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Singh D, Qiu Z, Jonathan SM, Fa P, Thomas H, Prasad CB, Cai S, Wang JJ, Yan C, Zhang X, Venere M, Li Z, Sizemore ST, Wang QE, Zhang J. PP2A B55α inhibits epithelial-mesenchymal transition via regulation of Slug expression in non-small cell lung cancer. Cancer Lett 2024; 598:217110. [PMID: 38986733 DOI: 10.1016/j.canlet.2024.217110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 07/03/2024] [Accepted: 07/04/2024] [Indexed: 07/12/2024]
Abstract
PP2A B55α, encoded by PPP2R2A, acts as a regulatory subunit of the serine/threonine phosphatase PP2A. Despite a frequent loss of heterozygosity of PPP2R2A in cases of non-small cell lung cancer (NSCLC), research on PP2A B55α's functions remains limited and controversial. To investigate the biological roles of PP2A B55α, we conducted bulk RNA-sequencing to assess the impact of PPP2R2A knockdown using two shRNAs in a NSCLC cell line. Gene set enrichment analysis (GSEA) of the RNA-sequencing data revealed significant enrichment of the epithelial-mesenchymal transition (EMT) pathway, with SNAI2 (the gene encoding Slug) emerging as one of the top candidates. Our findings demonstrate that PP2A B55α suppresses EMT, as PPP2R2A deficiency through knockdown or homozygous or hemizygous depletion promotes EMT and metastatic behavior in NSCLC cells, as evidenced by changes in EMT biomarkers, invasion and migration abilities, as well as metastasis in a tail vein assay. Mechanistically, PP2A B55α inhibits EMT by downregulating SNAI2 expression via the GSK3β-β-catenin pathway. Importantly, PPP2R2A deficiency also slows cell proliferation by disrupting DNA replication, particularly in PPP2R2A-/- cells. Furthermore, PPP2R2A deficiency, especially PPP2R2A-/- cells, leads to an increase in the cancer stem cell population, which correlates with enhanced resistance to chemotherapy. Overall, the decrease in PP2A B55α levels due to hemizygous/homozygous depletion heightens EMT and the metastatic or stemness/drug resistance potential of NSCLC cells despite their proliferation disadvantage. Our study highlights the significance of PP2A B55α in EMT and metastasis and suggests that targeting EMT/stemness could be a potential therapeutic strategy for treating PPP2R2A-deficient NSCLC.
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Affiliation(s)
- Deepika Singh
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Zhaojun Qiu
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Spehar M Jonathan
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Pengyan Fa
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Hannah Thomas
- The Ohio State University, Columbus, OH, United States
| | - Chandra Bhushan Prasad
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Shurui Cai
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Jing J Wang
- The Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Chunhong Yan
- Georgia Cancer Center, Augusta University, Augusta, GA, United States
| | - Xiaoli Zhang
- Center for Biostatistics, The Ohio State University, United States; Department of Biomedical Informatics, College of Medicine, The Ohio State University, United States
| | - Monica Venere
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States; The James Comprehensive Cancer Center, Pelotonia Institute for Immuno-Oncology, The Ohio State University, Columbus, OH, United States
| | - Zaibo Li
- Department of Pathology, The Ohio State University Wexner Medical Center, College of Medicine, Columbus, OH, 43210, United States
| | - Steven T Sizemore
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Qi-En Wang
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States
| | - Junran Zhang
- The Department of Radiation Oncology, The Ohio State University Comprehensive Cancer Center and College of Medicine, Columbus, OH, United States; The James Comprehensive Cancer Center, Pelotonia Institute for Immuno-Oncology, The Ohio State University, Columbus, OH, United States; The James Comprehensive Cancer Center, Center for Metabolism, United States.
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Chan KI, Zhang S, Li G, Xu Y, Cui L, Wang Y, Su H, Tan W, Zhong Z. MYC Oncogene: A Druggable Target for Treating Cancers with Natural Products. Aging Dis 2024; 15:640-697. [PMID: 37450923 PMCID: PMC10917530 DOI: 10.14336/ad.2023.0520] [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: 04/24/2023] [Accepted: 05/20/2023] [Indexed: 07/18/2023] Open
Abstract
Various diseases, including cancers, age-associated disorders, and acute liver failure, have been linked to the oncogene, MYC. Animal testing and clinical trials have shown that sustained tumor volume reduction can be achieved when MYC is inactivated, and different combinations of therapeutic agents including MYC inhibitors are currently being developed. In this review, we first provide a summary of the multiple biological functions of the MYC oncoprotein in cancer treatment, highlighting that the equilibrium points of the MYC/MAX, MIZ1/MYC/MAX, and MAD (MNT)/MAX complexes have further potential in cancer treatment that could be used to restrain MYC oncogene expression and its functions in tumorigenesis. We also discuss the multifunctional capacity of MYC in various cellular cancer processes, including its influences on immune response, metabolism, cell cycle, apoptosis, autophagy, pyroptosis, metastasis, angiogenesis, multidrug resistance, and intestinal flora. Moreover, we summarize the MYC therapy patent landscape and emphasize the potential of MYC as a druggable target, using herbal medicine modulators. Finally, we describe pending challenges and future perspectives in biomedical research, involving the development of therapeutic approaches to modulate MYC or its targeted genes. Patients with cancers driven by MYC signaling may benefit from therapies targeting these pathways, which could delay cancerous growth and recover antitumor immune responses.
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Affiliation(s)
- Ka Iong Chan
- Macao Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR 999078, China
| | - Siyuan Zhang
- Macao Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR 999078, China
| | - Guodong Li
- Macao Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR 999078, China
| | - Yida Xu
- Macao Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR 999078, China
| | - Liao Cui
- Guangdong Provincial Key Laboratory of Research and Development of Natural Drugs, School of Pharmacy, Guangdong Medical University, Zhanjiang 524000, China
| | - Yitao Wang
- Macao Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR 999078, China
| | - Huanxing Su
- Macao Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR 999078, China
| | - Wen Tan
- School of Pharmacy, Lanzhou University, Lanzhou 730000, China
| | - Zhangfeng Zhong
- Macao Centre for Research and Development in Chinese Medicine, State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao SAR 999078, China
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Pragati, Sarkar S. Reinstated Activity of Human Tau-induced Enhanced Insulin Signaling Restricts Disease Pathogenesis by Regulating the Functioning of Kinases/Phosphatases and Tau Hyperphosphorylation in Drosophila. Mol Neurobiol 2024; 61:982-1001. [PMID: 37674037 DOI: 10.1007/s12035-023-03599-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/18/2023] [Indexed: 09/08/2023]
Abstract
Tauopathies such as Alzheimer's disease (AD), Frontotemporal dementia, and parkinsonism linked to chromosome 17 (FTDP-17), etc. are characterized by tau hyperphosphorylation and distinguished accumulation of paired helical filaments (PHFs)/or neurofibrillary tangles (NFTs) in a specific-neuronal subset of the brain. Among different reported risk factors, type 2 diabetes (T2D) has gained attention due to its correlation with tau pathogenesis. However, mechanistic details and the precise contribution of insulin pathway in tau etiology is still debatable. We demonstrate that expression of human tau causes overactivation of insulin pathway in Drosophila disease models. We subsequently noted that tissue-specific downregulation of insulin signaling or even exclusive reduction of its growth-promoting sub-branch effectively reinstates the overactivated insulin signaling pathway in human tau expressing cells, which in turn restricts pathogenic tau hyperphosphorylation and aggregate formation. It was further noted that restored tau phosphorylation was achieved due to a reestablished balance between the levels of different kinase(s) (GSK3β and ERK/P38 MAP kinase) and phosphatase (PP2A). Taken together, our study demonstrates a precise involvement of the insulin pathway and associated molecular events in the pathogenesis of human tauopathies in Drosophila, which will be immensely helpful in developing novel therapeutic options against these devastating human brain disorders. Moreover, our study reveals an interesting link between tau etiology and aberrant insulin signaling, which is a characteristic feature of Type 2 Diabetes.
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Affiliation(s)
- Pragati
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
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Shaik MG, Joshi SV, Akunuri R, Rana P, Rahman Z, Polomoni A, Yaddanapudi VM, Dandekar MP, Srinivas N. Small molecule inhibitors of NLRP3 inflammasome and GSK-3β in the management of traumatic brain injury: A review. Eur J Med Chem 2023; 259:115718. [PMID: 37573828 DOI: 10.1016/j.ejmech.2023.115718] [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: 11/10/2022] [Revised: 07/28/2023] [Accepted: 08/08/2023] [Indexed: 08/15/2023]
Abstract
Traumatic brain injury (TBI) is a debilitating mental condition which causes physical disability and morbidity worldwide. TBI may damage the brain by direct injury that subsequently triggers a series of neuroinflammatory events. The activation of NLRP3 inflammasome and dysregulated host immune system has been documented in various neurological disorders such as TBI, ischemic stroke and multiple sclerosis. The activation of NLRP3 post-TBI increases the production of pro-inflammatory cytokines and caspase-1, which are major drivers of neuroinflammation and apoptosis. Similarly, GSK-3β regulates apoptosis through tyrosine kinase and canonical Wnt signalling pathways. Thus, therapeutic targeting of NLRP3 inflammasome and GSK-3β has emerged as promising strategies for regulating the post-TBI neuroinflammation and neurobehavioral disturbances. In this review, we discuss the identification & development of several structurally diverse and pharmacologically interesting small molecule inhibitors for targeting the NLRP3 inflammasome and GSK-3β in the management of TBI.
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Affiliation(s)
- Mahammad Ghouse Shaik
- Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, 500 037, India
| | - Swanand Vinayak Joshi
- Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, 500 037, India
| | - Ravikumar Akunuri
- Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, 500 037, India; Ellen and Ronald Caplan Cancer Center, The Wistar Institute, Philadelphia, PA, 19104, USA
| | - Preeti Rana
- Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, 500 037, India
| | - Ziaur Rahman
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, 500 037, India
| | - Anusha Polomoni
- Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, 500 037, India
| | - Venkata Madhavi Yaddanapudi
- Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, 500 037, India
| | - Manoj P Dandekar
- Department of Pharmacology & Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Balanagar, Hyderabad, Telangana, 500 037, India.
| | - Nanduri Srinivas
- Department of Chemical Sciences, National Institute of Pharmaceutical Education and Research (NIPER), Hyderabad, 500 037, India.
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Doha ZO, Sears RC. Unraveling MYC's Role in Orchestrating Tumor Intrinsic and Tumor Microenvironment Interactions Driving Tumorigenesis and Drug Resistance. PATHOPHYSIOLOGY 2023; 30:400-419. [PMID: 37755397 PMCID: PMC10537413 DOI: 10.3390/pathophysiology30030031] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Revised: 09/04/2023] [Accepted: 09/08/2023] [Indexed: 09/28/2023] Open
Abstract
The transcription factor MYC plays a pivotal role in regulating various cellular processes and has been implicated in tumorigenesis across multiple cancer types. MYC has emerged as a master regulator governing tumor intrinsic and tumor microenvironment interactions, supporting tumor progression and driving drug resistance. This review paper aims to provide an overview and discussion of the intricate mechanisms through which MYC influences tumorigenesis and therapeutic resistance in cancer. We delve into the signaling pathways and molecular networks orchestrated by MYC in the context of tumor intrinsic characteristics, such as proliferation, replication stress and DNA repair. Furthermore, we explore the impact of MYC on the tumor microenvironment, including immune evasion, angiogenesis and cancer-associated fibroblast remodeling. Understanding MYC's multifaceted role in driving drug resistance and tumor progression is crucial for developing targeted therapies and combination treatments that may effectively combat this devastating disease. Through an analysis of the current literature, this review's goal is to shed light on the complexities of MYC-driven oncogenesis and its potential as a promising therapeutic target.
