1
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Berlin M, Cantley J, Bookbinder M, Bortolon E, Broccatelli F, Cadelina G, Chan EW, Chen H, Chen X, Cheng Y, Cheung TK, Davenport K, DiNicola D, Gordon D, Hamman BD, Harbin A, Haskell R, He M, Hole AJ, Januario T, Kerry PS, Koenig SG, Li L, Merchant M, Pérez-Dorado I, Pizzano J, Quinn C, Rose CM, Rousseau E, Soto L, Staben LR, Sun H, Tian Q, Wang J, Wang W, Ye CS, Ye X, Zhang P, Zhou Y, Yauch R, Dragovich PS. PROTACs Targeting BRM (SMARCA2) Afford Selective In Vivo Degradation over BRG1 (SMARCA4) and Are Active in BRG1 Mutant Xenograft Tumor Models. J Med Chem 2024; 67:1262-1313. [PMID: 38180485 DOI: 10.1021/acs.jmedchem.3c01781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
The identification of VHL-binding proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) in SW1573 cell-based experiments is described. These molecules exhibit between 10- and 100-fold degradation selectivity for BRM over the closely related paralog protein BRG1 (SMARCA4). They also selectively impair the proliferation of the H1944 "BRG1-mutant" NSCLC cell line, which lacks functional BRG1 protein and is thus highly dependent on BRM for growth, relative to the wild-type Calu6 line. In vivo experiments performed with a subset of compounds identified PROTACs that potently and selectively degraded BRM in the Calu6 and/or the HCC2302 BRG1 mutant NSCLC xenograft models and also afforded antitumor efficacy in the latter system. Subsequent PK/PD analysis established a need to achieve strong BRM degradation (>95%) in order to trigger meaningful antitumor activity in vivo. Intratumor quantitation of mRNA associated with two genes whose transcription was controlled by BRM (PLAU and KRT80) also supported this conclusion.
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Affiliation(s)
- Michael Berlin
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Jennifer Cantley
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Mark Bookbinder
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Elizabeth Bortolon
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Fabio Broccatelli
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Greg Cadelina
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Emily W Chan
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Huifen Chen
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Xin Chen
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Yunxing Cheng
- Pharmaron Beijing, Co. Ltd., 6 Tai He Road, BDA, Beijing 100176, P. R. China
| | - Tommy K Cheung
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Kim Davenport
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Dean DiNicola
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Debbie Gordon
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Brian D Hamman
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Alicia Harbin
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Roy Haskell
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Mingtao He
- Pharmaron Beijing, Co. Ltd., 6 Tai He Road, BDA, Beijing 100176, P. R. China
| | - Alison J Hole
- Evotec (U.K.) Ltd., 95 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, U.K
| | - Thomas Januario
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Philip S Kerry
- Evotec (U.K.) Ltd., 95 Park Drive, Milton Park, Abingdon, Oxfordshire OX14 4RY, U.K
| | - Stefan G Koenig
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Limei Li
- Pharmaron Beijing, Co. Ltd., 6 Tai He Road, BDA, Beijing 100176, P. R. China
| | - Mark Merchant
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | | | - Jennifer Pizzano
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Connor Quinn
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Christopher M Rose
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Emma Rousseau
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Leofal Soto
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Leanna R Staben
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Hongming Sun
- Pharmaron Beijing, Co. Ltd., 6 Tai He Road, BDA, Beijing 100176, P. R. China
| | - Qingping Tian
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Jing Wang
- Arvinas LLC, 5 Science Park, New Haven, Connecticut 06511, United States
| | - Weifeng Wang
- Pharmaron Beijing, Co. Ltd., 6 Tai He Road, BDA, Beijing 100176, P. R. China
| | - Crystal S Ye
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Xiaofen Ye
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Penghong Zhang
- Pharmaron Beijing, Co. Ltd., 6 Tai He Road, BDA, Beijing 100176, P. R. China
| | - Yuhui Zhou
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Robert Yauch
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
| | - Peter S Dragovich
- Genentech Inc., 1 DNA Way, South San Francisco, California 94080, United States
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2
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Cantley J, Eizirik DL, Latres E, Dayan CM. Islet cells in human type 1 diabetes: from recent advances to novel therapies - a symposium-based roadmap for future research. J Endocrinol 2023; 259:e230082. [PMID: 37493471 PMCID: PMC10502961 DOI: 10.1530/joe-23-0082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/25/2023] [Indexed: 07/27/2023]
Abstract
There is a growing understanding that the early phases of type 1 diabetes (T1D) are characterised by a deleterious dialogue between the pancreatic beta cells and the immune system. This, combined with the urgent need to better translate this growing knowledge into novel therapies, provided the background for the JDRF-DiabetesUK-INNODIA-nPOD symposium entitled 'Islet cells in human T1D: from recent advances to novel therapies', which took place in Stockholm, Sweden, in September 2022. We provide in this article an overview of the main themes addressed in the symposium, pointing to both promising conclusions and key unmet needs that remain to be addressed in order to achieve better approaches to prevent or reverse T1D.
