stephens
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
| | - Phillip T Hawkins
- Signalling Programme, Babraham Institute, Babraham Research Campus, Cambridge CB22 3AT, UK.
| |
Collapse
|
12
|
Jin JR, Gogvadze E, Xavier AR, Bohnacker T, Voelzmann J, Wymann MP. PI3K γ Regulatory Protein p84 Determines Mast Cell Sensitivity to Ras Inhibition-Moving Towards Cell Specific PI3K Targeting? Front Immunol 2020; 11:585070. [PMID: 33193405 PMCID: PMC7655736 DOI: 10.3389/fimmu.2020.585070] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 09/30/2020] [Indexed: 12/21/2022] Open
Abstract
Mast cells are the major effector cells in immunoglobulin E (IgE)-mediated allergy. The high affinity IgE receptor FcεRI, as well as G protein-coupled receptors (GPCRs) on the mast cell surface signals to phosphoinositide 3-kinase γ (PI3Kγ) to initiate degranulation, cytokine release, and chemotaxis. PI3Kγ is therefore considered as a target for treatment of allergic disorders. However, leukocyte PI3Kγ is key to many functions in innate and adaptive immunity, and attenuation of host defense mechanisms is an expected adverse effect that complicates treatment of chronic illnesses. PI3Kγ operates as a p110γ/p84 or p110γ/p101 complex, where p110γ/p84 requires Ras activation. Here we investigated if modulation of Ras-isoprenylation could target PI3Kγ activity to attenuate PI3Kγ-dependent mast cell responses without impairment of macrophage functions. In murine bone marrow-derived mast cells, GPCR stimulation triggers activation of N-Ras and H-Ras isoforms, which is followed by the phosphorylation of protein kinase B (PKB/Akt) relayed through PI3Kγ. Although K-Ras is normally not activated in Ras wild-type cells, it is able to compensate for genetically deleted N- and H-Ras isoforms. Inhibition of Ras isoprenylation with farnesyltransferase inhibitor FTI-277 leads to a significant reduction of mast cell degranulation, cytokine production, and migration. Complementation experiments expressing PI3Kγ adaptor proteins p84 or p101 demonstrated a differential sensitivity towards Ras-inhibition depending on PI3Kγ complex composition. Mast cell responses are exclusively p84-dependent and were effectively controlled by FTI-277. Similar results were obtained when GTP-Ras was inactivated by overexpression of the GAP-domain of Neurofibromin-1 (NF-1). Unlike mast cells, macrophages express p84 and p101 but are p101-dominated and thus remain functional under treatment with FTI-277. Our work demonstrates that p101 and p84 have distinct physiological roles, and that Ras dependence of PI3Kγ signaling differs between cell types. FTI-277 reduces GPCR-activated PI3Kγ responses in p84-expressing but not p101-containing bone marrow derived cells. However, prenylation inhibitors have pleiotropic effects beyond Ras and non-tolerable side-effects that disfavor further clinical validation. Statins are, however, clinically well-established drugs that have previously been proposed to block mast cell degranulation by interference with protein prenylation. We show here that Simvastatin inhibits mast cell degranulation, but that this does not occur via Ras-PI3Kγ pathway alterations.
Collapse
|
13
|
Cai Y, Yu J, Ren P, He J, Wu Z, Xiao K, Jia H, Wang J, Sai Y, Dai G, Li X, Su W, Ngo K, Castro G, Acton PD, Fung‐Leung W, Edwards JP, Venable J, Rao TS. Immunological characterization of HM5023507, an orally active PI3Kδ/γ inhibitor. Pharmacol Res Perspect 2020; 8:e00559. [PMID: 31956418 PMCID: PMC6957347 DOI: 10.1002/prp2.559] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 12/10/2019] [Accepted: 12/12/2019] [Indexed: 12/31/2022] Open
Abstract
Phosphoinositide 3-kinases, delta (PI3Kδ) and gamma (PI3Kγ) are enriched in immune cells and regulate the development and function of innate and adaptive immunity. Dual PI3Kδγ inhibitors are considered high value targets for their potential to treat a variety of immune-mediated diseases, but their discovery has been challenging. Here we describe the preclinical pharmacology of HM5023507, an orally active dual inhibitor of δγ isoforms in immune signaling. HM5023507 inhibited PI3Kδ and PI3Kγ isoforms with greater than 100-fold selectivity against PI3Kα and PI3Kβ in recombinant enzymatic assays and in primary human immune cells with an exquisite selectivity against other targets. HM5023507 attenuated the PI3Kδ/γ signaling in human basophils (IC50: 42/340 nmol/L; selectivity ratio ~1:8). HM5023507 attenuated the activation and function of human B and T cells, Th17 differentiation of CD4 T cells in the blood of healthy donors and rheumatoid arthritis patients, and cytokine and IgG production in human T and B cell cocultures, in vitro. Orally dosed HM5023507 attenuated PI3K δ/γ-mediated immune signaling in the rat in a dose-related manner. In addition, HM5023507 inhibited semiestablished collagen-induced arthritic inflammation in the rats (ED50 of 0.25mg/kg, p.o. BID or 0.5 mg/kg, QD, AUC: 1422 ng/mL*h), improved histopathology- and micro-computed tomography (µCT)-based indices of joint damage, bone destruction, and attenuated the levels of anti-collagen antibody, with an overall anti-inflammatory profile matching that of a TNFα neutralizing antibody. The PI3K δγ inhibitory profile of HM5023507 and its selectivity make it a useful tool to further delineate immunobiology of dual PI3K δγ targeting.
Collapse
Affiliation(s)
- Yu Cai
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Jun Yu
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Ping Ren
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Jianlin He
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Zhipeng Wu
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Kun Xiao
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Hong Jia
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Jian Wang
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Yang Sai
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Guangxiu Dai
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Xiong Li
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Weiguo Su
- Hutchison MediPharma, Research and Development CenterPudongShanghaiChina
| | - Karen Ngo
- Janssen Pharmaceutical R&D, LLC.San DiegoCAUSA
| | | | | | | | | | | | | |
Collapse
|
14
|
Durrant TN, Hers I. PI3K inhibitors in thrombosis and cardiovascular disease. Clin Transl Med 2020; 9:8. [PMID: 32002690 PMCID: PMC6992830 DOI: 10.1186/s40169-020-0261-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 01/13/2020] [Indexed: 12/15/2022] Open
Abstract
Phosphoinositide 3-kinases (PI3Ks) are lipid kinases that regulate important intracellular signalling and vesicle trafficking events via the generation of 3-phosphoinositides. Comprising eight core isoforms across three classes, the PI3K family displays broad expression and function throughout mammalian tissues, and the (patho)physiological roles of these enzymes in the cardiovascular system present the PI3Ks as potential therapeutic targets in settings such as thrombosis, atherosclerosis and heart failure. This review will discuss the PI3K enzymes and their roles in cardiovascular physiology and disease, with a particular focus on platelet function and thrombosis. The current progress and future potential of targeting the PI3K enzymes for therapeutic benefit in cardiovascular disease will be considered, while the challenges of developing drugs against these master cellular regulators will be discussed.
Collapse
Affiliation(s)
- Tom N Durrant
- Department of Chemistry, University of Oxford, Oxford, OX1 3QZ, UK.
| | - Ingeborg Hers
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences Building, University Walk, Bristol, BS8 1TD, UK.
| |
Collapse
|
15
|
Borsari C, Rageot D, Beaufils F, Bohnacker T, Keles E, Buslov I, Melone A, Sele AM, Hebeisen P, Fabbro D, Hillmann P, Wymann MP. Preclinical Development of PQR514, a Highly Potent PI3K Inhibitor Bearing a Difluoromethyl-Pyrimidine Moiety. ACS Med Chem Lett 2019; 10:1473-1479. [PMID: 31620236 PMCID: PMC6792169 DOI: 10.1021/acsmedchemlett.9b00333] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 09/03/2019] [Indexed: 12/18/2022] Open
Abstract
![]()
The
phosphoinositide 3-kinase (PI3K)/mechanistic target of rapamycin
(mTOR) pathway is a critical regulator of cell growth and is frequently
hyperactivated in cancer. Therefore, PI3K inhibitors represent a valuable
asset in cancer therapy. Herein we have developed a novel anticancer
agent, the potent pan-PI3K inhibitor PQR514 (4), which
is a follow-up compound for the phase-II clinical compound PQR309
(1). Compound 4 has an improved potency
both in vitro and in cellular assays with respect to its predecessor
compounds. It shows superiority in the suppression of cancer cell
proliferation and demonstrates significant antitumor activity in an
OVCAR-3 xenograft model at concentrations approximately eight times
lower than PQR309 (1). The favorable pharmacokinetic
profile and a minimal brain penetration promote PQR514 (4) as an optimized candidate for the treatment of systemic tumors.