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Affiliation(s)
- Zinab O. Doha
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, USA;
- Department of Medical Laboratories Technology, Taibah University, Al-Madinah 42353, Saudi Arabia
| | - Rosalie C. Sears
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR 97239, USA;
- Brenden-Colson Center for Pancreatic Care, Oregon Health & Science University, Portland, OR 97201, USA
- Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97201, USA
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Anticancer polypyrrole-polyethylenimine drug-free nanozyme for precise B-cell lymphoma therapy. Biomed Pharmacother 2023; 160:114397. [PMID: 36796279 DOI: 10.1016/j.biopha.2023.114397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 02/08/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
As an alternative strategy for cancer treatment, the combination of cancer nanomedicine and immunotherapy is promising with regard to efficacy and safety; however, precise modulation of the activation of antitumor immunity remains challenging. Therefore, the aim of the present study was to describe an intelligent nanocomposite polymer immunomodulator, drug-free polypyrrole-polyethyleneimine nanozyme (PPY-PEI NZ), which responds to the B-cell lymphoma tumor microenvironment, for precision cancer immunotherapy. Earlier engulfment of PPY-PEI NZs in an endocytosis-dependent manner resulted in rapid binding in four different types of B-cell lymphoma cells. The PPY-PEI NZ effectively suppressed B cell colony-like growth in vitro accompanied by cytotoxicity via apoptosis induction. During PPY-PEI NZ-induced cell death, mitochondrial swelling, loss of mitochondrial transmembrane potential (MTP), downregulation of antiapoptotic proteins, and caspase-dependent apoptosis were observed. Deregulated AKT and ERK signaling contributed to glycogen synthase kinase-3-regulated cell apoptosis following deregulation of Mcl-1 and MTP loss. Additionally, PPY-PEI NZs induced lysosomal membrane permeabilization while inhibiting endosomal acidification, partly protecting cells from lysosomal apoptosis. PPY-PEI NZs selectively bound and eliminated exogenous malignant B cells in a mixed culture system with healthy leukocytes ex vivo. While PPY-PEI NZs showed no cytotoxicity in wild-type mice, they provided long-term and efficient inhibition of the growth of B-cell lymphoma-driven nodules in a subcutaneous xenograft model. This study explores a potential PPY-PEI NZ-based anticancer agent against B-cell lymphoma.
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Kornsuthisopon C, Tompkins KA, Osathanon T. Tideglusib enhances odontogenic differentiation in human dental pulp stem cells in vitro. Int Endod J 2023; 56:369-384. [PMID: 36458950 DOI: 10.1111/iej.13877] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/03/2022]
Abstract
AIM Tideglusib is a small molecule agonist of the canonical Wnt pathway. The present study investigated the influence of Tideglusib on human dental pulp stem cell (hDPSC) proliferation, apoptosis, migration and odonto/osteogenic differentiation. METHODOLOGY hDPSCs were treated with 50, 100 nM or 200 nM Tideglusib. β-catenin accumulation was detected by immunofluorescence staining. Colony-forming unit ability was assessed by staining with Coomassie blue. Cell cycle progression and cell apoptosis were investigated using flow cytometry. Cell migration was examined using an in vitro wound-healing assay. Osteogenic differentiation was examined using alkaline phosphatase (ALP) staining, alizarin red S staining and osteogenic-related gene expression. The gene expression profile was examined using a high-throughput RNA sequencing technique. All experiments were repeated using cells derived from at least four different donors (n = 4). The Mann-Whitney U-test was used to identify significant differences between two independent group comparisons. For three or more group comparisons, statistical differences were assessed using the Kruskal-Wallis test followed by pairwise comparison. The significance level was set at 5% (p < .05). RESULTS Tideglusib activated the Wnt signalling pathway in hDPSCs as demonstrated by an increase in cytoplasmic β-catenin accumulation and nuclear translocation. Tideglusib did not affect hDPSC proliferation, cell cycle progression, cell apoptosis or cell migration. In contrast, 50 and 100 nM Tideglusib significantly enhanced mineralization and osteogenic marker gene expression (RUNX2, ALP, BMP2 and DSPP; p < .05). CONCLUSIONS Tideglusib enhanced the odonto/osteogenic differentiation of hDPSCs. Therefore, incorporating this bioactive molecule in a pulp-capping material could be a promising strategy to promote dentine repair.
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Affiliation(s)
- Chatvadee Kornsuthisopon
- Dental Stem Cell Biology Research Unit, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Kevin A Tompkins
- Office of Research Affairs, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Thanaphum Osathanon
- Dental Stem Cell Biology Research Unit, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.,Office of Research Affairs, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.,Department of Anatomy, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
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The role of the PI3K/AKT signalling pathway in the corneal epithelium: recent updates. Cell Death Dis 2022; 13:513. [PMID: 35641491 PMCID: PMC9156734 DOI: 10.1038/s41419-022-04963-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 05/14/2022] [Accepted: 05/17/2022] [Indexed: 12/14/2022]
Abstract
Phosphatidylinositol 3 kinase (PI3K)/AKT (also called protein kinase B, PKB) signalling regulates various cellular processes, such as apoptosis, cell proliferation, the cell cycle, protein synthesis, glucose metabolism, and telomere activity. Corneal epithelial cells (CECs) are the outermost cells of the cornea; they maintain good optical performance and act as a physical and immune barrier. Various growth factors, including epidermal growth factor receptor (EGFR) ligands, insulin-like growth factor 1 (IGF1), neurokinin 1 (NK-1), and insulin activate the PI3K/AKT signalling pathway by binding their receptors and promote antiapoptotic, anti-inflammatory, proliferative, and migratory functions and wound healing in the corneal epithelium (CE). Reactive oxygen species (ROS) regulate apoptosis and inflammation in CECs in a concentration-dependent manner. Extreme environments induce excess ROS accumulation, inhibit PI3K/AKT, and cause apoptosis and inflammation in CECs. However, at low or moderate levels, ROS activate PI3K/AKT signalling, inhibiting apoptosis and stimulating proliferation of healthy CECs. Diabetes-associated hyperglycaemia directly inhibit PI3K/AKT signalling by increasing ROS and endoplasmic reticulum (ER) stress levels or suppressing the expression of growth factors receptors and cause diabetic keratopathy (DK) in CECs. Similarly, hyperosmolarity and ROS accumulation suppress PI3K/AKT signalling in dry eye disease (DED). However, significant overactivation of the PI3K/AKT signalling pathway, which mediates inflammation in CECs, is observed in both infectious and noninfectious keratitis. Overall, upon activation by growth factors and NK-1, PI3K/AKT signalling promotes the proliferation, migration, and anti-apoptosis of CECs, and these processes can be regulated by ROS in a concentration-dependent manner. Moreover, PI3K/AKT signalling pathway is inhibited in CECs from individuals with DK and DED, but is overactivated by keratitis.
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Chen CL, Tseng PC, Satria RD, Nguyen TT, Tsai CC, Lin CF. Role of Glycogen Synthase Kinase-3 in Interferon-γ-Mediated Immune Hepatitis. Int J Mol Sci 2022; 23:ijms23094669. [PMID: 35563060 PMCID: PMC9101719 DOI: 10.3390/ijms23094669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/16/2022] [Accepted: 04/20/2022] [Indexed: 12/04/2022] Open
Abstract
Glycogen synthase kinase-3 (GSK-3), a serine/threonine kinase, is a vital glycogen synthase regulator controlling glycogen synthesis, glucose metabolism, and insulin signaling. GSK-3 is widely expressed in different types of cells, and its abundant roles in cellular bioregulation have been speculated. Abnormal GSK-3 activation and inactivation may affect its original bioactivity. Moreover, active and inactive GSK-3 can regulate several cytosolic factors and modulate their diverse cellular functional roles. Studies in experimental liver disease models have illustrated the possible pathological role of GSK-3 in facilitating acute hepatic injury. Pharmacologically targeting GSK-3 is therefore suggested as a therapeutic strategy for liver protection. Furthermore, while the signaling transduction of GSK-3 facilitates proinflammatory interferon (IFN)-γ in vitro and in vivo, the blockade of GSK-3 can be protective, as shown by an IFN-γ-induced immune hepatitis model. In this study, we explored the possible regulation of GSK-3 and the potential relevance of GSK-3 blockade in IFN-γ-mediated immune hepatitis.
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Affiliation(s)
- Chia-Ling Chen
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Po-Chun Tseng
- Core Laboratory of Immune Monitoring, Office of Research & Development, Taipei Medical University, Taipei 110, Taiwan;
| | - Rahmat Dani Satria
- International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (R.D.S.); (T.T.N.)
- Department of Clinical Pathology and Laboratory Medicine, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia
- Clinical Laboratory Installation, Dr. Sardjito Central General Hospital, Yogyakarta 55281, Indonesia
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
| | - Thi Thuy Nguyen
- International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (R.D.S.); (T.T.N.)
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
- Department of Oncology, Hue University of Medicine and Pharmacy, Hue University, Hue City 530000, Vietnam
| | - Cheng-Chieh Tsai
- Department of Nursing, Chung Hwa University of Medical Technology, Tainan 703, Taiwan
- Department of Long Term Care Management, Chung Hwa University of Medical Technology, Tainan 703, Taiwan
- Correspondence: (C.-C.T.); (C.-F.L.)
| | - Chiou-Feng Lin
- Core Laboratory of Immune Monitoring, Office of Research & Development, Taipei Medical University, Taipei 110, Taiwan;
- International Ph.D. Program in Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan; (R.D.S.); (T.T.N.)
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 110, Taiwan
- Correspondence: (C.-C.T.); (C.-F.L.)
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Su J, Zhang J, Bao R, Xia C, Zhang Y, Zhu Z, Lv Q, Qi Y, Xue J. Mitochondrial dysfunction and apoptosis are attenuated through activation of AMPK/GSK-3β/PP2A pathway in Parkinson's disease. Eur J Pharmacol 2021; 907:174202. [PMID: 34048739 DOI: 10.1016/j.ejphar.2021.174202] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 12/22/2022]
Abstract
Parkinson's disease (PD) is a common neurological disorder worldwide, characterized by loss of dopaminergic neurons and decrease of dopamine content. Mitochondria plays an important role in the development of PD. Adenosine 5'-monophosphate-activated protein kinase (AMPK), glycogen synthase kinase 3 (GSK-3β) and protein phosphatase 2A (PP2A) are all key proteins that regulate mitochondrial metabolism and apoptosis, and they are involved in a variety of neurodegenerative diseases. Here, we aimed to explore the involvement of mitochondrial dysfunction and apoptosis in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine hydrochloride (MPTP)-induced PD mice and MPP+ iodide-induced PC12 cells. MPTP-induced mice were subjected to behavioral testing to assess PD-like behaviors. Various molecular biological techniques including ELISA, Western blot, TUNEL assay, flow cytometry, and the important instruments Seahorse XF24 Extracellular and high performance liquid chromatography (HPLC), were used to identify the underlying molecular events of mitochondria. Treatment with the AMPK activator GSK621 dramatically ameliorated PD by increasing the levels of dopamine and rescuing the loss of dopaminergic neurons, which is dependent on the mitochondrial pathway. Moreover, regulation of AMPK/GSK-3β/PP2A pathway-related proteins by GSK621 was partially inhibited the development of PD, suggesting a negative feedback loop exists between AMPK action and mitochondrial dysfunction-mediated apoptosis. Our data preliminarily indicated that mitochondrial dysfunction and apoptosis in the pathogenesis of PD might be mediated by AMPK/GSK-3β/PP2A pathway action, which might be a promising new option for future therapy of PD.