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Affiliation(s)
- J Cantley
- School of Medicine, University of Dundee, Dundee, United Kingdom of Great Britain and Northern Ireland
| | - D L Eizirik
- ULB Center for Diabetes Research, Université Libre de Bruxelles Faculté de Médecine, Bruxelles, Belgium
| | - E Latres
- JDRF International, New York, NY, USA
| | - C M Dayan
- Cardiff University School of Medicine, Cardiff, United Kingdom of Great Britain and Northern Ireland
| | - the JDRF-DiabetesUK-INNODIA-nPOD Stockholm Symposium 2022
- School of Medicine, University of Dundee, Dundee, United Kingdom of Great Britain and Northern Ireland
- ULB Center for Diabetes Research, Université Libre de Bruxelles Faculté de Médecine, Bruxelles, Belgium
- JDRF International, New York, NY, USA
- Cardiff University School of Medicine, Cardiff, United Kingdom of Great Britain and Northern Ireland
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3
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Kou P, Levy ES, Nguyen AD, Zhang D, Chen S, Cui Y, Zhang X, Broccatelli F, Pizzano J, Cantley J, Bortolon E, Rousseau E, Berlin M, Dragovich P, Sethuraman V. Development of Liposome Systems for Enhancing the PK Properties of Bivalent PROTACs. Pharmaceutics 2023; 15:2098. [PMID: 37631312 PMCID: PMC10458015 DOI: 10.3390/pharmaceutics15082098] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 07/29/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
Proteolysis-Targeting Chimeras (PROTACs) are a promising new technology in drug development. They have rapidly evolved in recent years, with several of them in clinical trials. While most of these advances have been associated with monovalent protein degraders, bivalent PROTACs have also entered clinical trials, although progression to market has been limited. One of the reasons is the complex physicochemical properties of the heterobifunctional PROTACs. A promising strategy to improve pharmacokinetics of highly lipophilic compounds, such as PROTACs, is encapsulation in liposome systems. Here we describe liposome systems for intravenous administration to enhance the PK properties of two bivalent PROTAC molecules, by reducing clearance and increasing systemic coverage. We developed and characterized a PROTAC-in-cyclodextrin liposome system where the drug was retained in the liposome core. In PK studies at 1 mg/kg for GNE-01 the PROTAC-in-cyclodextrin liposome, compared to the solution formulation, showed a 80- and a 380-fold enhancement in AUC for mouse and rat studies, respectively. We further investigated the same PROTAC-in-cyclodextrin liposome system with the second PROTAC (GNE-02), where we monitored both lipid and drug concentrations in vivo. Similarly, in a mouse PK study of GEN-02, the PROTAC-in-cyclodextrin liposome system exhibited enhancement in plasma concentration of a 23× increase over the conventional solution formulation. Importantly, the lipid CL correlated with the drug CL. Additionally, we investigated a conventional liposome approach for GNE-02, where the PROTAC resides in the lipid bilayer. Here, a 5× increase in AUC was observed, compared to the conventional solution formulation, and the drug CL was faster than the lipid CL. These results indicate that the different liposome systems can be tailored to translate across multiple PROTAC systems to modulate and improve plasma concentrations. Optimization of the liposomes could further improve tumor concentration and improve the overall therapeutic index (TI). This delivery technology may be well suited to bring novel protein targeted PROTACs into clinics.
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Affiliation(s)
- Ponien Kou
- Small Molecules Pharmaceutics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (P.K.); (E.S.L.); (A.D.N.)
| | - Elizabeth S. Levy
- Small Molecules Pharmaceutics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (P.K.); (E.S.L.); (A.D.N.)
| | - An D. Nguyen
- Small Molecules Pharmaceutics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (P.K.); (E.S.L.); (A.D.N.)
| | - Donglu Zhang
- Drug Metabolism & Pharmacokinetics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (D.Z.); (S.C.); (Y.C.); (X.Z.); (F.B.)
| | - Shu Chen
- Drug Metabolism & Pharmacokinetics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (D.Z.); (S.C.); (Y.C.); (X.Z.); (F.B.)
| | - Yusi Cui
- Drug Metabolism & Pharmacokinetics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (D.Z.); (S.C.); (Y.C.); (X.Z.); (F.B.)
| | - Xing Zhang
- Drug Metabolism & Pharmacokinetics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (D.Z.); (S.C.); (Y.C.); (X.Z.); (F.B.)
| | - Fabio Broccatelli
- Drug Metabolism & Pharmacokinetics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (D.Z.); (S.C.); (Y.C.); (X.Z.); (F.B.)
| | - Jennifer Pizzano
- Arvinas LLC, 5 Science Park, New Haven, CT 06511, USA; (J.P.); (J.C.); (E.B.); (E.R.); (M.B.)
| | - Jennifer Cantley
- Arvinas LLC, 5 Science Park, New Haven, CT 06511, USA; (J.P.); (J.C.); (E.B.); (E.R.); (M.B.)
| | - Elizabeth Bortolon
- Arvinas LLC, 5 Science Park, New Haven, CT 06511, USA; (J.P.); (J.C.); (E.B.); (E.R.); (M.B.)
| | - Emma Rousseau
- Arvinas LLC, 5 Science Park, New Haven, CT 06511, USA; (J.P.); (J.C.); (E.B.); (E.R.); (M.B.)
| | - Michael Berlin
- Arvinas LLC, 5 Science Park, New Haven, CT 06511, USA; (J.P.); (J.C.); (E.B.); (E.R.); (M.B.)
| | - Peter Dragovich
- Medicinal Chemistry, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA;
| | - Vijay Sethuraman
- Small Molecules Pharmaceutics, Genentech, 1 DNA Way, South San Francisco, CA 94080, USA; (P.K.); (E.S.L.); (A.D.N.)