Collapse
Affiliation(s)
- Chiara Borsari
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Denise Rageot
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Florent Beaufils
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Thomas Bohnacker
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Erhan Keles
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Ivan Buslov
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Anna Melone
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Alexander M. Sele
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | - Paul Hebeisen
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Doriano Fabbro
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Petra Hillmann
- PIQUR Therapeutics AG, Hochbergerstrasse 60, 4057 Basel, Switzerland
| | - Matthias P. Wymann
- Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| |
Collapse
|
16
|
Rathinaswamy MK, Burke JE. Class I phosphoinositide 3-kinase (PI3K) regulatory subunits and their roles in signaling and disease. Adv Biol Regul 2019; 75:100657. [PMID: 31611073 DOI: 10.1016/j.jbior.2019.100657] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 09/23/2019] [Accepted: 09/25/2019] [Indexed: 02/06/2023]
Abstract
The Class I phosphoinositide 3-kinases (PI3Ks) are a group of heterodimeric lipid kinases that regulate crucial cellular processes including proliferation, survival, growth, and metabolism. The diversity in functions controlled by the various catalytic isoforms (p110α, p110β, p110δ, and p110γ) depends on their abilities to be activated by distinct stimuli such as receptor tyrosine kinases (RTKs), G-protein coupled receptors (GPCRs), and the Ras family of small G-proteins. A major factor determining the ability of each p110 enzyme to be activated is the presence of regulatory binding partners. Given the overwhelming evidence for the involvement of PI3Ks in diseases such as cancer, inflammation, immunodeficiency and diabetes, an understanding of how these regulatory proteins influence PI3K function is essential. This article highlights research deciphering the role of regulatory subunits in PI3K signaling and their involvement in human disease.
Collapse
Affiliation(s)
- Manoj K Rathinaswamy
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, V8W 2Y2, Canada.
| |
Collapse
|
17
|
Function, Regulation and Biological Roles of PI3Kγ Variants. Biomolecules 2019; 9:biom9090427. [PMID: 31480354 PMCID: PMC6770443 DOI: 10.3390/biom9090427] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 12/19/2022] Open
Abstract
Phosphatidylinositide 3-kinase (PI3K) γ is the only class IB PI3K member playing significant roles in the G-protein-dependent regulation of cell signaling in health and disease. Originally found in the immune system, increasing evidence suggest a wide array of functions in the whole organism. PI3Kγ occur as two different heterodimeric variants: PI3Kγ (p87) and PI3Kγ (p101), which share the same p110γ catalytic subunit but differ in their associated non-catalytic subunit. Here we concentrate on specific PI3Kγ features including its regulation and biological functions. In particular, the roles of its non-catalytic subunits serving as the main regulators determining specificity of class IB PI3Kγ enzymes are highlighted.
Collapse
|
18
|
A class of highly selective inhibitors bind to an active state of PI3Kγ. Nat Chem Biol 2019; 15:348-357. [DOI: 10.1038/s41589-018-0215-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 12/12/2018] [Indexed: 12/20/2022]
|
19
|
Halova I, Bambouskova M, Draberova L, Bugajev V, Draber P. The transmembrane adaptor protein NTAL limits mast cell chemotaxis toward prostaglandin E2. Sci Signal 2018; 11:11/556/eaao4354. [DOI: 10.1126/scisignal.aao4354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Chemotaxis of mast cells is one of the crucial steps in their development and function. Non–T cell activation linker (NTAL) is a transmembrane adaptor protein that inhibits the activation of mast cells and B cells in a phosphorylation-dependent manner. Here, we studied the role of NTAL in the migration of mouse mast cells stimulated by prostaglandin E2 (PGE2). Although PGE2 does not induce the tyrosine phosphorylation of NTAL, unlike IgE immune complex antigens, we found that loss of NTAL increased the chemotaxis of mast cells toward PGE2. Stimulation of mast cells that lacked NTAL with PGE2 enhanced the phosphorylation of AKT and the production of phosphatidylinositol 3,4,5-trisphosphate. In resting NTAL-deficient mast cells, phosphorylation of an inhibitory threonine in ERM family proteins accompanied increased activation of β1-containing integrins, which are features often associated with increased invasiveness in tumors. Rescue experiments indicated that only full-length, wild-type NTAL restored the chemotaxis of NTAL-deficient cells toward PGE2. Together, these data suggest that NTAL is a key inhibitor of mast cell chemotaxis toward PGE2, which may act through the RHOA/ERM/β1-integrin and PI3K/AKT axes.
Collapse
|
20
|
Li M, Sala V, De Santis MC, Cimino J, Cappello P, Pianca N, Di Bona A, Margaria JP, Martini M, Lazzarini E, Pirozzi F, Rossi L, Franco I, Bornbaum J, Heger J, Rohrbach S, Perino A, Tocchetti CG, Lima BH, Teixeira MM, Porporato PE, Schulz R, Angelini A, Sandri M, Ameri P, Sciarretta S, Lima-Júnior RCP, Mongillo M, Zaglia T, Morello F, Novelli F, Hirsch E, Ghigo A. Phosphoinositide 3-Kinase Gamma Inhibition Protects From Anthracycline Cardiotoxicity and Reduces Tumor Growth. Circulation 2018; 138:696-711. [DOI: 10.1161/circulationaha.117.030352] [Citation(s) in RCA: 134] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Mingchuan Li
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Valentina Sala
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
- A.O.U. Città della Salute e della Scienza di Torino, S.C. Emergency Medicine, Torino, Italy (V.S., F.M.)
| | - Maria Chiara De Santis
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - James Cimino
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Paola Cappello
- Center for Experimental Research and Medical Studies, Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino, Italy (P.C., F.N.)
| | - Nicola Pianca
- Department of Biomedical Sciences, University of Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
- Venetian Institute of Molecular Medicine, Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
| | - Anna Di Bona
- Department of Biomedical Sciences, University of Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
- Venetian Institute of Molecular Medicine, Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Italy (A.D.B., A.A., T.Z.)
| | - Jean Piero Margaria
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Miriam Martini
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Edoardo Lazzarini
- Department of Internal Medicine, Cardiovascular Biology Laboratory, University of Genova and IRCCS Policlinic Hospital San Martino, Italy (E.L., P.A.)
| | - Flora Pirozzi
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
- Department of Translational Medical Sciences, Division of Internal Medicine, Federico II University, Napoli, Italy (F.P., C.G.T.)
| | - Luca Rossi
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Irene Franco
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Julia Bornbaum
- Institut für Physiologie, Justus Liebig University Giessen, Germany (J.B., J.H., S.R., R.S.)
| | - Jacqueline Heger
- Institut für Physiologie, Justus Liebig University Giessen, Germany (J.B., J.H., S.R., R.S.)
| | - Susanne Rohrbach
- Institut für Physiologie, Justus Liebig University Giessen, Germany (J.B., J.H., S.R., R.S.)
| | - Alessia Perino
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Carlo G. Tocchetti
- Department of Translational Medical Sciences, Division of Internal Medicine, Federico II University, Napoli, Italy (F.P., C.G.T.)
| | - Braulio H.F. Lima
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil (B.H.F.L., M.M.T.)
| | - Mauro M. Teixeira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil (B.H.F.L., M.M.T.)
| | - Paolo E. Porporato
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Rainer Schulz
- Institut für Physiologie, Justus Liebig University Giessen, Germany (J.B., J.H., S.R., R.S.)
| | - Annalisa Angelini
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Italy (A.D.B., A.A., T.Z.)
| | - Marco Sandri
- Department of Biomedical Sciences, University of Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
- Venetian Institute of Molecular Medicine, Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
| | - Pietro Ameri
- Department of Internal Medicine, Cardiovascular Biology Laboratory, University of Genova and IRCCS Policlinic Hospital San Martino, Italy (E.L., P.A.)
| | - Sebastiano Sciarretta
- Department of Medical and Surgical Sciences and Biotechnologies, University of Rome Sapienza, Latina, Italy (S.S.)
| | - Roberto César P. Lima-Júnior
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
- Department of Physiology and Pharmacology, Laboratory of Pharmacology of Inflammation and Cancer, Universidade Federal do Ceará/UFC, Fortaleza, Brazil (R.C.P.L.-J.)
| | - Marco Mongillo
- Department of Biomedical Sciences, University of Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
- Venetian Institute of Molecular Medicine, Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
| | - Tania Zaglia
- Department of Biomedical Sciences, University of Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
- Venetian Institute of Molecular Medicine, Padova, Italy (N.P., A.D.B., M.S., M.M., T.Z.)