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Affiliation(s)
- Jianhua Su
- Neurology Department, Jintan Hospital Affiliated to Jiangsu University, Changzhou, 213200, Jiangsu, China
| | - Junhua Zhang
- Neurology Department, Jintan Hospital Affiliated to Jiangsu University, Changzhou, 213200, Jiangsu, China
| | - Rui Bao
- School of Pharmacy, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Changbo Xia
- Department of Pharmacology, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210023, Jiangsu, China
| | - Yu Zhang
- Department of Rehabilitation Medicine, Jintan Hospital Affiliated to Jiangsu University, No. 16, Nanmen Street, Jintan District, Changzhou, 213200, Jiangsu, China
| | - Zhujun Zhu
- Department of Rehabilitation Medicine, Jintan Hospital Affiliated to Jiangsu University, No. 16, Nanmen Street, Jintan District, Changzhou, 213200, Jiangsu, China
| | - Qi Lv
- Department of Rehabilitation Medicine, Jintan Hospital Affiliated to Jiangsu University, No. 16, Nanmen Street, Jintan District, Changzhou, 213200, Jiangsu, China
| | - Yingjie Qi
- Neurology Department, Jintan Hospital Affiliated to Jiangsu University, Changzhou, 213200, Jiangsu, China
| | - Jianqin Xue
- Department of Rehabilitation Medicine, Jintan Hospital Affiliated to Jiangsu University, No. 16, Nanmen Street, Jintan District, Changzhou, 213200, Jiangsu, China.
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Ahmadi SE, Rahimi S, Zarandi B, Chegeni R, Safa M. MYC: a multipurpose oncogene with prognostic and therapeutic implications in blood malignancies. J Hematol Oncol 2021; 14:121. [PMID: 34372899 PMCID: PMC8351444 DOI: 10.1186/s13045-021-01111-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/12/2021] [Indexed: 12/17/2022] Open
Abstract
MYC oncogene is a transcription factor with a wide array of functions affecting cellular activities such as cell cycle, apoptosis, DNA damage response, and hematopoiesis. Due to the multi-functionality of MYC, its expression is regulated at multiple levels. Deregulation of this oncogene can give rise to a variety of cancers. In this review, MYC regulation and the mechanisms by which MYC adjusts cellular functions and its implication in hematologic malignancies are summarized. Further, we also discuss potential inhibitors of MYC that could be beneficial for treating hematologic malignancies.
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Affiliation(s)
- Seyed Esmaeil Ahmadi
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Samira Rahimi
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Bahman Zarandi
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Rouzbeh Chegeni
- Medical Laboratory Sciences Program, College of Health and Human Sciences, Northern Illinois University, DeKalb, IL, USA.
| | - Majid Safa
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran.
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
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12
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Myöhänen TT, Mertens F, Norrbacka S, Cui H. Deletion or inhibition of prolyl oligopeptidase blocks lithium-induced phosphorylation of GSK3b and Akt by activation of protein phosphatase 2A. Basic Clin Pharmacol Toxicol 2021; 129:287-296. [PMID: 34196102 DOI: 10.1111/bcpt.13632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/15/2021] [Accepted: 06/27/2021] [Indexed: 11/27/2022]
Abstract
Alterations in prolyl oligopeptidase (PREP) activity have been connected, for example, with bipolar and major depressive disorder, and several studies have reported that lack or inhibition of PREP blocks the effects of lithium on inositol 1,4,5-triphosphate (IP3 ) levels. However, the impact of PREP modulation on other intracellular targets of lithium, such as glycogen synthase kinase 3 beta (GSK3b) or protein kinase B (Akt), has not been studied. We recently found that PREP regulates protein phosphatase 2A (PP2A), and because GSK3b and Akt are PP2A substrates, we studied if PREP-related lithium insensitivity is dependent on PP2A. To assess this, HEK-293 and SH-SY5Y cells with PREP deletion or PREP inhibition (KYP-2047) were exposed to lithium, and thereafter, the phosphorylation levels of GSK3b and Akt were measured by Western blot. As expected, PREP deletion and inhibition blocked the lithium-induced phosphorylation on GSK3b and Akt in both cell lines. When lithium exposure was combined with okadaic acid, a PP2A inhibitor, KYP-2047 did not have effect on lithium-induced GSK3b and Akt phosphorylation. Therefore, we conclude that PREP deletion or inhibition blocks the intracellular effects of lithium on GSK3b and Akt via PP2A activation.
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Affiliation(s)
- Timo T Myöhänen
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, University of Helsinki, Helsinki, Finland.,Integrative Physiology and Pharmacology Unit, Institute of Biomedicine, University of Turku, Turku, Finland.,School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Freke Mertens
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, University of Helsinki, Helsinki, Finland
| | - Susanna Norrbacka
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, University of Helsinki, Helsinki, Finland
| | - Hengjing Cui
- Division of Pharmacology and Pharmacotherapy/Drug Research Program, University of Helsinki, Helsinki, Finland.,Department of Pharmacy, Ruijin hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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13
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Dacol EC, Wang S, Chen Y, Lepique AP. The interaction of SET and protein phosphatase 2A as target for cancer therapy. Biochim Biophys Acta Rev Cancer 2021; 1876:188578. [PMID: 34116173 DOI: 10.1016/j.bbcan.2021.188578] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/31/2021] [Accepted: 05/31/2021] [Indexed: 11/16/2022]
Abstract
In cancer cells, tumor suppressor proteins loss-of-function are usually the result of genetic mutations. Protein Phosphatase 2A is a tumor suppressor that inactivates several signaling pathways through removal of phosphate residues important for other proteins stability and/or activation. Different from other tumor suppressors, PP2A is, in many cancer types, inactivated by endogenous inhibitors. In physiological conditions, these inhibitors are important to balance PP2A activity. However, in cancer cells, overexpression of these inhibitors can keep PP2A inactive, resulting in sustained activation of mitogenic signaling pathways and transcription factors, metabolic reprogramming, with the resulting cancer progression and the resistance to anti-cancer therapies. One of these endogenous inhibitors is the protein SET (SE Translocation). SET is a multifunctional protein, which high expression has been associated with several types of cancer, as well as other diseases such as Alzheimer's disease. Disruption of the interaction between SET and PP2A to rescue the activity of PP2A may represent a new therapeutic strategy and opportunity for cancer treatment. This review brings up-to-date advances on the interactions between SET and PP2A and their biological consequences. Moreover, we review reported inhibitors of SET-PP2A interaction under investigation as therapeutic opportunities for the treatment of cancers.
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Affiliation(s)
- E C Dacol
- Department of Immunology, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av.Prof. Lineu Prestes, 1730, room 136, Biomedicas IV Building, São Paulo CEP 05508-000, SP, Brazil
| | - S Wang
- Laboratory of Chemical Biology, China Pharmaceutical University, 639 Longmian Avenue, Nanjing 211198, China
| | - Y Chen
- Laboratory of Chemical Biology, China Pharmaceutical University, 639 Longmian Avenue, Nanjing 211198, China.
| | - A P Lepique
- Department of Immunology, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av.Prof. Lineu Prestes, 1730, room 136, Biomedicas IV Building, São Paulo CEP 05508-000, SP, Brazil.
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14
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Fakhr Y, Brindley DN, Hemmings DG. Physiological and pathological functions of sphingolipids in pregnancy. Cell Signal 2021; 85:110041. [PMID: 33991614 DOI: 10.1016/j.cellsig.2021.110041] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 01/12/2023]
Abstract
Signaling by the bioactive sphingolipid, sphingosine 1-phosphate (S1P), and its precursors are emerging areas in pregnancy research. S1P and ceramide levels increase towards end of gestation, suggesting a physiological role in parturition. However, high levels of circulating S1P and ceramide are correlated with pregnancy disorders such as preeclampsia, gestational diabetes mellitus and intrauterine growth restriction. Expression of placental and decidual enzymes that metabolize S1P and S1P receptors are also dysregulated during pregnancy complications. In this review, we provide an in-depth examination of the signaling mechanism of S1P and ceramide in various reproductive tissues during gestation. These factors determine implantation and early pregnancy success by modulating corpus luteum function from progesterone production to luteolysis through to apoptosis. We also highlight the role of S1P through receptor signaling in inducing decidualization and angiogenesis in the decidua, as well as regulating extravillous trophoblast migration to anchor the placenta into the uterine wall. Recent advances on the role of the S1P:ceramide rheostat in controlling the fate of villous trophoblasts and the role of S1P as a negative regulator of trophoblast syncytialization to a multinucleated placental barrier are discussed. This review also explores the role of S1P in anti-inflammatory and pro-inflammatory signaling, its role as a vasoconstrictor, and the effects of S1P metabolizing enzymes and receptors in pregnancy.
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Affiliation(s)
- Yuliya Fakhr
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, AB T6G 2S2, Canada; Women and Children's Health Research Institute, University of Alberta, Edmonton, AB T6G 1C9, Canada
| | - David N Brindley
- Women and Children's Health Research Institute, University of Alberta, Edmonton, AB T6G 1C9, Canada; Signal Transduction Research Group, Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2S2, Canada; Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB T6G 2S2, Canada
| | - Denise G Hemmings
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, AB T6G 2S2, Canada; Women and Children's Health Research Institute, University of Alberta, Edmonton, AB T6G 1C9, Canada; Li Ka Shing Institute of Virology, University of Alberta, Edmonton, AB T6G 2E1, Canada; Cancer Research Institute of Northern Alberta, University of Alberta, Edmonton, AB T6G 2S2, Canada; Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB T6G 2S2, Canada.
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15
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Sarkar S. Shaggy functions downstream of dMyc and their concurrent downregulation confers additive rescue against tau toxicity in Drosophila. Biofactors 2021; 47:461-477. [PMID: 33651466 DOI: 10.1002/biof.1721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 02/15/2021] [Indexed: 12/16/2022]
Abstract
Neurodegenerative tauopathies such as Alzheimer's and Parkinson's diseases are characterized by hyperphosphorylation of tau protein and their subsequent aggregation in the forms of paired helical filaments and/or neurofibrillary tangles in specific areas of the brain. Despite several attempts, it remains a challenge to develop reliable biomarkers or effective drugs against tauopathies. It is increasingly evident now that due to the involvement of multiple cellular cascades affected by the pathogenic tau molecules, a single genetic modifier or a molecule is unlikely to be efficient enough to provide an inclusive rescue. Hence, multitargets based combinatorial approach(s) have been suggested to provide an efficient rescue against tauopathies. We have reported earlier that targeted downregulation of dmyc (a Drosophila homolog of human cmyc proto-oncogene) restricts tau etiology by limiting tau hyperphosphorylation and heterochromatin loss. Although, dmyc generates a significant rescue; however, it is not proficient enough to provide a complete alleviation against tauopathies. Here, we report that tissue-specific concurrent downregulation of dmyc and gsk3β conveys a near-complete rescue against tau toxicity in Drosophila. We noted that combinatorial downregulation of dmyc and gsk3β reduces tau hyperphosphorylation, restricts the formation of neurofibrillary tangles, and restores heterochromatin loss to the physiological level. Our subsequent investigations revealed that dmyc regulates gsk3β via protein phosphatase 2A (dPP2A) in a dose-dependent manner to regulate tau pathogenesis. We propose that dmyc and gsk3β candidates can be utilized in a synergistic manner for the development of an efficient combinatorial therapeutic approach against the devastating human tauopathies.