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4
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Cantley J, Ye X, Rousseau E, Januario T, Hamman BD, Rose CM, Cheung TK, Hinkle T, Soto L, Quinn C, Harbin A, Bortolon E, Chen X, Haskell R, Lin E, Yu SF, Del Rosario G, Chan E, Dunlap D, Koeppen H, Martin S, Merchant M, Grimmer M, Broccatelli F, Wang J, Pizzano J, Dragovich PS, Berlin M, Yauch RL. Selective PROTAC-mediated degradation of SMARCA2 is efficacious in SMARCA4 mutant cancers. Nat Commun 2022; 13:6814. [PMID: 36357397 PMCID: PMC9649729 DOI: 10.1038/s41467-022-34562-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 10/28/2022] [Indexed: 11/12/2022] Open
Abstract
The mammalian SWItch/Sucrose Non-Fermentable (SWI/SNF) helicase SMARCA4 is frequently mutated in cancer and inactivation results in a cellular dependence on its paralog, SMARCA2, thus making SMARCA2 an attractive synthetic lethal target. However, published data indicates that achieving a high degree of selective SMARCA2 inhibition is likely essential to afford an acceptable therapeutic index, and realizing this objective is challenging due to the homology with the SMARCA4 paralog. Herein we report the discovery of a potent and selective SMARCA2 proteolysis-targeting chimera molecule (PROTAC), A947. Selective SMARCA2 degradation is achieved in the absence of selective SMARCA2/4 PROTAC binding and translates to potent in vitro growth inhibition and in vivo efficacy in SMARCA4 mutant models, compared to wild type models. Global ubiquitin mapping and proteome profiling reveal no unexpected off-target degradation related to A947 treatment. Our study thus highlights the ability to transform a non-selective SMARCA2/4-binding ligand into a selective and efficacious in vivo SMARCA2-targeting PROTAC, and thereby provides a potential new therapeutic opportunity for patients whose tumors contain SMARCA4 mutations.
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Affiliation(s)
- Jennifer Cantley
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Xiaofen Ye
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Emma Rousseau
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Tom Januario
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Brian D. Hamman
- HotSpot Therapeutics, Inc. 1 Deerpark Dr., Ste C, Monmouth Junction, NJ 08852 USA
| | - Christopher M. Rose
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Tommy K. Cheung
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Trent Hinkle
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Leofal Soto
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Connor Quinn
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Alicia Harbin
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Elizabeth Bortolon
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Xin Chen
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Roy Haskell
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Eva Lin
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Shang-Fan Yu
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Geoff Del Rosario
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Emily Chan
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Debra Dunlap
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Hartmut Koeppen
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Scott Martin
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Mark Merchant
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Matt Grimmer
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Fabio Broccatelli
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Jing Wang
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Jennifer Pizzano
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Peter S. Dragovich
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
| | - Michael Berlin
- grid.504169.f0000 0004 7667 0983Arvinas, LLC, 5 Science Park, New Haven, CT 06511 USA
| | - Robert L. Yauch
- grid.418158.10000 0004 0534 4718Genentech, 1 DNA Way, South San Francisco, 94080 USA
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5
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Cottrill SB, Lermant A, Cantley J, Murdoch CE, Sneddon C. The microvascular endothelial redoxome established through tandem mass tag mass spectrometry. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Redox signalling plays an important role in endothelial cell (EC) physiology and pathophysiology. Proteins sense redox signals via cysteine thiol groups. A common oxidative post-translational modification (oxPTM) on cysteine thiols is S-glutathionylation which is reversed to a free thiol state by glutaredoxin (Glrx). OxPTMs alter protein function, location and stability. Identifying which proteins undergo modification will help determine the role of redox signalling in EC function. A proteome-wide screen of human cardiac microvascular endothelial cells identified redox-sensitive proteins involved in vascular signalling mechanisms.
Methods
Human microvascular endothelial cells (HCMVEC, Lonza) were exposed to VEGF (50ng/ml, 24h) or hypoxia (0.5% O2, 24h) with adenoviral (ad) Glrx (Vectorlabs) overexpression or adLacZ (control). A tandem mass tag mass spectrometry system (TMT) coupled with a thiol-switch technique was used to quantify changes in redox sensitive thiol modifications. Protein lysates were treated with MMTS to alkylate unmodified thiols. Iodo-TMT six-plex probes were tagged to redox-sensitive sites after reversal of oxPTMs by DTT. Samples were pooled and processed by nLC-MS/MS. The abundance of each peptide in different conditions was compared with either adGlrx or adLacZ (control) expression to provide a ratio of changes in redox modifications.
