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Hossain MM, Khalid A, Akhter Z, Parveen S, Ayaz MO, Bhat AQ, Badesra N, Showket F, Dar MS, Ahmed F, Dhiman S, Kumar M, Singh U, Hussain R, Keshari P, Mustafa G, Nargorta A, Taneja N, Gupta S, Mir RA, Kshatri AS, Nandi U, Khan N, Ramajayan P, Yadav G, Ahmed Z, Singh PP, Dar MJ. Discovery of a novel and highly selective JAK3 inhibitor as a potent hair growth promoter. J Transl Med 2024; 22:370. [PMID: 38637842 PMCID: PMC11025159 DOI: 10.1186/s12967-024-05144-4] [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] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 03/23/2024] [Indexed: 04/20/2024] Open
Abstract
JAK-STAT signalling pathway inhibitors have emerged as promising therapeutic agents for the treatment of hair loss. Among different JAK isoforms, JAK3 has become an ideal target for drug discovery because it only regulates a narrow spectrum of γc cytokines. Here, we report the discovery of MJ04, a novel and highly selective 3-pyrimidinylazaindole based JAK3 inhibitor, as a potential hair growth promoter with an IC50 of 2.03 nM. During in vivo efficacy assays, topical application of MJ04 on DHT-challenged AGA and athymic nude mice resulted in early onset of hair regrowth. Furthermore, MJ04 significantly promoted the growth of human hair follicles under ex-vivo conditions. MJ04 exhibited a reasonably good pharmacokinetic profile and demonstrated a favourable safety profile under in vivo and in vitro conditions. Taken together, we report MJ04 as a highly potent and selective JAK3 inhibitor that exhibits overall properties suitable for topical drug development and advancement to human clinical trials.
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Affiliation(s)
- Md Mehedi Hossain
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Arfan Khalid
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Zaheen Akhter
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Natural Products and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Sabra Parveen
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Mir Owais Ayaz
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Aadil Qadir Bhat
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Neetu Badesra
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Farheen Showket
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Mohmmad Saleem Dar
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
| | - Farhan Ahmed
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute (CDRI), Lucknow, 226031, India
| | - Sumit Dhiman
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Mukesh Kumar
- Medicinal Product Chemistry, Sussex Drug Discovery Centre, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Umed Singh
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Natural Products and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Razak Hussain
- Department of Entomology, University of Illinois Urbana-Champaign, Urbana, IL, 61801, USA
| | - Pankaj Keshari
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
| | - Ghulam Mustafa
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Amit Nargorta
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Natural Products and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Neha Taneja
- Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India
| | - Somesh Gupta
- Department of Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India
| | - Riyaz A Mir
- Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India
| | - Aravind Singh Kshatri
- Division of Neuroscience and Ageing Biology, CSIR-Central Drug Research Institute (CDRI), Lucknow, 226031, India
| | - Utpal Nandi
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Nooruddin Khan
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - P Ramajayan
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Govind Yadav
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Zabeer Ahmed
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India
- Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India
| | - Parvinder Pal Singh
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India.
- Natural Products and Medicinal Chemistry Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India.
| | - Mohd Jamal Dar
- Laboratory of Cell and Molecular Biology, Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, Jammu and Kashmir, 180001, India.
- Academy of Scientific & Innovative Research, Ghaziabad, Uttar Pradesh, 201002, India.