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Affiliation(s)
- Surajit Sarkar
- Department of Genetics, University of Delhi South Campus, New Delhi, India
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16
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Sayas CL, Ávila J. GSK-3 and Tau: A Key Duet in Alzheimer's Disease. Cells 2021; 10:721. [PMID: 33804962 PMCID: PMC8063930 DOI: 10.3390/cells10040721] [Citation(s) in RCA: 103] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/19/2021] [Accepted: 03/21/2021] [Indexed: 02/07/2023] Open
Abstract
Glycogen synthase kinase-3 (GSK-3) is a ubiquitously expressed serine/threonine kinase with a plethora of substrates. As a modulator of several cellular processes, GSK-3 has a central position in cell metabolism and signaling, with important roles both in physiological and pathological conditions. GSK-3 has been associated with a number of human disorders, such as neurodegenerative diseases including Alzheimer's disease (AD). GSK-3 contributes to the hyperphosphorylation of tau protein, the main component of neurofibrillary tangles (NFTs), one of the hallmarks of AD. GSK-3 is further involved in the regulation of different neuronal processes that are dysregulated during AD pathogenesis, such as the generation of amyloid-β (Aβ) peptide or Aβ-induced cell death, axonal transport, cholinergic function, and adult neurogenesis or synaptic function. In this review, we will summarize recent data about GSK-3 involvement in these processes contributing to AD pathology, mostly focusing on the crucial interplay between GSK-3 and tau protein. We further discuss the current development of potential AD therapies targeting GSK-3 or GSK-3-phosphorylated tau.
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Affiliation(s)
- Carmen Laura Sayas
- Instituto de Tecnologías Biomédicas (ITB), Universidad de La Laguna (ULL), 38200 Tenerife, Spain
| | - Jesús Ávila
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC) y la Universidad Autónoma de Madrid (UAM), 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Valderrebollo 5, 28031 Madrid, Spain
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17
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The Phenoxyphenol Compound diTFPP Mediates Exogenous C 2-Ceramide Metabolism, Inducing Cell Apoptosis Accompanied by ROS Formation and Autophagy in Hepatocellular Carcinoma Cells. Antioxidants (Basel) 2021; 10:antiox10030394. [PMID: 33807856 PMCID: PMC7998835 DOI: 10.3390/antiox10030394] [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: 02/04/2021] [Revised: 02/23/2021] [Accepted: 02/23/2021] [Indexed: 01/15/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is a severe disease that accounts for 80% of liver cancers. Chemotherapy is the primary therapeutic strategy for patients who cannot be treated with surgery or who have late-stage HCC. C2-ceramide is an effective reagent that has been found to inhibit the growth of many cancer types. The metabolism of C2-ceramide plays a vital role in the regulation of cell death/cell survival. The phenoxyphenol compound 4-{2,3,5,6-tetrafluoro-4-[2,3,5,6-tetrafluoro-4-(4-hydroxyphenoxy)phenyl]phenoxy}phenol (diTFPP) was found to have a synergistic effect with C2-ceramide, resulting in considerable cell death in the HA22T HCC cell line. diTFPP/C2-ceramide cotreatment induced a two- to threefold increase in cell death compared to that with C2-ceramide alone and induced pyknosis. Annexin V/7-aminoactinomycin D (7AAD) double staining and Western blotting indicated that apoptosis was involved in diTFPP/C2-ceramide cotreatment-mediated cell death. We next analyzed transcriptome alterations in diTFPP/C2-ceramide-cotreated HA22T cells with next-generation sequencing (NGS). The data indicated that diTFPP treatment disrupted sphingolipid metabolism, inhibited cell cycle-associated gene expression, and induced autophagy and reactive oxygen species (ROS)-responsive changes in gene expression. Additionally, we assessed the activation of autophagy with acridine orange (AO) staining and observed alterations in the expression of the autophagic proteins LC3B-II and Beclin-1, which indicated autophagy activation after diTFPP/C2-ceramide cotreatment. Elevated levels of ROS were also reported in diTFPP/C2-ceramide-treated cells, and the expression of the ROS-associated proteins SOD1, SOD2, and catalase was upregulated after diTFPP/C2-ceramide treatment. This study revealed the potential regulatory mechanism of the novel compound diTFPP in sphingolipid metabolism by showing that it disrupts ceramide metabolism and apoptotic sphingolipid accumulation.
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Zywno H, Bzdega W, Kolakowski A, Kurzyna P, Harasim-Symbor E, Sztolsztener K, Chabowski A, Konstantynowicz-Nowicka K. The Influence of Coumestrol on Sphingolipid Signaling Pathway and Insulin Resistance Development in Primary Rat Hepatocytes. Biomolecules 2021; 11:biom11020268. [PMID: 33673122 PMCID: PMC7918648 DOI: 10.3390/biom11020268] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 12/12/2022] Open
Abstract
Coumestrol is a phytoestrogen widely known for its anti-diabetic, anti-oxidant, and anti-inflammatory properties. Thus, it gets a lot of attention as a potential agent in the nutritional therapy of diseases such as obesity and type 2 diabetes. In our study, we evaluated whether coumestrol affects insulin resistance development via the sphingolipid signaling pathway in primary rat hepatocytes. The cells were isolated from the male Wistar rat's liver with the use of collagenase perfusion. Next, we incubated the cells with the presence or absence of palmitic acid and/or coumestrol. Additionally, some groups were incubated with insulin. The sphingolipid concentrations were assessed by HPLC whereas the expression of all the proteins was evaluated by Western blot. Coumestrol markedly reduced the accumulation of sphingolipids, namely, ceramide and sphinganine through noticeable inhibition of the ceramide de novo synthesis pathway in insulin-resistant hepatocytes. Moreover, coumestrol augmented the expression of fatty acid transport proteins, especially FATP5 and FAT/CD36, which also were responsible for excessive sphingolipid accumulation. Furthermore, coumestrol altered the sphingolipid salvage pathway, which was observed as the excessive deposition of the sphingosine-1-phosphate and sphingosine. Our study clearly showed that coumestrol ameliorated hepatic insulin resistance in primary rat hepatocytes. Thus, we believe that our study may contribute to the discovery of novel preventive and therapeutic methods for metabolic disorders.
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Fisher-Wellman KH, Hagen JT, Neufer PD, Kassai M, Cabot MC. On the nature of ceramide-mitochondria interactions - Dissection using comprehensive mitochondrial phenotyping. Cell Signal 2020; 78:109838. [PMID: 33212155 DOI: 10.1016/j.cellsig.2020.109838] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/12/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023]
Abstract
Sphingolipids are a unique class of lipids owing to their non-glycerol-containing backbone, ceramide, that is constructed from a long-chain aliphatic amino alcohol, sphinganine, to which a fatty acid is attached via an amide bond. Ceramide plays a star role in the initiation of apoptosis by virtue of its interactions with mitochondria, a control point for a downstream array of signaling cascades culminating in apoptosis. Many pathways converge on mitochondria to elicit mitochondrial outer membrane permeabilization (MOMP), a step that corrupts bioenergetic service. Although much is known regarding ceramides interaction with mitochondria and the ensuing cell signal transduction cascades, how ceramide impacts the elements of mitochondrial bioenergetic function is poorly understood. The objective of this review is to introduce the reader to sphingolipid metabolism, present a snapshot of mitochondrial respiration, elaborate on ceramides convergence on mitochondria and the upstream players that collaborate to elicit MOMP, and introduce a mitochondrial phenotyping platform that can be of utility in dissecting the fine-points of ceramide impact on cellular bioenergetics.
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Affiliation(s)
- Kelsey H Fisher-Wellman
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, United States of America; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States of America.
| | - James T Hagen
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, United States of America; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States of America
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States of America
| | - Miki Kassai
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, United States of America; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States of America
| | - Myles C Cabot
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC, United States of America; East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, NC, United States of America.
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20
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Kabir MT, Uddin MS, Zaman S, Begum Y, Ashraf GM, Bin-Jumah MN, Bungau SG, Mousa SA, Abdel-Daim MM. Molecular Mechanisms of Metal Toxicity in the Pathogenesis of Alzheimer’s Disease. Mol Neurobiol 2020; 58:1-20. [DOI: 10.1007/s12035-020-02096-w] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/25/2020] [Indexed: 12/24/2022]
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21
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Stuard WL, Titone R, Robertson DM. The IGF/Insulin-IGFBP Axis in Corneal Development, Wound Healing, and Disease. Front Endocrinol (Lausanne) 2020; 11:24. [PMID: 32194500 PMCID: PMC7062709 DOI: 10.3389/fendo.2020.00024] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/14/2020] [Indexed: 12/11/2022] Open
Abstract
The insulin-like growth factor (IGF) family plays key roles in growth and development. In the cornea, IGF family members have been implicated in proliferation, differentiation, and migration, critical events that maintain a smooth refracting surface that is essential for vision. The IGF family is composed of multiple ligands, receptors, and ligand binding proteins. Expression of IGF type 1 receptor (IGF-1R), IGF type 2 receptor (IGF-2R), and insulin receptor (INSR) in the cornea has been well characterized, including the presence of the IGF-1R and INSR hybrid (Hybrid-R) in the corneal epithelium. Recent data also indicates that each of these receptors display unique intracellular localization. Thus, in addition to canonical ligand binding at the plasma membrane and the initiation of downstream signaling cascades, IGF-1R, INSR, and Hybrid-R also function to regulate mitochondrial stability and nuclear gene expression. IGF-1 and IGF-2, two of three principal ligands, are polypeptide growth factors that function in all cellular layers of the cornea. Unlike IGF-1 and IGF-2, the hormone insulin plays a unique role in the cornea, different from many other tissues in the body. In the corneal epithelium, insulin is not required for glucose uptake, due to constitutive activation of the glucose transporter, GLUT1. However, insulin is needed for the regulation of metabolism, circadian rhythm, autophagy, proliferation, and migration after wounding. There is conflicting evidence regarding expression of the six IGF-binding proteins (IGFBPs), which function primarily to sequester IGF ligands. Within the cornea, IGFBP-2 and IGFBP-3 have identified roles in tissue homeostasis. While IGFBP-3 regulates growth control and intracellular receptor localization in the corneal epithelium, both IGFBP-2 and IGFBP-3 function in corneal fibroblast differentiation and myofibroblast proliferation, key events in stromal wound healing. IGFBP-2 has also been linked to cellular overgrowth in pterygium. There is a clear role for IGF family members in regulating tissue homeostasis in the cornea. This review summarizes what is known regarding the function of IGF and related proteins in corneal development, during wound healing, and in the pathophysiology of disease. Finally, we highlight key areas of research that are in need of future study.
