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Osawa J, Karakawa M, Taniguchi A, Inui Y, Usuki C, Ishida A, Kameshita I, Sueyoshi N. Functional regulation of the protein phosphatase PPM1M by phosphorylation at multiple sites with Ser/Thr-Pro motifs. Arch Biochem Biophys 2024; 753:109887. [PMID: 38224862 DOI: 10.1016/j.abb.2024.109887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/22/2023] [Accepted: 01/09/2024] [Indexed: 01/17/2024]
Abstract
The imbalance in the phosphorylation and the dephosphorylation of proteins leads to various diseases. Therefore, in vivo, the functions of protein kinases and protein phosphatases are strictly regulated. Mg2+/Mn2+-dependent protein phosphatase PPM1M has been implicated in immunity and cancer; however, the regulation mechanism remains unknown. In this study, we show that PPM1M is regulated in different ways by multiple phosphorylation. PPM1M has four Ser/Thr-Pro motifs (Ser27, Ser43, Ser60, and Thr254) that are recognized by proline-directed kinases, and Ser60 was found to be phosphorylated by cyclin-dependent kinase 5 (CDK5) in the cell. The phospho-mimetic mutation of Ser27 and Ser43 in the N-terminal domain suppresses the nuclear localization of PPM1M and promotes its accumulation in the cytoplasm. The phospho-mimetic mutation of Ser60 decreases PPM1M activity; conversely, the phospho-mimetic mutation of Thr254 increases PPM1M activity. These results suggest that the subcellular localization and phosphatase activity of PPM1M are regulated by protein kinases, including CDK5, via phosphorylation at multiple sites. Thus, PPM1M is differentially regulated by proline-directed kinases, including CDK5.
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Affiliation(s)
- Jin Osawa
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Masataka Karakawa
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Aoi Taniguchi
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Yuiko Inui
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Chika Usuki
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Atsuhiko Ishida
- Laboratory of Molecular Brain Science, Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-8521, Japan.
| | - Isamu Kameshita
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan
| | - Noriyuki Sueyoshi
- Department of Life Sciences, Faculty of Agriculture, Kagawa University, Kagawa, 761-0795, Japan.
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Chandra K, Swathi M, Keerthana B, Gopan S, Ghantasala JP, Joshi MB, Thondamal M, Parsa KVL. PHLPP1 regulates PINK1-parkin signalling and life span. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166718. [PMID: 37060964 DOI: 10.1016/j.bbadis.2023.166718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 04/17/2023]
Abstract
Adaptability to intracellular or extracellular cues is essential for maintaining cellular homeostasis. Metabolic signals intricately control the morphology and functions of mitochondria by regulating bioenergetics and metabolism. Here, we describe the involvement of PHLPP1, a Ser/Thr phosphatase, in mitochondrial homeostasis. Microscopic analysis showed the enhanced globular structure of mitochondria in PHLPP1-depleted HEK 293T and C2C12 cells, while forced expression of PHLPP1 promoted mitochondrial tubularity. We show that PHLPP1 promoted pro-fusion markers MFN2 and p-DRP1Ser637 levels using over-expression and knockdown strategies. Contrastingly, PHLPP1 induced mitochondrial fragmentation by augmenting pro-fission markers, t-DRP1 and pDrp1Ser616 upon mitochondrial stress. At the molecular level, PHLPP1 interacted with and caused dephosphorylation of calcineurin, a p-DRP1Ser637 phosphatase, under basal conditions. Likewise, PHLPP1 dimerized with PINK1 under basal conditions. However, the interaction of PHLPP1 with both calcineurin and PINK1 was impaired upon CCCP and oligomycin-induced mitochondrial stress. Interestingly, upon mitochondrial membrane depolarization, PHLPP1 promoted PINK1 stabilization and parkin recruitment to mitochondria, and thereby activated the mitophagy machinery providing a molecular explanation for the dual effects of PHLPP1 on mitochondria under different conditions. Consistent with our in-vitro findings, depletion of phlp-2, ortholog of PHLPP1 in C. elegans, led to mitochondrial fission under basal conditions, extended the lifespan of the worms, and enhanced survival of worms subjected to paraquat-induced oxidative stress.
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Affiliation(s)
- Kanika Chandra
- Centre for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad 500046, India; Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - M Swathi
- Centre for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad 500046, India
| | - B Keerthana
- Centre for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad 500046, India; Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Sooraj Gopan
- Centre for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad 500046, India
| | | | - Manjunath B Joshi
- Manipal School of Life Sciences, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Manjunatha Thondamal
- Department of Biotechnology, GITAM School of Technology, Gandhi Institute of Technology and Management (GITAM) (Deemed to be University), Visakhapatnam 530045, India
| | - Kishore V L Parsa
- Centre for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences, University of Hyderabad Campus, Hyderabad 500046, India.