Results
Iodo-TMT analysis revealed 113 unique thiol modifications identified on 78 different proteins using a ±1.5-fold threshold in a given treatment. Additionally, 44 modifications in 33 proteins were present in at least 2 different conditions, namely Glrx under VEGF and hypoxic conditions. A STRING interaction network identified clusters of 10 proteins involved in organonitrogen synthesis and 6 proteins in angiogenesis. Jagged-1 involved in the regulation of angiogenic sprouting through the Notch pathway was established as a target of redox signalling. Identified redox sensitive cysteines were found in extracellular EFG1 and the calcium binding EGF12 domains. Seven different In Silico programs (including MutationTaster, PolyPhen-2 and PANTHER) predicting the impact of substitution mutations indicated a functional affect for these redox sensitive sites, demonstrating the importance of these residues.
Conclusion
A non-biased proteomics approach identified novel thiol modifications on proteins involved in microvascular function. Future work will demonstrate the impact of these redox-sensitive thiol modifications on microvascular function to provide a better understanding of redox signalling in protein function and disease.
Funding Acknowledgement
Type of funding sources: Public Institution(s). Main funding source(s): MRC-DTP,European Union's Horizon 2020 research and innovation programme.
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Affiliation(s)
- S B Cottrill
- Ninewells Medical School, Systems Medicine, School of Medicine., Dundee, United Kingdom
| | - A Lermant
- Ninewells Medical School, Systems Medicine, School of Medicine., Dundee, United Kingdom
| | - J Cantley
- Ninewells Medical School, Systems Medicine, School of Medicine., Dundee, United Kingdom
| | - C E Murdoch
- Ninewells Medical School, Systems Medicine, School of Medicine., Dundee, United Kingdom
| | - C Sneddon
- Ninewells Medical School, Systems Medicine, School of Medicine., Dundee, United Kingdom
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6
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Berlin M, Cantley J, Wang J, Bookbinder M, Cadelina G, Chan E, Chen H, Chen X, Davenport K, Fernando T, Gordon D, Hamman B, Haskell R, Ishchenko A, Kirkpatrick DS, Maher J, Merchant M, Moffat J, Morgan A, Nguyen A, Pizzano J, Quinn C, Rose CM, Rousseau E, Sethuraman V, Staben L, Wilson C, Ye X, Broccatelli F, Yauch R, Dragovich PS. Abstract 5687: Selective, chemically-induced degradation of BRM ( SMARCA2) enables in vivo efficacy in BRG1 ( SMARCA4)-deficient xenograft tumor models. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-5687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The mammalian SWI/SNF complex catalyzes the remodeling of chromatin through the helicase activity of two mutually-exclusive, paralogous subunits, BRG1 and BRM. BRG1 is frequently mutated in cancer and its inactivation results in a cellular dependence on BRM. Despite the attractiveness of BRM as a synthetic lethal therapeutic target, the selective inhibition of BRM represents a considerable challenge due to the high degree of homology between BRM and BRG1. Furthermore, published data indicate that achieving such selectivity is likely essential to afford an acceptable therapeutic index. We sought to mimic the synthetic lethality observed in BRG1-mutant cancers by identifying proteolysis-targeting chimera (PROTAC®) molecules capable of selectively degrading BRM via trimeric complex formation with the von Hippel-Lindau (VHL) E3 ligase. In this disclosure, we report our initial discovery of potent and selective chimeric BRM-degrader molecules which exhibit BRM DC50 values <1 nM and BRG1/BRM DC50 ratios >25. Importantly, selective BRM degradation can be achieved in the absence of selective PROTAC® binding (BRG1/BRM Kd ratios <2). Global ubiquitin mapping and proteome profiling reveal no unexpected off-target activity of the selective BRM PROTAC® degraders. Treatment of a panel of NSCLC cell lines with a representative degrader molecule resulted in enhanced growth inhibition in BRG1-mutant relative to BRG1-wild-type cell lines. We also demonstrate that intermittent intravenous administration of an optimized BRM PROTAC® degrader exhibited strong in vivo modulation of pharmacodynamic biomarkers and afforded tumor growth inhibition in several BRG1-mutant xenograft models. Our study thus highlights the ability to transform a non-selective BRM-binding ligand into a selective and efficacious in vivo BRM PROTAC® degrader.
Citation Format: Michael Berlin, Jennifer Cantley, Jing Wang, Mark Bookbinder, Gregory Cadelina, Emily Chan, Huifen Chen, Xin Chen, Kim Davenport, Tharu Fernando, Debbie Gordon, Brian Hamman, Roy Haskell, Alexey Ishchenko, Donald S. Kirkpatrick, Jonathan Maher, Mark Merchant, John Moffat, Alicia Morgan, An Nguyen, Jennifer Pizzano, Connor Quinn, Christopher M. Rose, Emma Rousseau, Vijay Sethuraman, Leanna Staben, Catherine Wilson, Xiaofen Ye, Fabio Broccatelli, Robert Yauch, Peter S. Dragovich. Selective, chemically-induced degradation of BRM (SMARCA2) enables in vivo efficacy in BRG1 (SMARCA4)-deficient xenograft tumor models [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5687.