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22
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Titone R, Robertson DM. Insulin receptor preserves mitochondrial function by binding VDAC1 in insulin insensitive mucosal epithelial cells. FASEB J 2019; 34:754-775. [PMID: 31914671 DOI: 10.1096/fj.201901316rr] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 10/08/2019] [Accepted: 10/21/2019] [Indexed: 01/07/2023]
Abstract
Unlike many epithelial tissues, the corneal epithelium is insulin insensitive, meaning it does not require insulin for glucose uptake. In this study, we show that insulin differentially regulates mitochondrial respiration in two human mucosal epithelial cell types: insulin-insensitive corneal epithelial cells and insulin-sensitive bronchial epithelial cells. In both cell types, insulin blocks glycogen synthase kinase beta (GSK3β) activity. In the corneal epithelium however, insulin selectively regulates PTEN-induced kinase 1 (PINK-1)-mediated mitophagy and mitochondrial accumulation of insulin receptor (INSR). While insulin blocked basal levels of PINK-1-mediated mitophagy in bronchial epithelial cells, mitochondrial trafficking of INSR was not detectable. We further show that in corneal epithelia, INSR interacts with the voltage-dependent anion channel-1 (VDAC1) in mitochondria and that INSR knockdown triggers robust mitochondrial fragmentation, alterations in mitochondrial polarization, and blocks the induction of PINK-1-mediated mitophagy. Collectively, these data demonstrate that INSR interacts with VDAC1 to mediate mitochondrial stability. We also demonstrate unique interactions between VDAC1 and other receptor tyrosine kinases, indicating a novel role for this family of receptors in mitochondria.
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Affiliation(s)
- Rossella Titone
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Danielle M Robertson
- Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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23
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Sun Y, Ai JZ, Jin X, Liu LR, Lin TH, Xu H, Wei Q, Yang L. IL-8 protects prostate cancer cells from GSK-3β-induced oxidative stress by activating the mTOR signaling pathway. Prostate 2019; 79:1180-1190. [PMID: 31104320 DOI: 10.1002/pros.23836] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 04/19/2019] [Accepted: 05/03/2019] [Indexed: 02/05/2023]
Abstract
INTRODUCTION Both oxidative stress and inflammation play important roles in prostate cancer cell apoptosis or proliferation; however, the mechanisms underlying these processes remain unclear. Thus, we selected interleukin-8 (IL-8) as the bridge between inflammation and cancer cell oxidative stress-induced death and aimed to confirm its connection with mTOR and Glycogen synthase kinase-3 beta (GSK-3β). METHODS We overexpressed GSK-3β and observed its effect on reactive oxygen species (ROS) and oxidative stress-induced cell death. IL-8 was then upregulated or downregulated to determine its impact on preventing cell damage due to GSK-3β-induced oxidative stress. In addition, we overexpressed or knocked down mTOR to confirm its role in this process. Real-time PCR, Western blotting, transcription, Cell Counting Kit 8 (CCK-8), and flow cytometry analyses were performed in addition to the use of other techniques. RESULTS IL-8 promotes prostate cancer cell proliferation and decreases apoptosis, whereas GSK-3β activates the caspase-3 signaling pathway by increasing ROS and thereby induces oxidative stress-mediated cell death. In addition, mTOR can also decrease activation of the caspase-3 signaling pathway by inhibiting GSK-3 and thus decreasing ROS production. Moreover, the inhibitory effect of IL-8 on GSK-3β occurs through the regulation of mTOR. CONCLUSION The results of this study highlight the importance of GSK-3β, which increases the production of ROS and thereby induces oxidative stress in tumor cells, whereas IL-8 and mTOR attenuate oxidative stress to protect prostate cancer cells through inhibition of GSK-3β.
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Affiliation(s)
- Yi Sun
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
| | - Jian-Zhong Ai
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
| | - Xi Jin
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
| | - Liang-Ren Liu
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
| | - Tian-Hai Lin
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
| | - Hang Xu
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
| | - Qiang Wei
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
| | - Lu Yang
- Department of Urology, Institute of Urology, West China Hospital, Sichuan University, Guoxue Xiang, Chengdu, Sichuan, China
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Guo HT, Yang SD, Zhang F, Liu S, Yang DL, Ma L, Wang H, Ding WY. 17β‑Estradiol protects against interleukin‑1β‑induced apoptosis in rat nucleus pulposus cells via the mTOR/caspase‑3 pathway. Mol Med Rep 2019; 20:1523-1530. [PMID: 31257459 PMCID: PMC6625415 DOI: 10.3892/mmr.2019.10384] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 04/04/2019] [Indexed: 12/31/2022] Open
Abstract
Intervertebral disc degeneration (IVDD) is the main pathological basis of spinal degenerative diseases, and aberrant apoptosis of nucleus pulposus cells (NPCs) is the main cellular process that causes IVDD. In our previous studies, 17β-estradiol (E2) was demonstrated to protect rat NPCs from interleukin-1β (IL-1β)-induced apoptosis via the PI3K/Akt signaling pathway. However, the downstream signaling pathway of PI3K/Akt is currently unclear. The present study aimed to explore the signaling pathways that are downstream of the PI3K/Akt pathway, including mTOR, NF-κB and glycogen synthase kinase-3β (GSK-3β). Annexin V/propidium iodide double staining was used to determine the incidence of apoptosis. Cell Counting kit-8 and MTS assays were used to determine the proliferation and viability of NPCs, respectively. Cellular binding was evaluated using a cell-collagen binding assay. Western blotting was used to determine the protein expression levels of mTOR, NF-κB and GSK-3β, and their phosphorylation levels, as well as the expression levels of active caspase-3. The results revealed that IL-1β induced NPC apoptosis and increased the early apoptotic rate of NPCs. However, E2 reduced the early apoptosis of NPCs induced by IL-1β. In addition, E2 suppressed the decrease in cell viability and binding ability caused by IL-1β cytotoxicity. Western blotting revealed that E2 also reduced the expression of activated caspase-3, and increased the expression of activated mTOR. As a specific inhibitor of mTOR, rapamycin effectively attenuated the effects of E2. These findings indicated that E2 protected NPCs against apoptosis via activation of the mTOR/caspase-3 pathway.
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Affiliation(s)
- Hong-Tao Guo
- Department of Spinal Surgery, The First Hospital of Shijiazhuang City, Shijiazhuang, Hebei 050011, P.R. China
| | - Si-Dong Yang
- Department of Spinal Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
| | - Feng Zhang
- Department of Rehabilitation Medicine, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
| | - Sen Liu
- Department of Spinal Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
| | - Da-Long Yang
- Department of Spinal Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
| | - Lei Ma
- Department of Spinal Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
| | - Hui Wang
- Department of Spinal Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
| | - Wen-Yuan Ding
- Department of Spinal Surgery, The Third Hospital of Hebei Medical University, Shijiazhuang, Hebei 050051, P.R. China
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25
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Ding Y, Yu A, Tsokos GC, Malek TR. CD25 and Protein Phosphatase 2A Cooperate to Enhance IL-2R Signaling in Human Regulatory T Cells. THE JOURNAL OF IMMUNOLOGY 2019; 203:93-104. [PMID: 31085588 DOI: 10.4049/jimmunol.1801570] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/20/2019] [Indexed: 11/19/2022]
Abstract
Low-dose IL-2 therapy is a direct approach to boost regulatory T cells (Tregs) and promote immune tolerance in autoimmune patients. However, the mechanisms responsible for selective response of Tregs to low-dose IL-2 is not fully understood. In this study we directly assessed the contribution of CD25 and protein phosphatase 2A (PP2A) in promoting IL-2R signaling in Tregs. IL-2-induced tyrosine phosphorylation of STAT5 (pSTAT5) was proportional to CD25 levels on human CD4+ T cells and YT human NK cell line, directly demonstrating that CD25 promotes IL-2R signaling. Overexpression of the PP2A catalytic subunit (PP2Ac) by lentiviral transduction in human Tregs increased the level of IL-2R subunits and promoted tyrosine phosphorylation of Jak3 and STAT5. Interestingly, increased expression of CD25 only partially accounted for this enhanced activation of pSTAT5, indicating that PP2A promotes IL-2R signaling through multiple mechanisms. Consistent with these findings, knockdown of PP2Ac in human Tregs and impaired PP2Ac activity in mouse Tregs significantly reduced IL-2-dependent STAT5 activation. In contrast, overexpression or knockdown of PP2Ac in human T effector cells did not affect IL-2-dependent pSTAT5 activation. Overexpression of PP2Ac in human Tregs also increased the expressions of proteins related to survival, activation, and immunosuppressive function, and upregulated several IL-2-regulated genes. Collectively, these findings suggest that CD25 and PP2A cooperatively enhance the responsiveness of Tregs to IL-2, which provide potential therapeutic targets for low-dose IL-2 therapy.
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Affiliation(s)
- Ying Ding
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - Aixin Yu
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136
| | - George C Tsokos
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215; and
| | - Thomas R Malek
- Department of Microbiology and Immunology, Miller School of Medicine, University of Miami, Miami, FL 33136; .,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL 33136
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26
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Karunakaran U, Elumalai S, Moon JS, Won KC. CD36 dependent redoxosomes promotes ceramide-mediated pancreatic β-cell failure via p66Shc activation. Free Radic Biol Med 2019; 134:505-515. [PMID: 30735834 DOI: 10.1016/j.freeradbiomed.2019.02.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/01/2019] [Accepted: 02/04/2019] [Indexed: 12/14/2022]
Abstract
Altered metabolism is implicated in the pathogenesis of beta-cell failure in type 2 diabetes (T2D). Plasma and tissue levels of ceramide species play positive roles in inflammatory and oxidative stress responses in T2D. However, oxidative targets and mechanisms underlying ceramide signaling are unclear. We investigated the role of CD36-dependent redoxosome (redox-active endosome), a membrane-based signaling agent, in ceramide-induced beta-cell dysfunction and failure. Exposure of beta cells to C2-ceramide (N-acetyl-sphingosine) induced a CD36-dependent non-receptor tyrosine kinase Src-mediated redoxosome (Vav2-Rac1-NOX) formation. Activated Rac1-GTP-NADPH oxidase complex induced c-Jun-N-terminal kinase (JNK) activation and nuclear factor (NF)-kB transcription, which was associated with thioredoxin-interacting protein (TXNIP) upregulation and thioredoxin activity suppression. Upregulated JNK expression induced p66Shc serine36 phosphorylation and peroxiredoxin-3 hyperoxidation, causing beta-cell apoptosis via mitochondrial dysfunction. CD36 inhibition by sulfo-N-succinimidyl oleate (SSO) or CD36 siRNA blocked C2-ceramide-induced redoxosome activation, thereby decreasing JNK-dependent p66Shc serine36 phosphorylation. CD36 inhibition downregulated TXNIP expression and promoted thioredoxin activity via enhanced thioredoxin reductase activity, which prevented peroxiredoxin-3 oxidation. CD36 inhibition potentiated glucose-stimulated insulin secretion and prevented beta-cell apoptosis. Our results reveal a new role of CD36 during early molecular events that lead to Src-mediated redoxosome activation, which contributes to ceramide-induced pancreatic beta-cell dysfunction and failure.
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Affiliation(s)
- Udayakumar Karunakaran
- Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Suma Elumalai
- Institute of Medical Science, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Jun Sung Moon
- Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea
| | - Kyu Chang Won
- Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Republic of Korea; Institute of Medical Science, Yeungnam University College of Medicine, Daegu, Republic of Korea.