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Kapadia B, Behera S, Kumar ST, Shah T, Edwin RK, Babu PP, Chakrabarti P, Parsa KV, Misra P. PIMT regulates hepatic gluconeogenesis in mice. iScience 2023; 26:106120. [PMID: 36866247 PMCID: PMC9972567 DOI: 10.1016/j.isci.2023.106120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 11/29/2022] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The physiological and metabolic functions of PIMT/TGS1, a third-generation transcriptional apparatus protein, in glucose homeostasis sustenance are unclear. Here, we observed that the expression of PIMT was upregulated in the livers of short-term fasted and obese mice. Lentiviruses expressing Tgs1-specific shRNA or cDNA were injected into wild-type mice. Gene expression, hepatic glucose output, glucose tolerance, and insulin sensitivity were evaluated in mice and primary hepatocytes. Genetic modulation of PIMT exerted a direct positive impact on the gluconeogenic gene expression program and hepatic glucose output. Molecular studies utilizing cultured cells, in vivo models, genetic manipulation, and PKA pharmacological inhibition establish that PKA regulates PIMT at post-transcriptional/translational and post-translational levels. PKA enhanced 3'UTR-mediated translation of TGS1 mRNA and phosphorylated PIMT at Ser656, increasing Ep300-mediated gluconeogenic transcriptional activity. The PKA-PIMT-Ep300 signaling module and associated PIMT regulation may serve as a key driver of gluconeogenesis, positioning PIMT as a critical hepatic glucose sensor.
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Affiliation(s)
- Bandish Kapadia
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India
| | - Soma Behera
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India
| | - Sireesh T. Kumar
- Department of Biotechnology, University of Hyderabad, Hyderabad 500046, India
| | - Tapan Shah
- Department of Biochemistry, Saurashtra University, Rajkot 360005, India
| | - Rebecca Kristina Edwin
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India
| | | | | | - Kishore V.L. Parsa
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India,Corresponding author
| | - Parimal Misra
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy’s Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad, TG 500046, India,Corresponding author
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Lobert VH, Skardal ML, Malerød L, Simensen JE, Algra HA, Andersen AN, Fleischer T, Enserink HA, Liestøl K, Heath JK, Rusten TE, Stenmark HA. PHLPP1 regulates CFTR activity and lumen expansion through AMPK. Development 2022; 149:276412. [PMID: 35997536 PMCID: PMC9534488 DOI: 10.1242/dev.200955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/12/2022] [Indexed: 11/20/2022]
Abstract
ABSTRACT
Complex organ development depends on single lumen formation and its expansion during tubulogenesis. This can be achieved by correct mitotic spindle orientation during cell division, combined with luminal fluid filling that generates hydrostatic pressure. Using a human 3D cell culture model, we have identified two regulators of these processes. We find that pleckstrin homology leucine-rich repeat protein phosphatase (PHLPP) 2 regulates mitotic spindle orientation, and thereby midbody positioning and maintenance of a single lumen. Silencing the sole PHLPP family phosphatase in Drosophila melanogaster, phlpp, resulted in defective spindle orientation in Drosophila neuroblasts. Importantly, cystic fibrosis transmembrane conductance regulator (CFTR) is the main channel regulating fluid transport in this system, stimulated by phosphorylation by protein kinase A and inhibited by the AMP-activated protein kinase AMPK. During lumen expansion, CFTR remains open through the action of PHLPP1, which stops activated AMPK from inhibiting ion transport through CFTR. In the absence of PHLPP1, the restraint on AMPK activity is lost and this tips the balance in the favour of channel closing, resulting in the lack of lumen expansion and accumulation of mucus.
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Affiliation(s)
- Viola H. Lobert
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Maren L. Skardal
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Lene Malerød
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Julia E. Simensen
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Hermine A. Algra
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Aram N. Andersen
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Thomas Fleischer
- Institute for Cancer Research, Oslo University Hospital 3 Department of Cancer Genetics , , Montebello, Oslo 0379 , Norway
| | - Hilde A. Enserink
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Knut Liestøl
- University of Oslo 4 Department of Informatics , , Oslo 0316 , Norway
| | - Joan K. Heath
- Walter and Eliza Hall Institute of Medical Research 5 Epigenetics and Development Division , , Parkville, Victoria 3052 , Australia
| | - Tor Erik Rusten
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
| | - Harald A. Stenmark
- Institute for Cancer Research, Oslo University Hospital 1 Department of Molecular Cell Biology , , Montebello, Oslo 0379 , Norway
- Centre for Cancer Cell Reprogramming 2 , Faculty of Medicine , , Oslo 0379 , Norway
- University of Oslo 2 , Faculty of Medicine , , Oslo 0379 , Norway
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Balamurugan K, Chandra K, Sai Latha S, Swathi M, Joshi MB, Misra P, Parsa KVL. PHLPPs: Emerging players in metabolic disorders. Drug Discov Today 2022; 27:103317. [PMID: 35835313 DOI: 10.1016/j.drudis.2022.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/21/2022] [Accepted: 07/07/2022] [Indexed: 12/15/2022]
Abstract
That reversible protein phosphorylation by kinases and phosphatases occurs in metabolic disorders is well known. Various studies have revealed that a multi-faceted and tightly regulated phosphatase, pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP)-1/2 displays robust effects in cardioprotection, ischaemia/reperfusion (I/R), and vascular remodelling. PHLPP1 promotes foamy macrophage development through ChREBP/AMPK-dependent pathways. Adipocyte-specific loss of PHLPP2 reduces adiposity, improves glucose tolerance,and attenuates fatty liver via the PHLPP2-HSL-PPARα axis. Discoveries of PHLPP1-mediated insulin resistance and pancreatic β cell death via the PHLPP1/2-Mst1-mTORC1 triangular loop have shed light on its significance in diabetology. PHLPP1 downregulation attenuates diabetic cardiomyopathy (DCM) by restoring PI3K-Akt-mTOR signalling. In this review, we summarise the functional role of, and cellular signalling mediated by, PHLPPs in metabolic tissues and discuss their potential as therapeutic targets.