- Department of Cardiac, Thoracic, and Vascular Sciences, University of Padova, Italy (A.D.B., A.A., T.Z.)
| | - Fulvio Morello
- A.O.U. Città della Salute e della Scienza di Torino, S.C. Emergency Medicine, Torino, Italy (V.S., F.M.)
| | - Francesco Novelli
- Center for Experimental Research and Medical Studies, Azienda Ospedaliera Universitaria Città della Salute e della Scienza di Torino, Italy (P.C., F.N.)
| | - Emilio Hirsch
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| | - Alessandra Ghigo
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Italy (M.L., V.S., M.C.D.S., J.C., J.P.M., M.M., F.P., L.R., I.F., A.P., P.E.P., R.C.P.L.-J., E.H., A.G.)
| |
Collapse
|
21
|
Ali AY, Wu X, Eissa N, Hou S, Ghia JE, Murooka TT, Banerji V, Johnston JB, Lin F, Gibson SB, Marshall AJ. Distinct roles for phosphoinositide 3-kinases γ and δ in malignant B cell migration. Leukemia 2018; 32:1958-1969. [PMID: 29479062 PMCID: PMC6127087 DOI: 10.1038/s41375-018-0012-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 12/13/2017] [Accepted: 12/15/2017] [Indexed: 12/19/2022]
Abstract
The PI 3-kinases (PI3K) are essential mediators of chemokine receptor signaling necessary for migration of chronic lymphocytic leukemia (CLL) cells and their interaction with tissue-resident stromal cells. While the PI3Kδ-specific inhibitor idelalisib shows efficacy in treatment of CLL and other B cell malignancies, the function of PI3Kγ has not been extensively studied in B cells. Here, we assess whether PI3Kγ has non-redundant functions in CLL migration and adhesion to stromal cells. We observed that pharmaceutical PI3Kγ inhibition with CZC24832 significantly impaired CLL cell migration, while dual PI3Kδ/γ inhibitor duvelisib had a greater impact than single isoform-selective inhibitors. Knockdown of PI3Kγ reduced migration of CLL cells and cell lines. Expression of the PI3Kγ subunits increased in CLL cells in response to CD40L/IL-4, whereas BCR cross-linking had no effect. Overexpression of PI3Kγ subunits enhanced cell migration in response to SDF1α/CXCL12, with the strongest effect observed within ZAP70 + CLL samples. Microscopic tracking of cell migration within chemokine gradients revealed that PI3Kγ functions in gradient sensing and impacts cell morphology and F-actin polarization. PI3Kγ inhibition also reduced CLL adhesion to stromal cells to a similar extent as idelalisib. These findings provide the first evidence that PI3Kγ has unique functions in malignant B cells.
Collapse
Affiliation(s)
- Ahmed Y Ali
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada.,Research Institute in Oncology and Hematology, CancerCare Manitoba, 675 McDermot Ave., Winnipeg, MB, R3E 0V9, Canada
| | - Xun Wu
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada
| | - Nour Eissa
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada
| | - Sen Hou
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada
| | - Jean-Eric Ghia
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada.,Department of Internal Medicine, Section of Gastroenterology, University of Manitoba, 820 Sherbrooke St., Winnipeg, MB, R3A 1R9, Canada
| | - Thomas T Murooka
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada.,Department of Medical Microbiology and Infectious Diseases, University of Manitoba, 745 Bannatyne Ave., Winnipeg, MB, R3E 0J9, Canada
| | - Versha Banerji
- Research Institute in Oncology and Hematology, CancerCare Manitoba, 675 McDermot Ave., Winnipeg, MB, R3E 0V9, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Ave., Winnipeg, MB, R3E 0J9, Canada
| | - James B Johnston
- Research Institute in Oncology and Hematology, CancerCare Manitoba, 675 McDermot Ave., Winnipeg, MB, R3E 0V9, Canada
| | - Francis Lin
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada.,Department of Physics and Astronomy, University of Manitoba, Allen Building, Winnipeg, MB, R3T 2N2, Canada
| | - Spencer B Gibson
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada.,Research Institute in Oncology and Hematology, CancerCare Manitoba, 675 McDermot Ave., Winnipeg, MB, R3E 0V9, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Ave., Winnipeg, MB, R3E 0J9, Canada
| | - Aaron J Marshall
- Department of Immunology, University of Manitoba, 750 McDermot Avenue, Winnipeg, MB, R3E 0T5, Canada. .,Research Institute in Oncology and Hematology, CancerCare Manitoba, 675 McDermot Ave., Winnipeg, MB, R3E 0V9, Canada. .,Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Ave., Winnipeg, MB, R3E 0J9, Canada.
| |
Collapse
|
22
|
Srivastava S, Li Z, Skolnik EY. Phosphatidlyinositol-3-kinase C2 beta (PI3KC2β) is a potential new target to treat IgE mediated disease. PLoS One 2017; 12:e0183474. [PMID: 28820911 PMCID: PMC5562315 DOI: 10.1371/journal.pone.0183474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 08/04/2017] [Indexed: 12/14/2022] Open
Abstract
Cross linking of the IgE receptor (FcεRI) on mast cells plays a critical role in IgE-dependent allergy including allergic rhinitis, asthma, anaphylaxis, and delayed type hypersensitivity reactions. The Ca2+ activated K+ channel, KCa3.1, plays a critical role in IgE-stimulated Ca2+ entry and degranulation in mast cells by helping to maintain a negative membrane potential, which provides an electrochemical gradient to drive Ca2+ influx. Of the 3 classes of PI3K, the class II PI3Ks are the least studied and little is known about the roles for class II PI3Ks in vivo in the context of the whole organism under normal and pathological conditions. Studying bone marrow derived mast cells (BMMC) isolated from PI3KC2β-/- mice, we now show that the class II PI3KC2β is critical for FcεRI stimulated KCa3.1 channel activation and the subsequent activation of mast cells. We found FcεRI-stimulated Ca2+ entry, cytokine production, and degranulation are decreased in BMMC isolated from PI3KC2β-/- mice. In addition, PI3KC2β-/- mice are markedly resistant to both passive cutaneous and passive systemic anaphylaxis. These findings identify PI3KC2β as a new pharmacologic target to treat IgE-mediated disease.
Collapse
Affiliation(s)
- Shekhar Srivastava
- Division of Nephrology, New York University Langone Medical Center, New York, New York, United States of America
- Department of Molecular Pathogenesis, Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, New York, United States of America
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, New York, United States of America
| | - Zhai Li
- Division of Nephrology, New York University Langone Medical Center, New York, New York, United States of America
- Department of Molecular Pathogenesis, Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, New York, United States of America
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, New York, United States of America
| | - Edward Y. Skolnik
- Division of Nephrology, New York University Langone Medical Center, New York, New York, United States of America
- Department of Molecular Pathogenesis, Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, New York, United States of America
- The Helen L. and Martin S. Kimmel Center for Biology and Medicine, Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, New York, United States of America
- Department of Pharmacology, Skirball Institute for Biomolecular Medicine, New York University Langone Medical Center, New York, New York, United States of America
- * E-mail:
| |
Collapse
|
23
|
Design and purification of active truncated phosphoinositide 3-kinase gamma protein constructs for structural studies. Protein Expr Purif 2017; 135:1-7. [DOI: 10.1016/j.pep.2017.04.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 04/20/2017] [Accepted: 04/20/2017] [Indexed: 11/19/2022]
|
24
|
Bohnacker T, Prota AE, Beaufils F, Burke JE, Melone A, Inglis AJ, Rageot D, Sele AM, Cmiljanovic V, Cmiljanovic N, Bargsten K, Aher A, Akhmanova A, Díaz JF, Fabbro D, Zvelebil M, Williams RL, Steinmetz MO, Wymann MP. Deconvolution of Buparlisib's mechanism of action defines specific PI3K and tubulin inhibitors for therapeutic intervention. Nat Commun 2017; 8:14683. [PMID: 28276440 PMCID: PMC5347140 DOI: 10.1038/ncomms14683] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 01/19/2017] [Indexed: 12/17/2022] Open
Abstract
BKM120 (Buparlisib) is one of the most advanced phosphoinositide 3-kinase (PI3K) inhibitors for the treatment of cancer, but it interferes as an off-target effect with microtubule polymerization. Here, we developed two chemical derivatives that differ from BKM120 by only one atom. We show that these minute changes separate the dual activity of BKM120 into discrete PI3K and tubulin inhibitors. Analysis of the compounds cellular growth arrest phenotypes and microtubule dynamics suggest that the antiproliferative activity of BKM120 is mainly due to microtubule-dependent cytotoxicity rather than through inhibition of PI3K. Crystal structures of BKM120 and derivatives in complex with tubulin and PI3K provide insights into the selective mode of action of this class of drugs. Our results raise concerns over BKM120's generally accepted mode of action, and provide a unique mechanistic basis for next-generation PI3K inhibitors with improved safety profiles and flexibility for use in combination therapies. Buparlisib/BKM120 is in phase 3 clinical trials as a phosphoinositide 3-kinase (PI3K) inhibitor. Here, Bohnacker et al. combine chemical biology and structural biology approaches to segregate BKM120's biological actions, and suggest that it causes mitotic arrest predominantly by binding microtubules and disrupting their dynamics.