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27
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Zanca RM, Sanay S, Avila JA, Rodriguez E, Shair HN, Serrano PA. Contextual fear memory modulates PSD95 phosphorylation, AMPAr subunits, PKMζ and PI3K differentially between adult and juvenile rats. Neurobiol Stress 2019; 10:100139. [PMID: 30937346 PMCID: PMC6430186 DOI: 10.1016/j.ynstr.2018.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/16/2018] [Accepted: 11/16/2018] [Indexed: 02/07/2023] Open
Abstract
It is well known that young organisms do not maintain memories as long as adults, but the mechanisms for this ontogenetic difference are undetermined. Previous work has revealed that the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAr) subunits are trafficked into the synaptic membrane following memory retrieval in adults. Additionally, phosphorylated PSD-95-pS295 promotes AMPAr stabilization at the synapse. We investigated these plasticity related proteins as potential mediators in the differential contextual stress memory retrieval capabilities observed between adult and juvenile rats. Rats were assigned to either pedestal stress (1 h) or no stress control (home cage). Each animal was placed alone in an open field for 5 min at the base of a 6 × 6 sq inch pedestal (4ft high). Stress subjects were then placed on this pedestal for 1hr and control subjects were placed in their home cage following initial exploration. Each animal was returned to the open field for 5 min either 1d or 7d following initial exposure. Freezing postures were quantified during the memory retrieval test. The 1d test shows adult (P90) and juvenile (P26) stressed rats increase their freezing time compared to controls. However, the 7d memory retrieval test shows P90 stress rats but not P26 stress rats freeze while in the fear context. Twenty minutes after the memory retrieval test, hippocampi and amygdala were micro-dissected and prepared for western blot analysis. Our results show that 1d fear memory retrieval induced an upregulation of PSD-95 and pS295 in the adult amygdala but not in the juvenile. However, the juvenile animals upregulated PKMζ, PI3K and GluA2/3, GluA1-S845 in the dorsal hippocampus (DH), but the adults did not. Following the 7d memory retrieval test, adults upregulated GluA2 in the amygdala but not the juveniles. In the DH, adults increased PSD-95 and pS295 but not the juveniles. The adults appear to preferentially increase amygdala-driven processing at 1d and increase DH-driven context specific processing at 7d. These data identify molecular processes that may underlie the reduced fear-memory retrieval capability of juveniles. Together these data provide a potential molecular target that could be beneficial in treatment of anxiety disorders and PTSD.
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Affiliation(s)
- Roseanna M. Zanca
- Department of Psychology, Hunter College, City University of New York, New York, NY, 10065, USA
- The Graduate Center of CUNY, New York, NY, 10016, USA
| | - Shirley Sanay
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
| | - Jorge A. Avila
- Department of Psychology, Hunter College, City University of New York, New York, NY, 10065, USA
- The Graduate Center of CUNY, New York, NY, 10016, USA
| | - Edgar Rodriguez
- Department of Psychology, Hunter College, City University of New York, New York, NY, 10065, USA
| | - Harry N. Shair
- Division of Developmental Neuroscience, New York State Psychiatric Institute, New York, NY, 10032, USA
- Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Peter A. Serrano
- Department of Psychology, Hunter College, City University of New York, New York, NY, 10065, USA
- The Graduate Center of CUNY, New York, NY, 10016, USA
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28
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Conte M, Armani A, Conte G, Serra A, Franceschi C, Mele M, Sandri M, Salvioli S. Muscle-specific Perilipin2 down-regulation affects lipid metabolism and induces myofiber hypertrophy. J Cachexia Sarcopenia Muscle 2019; 10:95-110. [PMID: 30288961 PMCID: PMC6438344 DOI: 10.1002/jcsm.12355] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/06/2018] [Accepted: 08/30/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Perilipin2 (Plin2) belongs to a family of five highly conserved proteins, known for their role in lipid storage. Recent data indicate that Plin2 has an important function in cell metabolism and is involved in several human pathologies, including liver steatosis and Type II diabetes. An association between Plin2 and lower muscle mass and strength has been found in elderly and inactive people, but its function in skeletal muscle is still unclear. Here, we addressed the role of Plin2 in adult muscle by gain and loss of function experiments. METHODS By mean of in vivo Plin2 down-regulation (shPlin2) and overexpression (overPlin2) in murine tibialis anterior muscle, we analysed the effects of Plin2 genetic manipulations on myofiber size and lipid composition. An analysis of skeletal muscle lipid composition was also performed in vastus lateralis samples from young and old patients undergoing hip surgery. RESULTS We found that Plin2 down-regulation was sufficient to induce a 30% increase of myofiber cross-sectional area, independently of mTOR pathway. Alterations of lipid content and modulation of genes involved in lipid synthesis occurred in hypertrophic muscles. In particular, we showed a decrease of triglycerides, ceramides, and phosphatidylcoline:phosphatidylethanolamine ratio, a condition known to impact negatively on muscle function. Plin2 overexpression did not change fibre size; however, lipid composition was strongly affected in a way that is similar to that observed in human samples from old patients. CONCLUSIONS Altogether these data indicate that Plin2 is a critical mediator for the control of muscle mass, likely, but maybe not exclusively, through its critical role in the regulation of intracellular lipid content and composition.
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Affiliation(s)
- Maria Conte
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy.,Interdepartmental Centre "L. Galvani" (CIG), University of Bologna, Bologna, Italy
| | - Andrea Armani
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy
| | - Giuseppe Conte
- Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy
| | - Andrea Serra
- Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy.,Research Center of Nutraceuticals and Food for Health, University of Pisa, Pisa, Italy
| | | | - Marcello Mele
- Department of Agriculture, Food and Environment, University of Pisa, Pisa, Italy.,Research Center of Nutraceuticals and Food for Health, University of Pisa, Pisa, Italy
| | - Marco Sandri
- Venetian Institute of Molecular Medicine (VIMM), Padova, Italy.,Department of Biomedical Science, University of Padova, Padova, Italy
| | - Stefano Salvioli
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), University of Bologna, Bologna, Italy.,Interdepartmental Centre "L. Galvani" (CIG), University of Bologna, Bologna, Italy
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29
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Narla G, Sangodkar J, Ryder CB. The impact of phosphatases on proliferative and survival signaling in cancer. Cell Mol Life Sci 2018; 75:2695-2718. [PMID: 29725697 PMCID: PMC6023766 DOI: 10.1007/s00018-018-2826-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 03/24/2018] [Accepted: 04/23/2018] [Indexed: 02/06/2023]
Abstract
The dynamic and stringent coordination of kinase and phosphatase activity controls a myriad of physiologic processes. Aberrations that disrupt the balance of this interplay represent the basis of numerous diseases. For a variety of reasons, early work in this area portrayed kinases as the dominant actors in these signaling events with phosphatases playing a secondary role. In oncology, these efforts led to breakthroughs that have dramatically altered the course of certain diseases and directed vast resources toward the development of additional kinase-targeted therapies. Yet, more recent scientific efforts have demonstrated a prominent and sometimes driving role for phosphatases across numerous malignancies. This maturation of the phosphatase field has brought with it the promise of further therapeutic advances in the field of oncology. In this review, we discuss the role of phosphatases in the regulation of cellular proliferation and survival signaling using the examples of the MAPK and PI3K/AKT pathways, c-Myc and the apoptosis machinery. Emphasis is placed on instances where these signaling networks are perturbed by dysregulation of specific phosphatases to favor growth and persistence of human cancer.
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Affiliation(s)
| | - Jaya Sangodkar
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
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30
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Targeting sphingolipid metabolism as an approach for combination therapies in haematological malignancies. Cell Death Discov 2018; 4:72. [PMID: 30062053 PMCID: PMC6060109 DOI: 10.1038/s41420-018-0075-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 06/12/2018] [Indexed: 12/16/2022] Open
Abstract
Conventional chemotherapy-based drug combinations have, until recently, been the backbone of most therapeutic strategies for cancer. In a time of emerging rationale drug development, targeted therapies are beginning to be added to traditional chemotherapeutics to synergistically enhance clinical responses. Of note, the importance of pro-apoptotic ceramide in mediating the anti-cancer effects of these therapies is becoming more apparent. Furthermore, reduced cellular ceramide in favour of pro-survival sphingolipids correlates with tumorigenesis and most importantly, drug resistance. Thus, agents that manipulate sphingolipid metabolism have been explored as potential anti-cancer agents and have recently demonstrated exciting potential to augment the efficacy of anti-cancer therapeutics. This review examines the biology underpinning these observations and the potential use of sphingolipid manipulating agents in the context of existing and emerging therapies for haematological malignancies. • Efficacy of many chemotherapeutics and targeted therapies is dictated by cellular ceramide levels. • Oncogene activation skews sphingolipid metabolism to favour the production of pro-survival sphingolipids. • Inhibitors of enzymes involved in ceramide metabolism exhibit promise in the relapsed-refractory setting. • Anti-cancer activity of sphingosine kinase inhibitors provides several options for new drug combinations. Open Questions • What other clinically utilised drugs rely on increases in ceramide levels for their efficacy and can they be effectively partnered with other ceramide inducing agents? • How does ceramide modulate the Bcl-2 family proteins, Mcl-1 and Bcl-2? • Are sphingolipid enzyme inhibitors best suited in the frontline or relapsed-refractory setting?
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31
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Lallemand T, Rouahi M, Swiader A, Grazide MH, Geoffre N, Alayrac P, Recazens E, Coste A, Salvayre R, Nègre-Salvayre A, Augé N. nSMase2 (Type 2-Neutral Sphingomyelinase) Deficiency or Inhibition by GW4869 Reduces Inflammation and Atherosclerosis in Apoe -/- Mice. Arterioscler Thromb Vasc Biol 2018; 38:1479-1492. [PMID: 29794115 PMCID: PMC6039418 DOI: 10.1161/atvbaha.118.311208] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 05/07/2018] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Atherosclerosis is a chronic multifactorial and inflammatory disease of large and medium arteries and the leading cause of cardiovascular diseases worldwide. The aim of this study was to investigate whether and how the nSMase2 (type 2-neutral sphingomyelinase), a key enzyme of sphingolipid metabolism, may contribute to the development of atherosclerotic lesions. APPROACH AND RESULTS The role of nSMase2 in atherosclerosis was investigated in Apoe-/-;Smpd3fro/fro mice, mutant for nSMase2, and in Apoe-/-;Smpd3+/+ mice intraperitoneally injected with GW4869, a pharmacological nSMase2 inhibitor. The defect or inhibition of nSMase2 resulted in a reduction of atherosclerotic lesions and a decrease in macrophage infiltration and lipid deposition, although cholesterolemia remained unchanged. nSMase2 inhibition decreased the inflammatory response of murine endothelial cells to oxLDL (oxidized low-density lipoprotein), as assessed by the significant reduction of MCP-1 (monocyte chemoattractant protein 1), ICAM-1 (intercellular adhesion molecule-1), and VCAM-1 (vascular cell adhesion molecule-1) mRNA expressions and macrophage recruitment. Likewise, in RAW264.7 or in macrophages isolated from Apoe-/-/Smpd3fro/fro or Apoe-/-/Smpd3+/+ mice stimulated by lipopolysaccharides, nSMase2 inhibition resulted in a decrease in the expression of inflammatory molecules. Mechanistically, the anti-inflammatory response resulting from nSMase2 inhibition involves Nrf2 (nuclear factor [erythroid-derived 2]-like 2 or NF-E2-related factor-2) activation in both endothelial cells and macrophages, as assessed by the lack of protective effect of GW4869 in endothelial cells silenced for Nrf2 by small interfering RNAs, and in lipopolysaccharide-stimulated macrophages issued from Nrf2-KO mice. CONCLUSIONS The genetic deficiency or inhibition of nSMase2 strongly decreases the development of atherosclerotic lesions in Apoe-/- mice, by reducing inflammatory responses through a mechanism involving the Nrf2 pathway. Inhibitors of nSMase2 may, therefore, constitute a novel approach to slow down atherosclerosis progression.