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Affiliation(s)
- Keerthana Balamurugan
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India; Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Kanika Chandra
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India; Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - S Sai Latha
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - M Swathi
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - Manjunath B Joshi
- Department of Ageing Research, Manipal School of Life Sciences, Manipal Academy of Higher Education (MAHE), Manipal 576104, Karnataka, India
| | - Parimal Misra
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India
| | - Kishore V L Parsa
- Center for Innovation in Molecular and Pharmaceutical Sciences (CIMPS), Dr. Reddy's Institute of Life Sciences (DRILS), University of Hyderabad Campus, Hyderabad 500046, Telangana, India.
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MicroRNA-299a-5p Protects against Spinal Cord Injury through Activating AMPK Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:8659587. [PMID: 35602094 PMCID: PMC9122705 DOI: 10.1155/2022/8659587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 03/20/2022] [Accepted: 04/07/2022] [Indexed: 11/17/2022]
Abstract
Objective Inflammation and oxidative stress are implicated in the pathogenesis of spinal cord injury (SCI). The present study is aimed at investigating the function and molecular basis of microRNA-299a-5p (miR-299a-5p) during SCI in mice. Methods Mice were exposed to SCI surgery and then intrathecally injected with the agomir, antagomir, or matched negative controls of miR-299a-5p to overexpress or silence miR-299a-5p. To inhibit AMP-activated protein kinase (AMPK), mice were intraperitoneally injected with compound C (CC). To overexpress pH domain and leucine-rich repeat protein phosphatase 1 (PHLPP1), lentiviral vectors were used. Results The miR-299a-5p expression in the spinal cord was dramatically reduced by SCI stimulation. The miR-299a-5p agomir prevents, while the miR-299a-5p antagomir exacerbates inflammation, oxidative stress, and SCI in mice. Mechanistically, we found that miR-299a-5p directly inhibited PHLPP1 and subsequently activated AMPK pathway. The PHLPP1 overexpression of AMPK inhibition with either genetic or pharmacologic methods dramatically abolished the miR-299a-5p agomir-mediated protective effects against SCI. Conclusion miR-299a-5p protects against spinal cord injury through activating AMPK pathway.
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Wilson RJ, Lyons SP, Koves TR, Bryson VG, Zhang H, Li T, Crown SB, Ding JD, Grimsrud PA, Rosenberg PB, Muoio DM. Disruption of STIM1-mediated Ca 2+ sensing and energy metabolism in adult skeletal muscle compromises exercise tolerance, proteostasis, and lean mass. Mol Metab 2022; 57:101429. [PMID: 34979330 PMCID: PMC8814391 DOI: 10.1016/j.molmet.2021.101429] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVE Stromal interaction molecule 1 (STIM1) is a single-pass transmembrane endoplasmic/sarcoplasmic reticulum (E/SR) protein recognized for its role in a store operated Ca2+ entry (SOCE), an ancient and ubiquitous signaling pathway. Whereas STIM1 is known to be indispensable during development, its biological and metabolic functions in mature muscles remain unclear. METHODS Conditional and tamoxifen inducible muscle STIM1 knock-out mouse models were coupled with multi-omics tools and comprehensive physiology to understand the role of STIM1 in regulating SOCE, mitochondrial quality and bioenergetics, and whole-body energy homeostasis. RESULTS This study shows that STIM1 is abundant in adult skeletal muscle, upregulated by exercise, and is present at SR-mitochondria interfaces. Inducible tissue-specific deletion of STIM1 (iSTIM1 KO) in adult muscle led to diminished lean mass, reduced exercise capacity, and perturbed fuel selection in the settings of energetic stress, without affecting whole-body glucose tolerance. Proteomics and phospho-proteomics analyses of iSTIM1 KO muscles revealed molecular signatures of low-grade E/SR stress and broad activation of processes and signaling networks involved in proteostasis. CONCLUSION These results show that STIM1 regulates cellular and mitochondrial Ca2+ dynamics, energy metabolism and proteostasis in adult skeletal muscles. Furthermore, these findings provide insight into the pathophysiology of muscle diseases linked to disturbances in STIM1-dependent Ca2+ handling.
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Affiliation(s)
- Rebecca J Wilson
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA
| | - Scott P Lyons
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA
| | - Timothy R Koves
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Geriatrics, Duke University School of Medicine, Durham, NC 27705, USA
| | - Victoria G Bryson
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Hengtao Zhang
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - TianYu Li
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Scott B Crown
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA
| | - Jin-Dong Ding
- Department of Medicine, Division of Ophthalmology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Paul A Grimsrud
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University School of Medicine, Durham, NC 27705, USA
| | - Paul B Rosenberg
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Cardiology, Duke University School of Medicine, Durham, NC 27705, USA
| | - Deborah M Muoio
- Duke Molecular Physiology Institute, and Sarah W. Stedman Nutrition and Metabolism Center, Duke University School of Medicine, Durham, NC 27701, USA; Department of Medicine, Division of Endocrinology, Metabolism, and Nutrition, Duke University School of Medicine, Durham, NC 27705, USA; Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27705, USA.