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Menon PR, Staab J, Gregus A, Wirths O, Meyer T. An inhibitory effect on the nuclear accumulation of phospho-STAT1 by its unphosphorylated form. Cell Commun Signal 2022; 20:42. [PMID: 35361236 PMCID: PMC8974011 DOI: 10.1186/s12964-022-00841-3] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/05/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Unphosphorylated signal transducer and activator of transcription 1 (U-STAT1) has been reported to elicit a distinct gene expression profile as compared to tyrosine-phosphorylated STAT1 (P-STAT1) homodimers. However, the impact of U-STAT1 on the IFNγ-induced immune response mediated by P-STAT1 is unknown. By generating a double mutant of STAT1 with mutation R602L in the Src-homology 2 (SH2) domain and Y701F in the carboxy-terminal transactivation domain mimicking U-STAT1, we investigated the effects of U-STAT1 on P-STAT1-mediated signal transduction. RESULTS In this study, we discovered a novel activity of U-STAT1 that alters the nucleo-cytoplasmic distribution of cytokine-stimulated P-STAT1. While the dimerization-deficient mutant R602L/Y701F was not able to display cytokine-induced nuclear accumulation, it inhibited the nuclear accumulation of co-expressed IFNγ-stimulated wild-type P-STAT1. Disruption of the anti-parallel dimer interface in the R602L/Y701F mutant via additional R274W and T385A mutations did not rescue the impaired nuclear accumulation of co-expressed P-STAT1. The mutant U-STAT1 affected neither the binding of co-expressed P-STAT1 to gamma-activated sites in vitro, nor the transcription of reporter constructs and the activation of STAT1 target genes. However, the nuclear accumulation of P-STAT1 was diminished in the presence of mutant U-STAT1, which was not restored by mutations reducing the DNA affinity of mutant U-STAT1. Whereas single mutations in the amino-terminus of dimerization-deficient U-STAT1 similarly inhibited the nuclear accumulation of co-expressed P-STAT1, a complete deletion of the amino-terminus restored cytokine-stimulated nuclear accumulation of P-STAT1. Likewise, the disruption of a dimer-specific nuclear localization signal also rescued the U-STAT1-mediated inhibition of P-STAT1 nuclear accumulation. CONCLUSION Our data demonstrate a novel role of U-STAT1 in affecting nuclear accumulation of P-STAT1, such that a high intracellular concentration of U-STAT1 inhibits the detection of nuclear P-STAT1 in immunofluorescence assays. These observations hint at a possible physiological function of U-STAT1 in buffering the nuclear import of P-STAT1, while preserving IFNγ-induced gene expression. Based on these results, we propose a model of a hypothetical import structure, the assembly of which is impaired under high concentrations of U-STAT1. This mechanism maintains high levels of cytoplasmic STAT1, while simultaneously retaining signal transduction by IFNγ. Video Abstract.
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Affiliation(s)
- Priyanka Rajeev Menon
- Department of Psychosomatic Medicine and Psychotherapy, University Medical Centre Göttingen, and German Centre for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Julia Staab
- Department of Psychosomatic Medicine and Psychotherapy, University Medical Centre Göttingen, and German Centre for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Anke Gregus
- Department of Psychosomatic Medicine and Psychotherapy, University Medical Centre Göttingen, and German Centre for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, University Medical Centre Göttingen, Göttingen, Germany
| | - Thomas Meyer
- Department of Psychosomatic Medicine and Psychotherapy, University Medical Centre Göttingen, and German Centre for Cardiovascular Research (DZHK), Partner Site Göttingen, Göttingen, Germany.
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Sarais F, Kummerow S, Montero R, Rebl H, Köllner B, Goldammer T, Collet B, Rebl A. PIAS Factors from Rainbow Trout Control NF-κB- and STAT-Dependent Gene Expression. Int J Mol Sci 2021; 22:12815. [PMID: 34884614 DOI: 10.3390/ijms222312815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 11/24/2021] [Accepted: 11/24/2021] [Indexed: 11/30/2022] Open
Abstract
Four ‘protein inhibitors of activated STAT’ (PIAS) control STAT-dependent and NF-κB-dependent immune signalling in humans. The genome of rainbow trout (Oncorhynchus mykiss) contains eight pias genes, which encode at least 14 different pias transcripts that are differentially expressed in a tissue- and cell-specific manner. Pias1a2 was the most strongly expressed variant among the analysed pias genes in most tissues, while pias4a2 was commonly low or absent. Since the knock-out of Pias factors in salmonid CHSE cells using CRISPR/Cas9 technology failed, three structurally different Pias protein variants were selected for overexpression studies in CHSE-214 cells. All three factors quenched the basal activity of an NF-κB promoter in a dose-dependent fashion, while the activity of an Mx promoter remained unaffected. Nevertheless, all three overexpressed Pias variants from trout strongly reduced the transcript level of the antiviral Stat-dependent mx gene in ifnγ-expressing CHSE-214 cells. Unlike mx, the overexpressed Pias factors modulated the transcript levels of NF-κB-dependent immune genes (mainly il6, il10, ifna3, and stat4) in ifnγ-expressing CHSE-214 cells in different ways. This dissimilar modulation of expression may result from the physical cooperation of the Pias proteins from trout with differential sets of interacting factors bound to distinct nuclear structures, as reflected by the differential nuclear localisation of trout Pias factors. In conclusion, this study provides evidence for the multiplication of pias genes and their sub-functionalisation during salmonid evolution.