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Affiliation(s)
| | | | | | | | | | - Emily Chan
- 2Genentech, Inc., South San Francisco, CA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | - An Nguyen
- 2Genentech, Inc., South San Francisco, CA
| | | | | | | | | | | | | | | | - Xiaofen Ye
- 2Genentech, Inc., South San Francisco, CA
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7
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Rauniyar N, Yu X, Cantley J, Voss EZ, Belcher J, Colangelo CM, Stone KL, Dahl N, Parikh C, Lam TT, Cantley LG. Quantification of Urinary Protein Biomarkers of Autosomal Dominant Polycystic Kidney Disease by Parallel Reaction Monitoring. Proteomics Clin Appl 2018; 12:e1700157. [PMID: 29573172 DOI: 10.1002/prca.201700157] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 03/01/2018] [Indexed: 01/21/2023]
Abstract
PURPOSE Autosomal dominant polycystic kidney disease (ADPKD) is a life-long disease in which the genes responsible are known, but the pathogenesis of cyst formation and cyst growth are not understood. Cyst growth ultimately leads to end-stage renal failure in most patients. Analysis of the urinary proteome offers the potential to identify proteins that indicate the presence of cysts (and thus provides diagnosis) as well as the rates of cyst growth (providing prognostic information). EXPERIMENTAL DESIGN A scheduled parallel reaction monitoring (sPRM) assay is performed on urine samples from 14 patients and 18 normal controls. For relative quantification, stable isotope-labeled synthetic peptides are spiked in the urinary protein digests prior to data collection. The data are subsequently normalized to creatinine and protein concentration in the respective urine samples to control for variations in water intake between individuals. RESULTS Out of the 143 urinary proteins targeted for sPRM assay, 69 proteins are observed to be significantly dysregulated in ADPKD. The dysregulated proteins are used to cluster ADPKD patients into those who are more or less similar to normal controls. CONCLUSIONS AND CLINICAL RELEVANCE This study shows that sPRM is a promising approach to rapidly screen large numbers of proteins in urine in order to provide earlier diagnosis and potentially better understand the pathogenesis of ADPKD development and progression.
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Affiliation(s)
- Navin Rauniyar
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 06520, New Haven, CT, USA.,MS and Proteomics Resource, W.M. Keck Biotechnology Resource Laboratory, Yale University School of Medicine, 06511, New Haven, CT, USA
| | - Xiaoqing Yu
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, 33612, Tampa, FL, USA
| | - Jennifer Cantley
- Section of Nephrology, Yale University School of Medicine, 06520, New Haven, CT, USA
| | - Edward Z Voss
- MS and Proteomics Resource, W.M. Keck Biotechnology Resource Laboratory, Yale University School of Medicine, 06511, New Haven, CT, USA
| | - Justin Belcher
- Section of Nephrology, Yale University School of Medicine, 06520, New Haven, CT, USA
| | - Christopher M Colangelo
- MS and Proteomics Resource, W.M. Keck Biotechnology Resource Laboratory, Yale University School of Medicine, 06511, New Haven, CT, USA
| | - Kathryn L Stone
- MS and Proteomics Resource, W.M. Keck Biotechnology Resource Laboratory, Yale University School of Medicine, 06511, New Haven, CT, USA
| | - Neera Dahl
- Section of Nephrology, Yale University School of Medicine, 06520, New Haven, CT, USA
| | - Chirag Parikh
- Section of Nephrology, Yale University School of Medicine, 06520, New Haven, CT, USA.,Program of Applied Translational Research, Yale University School of Medicine, 06520, New Haven, CT, USA
| | - TuKiet T Lam
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 06520, New Haven, CT, USA.,MS and Proteomics Resource, W.M. Keck Biotechnology Resource Laboratory, Yale University School of Medicine, 06511, New Haven, CT, USA
| | - Lloyd G Cantley
- Section of Nephrology, Yale University School of Medicine, 06520, New Haven, CT, USA
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Albani D, Cantley J, Sherertz T, Ellis R, Herrmann K, Podder T. SU-E-T-237: Deformable Image Registration and Deformed Dose Composite for Volumetric Evaluation of Multimodal Gynecological Cancer Treatments. Med Phys 2015. [DOI: 10.1118/1.4924598] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cantley J, Albani D, Ellis R, Sherertz T, Herrmann K, Podder T. SU-E-T-680: Rigid Registration Image Fusion for Volumetric Dose Evaluation of Gynecological Patients Treated with EBRT and HDR Brachytherapy. Med Phys 2015. [DOI: 10.1118/1.4925043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cantley J, Colussi V. SU-E-T-162: Characterization of a New Oblong Cone for Use with the Intraoperative Mobetron Unit. Med Phys 2015. [DOI: 10.1118/1.4924524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Ferdaoussi M, Bergeron V, Zarrouki B, Kolic J, Cantley J, Fielitz J, Olson EN, Prentki M, Biden T, MacDonald PE, Poitout V. G protein-coupled receptor (GPR)40-dependent potentiation of insulin secretion in mouse islets is mediated by protein kinase D1. Diabetologia 2012; 55:2682-2692. [PMID: 22820510 PMCID: PMC3543464 DOI: 10.1007/s00125-012-2650-x] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 06/18/2012] [Indexed: 10/28/2022]
Abstract