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8
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Balamurugan K, Medishetti R, Kotha J, Behera P, Chandra K, Mavuduru VA, Joshi MB, Samineni R, Katika MR, Ball WB, Thondamal M, Challa A, Chatti K, Parsa KV. PHLPP1 promotes neutral lipid accumulation through AMPK/ChREBP-dependent lipid uptake and fatty acid synthesis pathways. iScience 2022; 25:103766. [PMID: 35141506 PMCID: PMC8810408 DOI: 10.1016/j.isci.2022.103766] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 11/25/2021] [Accepted: 01/11/2022] [Indexed: 01/26/2023] Open
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9
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PHLPP Signaling in Immune Cells. Curr Top Microbiol Immunol 2022; 436:117-143. [DOI: 10.1007/978-3-031-06566-8_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Phosphatase PHLPP2 regulates the cellular response to metabolic stress through AMPK. Cell Death Dis 2021; 12:904. [PMID: 34608126 PMCID: PMC8490465 DOI: 10.1038/s41419-021-04196-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 09/07/2021] [Accepted: 09/16/2021] [Indexed: 12/17/2022]
Abstract
PHLPP2 is a member of the PHLPP family of phosphatases, known to suppress cell growth by inhibiting proliferation or promoting apoptosis. Oncogenic kinases Akt, S6K, and PKC, and pro-apoptotic kinase Mst1, have been recognized as functional targets of the PHLPP family. However, we observed that, in T-leukemia cells subjected to metabolic stress from glucose limitation, PHLPP2 specifically targets the energy-sensing AMP-activated protein kinase, pAMPK, rather than Akt or S6K. PHLPP2 dephosphorylates pAMPK in several other human cancer cells as well. PHLPP2 and pAMPK interact with each other, and the pleckstrin homology (PH) domain on PHLPP2 is required for their interaction, for dephosphorylating and inactivating AMPK, and for the apoptotic response of the leukemia cells to glucose limitation. Silencing PHLPP2 protein expression prolongs the survival of leukemia cells subjected to severe glucose limitation by promoting a switch to AMPK-mediated fatty acid oxidation for energy generation. Thus, this study reveals a novel role for PHLPP2 in suppressing a survival response mediated through AMPK signaling. Given the multiple ways in which PHLPP phosphatases act to oppose survival signaling in cancers and the pivotal role played by AMPK in redox homeostasis via glucose and fatty acid metabolism, the revelation that AMPK is a target of PHLPP2 could lead to better therapeutics directed both at cancer and at metabolic diseases.
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Lemoine KA, Fassas JM, Ohannesian SH, Purcell NH. On the PHLPPside: Emerging roles of PHLPP phosphatases in the heart. Cell Signal 2021; 86:110097. [PMID: 34320369 PMCID: PMC8403656 DOI: 10.1016/j.cellsig.2021.110097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 07/20/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023]
Abstract
PH domain leucine-rich repeat protein phosphatase (PHLPP) is a family of enzymes made up of two isoforms (PHLPP1 and PHLPP2), whose actions modulate intracellular activity via the dephosphorylation of specific serine/threonine (Ser/Thr) residues on proteins such as Akt. Recent data generated in our lab, supported by findings from others, implicates the divergent roles of PHLPP1 and PHLPP2 in maintaining cellular homeostasis since dysregulation of these enzymes has been linked to various pathological states including cardiovascular disease, diabetes, ischemia/reperfusion injury, musculoskeletal disease, and cancer. Therefore, development of therapies to modulate specific isoforms of PHLPP could prove to be therapeutically beneficial in several diseases especially those targeting the cardiovascular system. This review is intended to provide a comprehensive summary of current literature detailing the role of the PHLPP isoforms in the development and progression of heart disease.
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Affiliation(s)
- Kellie A Lemoine
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA
| | - Julianna M Fassas
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA
| | - Shirag H Ohannesian
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA
| | - Nicole H Purcell
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92039, USA; Cardiovascular Molecular Signaling, Huntington Medical Research Institutes, Pasadena, CA 91105, USA.
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12
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Abstract
Over the last decades, research has focused on the role of pleckstrin homology (PH) domain leucine-rich repeat protein phosphatases (PHLPPs) in regulating cellular signaling via PI3K/Akt inhibition. The PKB/Akt signaling imbalances are associated with a variety of illnesses, including various types of cancer, inflammatory response, insulin resistance, and diabetes, demonstrating the relevance of PHLPPs in the prevention of diseases. Furthermore, identification of novel substrates of PHLPPs unveils their role as a critical mediator in various cellular processes. Recently, researchers have explored the increasing complexity of signaling networks involving PHLPPs whereby relevant information of PHLPPs in metabolic diseases was obtained. In this review, we discuss the current knowledge of PHLPPs on the well-known substrates and metabolic regulation, especially in liver, pancreatic beta cell, adipose tissue, and skeletal muscle in relation with the stated diseases. Understanding the context-dependent functions of PHLPPs can lead to a promising treatment strategy for several kinds of metabolic diseases.