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Affiliation(s)
- Tom Lallemand
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Myriam Rouahi
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Audrey Swiader
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Marie-Hélène Grazide
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Nancy Geoffre
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Paul Alayrac
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Emeline Recazens
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Agnès Coste
- PHARMA-DEV, IRD UMR 152, Toulouse, France (A.C.)
| | - Robert Salvayre
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Anne Nègre-Salvayre
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.).,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
| | - Nathalie Augé
- From the INSERM U-1048 Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.) .,Université Paul Sabatier, Toulouse, France (T.L., M.R., A.S., M.-H.G., N.G., P.A., E.R., R.S., A.N.-S., N.A.)
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Usuki S, Tamura N, Yuyama K, Tamura T, Mukai K, Igarashi Y. Konjac Ceramide (kCer) Regulates NGF-Induced Neurite Outgrowth via the Sema3A Signaling Pathway. J Oleo Sci 2018; 67:77-86. [PMID: 29238028 DOI: 10.5650/jos.ess17141] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The tuber of the konjac plant is a source enriched with GlcCer (kGlcCer), and has been used as a dietary supplement to improve the dry skin and itching that are caused by a deficiency of epidermal ceramide. Previously, we showed chemoenzymatically prepared konjac ceramide has a neurite-outgrowth inhibitory effect that is very similar to that of Sema3A and is not seen with animal-type ceramides. While, it has been unclear whether kCer may act on Sema3A or TrkA signaling pathway. In the present study, we showed kCer induces phosphorylation of CRMP2 and microtubules depolymerization via Sema3A signaling pathway not TrkA. It is concluded that kCer may be a potential Sema3A-like agonist that activates Sema3A signaling pathway directly.
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Affiliation(s)
- Seigo Usuki
- Lipid Biofunction Section, Frontier Research Center for Advanced Material and Life Science, Faculty of Advanced Life Science, Hokkaido University
| | - Noriko Tamura
- National Institute of Advanced Industrial Science and Technology (AIST)
| | - Kohei Yuyama
- Lipid Biofunction Section, Frontier Research Center for Advanced Material and Life Science, Faculty of Advanced Life Science, Hokkaido University
| | - Tomohiro Tamura
- National Institute of Advanced Industrial Science and Technology (AIST)
| | | | - Yasuyuki Igarashi
- Lipid Biofunction Section, Frontier Research Center for Advanced Material and Life Science, Faculty of Advanced Life Science, Hokkaido University
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33
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Taleski G, Sontag E. Protein phosphatase 2A and tau: an orchestrated 'Pas de Deux'. FEBS Lett 2017; 592:1079-1095. [PMID: 29121398 DOI: 10.1002/1873-3468.12907] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 10/18/2017] [Accepted: 11/02/2017] [Indexed: 12/21/2022]
Abstract
The neuronal microtubule-associated protein tau serves a critical role in regulating axonal microtubule dynamics to support neuronal and synaptic functions. Furthermore, it contributes to glutamatergic regulation and synaptic plasticity. Emerging evidence also suggests that tau serves as a signaling scaffold. Tau function and subcellular localization are tightly regulated, in part, by the orchestrated interplay between phosphorylation and dephosphorylation events. Significantly, protein phosphatase type 2A (PP2A), encompassing the regulatory PPP2R2A (or Bα) subunit, is a major brain heterotrimeric enzyme and the primary tau Ser/Thr phosphatase in vivo. Herein, we closely examine how the intimate and compartmentalized interactions between PP2A and tau regulate tau phosphorylation and function, and play an essential role in neuronal homeostasis. We also review evidence supporting a strong link between deregulation of tau-PP2A functional interactions and the molecular underpinnings of various neurodegenerative diseases collectively called tauopathies. Lastly, we discuss the opportunities and associated challenges in more specifically targeting PP2A-tau interactions for drug development for tauopathies.
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Affiliation(s)
- Goce Taleski
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
| | - Estelle Sontag
- School of Biomedical Sciences and Pharmacy, Faculty of Health and Medicine, Hunter Medical Research Institute, University of Newcastle, Callaghan, Australia
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Gene pathways associated with mitochondrial function, oxidative stress and telomere length are differentially expressed in the liver of rats fed lifelong on virgin olive, sunflower or fish oils. J Nutr Biochem 2017; 52:36-44. [PMID: 29144994 DOI: 10.1016/j.jnutbio.2017.09.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 08/08/2017] [Accepted: 09/05/2017] [Indexed: 12/20/2022]
Abstract
This study investigates the effect of lifelong intake of different fat sources rich in monounsaturated (virgin olive oil), n6 polyunsaturated (sunflower oil) or n3 polyunsaturated (fish oil) fatty acids in the aged liver. Male Wistar rats fed lifelong on diets differing in the fat source were killed at 6 and at 24 months of age. Liver histopathology, mitochondrial ultrastructure, biogenesis, oxidative stress, mitochondrial electron transport chain, relative telomere length and gene expression profiles were studied. Aging led to lipid accumulation in the liver. Virgin olive oil led to the lowest oxidation and ultrastructural alterations. Sunflower oil induced fibrosis, ultrastructural alterations and high oxidation. Fish oil intensified oxidation associated with age, lowered electron transport chain activity and enhanced the relative telomere length. Gene expression changes associated with age in animals fed virgin olive oil and fish oil were related mostly to mitochondrial function and oxidative stress pathways, followed by cell cycle and telomere length control. Sunflower oil avoided gene expression changes related to age. According to the results, virgin olive oil might be considered the dietary fat source that best preserves the liver during the aging process.
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Haruki K, Shiba H, Shimada Y, Shirai Y, Iwase R, Fujiwara Y, Uwagawa T, Ohashi T, Yanaga K. Glycogen synthase kinase-3β activity plays a key role in the antitumor effect of nafamostat mesilate in pancreatic cancer cells. Ann Gastroenterol Surg 2017; 2:65-71. [PMID: 29863120 PMCID: PMC5868870 DOI: 10.1002/ags3.12025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 06/19/2017] [Indexed: 12/26/2022] Open
Abstract
Pancreatic cancer is often resistant to chemotherapy. We previously showed the efficacy of combination treatment using gemcitabine and nafamostat mesilate (FUT‐175) for patients with unresectable pancreatic cancer. However, the mechanisms that affect the sensitivity of FUT‐175 are not fully understood. The purpose of the present study was to clarify the mechanism of the sensitivity to FUT‐175, with a focus on the activity of glycogen synthase kinase‐3β (GSK‐3β). In vitro, we assessed sensitivity to FUT‐175 in human pancreatic cancer cell lines (PANC‐1 and MIAPaCa‐2) and difference of signaling in these cells by cell proliferation assay, Western blot analysis and microarray. Next, we assessed cell viability, apoptotic signal and nuclear factor‐kappa B (NF‐κB) activity in response to treatment with FUT‐175 alone and in combination with GSK‐3 inhibitor or protein phosphatase 2A (PP2A) by cell proliferation assay, Western blot analysis and enzyme‐linked immunosorbent assay. Phosphorylated GSK‐3β level was significantly higher in MIAPaCa‐2 (high sensitivity cell) than in PANC‐1 (low sensitivity cell). Cell viability and NF‐κB activity were significantly decreased by addition of GSK‐3 inhibitor to FUT‐175, and levels of cleaved caspase‐8 were increased by inhibition of GSK‐3. PP2A inhibitor increased the levels of phosphorylated GSK‐3β and sensitized both cell lines to FUT‐175 as measured by cell viability and apoptotic signal. The results indicate that GSK‐3β activity plays a key role in the antitumor effect of FUT‐175 in pancreatic cancer cells, and regulation of GSK‐3β by PP2A inhibition could be a novel therapeutic approach for pancreatic cancer.
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Affiliation(s)
- Koichiro Haruki
- Department of Surgery The Jikei University School of Medicine Tokyo Japan.,Division of Gene Therapy Research Center for Medical Science The Jikei University School of Medicine Tokyo Japan
| | - Hiroaki Shiba
- Department of Surgery The Jikei University School of Medicine Tokyo Japan
| | - Yohta Shimada
- Division of Gene Therapy Research Center for Medical Science The Jikei University School of Medicine Tokyo Japan
| | - Yoshihiro Shirai
- Department of Surgery The Jikei University School of Medicine Tokyo Japan.,Division of Gene Therapy Research Center for Medical Science The Jikei University School of Medicine Tokyo Japan
| | - Ryota Iwase
- Department of Surgery The Jikei University School of Medicine Tokyo Japan.,Division of Gene Therapy Research Center for Medical Science The Jikei University School of Medicine Tokyo Japan
| | - Yuki Fujiwara
- Department of Surgery The Jikei University School of Medicine Tokyo Japan
| | - Tadashi Uwagawa
- Department of Surgery The Jikei University School of Medicine Tokyo Japan
| | - Toya Ohashi
- Division of Gene Therapy Research Center for Medical Science The Jikei University School of Medicine Tokyo Japan
| | - Katsuhiko Yanaga
- Department of Surgery The Jikei University School of Medicine Tokyo Japan
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Velmurugan BK, Lee CH, Chiang SL, Hua CH, Chen MC, Lin SH, Yeh KT, Ko YC. PP2A deactivation is a common event in oral cancer and reactivation by FTY720 shows promising therapeutic potential. J Cell Physiol 2017; 233:1300-1311. [PMID: 28516459 DOI: 10.1002/jcp.26001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2017] [Accepted: 05/09/2017] [Indexed: 12/17/2022]
Abstract
Protein phosphatase 2A (PP2A) is a tumor suppressor gene, that has been frequently deactivated in many types of cancer. However, its molecular and clinical relevance in oral squamous cell carcinoma (OSCC) remain unclear. Here we show that, PP2A deactivation is a common event in oral cancer cells and hyperphosphorylation in its tyrosine-307 (Y307) residue contributes to PP2A deactivation. PP2A restoration by FTY720 treatment reduced cell growth and decreased GSK-3β phosphorylation without significantly altering other PP2A targets. We further detected PP2A phosphorylation in 262 OSCC tissues. Increased expression of p-PP2A in the tumor tissues was significantly correlated with higher N2/N3-stage (aOR = 2.1, 95%CI: 1.2-3.8). Patients with high p-PP2A expression had lower overall survival rates than those with low expression. Hazard ratio analysis showed that, high p-PP2A expression was significantly associated with mortality density (aOR = 2.2, 95%CI: 1.2-4.0) and lower 10-year overall survival (p = 0.027) in lymph node metastasis. However, no interaction was observed between p-PP2A expression and lymph node metastasis. All our results suggest that PP2A is frequently deactivated in oral cancer and determines poor outcome, restoring its expression by FTY720 can be an alternative therapeutic approach in OSCC.