AIMS/HYPOTHESIS Activation of the G protein-coupled receptor (GPR)40 by long-chain fatty acids potentiates glucose-stimulated insulin secretion (GSIS) from pancreatic beta cells, and GPR40 agonists are in clinical development for type 2 diabetes therapy. GPR40 couples to the G protein subunit Gα(q/11) but the signalling cascade activated downstream is unknown. This study aimed to determine the mechanisms of GPR40-dependent potentiation of GSIS by fatty acids. METHODS Insulin secretion in response to glucose, oleate or diacylglycerol (DAG) was assessed in dynamic perifusions and static incubations in islets from wild-type (WT) and Gpr40 (-/-) mice. Depolymerisation of filamentous actin (F-actin) was visualised by phalloidin staining and epifluorescence. Pharmacological and molecular approaches were used to ascertain the roles of protein kinase D (PKD) and protein kinase C delta in GPR40-mediated potentiation of GSIS. RESULTS Oleate potentiates the second phase of GSIS, and this effect is largely dependent upon GPR40. Accordingly, oleate induces rapid F-actin remodelling in WT but not in Gpr40 (-/-) islets. Exogenous DAG potentiates GSIS in both WT and Gpr40 (-/-) islets. Oleate induces PKD phosphorylation at residues Ser-744/748 and Ser-916 in WT but not Gpr40 (-/-) islets. Importantly, oleate-induced F-actin depolymerisation and potentiation of GSIS are lost upon pharmacological inhibition of PKD1 or deletion of Prkd1. CONCLUSIONS/INTERPRETATION We conclude that the signalling cascade downstream of GPR40 activation by fatty acids involves activation of PKD1, F-actin depolymerisation and potentiation of second-phase insulin secretion. These results provide important information on the mechanisms of action of GPR40, a novel drug target for type 2 diabetes.
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Affiliation(s)
- M Ferdaoussi
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - V Bergeron
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - B Zarrouki
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Department of Medicine, University of Montreal, Montreal, QC, Canada
| | - J Kolic
- Department of Pharmacology and the Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - J Cantley
- Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, Sydney, NSW, Australia
| | - J Fielitz
- Experimental and Clinical Research Center, a joint cooperation between the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany
- Medical Department, Division of Cardiology, Charité University, Campus Virchow-Klinikum, Berlin, Germany
| | - E N Olson
- Departments of Molecular Biology, Internal Medicine, and Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - M Prentki
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4
- Departments of Nutrition and Biochemistry, University of Montreal, Montreal, QC, Canada
| | - T Biden
- Garvan Institute of Medical Research, St Vincent's Hospital, Darlinghurst, Sydney, NSW, Australia
| | - P E MacDonald
- Department of Pharmacology and the Alberta Diabetes Institute, University of Alberta, Edmonton, AB, Canada
| | - V Poitout
- Montreal Diabetes Research Center, CRCHUM, Technopole Angus, 2901 Rachel Est, Montréal, QC, Canada, H1W 4A4.
- Department of Medicine, University of Montreal, Montreal, QC, Canada.
- Departments of Nutrition and Biochemistry, University of Montreal, Montreal, QC, Canada.
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Cantley J, Chell E, Firpo M, Hanlon J, Lee C, Bolch W. SU-E-T-477: Influence of Eye Size on Radiation Absorbed Dose Delivered to Non- Targeted Tissues during Stereotactic Radiosurgery for Age-Related Macular Degeneration. Med Phys 2012; 39:3815. [DOI: 10.1118/1.4735566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Chan K, Dunn L, Bao S, Lam M, Guillou M, Ni J, Midwinter R, Suarna C, Maghzal G, Cantley J, Ng M, Stocker R. Heme Oxygenase-1 is Necessary for Ischaemia-mediated Neovascularisation and Hypoxia-induced Metabolic Reprogramming. Heart Lung Circ 2012. [DOI: 10.1016/j.hlc.2012.05.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Raddatz K, Turner N, Frangioudakis G, Liao BM, Pedersen DJ, Cantley J, Wilks D, Preston E, Hegarty BD, Leitges M, Raftery MJ, Biden TJ, Schmitz-Peiffer C. Time-dependent effects of Prkce deletion on glucose homeostasis and hepatic lipid metabolism on dietary lipid oversupply in mice. Diabetologia 2011; 54:1447-56. [PMID: 21347625 DOI: 10.1007/s00125-011-2073-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 01/10/2011] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS We examined the time-dependent effects of deletion of the gene encoding protein kinase C epsilon (Prkce) on glucose homeostasis, insulin secretion and hepatic lipid metabolism in fat-fed mice. METHODS Prkce(-/-) and wild-type (WT) mice were fed a high-fat diet for 1 to 16 weeks and subjected to i.p. glucose tolerance tests (ipGTT) and indirect calorimetry. We also investigated gene expression and protein levels by RT-PCR, quantitative protein profiling (isobaric tag for relative and absolute quantification; iTRAQ) and immunoblotting. Lipid levels, mitochondrial oxidative capacity and lipid metabolism were assessed in liver and primary hepatocytes. RESULTS While fat-fed WT mice became glucose intolerant after 1 week, Prkce(-/-) mice exhibited normal glucose and insulin levels. iTRAQ suggested differences in lipid metabolism and oxidative phosphorylation between fat-fed WT and Prkce(-/-) animals. Liver triacylglycerols were increased in fat-fed Prkce(-/-) mice, resulting from altered lipid partitioning which promoted esterification of fatty acids in hepatocytes. In WT mice, fat feeding elevated oxygen consumption in vivo and in isolated liver mitochondria, but these increases were not seen in Prkce(-/-) mice. Prkce(-/-) hepatocytes also exhibited reduced production of reactive oxygen species (ROS) in the presence of palmitate. After 16 weeks of fat feeding, however, the improved glucose tolerance in fat-fed Prkce(-/-) mice was instead associated with increased insulin secretion during ipGTT, as we have previously reported. CONCLUSIONS/INTERPRETATION Prkce deletion ameliorates diet-induced glucose intolerance via two temporally distinct phenotypes. Protection against insulin resistance is associated with changes in hepatic lipid partitioning, which may reduce the acute inhibitory effects of fatty acid catabolism, such as ROS generation. In the longer term, enhancement of glucose-stimulated insulin secretion prevails.