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Affiliation(s)
- Jong-Ho Cha
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
| | - Yelin Jeong
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - Ah-Reum Oh
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - Sang Bae Lee
- Division of Life Sciences, Jeonbuk National University; Sarcopenia Total Solution Center, Jeonju 54896, Korea
| | - Soon-Sun Hong
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
| | - KyeongJin Kim
- Department of Biomedical Sciences, College of Medicine, Inha University, Incheon 22212, Korea
- Program in Biomedical Science & Engineering, Inha University, Incheon 22212, Korea
- Research Center for Controlling Intercellular Communication (RCIC), College of Medicine, Inha University, Incheon 22212, Korea
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13
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Lupse B, Annamalai K, Ibrahim H, Kaur S, Geravandi S, Sarma B, Pal A, Awal S, Joshi A, Rafizadeh S, Madduri MK, Khazaei M, Liu H, Yuan T, He W, Gorrepati KDD, Azizi Z, Qi Q, Ye K, Oberholzer J, Maedler K, Ardestani A. Inhibition of PHLPP1/2 phosphatases rescues pancreatic β-cells in diabetes. Cell Rep 2021; 36:109490. [PMID: 34348155 PMCID: PMC8421018 DOI: 10.1016/j.celrep.2021.109490] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 06/06/2021] [Accepted: 07/14/2021] [Indexed: 12/16/2022] Open
Abstract
Pancreatic β-cell failure is the key pathogenic element of the complex metabolic deterioration in type 2 diabetes (T2D); its underlying pathomechanism is still elusive. Here, we identify pleckstrin homology domain leucine-rich repeat protein phosphatases 1 and 2 (PHLPP1/2) as phosphatases whose upregulation leads to β-cell failure in diabetes. PHLPP levels are highly elevated in metabolically stressed human and rodent diabetic β-cells. Sustained hyper-activation of mechanistic target of rapamycin complex 1 (mTORC1) is the primary mechanism of the PHLPP upregulation linking chronic metabolic stress to ultimate β-cell death. PHLPPs directly dephosphorylate and regulate activities of β-cell survival-dependent kinases AKT and MST1, constituting a regulatory triangle loop to control β-cell apoptosis. Genetic inhibition of PHLPPs markedly improves β-cell survival and function in experimental models of diabetes in vitro, in vivo, and in primary human T2D islets. Our study presents PHLPPs as targets for functional regenerative therapy of pancreatic β cells in diabetes.
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Affiliation(s)
- Blaz Lupse
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Karthika Annamalai
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Hazem Ibrahim
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Supreet Kaur
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Shirin Geravandi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Bhavishya Sarma
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Anasua Pal
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Sushil Awal
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Arundhati Joshi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Sahar Rafizadeh
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Murali Krishna Madduri
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Mona Khazaei
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Huan Liu
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Ting Yuan
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | - Wei He
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany
| | | | - Zahra Azizi
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany; Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1449614535, Iran
| | - Qi Qi
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Keqiang Ye
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jose Oberholzer
- Charles O. Strickler Transplant Center, University of Virginia Medical Center, Charlottesville, VA 22903, USA
| | - Kathrin Maedler
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany.
| | - Amin Ardestani
- Centre for Biomolecular Interactions Bremen, University of Bremen, 28359 Bremen, Germany; Department of Molecular Medicine, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran 1449614535, Iran.
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14
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Ravikanth V, Sasikala M, Naveen V, Latha SS, Parsa KVL, Vijayasarathy K, Amanchy R, Avanthi S, Govardhan B, Rakesh K, Kumari DS, Srikaran B, Rao GV, Reddy DN. A variant in TMPRSS2 is associated with decreased disease severity in COVID-19. Meta Gene 2021; 29:100930. [PMID: 34075330 PMCID: PMC8161869 DOI: 10.1016/j.mgene.2021.100930] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/18/2021] [Accepted: 05/24/2021] [Indexed: 12/11/2022] Open
Abstract
Background Mortality due to COVID-19 caused by SARS-CoV-2 infection varies among populations. Functional relevance of genetic variations in Angiotensin-converting enzyme 2 (ACE2) and Transmembrane serine protease 2 (TMPRSS2), two crucial host factors for viral entry, might explain some of this variation. Methods In this comparative study in Indian subjects, we recruited 510 COVID-19 patients and retrieved DNA from 520 controls from a repository. Associations between variants in ACE2 and TMPRSS2 with disease severity were identified by whole exome sequencing (WES, n = 20) and targeted genotyping (n = 1010). Molecular dynamic simulations (MDS) were performed to explore functional relevance of the variants. Cleavage of spike glycoprotein by wild and variant TMPRSS2 was determined in HEK293T cells. Potential effects of confounders on the association between genotype and disease severity were tested (Mantel-Haenszel test). Results WES identified deleterious variant in TMPRSS2 (rs12329760, G > A, p. V160M). The minor allele frequency (MAF) was 0·27 in controls, 0·31 in asymptomatic, 0·21 in mild-to-moderately affected and 0·19 in severely affected COVID-19 patients. Risk of severity increased with decreasing MAF: Asymptomatic: Odds ratio-0·69 (95% CI–0·52–0·93; p = 0·01); mild-to-moderate: Odds ratio-1·89 (95% CI–1·22–2.92;p = 0·004) and severe: Odds ratio-1·79 (95% CI–1·11–2.88;p = 0·01). No confounding effect of diabetes and hypertension were observed on the risk of developing severe COVID-19 disease with respect to genotype. MDS revealed decreased stability of TMPRSS2 with 160 M variant. Spike glycoprotein cleavage by TMPRSS2 reduced ~2·4-fold in cells expressing 160 M variant. Conclusion We demonstrate association of TMPRSS2 variant rs12329760 with decreased disease severity in COVID-19 patients from India.
