1
|
Abstract
Phosphatases and kinases maintain an equilibrium of dephosphorylated and phosphorylated proteins, respectively, that are required for critical cellular functions. Imbalance in this equilibrium or irregularity in their function causes unfavorable cellular effects that have been implicated in the development of numerous diseases. Protein tyrosine phosphatases (PTPs) catalyze the dephosphorylation of protein substrates on tyrosine residues, and their involvement in cell signaling and diseases such as cancer and inflammatory and metabolic diseases has made them attractive therapeutic targets. However, PTPs have proved challenging in therapeutics development, garnering them the unfavorable reputation of being undruggable. Nonetheless, great strides have been made toward the inhibition of PTPs over the past decade. Here, we discuss the advancement in small-molecule inhibition for the PTP subfamily known as the mitogen-activated protein kinase (MAPK) phosphatases (MKPs). We review strategies and inhibitor discovery tools that have proven successful for small-molecule inhibition of the MKPs and discuss what the future of MKP inhibition potentially might yield.
Collapse
Affiliation(s)
- Shanelle R Shillingford
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, USA;
- Department of Chemistry, Yale University, New Haven, Connecticut, USA
| | - Anton M Bennett
- Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut, USA;
- Yale Center for Molecular and Systems Metabolism, Yale University School of Medicine, New Haven, Connecticut, USA
| |
Collapse
|
2
|
Metabolic Impact of MKP-2 Upregulation in Obesity Promotes Insulin Resistance and Fatty Liver Disease. Nutrients 2022; 14:nu14122475. [PMID: 35745205 PMCID: PMC9228271 DOI: 10.3390/nu14122475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/08/2022] [Accepted: 06/13/2022] [Indexed: 11/23/2022] Open
Abstract
The mechanisms connecting obesity with type 2 diabetes, insulin resistance, nonalcoholic fatty liver disease, and cardiovascular diseases remain incompletely understood. The function of MAPK phosphatase-2 (MKP-2), a type 1 dual-specific phosphatase (DUSP) in whole-body metabolism, and how this contributes to the development of diet-induced obesity, type 2 diabetes (T2D), and insulin resistance is largely unknown. We investigated the physiological contribution of MKP-2 in whole-body metabolism and whether MKP-2 is altered in obesity and human fatty liver disease using MKP-2 knockout mice models and human liver tissue derived from fatty liver disease patients. We demonstrate that, for the first time, MKP-2 expression was upregulated in liver tissue in humans with obesity and fatty liver disease and in insulin-responsive tissues in mice with obesity. MKP-2-deficient mice have enhanced p38 MAPK, JNK, and ERK activities in insulin-responsive tissues compared with wild-type mice. MKP-2 deficiency in mice protects against diet-induced obesity and hepatic steatosis and was accompanied by improved glucose homeostasis and insulin sensitivity. Mkp-2−/− mice are resistant to diet-induced obesity owing to reduced food intake and associated lower respiratory exchange ratio. This was associated with enhanced circulating insulin-like growth factor-1 (IGF-1) and stromal cell-derived factor 1 (SDF-1) levels in Mkp-2−/− mice. PTEN, a negative regulator of Akt, was downregulated in livers of Mkp-2−/− mice, resulting in enhanced Akt activity consistent with increased insulin sensitivity. These studies identify a novel role for MKP-2 in the regulation of systemic metabolism and pathophysiology of obesity-induced insulin resistance and fatty liver disease.