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Affiliation(s)
- K Raddatz
- Garvan Institute of Medical Research, 384 Victoria Street, Sydney, NSW 2010, Australia.
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Tien C, Cantley J, Hintenlang D, Bolch W, Firpo M, Chell E. SU-E-T-204: Real-Time Monitoring of Age-Related Macular Degeneration Radiosurgery Using Plastic Scintillation Dosimetry. Med Phys 2011. [DOI: 10.1118/1.3612154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Cantley J, Boslem E, Laybutt DR, Cordery DV, Pearson G, Carpenter L, Leitges M, Biden TJ. Deletion of protein kinase Cδ in mice modulates stability of inflammatory genes and protects against cytokine-stimulated beta cell death in vitro and in vivo. Diabetologia 2011; 54:380-9. [PMID: 21103982 DOI: 10.1007/s00125-010-1962-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 10/06/2010] [Indexed: 12/23/2022]
Abstract
AIMS/HYPOTHESIS Proinflammatory cytokines contribute to beta cell destruction in type 1 diabetes, but the mechanisms are incompletely understood. The aim of the current study was to address the role of the protein kinase C (PKC) isoform PKCδ, a diverse regulator of cell death, in cytokine-stimulated apoptosis in primary beta cells. METHODS Islets isolated from wild-type or Prkcd(-/-) mice were treated with IL-1β, TNF-α and IFNγ and assayed for apoptosis, nitric oxide (NO) generation and insulin secretion. Activation of signalling pathways, apoptosis and endoplasmic reticulum (ER) stress were determined by immunoblotting. Stabilisation of mRNA transcripts was measured by RT-PCR following transcriptional arrest. Mice were injected with multiple low doses of streptozotocin (MLD-STZ) and fasting blood glucose monitored. RESULTS Deletion of Prkcd inhibited apoptosis and NO generation in islets stimulated ex vivo with cytokines. It also delayed the onset of hyperglycaemia in MLD-STZ-treated mice. Activation of ERK, p38, JNK, AKT1, the ER stress markers DDIT3 and phospho-EIF2α and the intrinsic apoptotic markers BCL2 and MCL1 was not different between genotypes. However, deletion of Prkcd destabilised mRNA transcripts for Nos2, and for multiple components of the toll-like receptor 2 (TLR2) signalling complex, which resulted in disrupted TLR2 signalling. CONCLUSIONS/INTERPRETATION Loss of PKCδ partially protects against hyperglycaemia in the MLD-STZ model in vivo, and against cytokine-mediated apoptosis in vitro. This is accompanied by reduced NO generation and destabilisation of Nos2 and components of the TLR2 signalling pathway. The results highlight a mechanism for regulating proinflammatory gene expression in beta cells independently of transcription.
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Affiliation(s)
- J Cantley
- Garvan Institute of Medical Research, St Vincent's Hospital, 384 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia
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Abstract
β-cells sense glucose and secrete appropriate amounts of insulin by coupling glucose uptake and glycolysis with quantitative ATP production via mitochondrial oxidative pathways. Therefore, oxidative phosphorylation is essential for normal β-cell function. Multiple cell types adapt to hypoxia by inducing a transcriptional programme coordinated by the transcription factor hypoxia-inducible factor (HIF). HIF activity is regulated by the von Hippel-Lindau (Vhl) protein, which targets the HIFα subunit for proteasomal degradation in the presence of oxygen. Several recent studies have shown that Vhl deletion in β-cells results in Hif1α activation, impaired glucose-stimulated insulin secretion (GSIS) and glucose intolerance. This was found to be because of alterations in β-cell gene expression inducing a switch from aerobic glucose metabolism to anaerobic glycolysis, thus disrupting the GSIS triggering pathway. Situations in which islets may become hypoxic are discussed, in particular islet transplantation which has been reported to cause islet hypoxia because of an inadequate blood supply post-transplant. Aside from this principal role for HIF in negatively regulating β-cell glucose sensing, other aspects of hypoxia signalling are discussed including β-cell differentiation, development and vascularization. In conclusion, recent studies clearly show that hypoxia response mechanisms can negatively impact on glucose sensing mechanisms in the β-cell and this has the potential to impair β-cell function in a number of physiological and clinical situations.