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Dolatabadi S, Jonasson E, Lindén M, Fereydouni B, Bäcksten K, Nilsson M, Martner A, Forootan A, Fagman H, Landberg G, Åman P, Ståhlberg A. JAK-STAT signalling controls cancer stem cell properties including chemotherapy resistance in myxoid liposarcoma. Int J Cancer 2019; 145:435-449. [PMID: 30650179 PMCID: PMC6590236 DOI: 10.1002/ijc.32123] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 12/03/2018] [Accepted: 01/07/2019] [Indexed: 12/14/2022]
Abstract
Myxoid liposarcoma (MLS) shows extensive intratumoural heterogeneity with distinct subpopulations of tumour cells. Despite improved survival of MLS patients, existing therapies have shortcomings as they fail to target all tumour cells. The nature of chemotherapy‐resistant cells in MLS remains unknown. Here, we show that MLS cell lines contained subpopulations of cells that can form spheres, efflux Hoechst dye and resist doxorubicin, all properties attributed to cancer stem cells (CSCs). By single‐cell gene expression, western blot, phospho‐kinase array, immunoprecipitation, immunohistochemistry, flow cytometry and microarray analysis we showed that a subset of MLS cells expressed JAK–STAT genes with active signalling. JAK1/2 inhibition via ruxolitinib decreased, while stimulation with LIF increased, phosphorylation of STAT3 and the number of cells with CSC properties indicating that JAK–STAT signalling controlled the number of cells with CSC features. We also show that phosphorylated STAT3 interacted with the SWI/SNF complex. We conclude that MLS contains JAK–STAT‐regulated subpopulations of cells with CSC features. Combined doxorubicin and ruxolitinib treatment targeted both proliferating cells as well as cells with CSC features, providing new means to circumvent chemotherapy resistance in treatment of MLS patients. What's new? Despite improved survival of patients, existing therapies for Myxoid liposarcoma (MLS) present shortcomings as they fail to target all tumour cells. The nature of chemotherapy‐resistant cells in MLS remains unknown, however. Here, the authors show that myxoid liposarcomas are heterogeneous and contain subpopulations of cells with stem cell properties, including chemotherapy resistance. Moreover, JAK‐STAT signalling is active in MLS and regulates the size of the cancer stem cells‐like subpopulation via the SWI/SNF complex. The results shed light on the mechanisms of therapy resistance in MLS and point to JAK‐STAT inhibitors as a new avenue for targeted MLS therapies.
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Affiliation(s)
- Soheila Dolatabadi
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
| | - Emma Jonasson
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
| | - Malin Lindén
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
| | - Bentolhoda Fereydouni
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
| | - Karin Bäcksten
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
| | - Malin Nilsson
- TIMM Laboratory, Sahlgrenska Cancer CenterUniversity of GothenburgGothenburgSweden
| | - Anna Martner
- TIMM Laboratory, Sahlgrenska Cancer CenterUniversity of GothenburgGothenburgSweden
| | - Amin Forootan
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
- MultiD Analysis ABGothenburgSweden
| | - Henrik Fagman
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
- Department of Clinical Pathology and GeneticsSahlgrenska University HospitalGothenburgSweden
| | - Göran Landberg
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
| | - Pierre Åman
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
| | - Anders Ståhlberg
- Sahlgrenska Cancer Center, Department of Pathology and GeneticsInstitute of Biomedicine, Sahlgrenska Academy at University of GothenburgGothenburgSweden
- Department of Clinical Pathology and GeneticsSahlgrenska University HospitalGothenburgSweden
- Wallenberg Centre for Molecular and Translational MedicineUniversity of GothenburgGothenburgSweden
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Southworth T, Mason S, Bell A, Ramis I, Calbet M, Domenech A, Prats N, Miralpeix M, Singh D. PI3K, p38 and JAK/STAT signalling in bronchial tissue from patients with asthma following allergen challenge. Biomark Res 2018; 6:14. [PMID: 29651336 PMCID: PMC5896031 DOI: 10.1186/s40364-018-0128-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 04/02/2018] [Indexed: 01/01/2023] Open
Abstract
Background Inhaled allergen challenges are often used to evaluate novel asthma treatments in early phase clinical trials. Current novel therapeutic targets in asthma include phosphoinositide 3-kinases (PI3K) delta and gamma, p38 mitogen-activated protein kinase (p38) and Janus kinase/Signal Transducer and Activator of Transcription (JAK/STAT) signalling pathways. The activation of these pathways following allergen exposure in atopic asthma patients it is not known. Methods We collected bronchial biopsies from 11 atopic asthma patients at baseline and after allergen challenge to investigate biomarkers of PI3K, p38 MAPK and JAK/STAT activation by immunohistochemistry. Cell counts and levels of eosinophil cationic protein and interleukin-5 were also assessed in sputum and bronchoalvelar lavage. Results Biopsies collected post-allergen had an increased percentage of epithelial cells expressing phospho-p38 (17.5 vs 25.6%, p = 0.04), and increased numbers of sub-epithelial cells expressing phospho-STAT5 (122.2 vs 540.6 cells/mm2, p = 0.01) and the PI3K marker phospho-ribosomal protein S6 (180.7 vs 777.3 cells/mm2,p = 0.005). Type 2 inflammation was increased in the airways post allergen, with elevated levels of eosinophils, interleukin-5 and eosinophil cationic protein. Conclusions Future clinical trials of novel kinase inhibitors could use the allergen challenge model in proof of concept studies, while employing these biomarkers to investigate pharmacological inhibition in the lungs.