Collapse
Affiliation(s)
- Thomas Bohnacker
- Department of Biomedicine, University of Basel, 4058 Basel, Switzerland
| | - Andrea E Prota
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Florent Beaufils
- Department of Biomedicine, University of Basel, 4058 Basel, Switzerland
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia BC V8W 2Y2, Canada
| | - Anna Melone
- Department of Biomedicine, University of Basel, 4058 Basel, Switzerland
| | | | - Denise Rageot
- Department of Biomedicine, University of Basel, 4058 Basel, Switzerland
| | - Alexander M Sele
- Department of Biomedicine, University of Basel, 4058 Basel, Switzerland
| | | | | | - Katja Bargsten
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Amol Aher
- Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Anna Akhmanova
- Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - J Fernando Díaz
- CIB Centro de Investigaciones Biológicas, 28040 Madrid, Spain
| | | | | | | | - Michel O Steinmetz
- Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institut, 5232 Villigen, Switzerland
| | - Matthias P Wymann
- Department of Biomedicine, University of Basel, 4058 Basel, Switzerland
| |
Collapse
|
25
|
Schneble N, Schmidt C, Bauer R, Müller JP, Monajembashi S, Wetzker R. Phosphoinositide 3-kinase γ ties chemoattractant- and adrenergic control of microglial motility. Mol Cell Neurosci 2016; 78:1-8. [PMID: 27825984 DOI: 10.1016/j.mcn.2016.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 09/15/2016] [Accepted: 11/03/2016] [Indexed: 12/18/2022] Open
Abstract
Microglial motility is tightly controlled by multitude of agonistic and antagonistic factors. Chemoattractants, released after infection or damage of the brain, provoke directed migration of microglia to the pathogenic incident. In contrast, noradrenaline and other stress hormones have been shown to suppress microglial movement. Here we asked for the signaling reactions involved in the positive and negative control of microglial motility. Using pharmacological and genetic approaches we identified the lipid kinase activity of phosphoinositide 3-kinase species γ (PI3Kγ) as an essential mediator of microglial migration provoked by the complement component C5a and other chemoattractants. Inhibition of PI3Kγ lipid kinase activity by protein kinase A was disclosed as mechanism causing suppression of microglial migration by noradrenaline. Together these data characterize PI3Kγ as a nodal point in the control of microglial motility.
Collapse
Affiliation(s)
- Nadine Schneble
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital of Jena, Hans -Knöll -Straße 2, 07745 Jena, Germany.
| | - Caroline Schmidt
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital of Jena, Hans -Knöll -Straße 2, 07745 Jena, Germany.
| | - Reinhard Bauer
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital of Jena, Hans -Knöll -Straße 2, 07745 Jena, Germany.
| | - Jörg P Müller
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital of Jena, Hans -Knöll -Straße 2, 07745 Jena, Germany.
| | - Shamci Monajembashi
- Leibnitz Institute for Age Research, Fritz Lipmann Institute (FLI), Beutenberg-Straße 11, 07745 Jena, Germany.
| | - Reinhard Wetzker
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine (CMB), University Hospital of Jena, Hans -Knöll -Straße 2, 07745 Jena, Germany.
| |
Collapse
|
26
|
Lonetti A, Cappellini A, Spartà AM, Chiarini F, Buontempo F, Evangelisti C, Evangelisti C, Orsini E, McCubrey JA, Martelli AM. PI3K pan-inhibition impairs more efficiently proliferation and survival of T-cell acute lymphoblastic leukemia cell lines when compared to isoform-selective PI3K inhibitors. Oncotarget 2016; 6:10399-414. [PMID: 25871383 PMCID: PMC4496363 DOI: 10.18632/oncotarget.3295] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 02/06/2015] [Indexed: 11/25/2022] Open
Abstract
Class I phosphatidylinositol 3-kinases (PI3Ks) are frequently activated in T-cell acute lymphoblastic leukemia (T-ALL), mainly due to the loss of PTEN function. Therefore, targeting PI3Ks is a promising innovative approach for T-ALL treatment, however at present no definitive evidence indicated which is the better therapeutic strategy between pan or selective isoform inhibition, as all the four catalytic subunits might participate in leukemogenesis. Here, we demonstrated that in both PTEN deleted and PTEN non deleted T-ALL cell lines, PI3K pan-inhibition exerted the highest cytotoxic effects when compared to both selective isoform inhibition or dual p110γ/δ inhibition. Intriguingly, the dual p110γ/δ inhibitor IPI-145 was effective in Loucy cells, which are representative of early T-precursor (ETP)-ALL, a T-ALL subtype associated with a poor outcome. PTEN gene deletion did not confer a peculiar reliance of T-ALL cells on PI3K activity for their proliferation/survival, as PTEN was inactivated in PTEN non deleted cells, due to posttranslational mechanisms. PI3K pan-inhibition suppressed Akt activation and induced caspase-independent apoptosis. We further demonstrated that in some T-ALL cell lines, autophagy could exert a protective role against PI3K inhibition. Our findings strongly support clinical application of class I PI3K pan-inhibitors in T-ALL treatment, with the possible exception of ETP-ALL cases.
Collapse
Affiliation(s)
- Annalisa Lonetti
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Alessandra Cappellini
- Department of Human, Social and Health Sciences, University of Cassino, Cassino, Italy
| | - Antonino Maria Spartà
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Francesca Chiarini
- Muscoloskeletal Cell Biology Laboratory, IOR, Bologna, Italy.,Institute of Molecular Genetics, National Research Council-Rizzoli Orthopedic Institute, Bologna, Italy
| | - Francesca Buontempo
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Camilla Evangelisti
- Muscoloskeletal Cell Biology Laboratory, IOR, Bologna, Italy.,Institute of Molecular Genetics, National Research Council-Rizzoli Orthopedic Institute, Bologna, Italy
| | - Cecilia Evangelisti
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Ester Orsini
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - James A McCubrey
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | | |
Collapse
|
27
|
Localizing the lipid products of PI3Kγ in neutrophils. Adv Biol Regul 2015; 60:36-45. [PMID: 26596865 PMCID: PMC4739120 DOI: 10.1016/j.jbior.2015.10.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 10/07/2015] [Accepted: 10/07/2015] [Indexed: 11/23/2022]
Abstract
Class I phosphoinositide 3-kinases (PI3Ks) are important regulators of neutrophil migration in response to a range of chemoattractants. Their primary lipid products PtdIns(3,4,5)P3 and PtdIns(3,4)P2 preferentially accumulate near to the leading edge of migrating cells and are thought to act as an important cue organizing molecular and morphological polarization. We have investigated the distribution and accumulation of these lipids independently in mouse neutrophils using eGFP-PH reportersand electron microscopy (EM). We found that authentic mouse neutrophils rapidly polarized their Class I PI3K signalling, as read-out by eGFP-PH reporters, both at the up-gradient leading edge in response to local stimulation with fMLP as well as spontaneously and randomly in response to uniform stimulation. EM studies revealed these events occurred at the plasma membrane, were dominated by accumulation of PtdIns(3,4,5)P3, but not PtdIns(3,4)P2, and were dependent on PI3Kγ and its upstream activation by both Ras and Gβγs.