Collapse
|
3
|
Liu W, Taso O, Wang R, Bayram S, Graham AC, Garcia-Reitboeck P, Mallach A, Andrews WD, Piers TM, Botia JA, Pocock JM, Cummings DM, Hardy J, Edwards FA, Salih DA. Trem2 promotes anti-inflammatory responses in microglia and is suppressed under pro-inflammatory conditions. Hum Mol Genet 2021; 29:3224-3248. [PMID: 32959884 PMCID: PMC7689298 DOI: 10.1093/hmg/ddaa209] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/07/2020] [Accepted: 09/09/2020] [Indexed: 12/22/2022] Open
Abstract
Genome-wide association studies have reported that, amongst other microglial genes, variants in TREM2 can profoundly increase the incidence of developing Alzheimer’s disease (AD). We have investigated the role of TREM2 in primary microglial cultures from wild type mice by using siRNA to decrease Trem2 expression, and in parallel from knock-in mice heterozygous or homozygous for the Trem2 R47H AD risk variant. The prevailing phenotype of Trem2 R47H knock-in mice was decreased expression levels of Trem2 in microglia, which resulted in decreased density of microglia in the hippocampus. Overall, primary microglia with reduced Trem2 expression, either by siRNA or from the R47H knock-in mice, displayed a similar phenotype. Comparison of the effects of decreased Trem2 expression under conditions of lipopolysaccharide (LPS) pro-inflammatory or IL-4 anti-inflammatory stimulation revealed the importance of Trem2 in driving a number of the genes up-regulated in the anti-inflammatory phenotype. RNA-seq analysis showed that IL-4 induced the expression of a program of genes including Arg1 and Ap1b1 in microglia, which showed an attenuated response to IL-4 when Trem2 expression was decreased. Genes showing a similar expression profile to Arg1 were enriched for STAT6 transcription factor recognition elements in their promoter, and Trem2 knockdown decreased levels of STAT6. LPS-induced pro-inflammatory stimulation suppressed Trem2 expression, thus preventing TREM2’s anti-inflammatory drive. Given that anti-inflammatory signaling is associated with tissue repair, understanding the signaling mechanisms downstream of Trem2 in coordinating the pro- and anti-inflammatory balance of microglia, particularly mediating effects of the IL-4-regulated anti-inflammatory pathway, has important implications for fighting neurodegenerative disease.
Collapse
Affiliation(s)
- Wenfei Liu
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | - Orjona Taso
- UK Dementia Research Institute at UCL, London WC1E 6BT, UK
| | - Rui Wang
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | | | | | | | - Anna Mallach
- Department of Neuroinflammation, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - William D Andrews
- Department of Cell and Developmental Biology, UCL, London WC1E 6BT, UK
| | - Thomas M Piers
- Department of Neuroinflammation, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Juan A Botia
- Department of Information and Communications Engineering, Universidad de Murcia, Murcia E-30100, Spain.,Department of Neurodegenerative Diseases, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Jennifer M Pocock
- Department of Neuroinflammation, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Damian M Cummings
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | - John Hardy
- UK Dementia Research Institute at UCL, London WC1E 6BT, UK.,Department of Neurodegenerative Diseases, Institute of Neurology, UCL, London WC1N 1PJ, UK
| | - Frances A Edwards
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK
| | - Dervis A Salih
- Department of Neuroscience, Physiology and Pharmacology, UCL, London WC1E 6BT, UK.,UK Dementia Research Institute at UCL, London WC1E 6BT, UK
| |
Collapse
|
4
|
Neamatallah T, Jabbar S, Tate R, Schroeder J, Shweash M, Alexander J, Plevin R. Whole Genome Microarray Analysis of DUSP4-Deletion Reveals A Novel Role for MAP Kinase Phosphatase-2 (MKP-2) in Macrophage Gene Expression and Function. Int J Mol Sci 2019; 20:ijms20143434. [PMID: 31336892 PMCID: PMC6679025 DOI: 10.3390/ijms20143434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/08/2019] [Accepted: 07/09/2019] [Indexed: 12/22/2022] Open
Abstract