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Affiliation(s)
- Thomas Southworth
- 1Division of Infection, Immunity & Respiratory Medicine, The Medicines Evaluation Unit, The University of Manchester, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester, UK.,3The University of Manchester, 2nd Floor Education and Research Center, Wythenshawe Hospital, Southmoor Road, Manchester, M23 9LT UK
| | - Sarah Mason
- 1Division of Infection, Immunity & Respiratory Medicine, The Medicines Evaluation Unit, The University of Manchester, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester, UK
| | - Alan Bell
- 1Division of Infection, Immunity & Respiratory Medicine, The Medicines Evaluation Unit, The University of Manchester, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester, UK
| | - Isabel Ramis
- Almirall R&D Center, Sant Feliu de Llobregat, Barcelona, Spain
| | - Marta Calbet
- Almirall R&D Center, Sant Feliu de Llobregat, Barcelona, Spain
| | - Anna Domenech
- Almirall R&D Center, Sant Feliu de Llobregat, Barcelona, Spain
| | - Neus Prats
- Almirall R&D Center, Sant Feliu de Llobregat, Barcelona, Spain
| | | | - Dave Singh
- 1Division of Infection, Immunity & Respiratory Medicine, The Medicines Evaluation Unit, The University of Manchester, Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, Manchester, UK
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Leroy E, Dusa A, Colau D, Motamedi A, Cahu X, Mouton C, Huang LJ, Shiau AK, Constantinescu SN. Uncoupling JAK2 V617F activation from cytokine-induced signalling by modulation of JH2 αC helix. Biochem J 2016; 473:1579-91. [PMID: 27029346 DOI: 10.1042/BCJ20160085] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/30/2016] [Indexed: 01/12/2023]
Abstract
The mechanisms by which JAK2 is activated by the prevalent pseudokinase (JH2) V617F mutation in blood cancers remain elusive. Via structure-guided mutagenesis and transcriptional and functional assays, we identify a community of residues from the JH2 helix αC, SH2-JH2 linker and JH1 kinase domain that mediate V617F-induced activation. This circuit is broken by altering the charge of residues along the solvent-exposed face of the JH2 αC, which is predicted to interact with the SH2-JH2 linker and JH1. Mutations that remove negative charges or add positive charges, such as E596A/R, do not alter the JH2 V617F fold, as shown by the crystal structure of JH2 V617F E596A. Instead, they prevent kinase domain activation via modulation of the C-terminal residues of the SH2-JH2 linker. These results suggest strategies for selective V617F JAK2 inhibition, with preservation of wild-type function.