Collapse
|
28
|
Different inhibition of Gβγ-stimulated class IB phosphoinositide 3-kinase (PI3K) variants by a monoclonal antibody. Specific function of p101 as a Gβγ-dependent regulator of PI3Kγ enzymatic activity. Biochem J 2015; 469:59-69. [PMID: 26173259 DOI: 10.1042/bj20150099] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Class IB phosphoinositide 3-kinases γ (PI3Kγ) are second-messenger-generating enzymes downstream of signalling cascades triggered by G-protein-coupled receptors (GPCRs). PI3Kγ variants have one catalytic p110γ subunit that can form two different heterodimers by binding to one of a pair of non-catalytic subunits, p87 or p101. Growing experimental data argue for a different regulation of p87-p110γ and p101-p110γ allowing integration into distinct signalling pathways. Pharmacological tools enabling distinct modulation of the two variants are missing. The ability of an anti-p110γ monoclonal antibody [mAb(A)p110γ] to block PI3Kγ enzymatic activity attracted us to characterize this tool in detail using purified proteins. In order to get insight into the antibody-p110γ interface, hydrogen-deuterium exchange coupled to MS (HDX-MS) measurements were performed demonstrating binding of the monoclonal antibody to the C2 domain in p110γ, which was accompanied by conformational changes in the helical domain harbouring the Gβγ-binding site. We then studied the modulation of phospholipid vesicles association of PI3Kγ by the antibody. p87-p110γ showed a significantly reduced Gβγ-mediated phospholipid recruitment as compared with p101-p110γ. Concomitantly, in the presence of mAb(A)p110γ, Gβγ did not bind to p87-p110γ. These data correlated with the ability of the antibody to block Gβγ-stimulated lipid kinase activity of p87-p110γ 30-fold more potently than p101-p110γ. Our data argue for differential regulatory functions of the non-catalytic subunits and a specific Gβγ-dependent regulation of p101 in PI3Kγ activation. In this scenario, we consider the antibody as a valuable tool to dissect the distinct roles of the two PI3Kγ variants downstream of GPCRs.
Collapse
|
29
|
Turvey ME, Klingler-Hoffmann M, Hoffmann P, McColl SR. p84 forms a negative regulatory complex with p110γ to control PI3Kγ signalling during cell migration. Immunol Cell Biol 2015; 93:735-43. [PMID: 25753393 DOI: 10.1038/icb.2015.35] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/23/2015] [Accepted: 02/23/2015] [Indexed: 02/05/2023]
Abstract
Phosphoinositide 3-kinase γ (PI3Kγ) consists of the catalytic subunit p110γ that forms a mutually exclusive heterodimer with one of the two adaptor subunits, p101 or p84. Although activation of PI3Kγ is necessary for cell migration downstream of G-protein-coupled receptor engagement, particularly within the immune system, aberrant PI3Kγ signalling has been associated with transformation, increased migration and the progression of multiple cancer types. Regulation of PI3Kγ signal activation and duration is critical to controlling and maintaining coordinated cellular migration; however, the mechanistic basis for this is not well understood. We have recently demonstrated that, in contrast to the tumour-promoting potential of p110γ and p101, p84 possesses tumour-suppressor activity, suggesting a negative regulatory role within PI3Kγ signalling. The present study investigated the role of p84 phosphorylation in the context of PI3Kγ signalling, cell migration and p84-mediated tumour suppression. Two putative phosphorylation sites were characterised within p84, Ser358 and Thr607. Expression of wild-type p84 reduced the oncogenic potential of MDA.MB.231 cells and inhibited metastatic lung colonisation in vivo, effects that were dependent on Thr607. Furthermore, loss of Thr607 enhanced migration of MDA.MB.231 cells in vitro and prevented the induction of p84/p110γ dimers. The dimerisation of wild-type p84 with p110γ was not detected at the plasma membrane, indicating an inhibitory interaction preventing PI3Kγ lipid-kinase activity. In contrast, Ser358 phosphorylation was not determined to be critical for p84 activity in the context of migration. Our findings suggest that p84 binding to p110γ may represent a novel negative feedback signal that terminates PI3Kγ activity.
Collapse
Affiliation(s)
- Michelle E Turvey
- Chemokine Biology Laboratory, School of Molecular and Biomedical Sciences, The University of Adelaide and Centre for Molecular Pathology, Adelaide, South Australia, Australia
| | | | - Peter Hoffmann
- Adelaide Proteomics Centre, The University of Adelaide, Adelaide, South Australia, Australia
| | - Shaun R McColl
- Chemokine Biology Laboratory, School of Molecular and Biomedical Sciences, The University of Adelaide and Centre for Molecular Pathology, Adelaide, South Australia, Australia
| |
Collapse
|
30
|
Hammond GRV, Balla T. Polyphosphoinositide binding domains: Key to inositol lipid biology. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:746-58. [PMID: 25732852 DOI: 10.1016/j.bbalip.2015.02.013] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 01/29/2015] [Accepted: 02/17/2015] [Indexed: 01/01/2023]
Abstract
Polyphosphoinositides (PPIn) are an important family of phospholipids located on the cytoplasmic leaflet of eukaryotic cell membranes. Collectively, they are critical for the regulation of many aspects of membrane homeostasis and signaling, with notable relevance to human physiology and disease. This regulation is achieved through the selective interaction of these lipids with hundreds of cellular proteins, and thus the capability to study these localized interactions is crucial to understanding their functions. In this review, we discuss current knowledge of the principle types of PPIn-protein interactions, focusing on specific lipid-binding domains. We then discuss how these domains have been re-tasked by biologists as molecular probes for these lipids in living cells. Finally, we describe how the knowledge gained with these probes, when combined with other techniques, has led to the current view of the lipids' localization and function in eukaryotes, focusing mainly on animal cells. This article is part of a Special Issue entitled Phosphoinositides.
Collapse
Affiliation(s)
- Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Tamas Balla
- Section on Molecular Signal Transduction, Eunice Shriver Kennedy National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
31
|
Deladeriere A, Gambardella L, Pan D, Anderson KE, Hawkins PT, Stephens LR. The regulatory subunits of PI3Kγ control distinct neutrophil responses. Sci Signal 2015; 8:ra8. [DOI: 10.1126/scisignal.2005564] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
|
32
|
Thorpe LM, Yuzugullu H, Zhao JJ. PI3K in cancer: divergent roles of isoforms, modes of activation and therapeutic targeting. Nat Rev Cancer 2015; 15:7-24. [PMID: 25533673 PMCID: PMC4384662 DOI: 10.1038/nrc3860] [Citation(s) in RCA: 964] [Impact Index Per Article: 107.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Phosphatidylinositol 3-kinases (PI3Ks) are crucial coordinators of intracellular signalling in response to extracellular stimuli. Hyperactivation of PI3K signalling cascades is one of the most common events in human cancers. In this Review, we discuss recent advances in our knowledge of the roles of specific PI3K isoforms in normal and oncogenic signalling, the different ways in which PI3K can be upregulated, and the current state and future potential of targeting this pathway in the clinic.
Collapse
Affiliation(s)
- Lauren M. Thorpe
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Program in Virology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Haluk Yuzugullu
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jean J. Zhao
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
- Correspondence to J.J.Z. by
| |
Collapse
|
33
|
PI3K signalling in inflammation. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1851:882-97. [PMID: 25514767 DOI: 10.1016/j.bbalip.2014.12.006] [Citation(s) in RCA: 341] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 11/24/2014] [Accepted: 12/09/2014] [Indexed: 12/13/2022]
Abstract
PI3Ks regulate several key events in the inflammatory response to damage and infection. There are four Class I PI3K isoforms (PI3Kα,β,γ,δ), three Class II PI3K isoforms (PI3KC2α, C2β, C2γ) and a single Class III PI3K. The four Class I isoforms synthesise the phospholipid 'PIP3'. PIP3 is a 'second messenger' used by many different cell surface receptors to control cell movement, growth, survival and differentiation. These four isoforms have overlapping functions but each is adapted to receive efficient stimulation by particular receptor sub-types. PI3Kγ is highly expressed in leukocytes and plays a particularly important role in chemokine-mediated recruitment and activation of innate immune cells at sites of inflammation. PI3Kδ is also highly expressed in leukocytes and plays a key role in antigen receptor and cytokine-mediated B and T cell development, differentiation and function. Class III PI3K synthesises the phospholipid PI3P, which regulates endosome-lysosome trafficking and the induction of autophagy, pathways involved in pathogen killing, antigen processing and immune cell survival. Much less is known about the function of Class II PI3Ks, but emerging evidence indicates they can synthesise PI3P and PI34P2 and are involved in the regulation of endocytosis. The creation of genetically-modified mice with altered PI3K signalling, together with the development of isoform-selective, small-molecule PI3K inhibitors, has allowed the evaluation of the individual roles of Class I PI3K isoforms in several mouse models of chronic inflammation. Selective inhibition of PI3Kδ, γ or β has each been shown to reduce the severity of inflammation in one or more models of autoimmune disease, respiratory disease or allergic inflammation, with dual γ/δ or β/δ inhibition generally proving more effective. The inhibition of Class I PI3Ks may therefore offer a therapeutic opportunity to treat non-resolving inflammatory pathologies in humans. This article is part of a Special Issue entitled Phosphoinositides.