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Affiliation(s)
- Vishnubhotla Ravikanth
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Mitnala Sasikala
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Vankadari Naveen
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Sabbu Sai Latha
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy's Institute of Life Sciences, Gachibowli, Hyderabad, India
| | - Kishore Venkata Laxmi Parsa
- Center for Innovation in Molecular and Pharmaceutical Sciences, Dr. Reddy's Institute of Life Sciences, Gachibowli, Hyderabad, India
| | - Ketavarapu Vijayasarathy
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Ramars Amanchy
- Division of Applied Biology, CSIR-IICT (Indian Institute of Chemical Technology), Ministry of Science and Technology (GOI), Hyderabad 500007, Telangana, India
| | - Steffie Avanthi
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Bale Govardhan
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Kalapala Rakesh
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Daram Sarala Kumari
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Bojja Srikaran
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - Guduru Venkat Rao
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
| | - D Nageshwar Reddy
- Institute of Translational Research, Department of Genomics and Molecular Biology, Asian Institute of Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, Hyderabad 500032, Telangana, India
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15
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Baffi TR, Cohen-Katsenelson K, Newton AC. PHLPPing the Script: Emerging Roles of PHLPP Phosphatases in Cell Signaling. Annu Rev Pharmacol Toxicol 2021; 61:723-743. [PMID: 32997603 PMCID: PMC11003498 DOI: 10.1146/annurev-pharmtox-031820-122108] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Whereas protein kinases have been successfully targeted for a variety of diseases, protein phosphatases remain an underutilized therapeutic target, in part because of incomplete characterization of their effects on signaling networks. The pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) is a relatively new player in the cell signaling field, and new roles in controlling the balance among cell survival, proliferation, and apoptosis are being increasingly identified. Originally characterized for its tumor-suppressive function in deactivating the prosurvival kinase Akt, PHLPP may have an opposing role in promoting survival, as recent evidence suggests. Additionally, identification of the transcription factor STAT1 as a substrate unveils a role for PHLPP as a critical mediator of transcriptional programs in cancer and the inflammatory response. This review summarizes the current knowledge of PHLPP as both a tumor suppressor and an oncogene and highlights emerging functions in regulating gene expression and the immune system. Understanding the context-dependent functions of PHLPP is essential for appropriate therapeutic intervention.
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Affiliation(s)
- Timothy R Baffi
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0721, USA;
| | - Ksenya Cohen-Katsenelson
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0721, USA;
| | - Alexandra C Newton
- Department of Pharmacology, University of California, San Diego, La Jolla, California 92093-0721, USA;
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16
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Lin MW, Chen CI, Cheng TT, Huang CC, Tsai JW, Feng GM, Hwang TZ, Lam CF. Prolonged preoperative fasting induces postoperative insulin resistance by ER-stress mediated Glut4 down-regulation in skeletal muscles. Int J Med Sci 2021; 18:1189-1197. [PMID: 33526980 PMCID: PMC7847634 DOI: 10.7150/ijms.52701] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/21/2020] [Indexed: 01/14/2023] Open
Abstract
Preoperative fasting aims to prevent pulmonary aspiration and improve bowel preparation, but it may induce profound systemic catabolic responses that lead to protein breakdown and insulin-resistant hyperglycemia after operation. However, the molecular mechanisms of catabolic reaction induced by prolonged preoperative fasting and surgical stress are undetermined. In this study, anesthetized rats were randomly assigned to receive a sham operation or laparotomy cecectomy. Fasting groups were restricted from food and water for 12 h before operation, while the feeding group had free access to food throughout the study period. Twenty-four hours after operation, the animals were sacrificed to collect blood samples and soleus muscles for analysis. Postoperative blood glucose level was significantly increased in the fasting group with elevated serum insulin and C-peptide. Continuous feeding reduced serum myoglobin and lactate dehydrogenase concentrations. Preoperative fasting activated inositol-requiring transmembrane kinase/endoribonuclease (IRE)-1α and c-Jun N-terminal kinase (JNK) mediated endoplasmic reticulum (ER)-stress, and reduced glucose transporter type 4 (Glut4) expression in the soleus muscle. Phospholamban phosphorylation was reduced and intracellular calcium levels were increased in the isolated skeletal muscle cells. Similar results were found in ER stress-induced C1C12 myoblasts. The expression of Glut4 was suppressed in the stressed C1C12, but was potentiated following inhibition of ER stress and chelation of intracellular free calcium. This study provides evidence demonstrating that prolonged preoperative fasting induces ER stress and generates insulin resistance in the skeletal muscle through suppression of Glut4 and inactivation of Ca2+-ATPase, leading to intracellular calcium homeostasis disruption and peripheral insulin resistance.
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Affiliation(s)
- Ming-Wei Lin
- Department of Medical Research, E-Da Hospital/E-Da Cancer Hospital, Kaohsiung, Taiwan.,Department of Nursing, I-Shou University College of Medicine, Kaohsiung, Taiwan.,Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-I Chen
- Colorectal Surgery, Department of Surgery, E-Da Hospital/E-Da Cancer Hospital, Kaohsiung, Taiwan
| | - Tzu-Ting Cheng
- Department of Anesthesiology, E-Da Hospital/E-Da Cancer Hospital, Kaohsiung, Taiwan
| | - Chien-Chi Huang
- Department of Medical Research, E-Da Hospital/E-Da Cancer Hospital, Kaohsiung, Taiwan
| | - Jen-Wei Tsai
- Department of Pathology, E-Da Hospital, Kaohsiung, Taiwan
| | - Guan-Ming Feng
- Department of Plastic Surgery, E-Da Hospital, Kaohsiung, Taiwan
| | - Tzer-Zen Hwang
- Department of Otolaryngology, E-Da Hospital, Kaohsiung, Taiwan