Background: Mitogen-activated protein kinase phosphatase-2 (MKP-2) is a type 1 nuclear dual specific phosphatase (DUSP-4). It plays an important role in macrophage inflammatory responses through the negative regulation of Mitogen activated protein kinase (MAPK) signalling. However, information on the effect of MKP-2 on other aspect of macrophage function is limited. Methods: We investigated the impact of MKP-2 in the regulation of several genes that are involved in function while using comparative whole genome microarray analysis in macrophages from MKP-2 wild type (wt) and knock out (ko) mice. Results: Our data showed that the lack of MKP-2 caused a significant down-regulation of colony-stimulating factor-2 (Csf2) and monocyte to macrophage-associated differentiation (Mmd) genes, suggesting a role of MKP-2 in macrophage development. When treated with macrophage colony stimulating factor (M-CSF), Mmd and Csf2 mRNA levels increased but significantly reduced in ko cells in comparison to wt counterparts. This effect of MKP-2 deletion on macrophage function was also observed by cell counting and DNA measurements. On the signalling level, M-CSF stimulation induced extracellular signal-regulated kinases (ERK) phosphorylation, which was significantly enhanced in the absence of MKP-2. Pharmacological inhibition of ERK reduced both Csf2 and Mmd genes in both wild type and ko cultures, which suggested that enhanced ERK activation in ko cultures may not explain effects on gene expression. Interestingly other functional markers were also shown to be reduced in ko macrophages in comparison to wt mice; the expression of CD115, which is a receptor for M-CSF, and CD34, a stem/progenitor cell marker, suggesting global regulation of gene expression by MKP-2. Conclusions: Transcriptome profiling reveals that MKP-2 regulates macrophage development showing candidate targets from monocyte-to-macrophage differentiation and macrophage proliferation. However, it is unclear whether effects upon ERK signalling are able to explain the effects of DUSP-4 deletion on macrophage function.
Collapse
Affiliation(s)
- Thikryat Neamatallah
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, King Abdulaziz University, P.O. Box 80260, Jeddah 21589, Saudi Arabia.
| | - Shilan Jabbar
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Rothwelle Tate
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Juliane Schroeder
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Muhannad Shweash
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - James Alexander
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| | - Robin Plevin
- Strathclyde Institute for Pharmacy & Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK
| |
Collapse
|
5
|
Lang R, Raffi FAM. Dual-Specificity Phosphatases in Immunity and Infection: An Update. Int J Mol Sci 2019; 20:ijms20112710. [PMID: 31159473 PMCID: PMC6600418 DOI: 10.3390/ijms20112710] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 05/28/2019] [Accepted: 05/30/2019] [Indexed: 12/26/2022] Open
Abstract
Kinase activation and phosphorylation cascades are key to initiate immune cell activation in response to recognition of antigen and sensing of microbial danger. However, for balanced and controlled immune responses, the intensity and duration of phospho-signaling has to be regulated. The dual-specificity phosphatase (DUSP) gene family has many members that are differentially expressed in resting and activated immune cells. Here, we review the progress made in the field of DUSP gene function in regulation of the immune system during the last decade. Studies in knockout mice have confirmed the essential functions of several DUSP-MAPK phosphatases (DUSP-MKP) in controlling inflammatory and anti-microbial immune responses and support the concept that individual DUSP-MKP shape and determine the outcome of innate immune responses due to context-dependent expression and selective inhibition of different mitogen-activated protein kinases (MAPK). In addition to the canonical DUSP-MKP, several small-size atypical DUSP proteins regulate immune cells and are therefore also reviewed here. Unexpected and complex findings in DUSP knockout mice pose new questions regarding cell type-specific and redundant functions. Another emerging question concerns the interaction of DUSP-MKP with non-MAPK binding partners and substrate proteins. Finally, the pharmacological targeting of DUSPs is desirable to modulate immune and inflammatory responses.
Collapse
Affiliation(s)
- Roland Lang
- Institute of Clinical Microbiology, Immunology and Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
| | - Faizal A M Raffi
- Institute of Clinical Microbiology, Immunology and Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
| |
Collapse
|