Collapse
|
34
|
Autocrine hemokinin-1 functions as an endogenous adjuvant for IgE-mediated mast cell inflammatory responses. J Allergy Clin Immunol 2014; 135:1019-1030.e8. [PMID: 25201259 DOI: 10.1016/j.jaci.2014.07.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 07/18/2014] [Accepted: 07/18/2014] [Indexed: 01/24/2023]
Abstract
BACKGROUND Efficient development of atopic diseases requires interactions between allergen and adjuvant to initiate and amplify the underlying inflammatory responses. Substance P (SP) and hemokinin-1 (HK-1) are neuropeptides that signal through the neurokinin-1 receptor (NK1R) to promote inflammation. Mast cells initiate the symptoms and tissue effects of atopic disorders, secreting TNF and IL-6 after FcεRI cross-linking by antigen-IgE complexes (FcεRI-activated mast cells [FcεRI-MCs]). Additionally, MCs express the NK1R, suggesting an adjuvant role for NK1R agonists in FcεRI-MC-mediated pathologies; however, in-depth research addressing this relevant aspect of MC biology is lacking. OBJECTIVE We sought to investigate the effect of NK1R signaling and the individual roles of SP and HK-1 as potential adjuvants for FcεRI-MC-mediated allergic disorders. METHODS Bone marrow-derived mast cells (BMMCs) from C57BL/6 wild-type (WT) or NK1R(-/-) mice were used to investigate the effects of NK1R signaling on FcεRI-MCs. BMMCs generated from Tac1(-/-) mice or after culture with Tac4 small interfering RNA were used to address the adjuvancy of SP and HK-1. WT, NK1R(-/-), and c-Kit(W-sh/W-sh) mice reconstituted with WT or NK1R(-/-) BMMCs were used to evaluate NK1R signaling on FcεRI-MC-mediated passive local and systemic anaphylaxis and on airway inflammation. RESULTS FcεRI-activated MCs upregulated NK1R and HK-1 transcripts and protein synthesis, without modifying SP expression. In a positive signaling loop HK-1 promoted TNF and IL-6 secretion by MC degranulation and protein synthesis, the latter through the phosphoinositide 3-kinase/Akt/nuclear factor κB pathways. In vivo NK1R signaling was necessary for the development of passive local and systemic anaphylaxis and airway inflammation. CONCLUSIONS FcεRI stimulation of MCs promotes autocrine secretion of HK-1, which signals through NK1R to provide adjuvancy for efficient development of FcεRI-MC-mediated disorders.
Collapse
|
35
|
PI3K inhibitors as potential therapeutics for autoimmune disease. Drug Discov Today 2014; 19:1195-9. [DOI: 10.1016/j.drudis.2014.04.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 04/02/2014] [Indexed: 12/13/2022]
|
36
|
Biethahn K, Orinska Z, Vigorito E, Goyeneche-Patino DA, Mirghomizadeh F, Föger N, Bulfone-Paus S. miRNA-155 controls mast cell activation by regulating the PI3Kγ pathway and anaphylaxis in a mouse model. Allergy 2014; 69:752-62. [PMID: 24734904 DOI: 10.1111/all.12407] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mast cells (MCs) play a central role in allergic and inflammatory disorders by rapid degranulation and release of inflammatory mediators upon antigen-driven engagement of the FcεRI. Receptor-mediated MC responses are controlled by the activation of different isoforms of phosphoinositide-3-kinase (PI3K) and the downstream signaling processes. Recent evidence suggests that miRNAs are important molecular players regulating the PI3K/Akt pathway. METHODS The role of miR-155 in the regulation of MC functions in vivo was studied in the passive cutaneous anaphylaxis (PCA) MC-dependent model. WT and miR-155(-/-) mice were injected intradermally with anti-DNP-IgE and intravenously with the antigen DNP-HSA. Ear swelling was assessed to evaluate the anaphylactic response. All investigations, to characterize miR-155 specific activities in MCs, were conducted comparing WT and miR-155(-/-) bone marrow-derived MCs (BMMCs). RESULTS We report that miR-155(-/-) mice display enhanced anaphylaxis reactions. Although miR-155(-/-) BMMCs show normal development, proliferation, and survival, miR-155 deficiency enhances FcεRI-mediated degranulation and release of TNF-α, IL-13, and IL-6. Interestingly, the level of Akt phosphorylation on both of its regulatory residues Thr308 and Ser473 was increased in miR-155(-/-) compared to WT BMMCs. Gene expression profiling showed that miR-155(-/-) BMMCs exhibited significantly increased expression of the adapter PI3Kγ subunits Pik3r5 (p101) and Pik3r6 (p84, p87(PIKAP) ). Furthermore, selective blockade of the PI3Kγ pathway inhibited degranulation in miR-155(-/-) BMMCs. CONCLUSIONS Thus, we suggest that miR-155 plays a critical role in FcεRI-mediated MC responses by modulating components of the PI3Kγ pathway. This newly identified mechanism of miRNA-controlled MC activation may affect the initiation and maintenance of allergic disorders.
Collapse
Affiliation(s)
| | - Z. Orinska
- Research Center Borstel; Borstel Germany
| | | | | | | | - N. Föger
- Research Center Borstel; Borstel Germany
- Institute for Clinical Chemistry; Hannover Medical School; Hannover Germany
| | - S. Bulfone-Paus
- Research Center Borstel; Borstel Germany
- Faculty of Human and Medical Sciences; Institute for Inflammation and Repair and MCCIR; University of Manchester; Manchester UK
| |
Collapse
|
37
|
Salamon RS, Backer JM. Phosphatidylinositol-3,4,5-trisphosphate: tool of choice for class I PI 3-kinases. Bioessays 2014; 35:602-11. [PMID: 23765576 DOI: 10.1002/bies.201200176] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Class I PI 3-kinases signal by producing the signaling lipid phosphatidylinositol(3,4,5) trisphosphate, which in turn acts by recruiting downstream effectors that contain specific lipid-binding domains. The class I PI 3-kinases comprise four distinct catalytic subunits linked to one of seven different regulatory subunits. All the class I PI 3-kinases produce the same signaling lipid, PIP3, and the different isoforms have overlapping expression patterns and are coupled to overlapping sets of upstream activators. Nonetheless, studies in cultured cells and in animals have demonstrated that the different isoforms are coupled to distinct ranges of downstream responses. This review focuses on the mechanisms by which the production of a common product, PIP3, can produce isoform-specific signaling by PI 3-kinases.
Collapse
Affiliation(s)
- Rachel Schnur Salamon
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | | |
Collapse
|
38
|
Wymann MP, Solinas G. Inhibition of phosphoinositide 3-kinase γ attenuates inflammation, obesity, and cardiovascular risk factors. Ann N Y Acad Sci 2013; 1280:44-7. [PMID: 23551103 DOI: 10.1111/nyas.12037] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Phosphoinositide 3-kinase γ (PI3Kγ) plays a central role in inflammation, allergy, cardiovascular, and metabolic disease. Obesity is accompanied by chronic, low-grade inflammation. As PI3Kγ plays a major role in leukocyte recruitment, targeting of PI3Kγ has been considered to be a strategy for attenuating progression of obesity to insulin resistance and type 2 diabetes. Indeed, PI3Kγ null mice are protected from high fat diet-induced obesity, metabolic inflammation, fatty liver, and insulin resistance. The lean phenotype of the PI3Kγ-null mice has been linked to increased thermogenesis and energy expenditure. Surprisingly, the increase in fat mass and metabolic aberrations were not linked to PI3Kγ activity in the hematopoietic compartment. Thermogenesis and oxygen consumption are modulated by PI3Kγ lipid kinase-dependent and -independent signaling mechanisms. PI3Kγ signaling controls metabolic and inflammatory stress, and may provide an entry point for therapeutic strategies in metabolic disease, inflammation, and cardiovascular disease.