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Affiliation(s)
- J Cantley
- Faculty of Medicine, Rayne Institute, University College London, London, UK.
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Cantley J, Choudhury AI, Asare-Anane H, Selman C, Lingard S, Heffron H, Herrera P, Persaud SJ, Withers DJ. Pancreatic deletion of insulin receptor substrate 2 reduces beta and alpha cell mass and impairs glucose homeostasis in mice. Diabetologia 2007; 50:1248-56. [PMID: 17393136 DOI: 10.1007/s00125-007-0637-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2006] [Accepted: 01/25/2007] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Insulin signalling pathways regulate pancreatic beta cell function. Conditional gene targeting using the Cre/loxP system has demonstrated that mice lacking insulin receptor substrate 2 (IRS2) in the beta cell have reduced beta cell mass. However, these studies have been complicated by hypothalamic deletion when the RIPCre (B6.Cg-tg(Ins2-cre)25Mgn/J) transgenic mouse (expressing Cre recombinase under the control of the rat insulin II promoter) is used to delete floxed alleles in insulin-expressing cells. These features have led to marked insulin resistance making the beta cell-autonomous role of IRS2 difficult to determine. To establish the effect of deleting Irs2 only in the pancreas, we generated PIrs2KO mice in which Cre recombinase expression was driven by the promoter of the pancreatic and duodenal homeobox factor 1 (Pdx1, also known as Ipf1) gene. MATERIALS AND METHODS In vivo glucose homeostasis was examined in PIrs2KO mice using glucose tolerance and glucose-stimulated insulin secretion tests. Endocrine cell mass was determined by morphometric analysis. Islet function was examined in static cultures and by performing calcium imaging in Fluo3am-loaded beta cells. Islet gene expression was determined by RT-PCR. RESULTS The PIrs2KO mice displayed glucose intolerance and impaired glucose-stimulated insulin secretion in vivo. Pancreatic insulin and glucagon content and beta and alpha cell mass were reduced. Glucose-stimulated insulin secretion and calcium mobilisation were attenuated in PIrs2KO islets. Expression of the Glut2 gene (also known as Slc2a2) was also reduced in PIrs2KO mice. CONCLUSIONS/INTERPRETATION These studies suggest that IRS2-dependent signalling in pancreatic islets is required not only for the maintenance of normal beta and alpha cell mass but is also involved in the regulation of insulin secretion.
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Affiliation(s)
- J Cantley
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, University Street, London, UK
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Simmgen M, Knauf C, Lopez M, Choudhury AI, Charalambous M, Cantley J, Bedford DC, Claret M, Iglesias MA, Heffron H, Cani PD, Vidal-Puig A, Burcelin R, Withers DJ. Liver-specific deletion of insulin receptor substrate 2 does not impair hepatic glucose and lipid metabolism in mice. Diabetologia 2006; 49:552-61. [PMID: 16404553 DOI: 10.1007/s00125-005-0084-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Accepted: 09/25/2005] [Indexed: 10/25/2022]
Abstract
AIMS/HYPOTHESIS Hepatic insulin resistance is thought to be a critical component in the pathogenesis of type 2 diabetes but the role of intrinsic insulin signalling pathways in the regulation of hepatic metabolism remains controversial. Global gene targeting in mice and in vitro studies have suggested that IRS2 mediates the physiological effects of insulin in the liver. Reduced hepatic production of IRS2 is found in many cases of insulin resistance. To investigate the role of IRS2 in regulating liver function in vivo, we generated mice that specifically lack Irs2 in the liver (LivIrs2KO). MATERIALS AND METHODS Hepatic insulin signalling events were examined in LivIrs2KO mice by western blotting. Glucose homeostasis and insulin sensitivity were assessed by glucose tolerance tests and hyperinsulinaemic-euglycaemic clamp studies. The effects of high-fat feeding upon glucose homeostasis were also determined. Liver function tests were performed and expression of key metabolic genes in the liver was determined by RT-PCR. RESULTS Proximal insulin signalling events and forkhead box O1 and A2 function were normal in the liver of LivIrs2KO mice, which displayed minimal abnormalities in glucose and lipid homeostasis, hepatic gene expression and liver function. In addition, hepatic lipid homeostasis and the metabolic response to a high-fat diet did not differ between LivIrs2KO and control mice. CONCLUSIONS/INTERPRETATION Our findings suggest that liver IRS2 signalling, surprisingly, is not required for the long-term maintenance of glucose and lipid homeostasis, and that extra-hepatic IRS2-dependent mechanisms are involved in the regulation of these processes.
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Affiliation(s)
- M Simmgen
- Centre for Diabetes and Endocrinology, Rayne Institute, University College London, University Street, London, UK
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