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Shahni R, Cale CM, Anderson G, Osellame LD, Hambleton S, Jacques TS, Wedatilake Y, Taanman JW, Chan E, Qasim W, Plagnol V, Chalasani A, Duchen MR, Gilmour KC, Rahman S. Signal transducer and activator of transcription 2 deficiency is a novel disorder of mitochondrial fission. Brain 2015; 138:2834-46. [PMID: 26122121 PMCID: PMC5808733 DOI: 10.1093/brain/awv182] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/28/2015] [Indexed: 01/17/2023] Open
Abstract
Defects of mitochondrial dynamics are emerging causes of neurological disease. In two children presenting with severe neurological deterioration following viral infection we identified a novel homozygous STAT2 mutation, c.1836 C>A (p.Cys612Ter), using whole exome sequencing. In muscle and fibroblasts from these patients, and a third unrelated STAT2-deficient patient, we observed extremely elongated mitochondria. Western blot analysis revealed absence of the STAT2 protein and that the mitochondrial fission protein DRP1 (encoded by DNM1L) is inactive, as shown by its phosphorylation state. All three patients harboured decreased levels of DRP1 phosphorylated at serine residue 616 (P-DRP1(S616)), a post-translational modification known to activate DRP1, and increased levels of DRP1 phosphorylated at serine 637 (P-DRP1(S637)), associated with the inactive state of the DRP1 GTPase. Knockdown of STAT2 in SHSY5Y cells recapitulated the fission defect, with elongated mitochondria and decreased P-DRP1(S616) levels. Furthermore the mitochondrial fission defect in patient fibroblasts was rescued following lentiviral transduction with wild-type STAT2 in all three patients, with normalization of mitochondrial length and increased P-DRP1(S616) levels. Taken together, these findings implicate STAT2 as a novel regulator of DRP1 phosphorylation at serine 616, and thus of mitochondrial fission, and suggest that there are interactions between immunity and mitochondria. This is the first study to link the innate immune system to mitochondrial dynamics and morphology. We hypothesize that variability in JAK-STAT signalling may contribute to the phenotypic heterogeneity of mitochondrial disease, and may explain why some patients with underlying mitochondrial disease decompensate after seemingly trivial viral infections. Modulating JAK-STAT activity may represent a novel therapeutic avenue for mitochondrial diseases, which remain largely untreatable. This may also be relevant for more common neurodegenerative diseases, including Alzheimer's, Huntington's and Parkinson's diseases, in which abnormalities of mitochondrial morphology have been implicated in disease pathogenesis.
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Affiliation(s)
- Rojeen Shahni
- 1 Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Institute of Child Health, Guilford Street, London, UK
| | - Catherine M Cale
- 2 Molecular Immunology Unit, Great Ormond Street Hospital, London, UK
| | - Glenn Anderson
- 3 Histopathology Unit, Great Ormond Street Hospital, London, UK
| | - Laura D Osellame
- 4 Department of Biochemistry and Molecular Biology, Monash University, Melbourne 3800, Australia
| | - Sophie Hambleton
- 5 Primary Immunodeficiency Group, Institute of Cellular Medicine, Newcastle University, UK
| | - Thomas S Jacques
- 3 Histopathology Unit, Great Ormond Street Hospital, London, UK 6 Developmental Neurosciences, UCL Institute of Child Health, London, UK
| | - Yehani Wedatilake
- 1 Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Institute of Child Health, Guilford Street, London, UK
| | - Jan-Willem Taanman
- 7 Department of Clinical Neurosciences, UCL Institute of Neurology, Rowland Hill Street, London, UK
| | - Emma Chan
- 2 Molecular Immunology Unit, Great Ormond Street Hospital, London, UK
| | - Waseem Qasim
- 2 Molecular Immunology Unit, Great Ormond Street Hospital, London, UK
| | | | - Annapurna Chalasani
- 9 Neurometabolic Unit, National Hospital for Neurology and Neurosurgery, London, UK
| | - Michael R Duchen
- 10 Cell and Developmental Biology, University College London, UK
| | | | - Shamima Rahman
- 1 Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Institute of Child Health, Guilford Street, London, UK 1 Mitochondrial Research Group, Genetics and Genomic Medicine, UCL Institute of Child Health, Guilford Street, London, UK
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Abstract
Tyrosine kinase 2 (TYK2) is a member of the Janus family of non-receptor tyrosine kinases involved in cytokine signaling. TYK2 deficiency is associated with increased susceptibility to mycobacterial and viral infections, hyper IgE syndrome as well as with allergic asthma. However the precise role of TYK2 in oncogenesis and tumor progression is not clear yet. Tyk2-deficient mice are prone to develop tumors because they lack efficient cytotoxic CD8+ T-cell antitumor responses as a result of deficient Type I interferon signaling. However, as TYK2 functions downstream of growth factor receptors that are often hyperactivated in cancer, inhibiting TYK2 might also have beneficial effects for cancer treatment.
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Affiliation(s)
- Caroline Ubel
- Laboratory of Cellular and Molecular Lung Immunology; Institute of Molecular Pneumology; University of Erlangen-Nürnberg, Erlangen, Germany
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