Collapse
|
39
|
Shymanets A, Prajwal, Bucher K, Beer-Hammer S, Harteneck C, Nürnberg B. p87 and p101 subunits are distinct regulators determining class IB phosphoinositide 3-kinase (PI3K) specificity. J Biol Chem 2013; 288:31059-68. [PMID: 24014027 DOI: 10.1074/jbc.m113.508234] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Class IB phosphoinositide 3-kinase γ (PI3Kγ) comprises a single catalytic p110γ subunit, which binds to two non-catalytic subunits, p87 or p101, and controls a plethora of fundamental cellular responses. The non-catalytic subunits are assumed to be redundant adaptors for Gβγ enabling G-protein-coupled receptor-mediated regulation of PI3Kγ. Growing experimental data provide contradictory evidence. To elucidate the roles of the non-catalytic subunits in determining the specificity of PI3Kγ, we tested the impact of p87 and p101 in heterodimeric p87-p110γ and p101-p110γ complexes on the modulation of PI3Kγ activity in vitro and in living cells. RT-PCR, biochemical, and imaging data provide four lines of evidence: (i) specific expression patterns of p87 and p101, (ii) up-regulation of p101, providing the basis to consider p87 as a protein forming a constitutively and p101 as a protein forming an inducibly expressed PI3Kγ, (iii) differences in basal and stimulated enzymatic activities, and (iv) differences in complex stability, all indicating apparent diversity within class IB PI3Kγ. In conclusion, expression and activities of PI3Kγ are modified differently by p87 and p101 in vitro and in living cells, arguing for specific regulatory roles of the non-catalytic subunits in the differentiation of PI3Kγ signaling pathways.
Collapse
Affiliation(s)
- Aliaksei Shymanets
- From the Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics and Interfaculty Centre of Pharmacogenomics and Pharmaceutical Research, University of Tübingen, 72074 Tübingen, Germany
| | | | | | | | | | | |
Collapse
|
40
|
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
|
41
|
Affiliation(s)
- Len Stephens
- The Babraham Institute, Cambridge, United Kingdom.
| | | |
Collapse
|
42
|
Walser R, Burke JE, Gogvadze E, Bohnacker T, Zhang X, Hess D, Küenzi P, Leitges M, Hirsch E, Williams RL, Laffargue M, Wymann MP. PKCβ phosphorylates PI3Kγ to activate it and release it from GPCR control. PLoS Biol 2013; 11:e1001587. [PMID: 23824069 PMCID: PMC3692425 DOI: 10.1371/journal.pbio.1001587] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 05/08/2013] [Indexed: 12/31/2022] Open
Abstract
All class I phosphoinositide 3-kinases (PI3Ks) associate tightly with regulatory subunits through interactions that have been thought to be constitutive. PI3Kγ is key to the regulation of immune cell responses activated by G protein-coupled receptors (GPCRs). Remarkably we find that PKCβ phosphorylates Ser582 in the helical domain of the PI3Kγ catalytic subunit p110γ in response to clustering of the high-affinity IgE receptor (FcεRI) and/or store-operated Ca²⁺- influx in mast cells. Phosphorylation of p110γ correlates with the release of the p84 PI3Kγ adapter subunit from the p84-p110γ complex. Ser582 phospho-mimicking mutants show increased p110γ activity and a reduced binding to the p84 adapter subunit. As functional p84-p110γ is key to GPCR-mediated p110γ signaling, this suggests that PKCβ-mediated p110γ phosphorylation disconnects PI3Kγ from its canonical inputs from trimeric G proteins, and enables p110γ to operate downstream of Ca²⁺ and PKCβ. Hydrogen deuterium exchange mass spectrometry shows that the p84 adaptor subunit interacts with the p110γ helical domain, and reveals an unexpected mechanism of PI3Kγ regulation. Our data show that the interaction of p110γ with its adapter subunit is vulnerable to phosphorylation, and outline a novel level of PI3K control.
Collapse
Affiliation(s)
- Romy Walser
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - John E. Burke
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Elena Gogvadze
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Thomas Bohnacker
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Xuxiao Zhang
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Peter Küenzi
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | | | - Emilio Hirsch
- Department of Genetics, Biology and Biochemistry, University of Torino, Torino, Italy
| | - Roger L. Williams
- Medical Research Council, Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Muriel Laffargue
- INSERM, UMR1048, Institut des Maladies Métaboliques et Cardiovasculaires, Toulouse, France
| | - Matthias P. Wymann
- Department of Biomedicine, University of Basel, Basel, Switzerland
- * E-mail:
| |
Collapse
|
43
|
Collmann E, Bohnacker T, Marone R, Dawson J, Rehberg M, Stringer R, Krombach F, Burkhart C, Hirsch E, Hollingworth GJ, Thomas M, Wymann MP. Transient targeting of phosphoinositide 3-kinase acts as a roadblock in mast cells' route to allergy. J Allergy Clin Immunol 2013; 132:959-68. [PMID: 23683463 DOI: 10.1016/j.jaci.2013.03.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 02/05/2013] [Accepted: 03/06/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND Tissue mast cell numbers are dynamically regulated by recruitment of progenitors from the vasculature. It is unclear whether progenitors are recruited during allergic sensitization and whether recruitment promotes allergic responses. OBJECTIVE We sought to (1) determine the effect of mast cell recruitment on acute allergic responses and (2) to define the role of phosphoinositide 3-kinase (PI3K) isoforms in sequential steps to allergic responses. METHODS Gene-targeted mice for PI3Kγ or PI3Kδ or mice treated with isoform-specific PI3K inhibitors (a novel PI3Kγ-specific inhibitor [NVS-PI3-4] and the PI3Kδ inhibitor IC87114) were used to monitor IgE-mediated mast cell recruitment, migration, adhesion by means of intravital microscopy, degranulation, TNF-α release, and subsequent endothelial cell activation in vivo or in bone marrow-derived mast cells. RESULTS Functional PI3Kγ, but not PI3Kδ, was crucial for mast cell accumulation in IgE-challenged skin, TNF-α release from IgE/antigen-stimulated mast cells, and mast cell/endothelial interactions and chemotaxis. PI3Kγ-deficient bone marrow-derived mast cells did not adhere to the endothelium in TNF-α-treated cremaster muscle, whereas PI3Kδ was not required. Depletion of TNF-α blocked IgE-induced mast cell recruitment, which links tissue mast cell-derived cytokine release to endothelial activation and mast cell recruitment. Interference with mast cell recruitment protected against anaphylaxis and was superior to blockage of tissue mast cell degranulation. CONCLUSIONS Interference with mast cell recruitment to exacerbated tissues provides a novel strategy to alleviate allergic reactions and surpassed attenuation of tissue mast cell degranulation. This results in prolonged drug action and allows for reduction of drug doses required to block anaphylaxis, an important feature for drugs targeting inflammatory disease in general.
Collapse
Affiliation(s)
- Emilie Collmann
- Institute of Biochemistry and Genetics, Department of Biomedicine, University of Basel, Basel, Switzerland
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Zhang P, Guo A, Possemato A, Wang C, Beard L, Carlin C, Markowitz SD, Polakiewicz RD, Wang Z. Identification and functional characterization of p130Cas as a substrate of protein tyrosine phosphatase nonreceptor 14. Oncogene 2013; 32:2087-95. [PMID: 22710723 PMCID: PMC3631434 DOI: 10.1038/onc.2012.220] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/01/2012] [Accepted: 05/01/2012] [Indexed: 01/12/2023]
Abstract
Protein tyrosine phosphatase nonreceptor type 14 (PTPN14) is frequently mutated in a variety of human cancers. However, the cell signaling pathways regulated by PTPN14 largely remain to be elucidated. Here, we identify a list of potential substrates of PTPN14 using a phospho-proteomic approach. We show that p130 Crk-associated substrate (p130Cas) is a direct substrate of PTPN14 and that PTPN14 specifically regulates p130Cas phosphorylation at tyrosine residue 128 (Y128) in colorectal cancer (CRC) cells. We engineered CRC cells homozygous for a p130Cas Y128F knock-in mutant and found that these cells exhibit significantly reduced migration and colony formation, impaired anchorage-independent growth, slower xenograft tumor growth in nude mice and have decreased phosphorylation of AKT. Furthermore, we demonstrate that SRC phosphorylates p130Cas Y128 and that CRC cell lines harboring high levels of pY128Cas are more sensitive to SRC family kinase inhibitor Dasatinib. These findings suggest that p130Cas Y128 phosphorylation may be exploited as a predictive marker for Dasatinib response in cancer patients. In aggregate, our studies reveal a novel signaling pathway that has an important role in colorectal tumorigenesis.