| | - Chen-Fuh Lam
- Department of Anesthesiology, E-Da Hospital/E-Da Cancer Hospital, Kaohsiung, Taiwan.,School of Medicine, I-Shou University College of Medicine, Kaohsiung, Taiwan
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17
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Zhang X, Lu Y, He N, Wang F. Downregulation of PHLPP1 ameliorates high glucose-evoked injury in retinal ganglion cells by attenuating apoptosis and oxidative stress through enhancement of Nrf2 activation. Exp Cell Res 2020; 397:112344. [PMID: 33164862 DOI: 10.1016/j.yexcr.2020.112344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/21/2020] [Accepted: 10/23/2020] [Indexed: 12/18/2022]
Abstract
High glucose (HG)-induced oxidative stress contributes significantly to the pathogenesis of diabetic retinopathy. Pleckstrin homology domain and leucine rich repeat protein phosphatase 1 (PHLPP1) has emerged as a key regulator of oxidative stress implicated in various pathological processes. However, whether PHLPP1 participates in the regulation of HG-induced oxidative stress injury of retinal ganglion cells (RGCs) in diabetic retinopathy is undetermined. The purpose of this study was to explore the potential role and molecular mechanism of PHLPP1 in regulating HG-induced injury of RGCs. Our data showed that PHLPP1 expression was markedly elevated in RGCs from diabetic rats and HG-exposed RGCs. Our functional assay elucidated that knockdown of PHLPP1 improved cell viability and decreased cell apoptosis and reactive oxygen species (ROS) production in HG-exposed RGCs. Additionally, upregulation of PHLPP1 lowered cell viability and increased cell apoptosis and ROS production in HG-exposed RGCs. Mechanistically, knockdown of PHLPP1 resulted in an increase in nuclear factor erythroid-2 related factor 2 (Nrf2) nuclear expression and Nrf2/antioxidant response element (ARE)-mediated transcription associated with upregulation of glycogen synthase kinase-3β (GSK-3β) phosphorylation. Moreover, inhibition of GSK-3β significantly reversed the suppressive effect of PHLPP1 overexpression on Nrf2/ARE activation. Notably, the protective effect of PHLPP1 knockdown on HG-induced injury in RGCs was markedly abolished by Nrf2 inhibition. In conclusion, Our findings demonstrate that downregulation of PHLPP1 activates Nrf2/ARE signaling to protect RGCs from HG-induced apoptosis and oxidative stress. This study indicates a potential role of PHLPP1 in regulating HG-induced injury of RGCs during the development and progression of diabetic retinopathy.
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Affiliation(s)
- Xiaohui Zhang
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China
| | - Ye Lu
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China
| | - Na He
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China
| | - Feng Wang
- Ophthalmology Department, The Second Affiliated Hospital, Medical College, Xi'an Jiaotong University, Xi'an, 710004, PR China.
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Kassouf T, Sumara G. Impact of Conventional and Atypical MAPKs on the Development of Metabolic Diseases. Biomolecules 2020; 10:biom10091256. [PMID: 32872540 PMCID: PMC7563211 DOI: 10.3390/biom10091256] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 02/06/2023] Open
Abstract
The family of mitogen-activated protein kinases (MAPKs) consists of fourteen members and has been implicated in regulation of virtually all cellular processes. MAPKs are divided into two groups, conventional and atypical MAPKs. Conventional MAPKs are further classified into four sub-families: extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK1, 2 and 3), p38 (α, β, γ, δ), and extracellular signal-regulated kinase 5 (ERK5). Four kinases, extracellular signal-regulated kinase 3, 4, and 7 (ERK3, 4 and 7) as well as Nemo-like kinase (NLK) build a group of atypical MAPKs, which are activated by different upstream mechanisms than conventional MAPKs. Early studies identified JNK1/2 and ERK1/2 as well as p38α as a central mediators of inflammation-evoked insulin resistance. These kinases have been also implicated in the development of obesity and diabetes. Recently, other members of conventional MAPKs emerged as important mediators of liver, skeletal muscle, adipose tissue, and pancreatic β-cell metabolism. Moreover, latest studies indicate that atypical members of MAPK family play a central role in the regulation of adipose tissue function. In this review, we summarize early studies on conventional MAPKs as well as recent findings implicating previously ignored members of the MAPK family. Finally, we discuss the therapeutic potential of drugs targeting specific members of the MAPK family.
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19
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Sarcoplasmic reticulum and calcium signaling in muscle cells: Homeostasis and disease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 350:197-264. [PMID: 32138900 DOI: 10.1016/bs.ircmb.2019.12.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The sarco/endoplasmic reticulum is an extensive, dynamic and heterogeneous membranous network that fulfills multiple homeostatic functions. Among them, it compartmentalizes, stores and releases calcium within the intracellular space. In the case of muscle cells, calcium released from the sarco/endoplasmic reticulum in the vicinity of the contractile machinery induces cell contraction. Furthermore, sarco/endoplasmic reticulum-derived calcium also regulates gene transcription in the nucleus, energy metabolism in mitochondria and cytosolic signaling pathways. These diverse and overlapping processes require a highly complex fine-tuning that the sarco/endoplasmic reticulum provides by means of its numerous tubules and cisternae, specialized domains and contacts with other organelles. The sarco/endoplasmic reticulum also possesses a rich calcium-handling machinery, functionally coupled to both contraction-inducing stimuli and the contractile apparatus. Such is the importance of the sarco/endoplasmic reticulum for muscle cell physiology, that alterations in its structure, function or its calcium-handling machinery are intimately associated with the development of cardiometabolic diseases. Cardiac hypertrophy, insulin resistance and arterial hypertension are age-related pathologies with a common mechanism at the muscle cell level: the accumulation of damaged proteins at the sarco/endoplasmic reticulum induces a stress response condition termed endoplasmic reticulum stress, which impairs proper organelle function, ultimately leading to pathogenesis.