Collapse
Affiliation(s)
- Peng Zhang
- Department of Genetics, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | - Ailan Guo
- Cell Signaling Technology Inc., 3 Trask Lane, Danvers, MA 01923
| | | | - Chao Wang
- Department of Genetics, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | - Lydia Beard
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
- Department of Medicine, Case Medical Center, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | - Cathleen Carlin
- Department of Microbiology and Molecular Biology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | - Sanford D. Markowitz
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
- Department of Medicine, Case Medical Center, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| | | | - Zhenghe Wang
- Department of Genetics, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
- Department of Medicine, Case Medical Center, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106
| |
Collapse
|
45
|
Foster JG, Blunt MD, Carter E, Ward SG. Inhibition of PI3K signaling spurs new therapeutic opportunities in inflammatory/autoimmune diseases and hematological malignancies. Pharmacol Rev 2013; 64:1027-54. [PMID: 23023033 DOI: 10.1124/pr.110.004051] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The phosphoinositide 3-kinase/mammalian target of rapamycin/protein kinase B (PI3K/mTOR/Akt) signaling pathway is central to a plethora of cellular mechanisms in a wide variety of cells including leukocytes. Perturbation of this signaling cascade is implicated in inflammatory and autoimmune disorders as well as hematological malignancies. Proteins within the PI3K/mTOR/Akt pathway therefore represent attractive targets for therapeutic intervention. There has been a remarkable evolution of PI3K inhibitors in the past 20 years from the early chemical tool compounds to drugs that are showing promise as anticancer agents in clinical trials. The use of animal models and pharmacological tools has expanded our knowledge about the contribution of individual class I PI3K isoforms to immune cell function. In addition, class II and III PI3K isoforms are emerging as nonredundant regulators of immune cell signaling revealing potentially novel targets for disease treatment. Further complexity is added to the PI3K/mTOR/Akt pathway by a number of novel signaling inputs and feedback mechanisms. These can present either caveats or opportunities for novel drug targets. Here, we consider recent advances in 1) our understanding of the contribution of individual PI3K isoforms to immune cell function and their relevance to inflammatory/autoimmune diseases as well as lymphoma and 2) development of small molecules with which to inhibit the PI3K pathway. We also consider whether manipulating other proximal elements of the PI3K signaling cascade (such as class II and III PI3Ks or lipid phosphatases) are likely to be successful in fighting off different immune diseases.
Collapse
Affiliation(s)
- John G Foster
- Inflammatory Cell Biology Laboratory, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, UK.
| | | | | | | |
Collapse
|
46
|
Schmidt C, Schneble N, Müller JP, Bauer R, Perino A, Marone R, Rybalkin SD, Wymann MP, Hirsch E, Wetzker R. Phosphoinositide 3-kinase γ mediates microglial phagocytosis via lipid kinase-independent control of cAMP. Neuroscience 2012; 233:44-53. [PMID: 23276671 DOI: 10.1016/j.neuroscience.2012.12.036] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 12/18/2012] [Accepted: 12/19/2012] [Indexed: 02/08/2023]
Abstract
Microglial phagocytosis plays a key role in neuroprotective and neurodegenerative responses of the innate immune system in the brain. Here we investigated the regulatory function of phosphoinositide 3-kinase γ (PI3Kγ) in phagocytosis of bacteria and Zymosan particles by mouse brain microglia in vitro and in vivo. Using genetic and pharmacological approaches our data revealed PI3Kγ as an essential mediator of microglial phagocytosis. Unexpectedly, microglia expressing lipid kinase deficient mutant PI3Kγ exhibited similar phagocytosis as wild-type cells. These data suggest kinase-independent stimulation of cAMP phosphodiesterase activity by PI3Kγ as a crucial mediator of phagocytosis. In sum our findings indicate PI3Kγ-dependent suppression of cAMP signaling as a critical regulatory element of microglial phagocytosis.
Collapse
Affiliation(s)
- C Schmidt
- Institute of Molecular Cell Biology, Center for Molecular Biomedicine, Jena University Hospital, 07745 Jena, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Wymann MP, Schultz C. The chemical biology of phosphoinositide 3-kinases. Chembiochem 2012; 13:2022-35. [PMID: 22965647 DOI: 10.1002/cbic.201200089] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 07/13/2012] [Indexed: 01/14/2023]
Abstract
Since its discovery in the late 1980s, phosphoinositide 3-kinase (PI3K), and its isoforms have arguably reached the forefront of signal transduction research. Regulation of this lipid kinase, its functions, its effectors, in short its entire signaling network, has been extensively studied. PI3K inhibitors are frequently used in biochemistry and cell biology. In addition, many pharmaceutical companies have launched drug-discovery programs to identify modulators of PI3Ks. Despite these efforts and a fairly good knowledge of the PI3K signaling network, we still have only a rudimentary picture of the signaling dynamics of PI3K and its lipid products in space and time. It is therefore essential to create and use novel biological and chemical tools to manipulate the phosphoinositide signaling network with spatial and temporal resolution. In this review, we discuss the current and potential future tools that are available and necessary to unravel the various functions of PI3K and its isoforms.
Collapse
Affiliation(s)
- Matthias P Wymann
- Institute of Biochemistry & Genetics, Department of Biomedicine, University of Basel, Mattenstrasse 28, 4058 Basel, Switzerland
| | | |
Collapse
|
48
|
Bell K, Sunose M, Ellard K, Cansfield A, Taylor J, Miller W, Ramsden N, Bergamini G, Neubauer G. SAR studies around a series of triazolopyridines as potent and selective PI3Kγ inhibitors. Bioorg Med Chem Lett 2012; 22:5257-63. [DOI: 10.1016/j.bmcl.2012.06.049] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 06/14/2012] [Accepted: 06/15/2012] [Indexed: 11/26/2022]
|
49
|
Schmidt N, Basu S, Sladecek S, Gatti S, van Haren J, Treves S, Pielage J, Galjart N, Brenner HR. Agrin regulates CLASP2-mediated capture of microtubules at the neuromuscular junction synaptic membrane. ACTA ACUST UNITED AC 2012; 198:421-37. [PMID: 22851317 PMCID: PMC3413356 DOI: 10.1083/jcb.201111130] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Agrin regulates acetylcholine receptors at the neuromuscular junction by locally stabilizing microtubules through the plus end tracking proteins CLASP2 and CLIP-170. Agrin is the major factor mediating the neuronal regulation of postsynaptic structures at the vertebrate neuromuscular junction, but the details of how it orchestrates this unique three-dimensional structure remain unknown. Here, we show that agrin induces the formation of the dense network of microtubules in the subsynaptic cytoplasm and that this, in turn, regulates acetylcholine receptor insertion into the postsynaptic membrane. Agrin acted in part by locally activating phosphatidylinositol 3-kinase and inactivating GSK3β, which led to the local capturing of dynamic microtubules at agrin-induced acetylcholine receptor (AChR) clusters, mediated to a large extent by the microtubule plus-end tracking proteins CLASP2 and CLIP-170. Indeed, in the absence of CLASP2, microtubule plus ends at the subsynaptic muscle membrane, the density of synaptic AChRs, the size of AChR clusters, and the numbers of subsynaptic muscle nuclei with their selective gene expression programs were all reduced. Thus, the cascade linking agrin to CLASP2-mediated microtubule capturing at the synaptic membrane is essential for the maintenance of a normal neuromuscular phenotype.
Collapse
Affiliation(s)
- Nadine Schmidt
- Department of Biomedicine, Institute of Physiology, University of Basel, CH-4056 Basel, Switzerland
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Abstract
Activation of PI3K (phosphoinositide 3-kinase) is a shared response to engagement of diverse types of transmembrane receptors. Depending on the cell type and stimulus, PI3K activation can promote different fates including proliferation, survival, migration and differentiation. The diverse roles of PI3K signalling are well illustrated by studies of lymphocytes, the cells that mediate adaptive immunity. Genetic and pharmacological experiments have shown that PI3K activation regulates many steps in the development, activation and differentiation of both B- and T-cells. These findings have prompted the development of PI3K inhibitors for the treatment of autoimmunity and inflammatory diseases. PI3K activation, however, has both positive and negative roles in immune system activation. Consequently, although PI3K suppression can attenuate immune responses it can also enhance inflammation, disrupt peripheral tolerance and promote autoimmunity. An exciting discovery is that a selective inhibitor of the p110δ catalytic isoform of PI3K, CAL-101, achieves impressive clinical efficacy in certain B-cell malignancies. A model is emerging in which p110δ inhibition disrupts signals from the lymphoid microenvironment, leading to release of leukaemia and lymphoma cells from their protective niche. These encouraging findings have given further momentum to PI3K drug development efforts in both cancer and immune diseases.
Collapse
|