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20
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Hribal ML, Mancuso E, Arcidiacono GP, Greco A, Musca D, Procopio T, Ruffo M, Sesti G. The Phosphatase PHLPP2 Plays a Key Role in the Regulation of Pancreatic Beta-Cell Survival. Int J Endocrinol 2020; 2020:1027386. [PMID: 32411219 PMCID: PMC7199632 DOI: 10.1155/2020/1027386] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/03/2019] [Accepted: 12/10/2019] [Indexed: 02/06/2023] Open
Abstract
Currently available antidiabetic treatments fail to halt, and may even exacerbate, pancreatic β-cell exhaustion, a key feature of type 2 diabetes pathogenesis; thus, strategies to prevent, or reverse, β-cell failure should be actively sought. The serine threonine kinase Akt has a key role in the regulation of β-cell homeostasis; among Akt modulators, a central role is played by pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP) family. Here, taking advantage of an in vitro model of chronic exposure to high glucose, we demonstrated that PHLPPs, particularly the second family member called PHLPP2, are implicated in the ability of pancreatic β cells to deal with glucose toxicity. We observed that INS-1 rat pancreatic β cell line maintained for 12-15 passages at high (30 mM) glucose concentrations (INS-1 HG) showed increased expression of PHLPP2 and PHLPP1 both at mRNA and protein level as compared to INS-1 maintained for the same number of passages in the presence of normal glucose levels (INS-1 NG). These changes were paralleled by decreased phosphorylation of Akt and by increased expression of apoptotic and autophagic markers. To investigate if PHLPPs had a casual role in the alteration of INS-1 homeostasis observed upon chronic exposure to high glucose concentrations, we took advantage of shRNA technology to specifically knock-down PHLPPs. We obtained proof-of-concept evidence that modulating PHLPPs expression may help to restore a healthy β cell mass, as the reduced expression of PHLPP2/1 was accompanied by a recovered balance between pro- and antiapoptotic factor levels. In conclusion, our data provide initial support for future studies aimed to identify pharmacological PHLPPs modulator to treat beta-cell survival impairment. They also contribute to shed some light on β-cell dysfunction, a complex and unsatisfactorily characterized phenomenon that has a central causative role in the pathogenesis of type 2 diabetes.
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Affiliation(s)
- Marta Letizia Hribal
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Elettra Mancuso
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Gaetano Paride Arcidiacono
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
- Department of Medicine, University of Padua, Padua, Italy
| | - Annalisa Greco
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Donatella Musca
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Teresa Procopio
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
| | - Mariafrancesca Ruffo
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
- Department of Medicine, Ausl of Bologna, Bologna, Italy
| | - Giorgio Sesti
- Department of Medical and Surgical Sciences, University Magna Græcia of Catanzaro, Catanzaro, Italy
- Department of Clinical and Molecular Medicine, University of Rome La Sapienza, Rome, Italy
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Fix DK, VanderVeen BN, Counts BR, Carson JA. Regulation of Skeletal Muscle DRP-1 and FIS-1 Protein Expression by IL-6 Signaling. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:8908457. [PMID: 30918582 PMCID: PMC6408992 DOI: 10.1155/2019/8908457] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/13/2018] [Accepted: 12/04/2018] [Indexed: 12/15/2022]
Abstract
IL-6 signals through the ubiquitously expressed glycoprotein 130 (gp130) transmembrane protein to activate intracellular signaling that includes signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated kinase 1/2 (ERK1/2). Dynamin-1-like protein (DRP-1) and mitochondrial fission 1 protein (FIS-1) are key proteins in the process of mitochondrial fission and have emerged as IL-6-sensitive targets. The purpose of this study was to examine the regulation of DRP-1 and FIS-1 expression by IL-6 and gp130 signaling in myotubes and skeletal muscle. Fully differentiated C2C12 myotubes were treated with 100 ng of IL-6 for 24 hours in the presence of gp130siRNA, C188-9 (STAT3 inhibitor), or PD98059 (ERK1/2 inhibitor). Male C57BL/6 (B6) and muscle-specific gp130 knockout mice (KO) had IL-6 systemically overexpressed for 2 weeks by transient transfection with 50 ng of an IL-6-expressing or control plasmid in the quadriceps muscles, and the tibialis anterior muscle was analyzed to determine systemic effects of IL-6. IL-6 induced DRP-1 and FIS-1 expression in myotubes 124% and 82% (p = .001) and in skeletal muscle 97% and 187% (p = .001). Myotube gp130 knockdown suppressed the IL-6 induction of DRP-1 68% (p = .002) and FIS-1 65% (p = .001). Muscle KO suppressed the IL-6 induction of DRP-1 220% (p = .001) and FIS-1 121% (p = .001). ERK1/2 inhibition suppressed the IL-6 induction of DRP-1 59% (p = .0003) and FIS-1 102% (p = .0001) in myotubes, while there was no effect of STAT3 inhibition. We report that chronically elevated IL-6 can directly induce DRP-1 and FIS-1 expression through gp130 signaling in cultured myotubes and skeletal muscle. Furthermore, ERK 1/2 signaling is necessary for the IL-6 induction of DRP-1 and FIS-1 expression in myotubes.
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Affiliation(s)
- Dennis K. Fix
- Integrative Muscle Biology Laboratory, Division of Applied Physiology, Department of Exercise Science, University of South Carolina, Columbia, SC, USA
| | - Brandon N. VanderVeen
- Integrative Muscle Biology Laboratory, Division of Applied Physiology, Department of Exercise Science, University of South Carolina, Columbia, SC, USA
| | - Brittany R. Counts
- Integrative Muscle Biology Laboratory, Division of Applied Physiology, Department of Exercise Science, University of South Carolina, Columbia, SC, USA
| | - James A. Carson
- College of Health Professions, Department of Physical Therapy, University of Tennessee Health Sciences Center, Memphis, TN 38163, USA
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