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Affiliation(s)
- Bharath K Velmurugan
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Chien-Hung Lee
- Department of Public Health, College of Health Science, Kaohsiung Medical University, Kaohsuing, Taiwan.,Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shang-Lun Chiang
- Environment-Omics-Diseases Research Center, China Medical University Hospital, Taichung, Taiwan.,Department of Health Risk Management, College of Public Health, China Medical University, Taichung, Taiwan
| | - Chun-Hung Hua
- Department of Otorhinolaryngology, China Medical University Hospital, Taichung, Taiwan
| | - Mei-Chung Chen
- Department of Pathology, Changhua Christian Hospital, Changhua, Taiwan
| | - Shu-Hui Lin
- Department of Pathology, Changhua Christian Hospital, Changhua, Taiwan.,School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Kun-Tu Yeh
- Department of Pathology, Changhua Christian Hospital, Changhua, Taiwan.,School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Ying-Chin Ko
- Environment-Omics-Diseases Research Center, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
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37
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Targeting sphingosine-1-phosphate signaling for cancer therapy. SCIENCE CHINA-LIFE SCIENCES 2017. [DOI: 10.1007/s11427-017-9046-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Hernández-Corbacho MJ, Salama MF, Canals D, Senkal CE, Obeid LM. Sphingolipids in mitochondria. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:56-68. [PMID: 27697478 DOI: 10.1016/j.bbalip.2016.09.019] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 08/01/2016] [Accepted: 09/24/2016] [Indexed: 01/16/2023]
Abstract
Sphingolipids are bioactive lipids found in cell membranes that exert a critical role in signal transduction. In recent years, it has become apparent that sphingolipids participate in growth, senescence, differentiation and apoptosis. The anabolism and catabolism of sphingolipids occur in discrete subcellular locations and consist of a strictly regulated and interconnected network, with ceramide as the central hub. Altered sphingolipid metabolism is linked to several human diseases. Hence, an advanced knowledge of how and where sphingolipids are metabolized is of paramount importance in order to understand the role of sphingolipids in cellular functions. In this review, we provide an overview of sphingolipid metabolism. We focus on the distinct pathways of ceramide synthesis, highlighting the mitochondrial ceramide generation, transport of ceramide to mitochondria and its role in the regulation of mitochondrial-mediated apoptosis, mitophagy and implications to disease. We will discuss unanswered questions and exciting future directions. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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Affiliation(s)
- María José Hernández-Corbacho
- Stony Brook Cancer Center and the Department of Medicine, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794, USA
| | - Mohamed F Salama
- Stony Brook Cancer Center and the Department of Medicine, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794, USA; Department of Biochemistry, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Daniel Canals
- Stony Brook Cancer Center and the Department of Medicine, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794, USA
| | - Can E Senkal
- Stony Brook Cancer Center and the Department of Medicine, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794, USA
| | - Lina M Obeid
- Stony Brook Cancer Center and the Department of Medicine, Stony Brook University, Health Sciences Center, Stony Brook, NY 11794, USA; The Northport VA Medical Center, Northport, NY 11768, USA.
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40
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Knockdown of GSK3β increases basal autophagy and AMPK signalling in nutrient-laden human aortic endothelial cells. Biosci Rep 2016; 36:BSR20160174. [PMID: 27534430 PMCID: PMC5025810 DOI: 10.1042/bsr20160174] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/14/2016] [Indexed: 12/28/2022] Open
Abstract
Suppression of the enzyme glycogen synthase kinase 3β (GSK3β) increases both the turnover of damaged cellular material and the activity of the enzyme AMP-activated protein kinase (AMPK) to potentially attenuate the damage inflicted by excess sugar and fat on blood vessels. High concentrations of glucose and palmitate increase endothelial cell inflammation and apoptosis, events that often precede atherogenesis. They may do so by decreasing basal autophagy and AMP-activated protein kinase (AMPK) activity, although the mechanisms by which this occurs are not clear. Decreased function of the lysosome, an organelle required for autophagy and AMPK, have been associated with hyperactivity of glycogen synthase kinase 3β (GSK3β). To determine whether GSK3β affects nutrient-induced changes in autophagy and AMPK activity, we used a primary human aortic endothelial cell (HAEC) model of type 2 diabetes that we had previously characterized with impaired AMPK activity and autophagy [Weikel et al. (2015) Am. J. Phys. Cell Physiol. 308, C249–C263]. Presently, we found that incubation of HAECs with excess nutrients (25 mM glucose and 0.4 mM palmitate) increased GSK3β activity and impaired lysosome acidification. Suppression of GSK3β in these cells by treatment with a chemical inhibitor or overexpression of kinase-dead GSK3β attenuated these lysosomal changes. Under control and excess nutrient conditions, knockdown of GSK3β increased autophagosome formation, forkhead box protein O1 (FOXO1) activity and AMPK signalling and decreased Akt signalling. Similar changes in autophagy, AMPK and Akt signalling were observed in aortas from mice treated with the GSK3β inhibitor CHIR 99021. Thus, increasing basal autophagy and AMPK activity by inhibiting GSK3β may be an effective strategy in the setting of hyperglycaemia and dyslipidaemia for restoring endothelial cell health and reducing atherogenesis.
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Matsuura K, Canfield K, Feng W, Kurokawa M. Metabolic Regulation of Apoptosis in Cancer. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 327:43-87. [PMID: 27692180 DOI: 10.1016/bs.ircmb.2016.06.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Apoptosis is a cellular suicide program that plays a critical role in development and human diseases, including cancer. Cancer cells evade apoptosis, thereby enabling excessive proliferation, survival under hypoxic conditions, and acquired resistance to therapeutic agents. Among various mechanisms that contribute to the evasion of apoptosis in cancer, metabolism is emerging as one of the key factors. Cellular metabolites can regulate functions of pro- and antiapoptotic proteins. In turn, p53, a regulator of apoptosis, also controls metabolism by limiting glycolysis and facilitating mitochondrial respiration. Consequently, with dysregulated metabolism and p53 inactivation, cancer cells are well-equipped to disable the apoptotic machinery. In this article, we review how cellular apoptosis is regulated and how metabolism can influence the signaling pathways leading to apoptosis, especially focusing on how glucose and lipid metabolism are altered in cancer cells and how these alterations can impact the apoptotic pathways.
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Affiliation(s)
- K Matsuura
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, United States
| | - K Canfield
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - W Feng
- Norris Cotton Cancer Center, Lebanon, NH, United States
| | - M Kurokawa
- Department of Molecular & Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States; Norris Cotton Cancer Center, Lebanon, NH, United States.
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Weikel KA, Ruderman NB, Cacicedo JM. Unraveling the actions of AMP-activated protein kinase in metabolic diseases: Systemic to molecular insights. Metabolism 2016; 65:634-645. [PMID: 27085772 PMCID: PMC4834453 DOI: 10.1016/j.metabol.2016.01.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 12/13/2022]
Abstract
AMP-activated protein kinase (AMPK) plays a critical role both in sensing and regulating cellular energy state. In experimental animals, its activation has been shown to reduce the risk of obesity and diabetes-related co-morbidities such as insulin resistance, the metabolic syndrome and atherosclerotic cardiovascular disease. However, in humans, AMPK activation alone often does not completely resolve these conditions. Thus, an improved understanding of AMPK action and regulation in metabolic and other diseases is needed. Herein, we provide a brief description of the enzymatic regulation of AMPK and review its role in maintaining energy homeostasis. We then discuss tissue-specific actions of AMPK that become distorted during such conditions as obesity, type 2 diabetes and certain cancers. Finally, we explore recent findings regarding the interactions of AMPK with mammalian target of rapamycin complex 1 and the lysosome and discuss how changes in these relationships during overnutrition may lead to AMPK dysfunction. A more thorough understanding of AMPK's molecular interactions during diseases of overnutrition may provide key insights for the development of AMPK-based combinatorial treatments for metabolic disease.
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Affiliation(s)
- Karen A Weikel
- Department of Medicine, Boston University School of Medicine and Boston Medical Center, 650 Albany Street, Boston, MA, 02118, USA.
| | - Neil B Ruderman
- Department of Medicine, Boston University School of Medicine and Boston Medical Center, 650 Albany Street, Boston, MA, 02118, USA
| | - José M Cacicedo
- Department of Medicine, Boston University School of Medicine and Boston Medical Center, 650 Albany Street, Boston, MA, 02118, USA
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Sangodkar J, Farrington C, McClinch K, Galsky MD, Kastrinsky DB, Narla G. All roads lead to PP2A: exploiting the therapeutic potential of this phosphatase. FEBS J 2016; 283:1004-24. [PMID: 26507691 PMCID: PMC4803620 DOI: 10.1111/febs.13573] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 09/29/2015] [Accepted: 10/21/2015] [Indexed: 12/22/2022]
Abstract
Protein phosphatase 2A (PP2A) is a serine/threonine phosphatase involved in the regulation of many cellular processes. A confirmed tumor suppressor protein, PP2A is genetically altered or functionally inactivated in many cancers highlighting a need for its therapeutic reactivation. In this review we discuss recent literature on PP2A: the elucidation of its structure and the functions of its subunits, and the identification of molecular lesions and post-translational modifications leading to its dysregulation in cancer. A final section will discuss the proteins and small molecules that modulate PP2A and how these might be used to target dysregulated forms of PP2A to treat cancers and other diseases.
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Affiliation(s)
- Jaya Sangodkar
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mt. Sinai, New York, NY, USA
| | - Caroline Farrington
- Department of Medicine and Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Kimberly McClinch
- Department of Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Matthew D. Galsky
- Department of Hematology and Medical Oncology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - David B. Kastrinsky
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Goutham Narla
- Department of Medicine and Institute for Transformative Molecular Medicine, Case Western Reserve University, Cleveland, OH, USA
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Qiu L, Feng B, Ni Z, Wu X, Sun W. Exposure to a 50-Hz magnetic field induced ceramide generation in cultured cells. Int J Radiat Biol 2016; 92:215-21. [DOI: 10.3109/09553002.2016.1144943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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45
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Lin CF, Tsai CC, Huang WC, Wang YC, Tseng PC, Tsai TT, Chen CL. Glycogen Synthase Kinase-3β and Caspase-2 Mediate Ceramide- and Etoposide-Induced Apoptosis by Regulating the Lysosomal-Mitochondrial Axis. PLoS One 2016; 11:e0145460. [PMID: 26727221 PMCID: PMC4699703 DOI: 10.1371/journal.pone.0145460] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/03/2015] [Indexed: 11/18/2022] Open
Abstract
Glycogen synthase kinase-3β (GSK-3β) regulates the sequential activation of caspase-2 and caspase-8 before mitochondrial apoptosis. Here, we report the regulation of Mcl-1 destabilization and cathepsin D-regulated caspase-8 activation by GSK-3β and caspase-2. Treatment with either the ceramide analogue C2-ceramide or the topoisomerase II inhibitor etoposide sequentially induced lysosomal membrane permeabilization (LMP), the reduction of mitochondrial transmembrane potential, and apoptosis. Following LMP, cathepsin D translocated from lysosomes to the cytoplasm, whereas inhibiting cathepsin D blocked mitochondrial apoptosis. Furthermore, cathepsin D caused the activation of caspase-8 but not caspase-2. Inhibiting GSK-3β and caspase-2 blocked Mcl-1 destabilization, LMP, cathepsin D re-localization, caspase-8 activation, and mitochondrial apoptosis. Expression of Mcl-1 was localized to the lysosomes, and forced expression of Mcl-1 prevented apoptotic signaling via the lysosomal-mitochondrial pathway. These results demonstrate the importance of GSK-3β and caspase-2 in ceramide- and etoposide-induced apoptosis through mechanisms involving Mcl-1 destabilization and the lysosomal-mitochondrial axis.
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Affiliation(s)
- Chiou-Feng Lin
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 110, Taiwan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, 110, Taiwan
| | - Cheng-Chieh Tsai
- Department of Nursing, Chung Hwa University of Medical Technology, Tainan, 717, Taiwan
| | - Wei-Ching Huang
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
| | - Yu-Chih Wang
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 110, Taiwan
| | - Po-Chun Tseng
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, 701, Taiwan
| | - Tsung-Ting Tsai
- Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 110, Taiwan
| | - Chia-Ling Chen
- Translational Research Center, Taipei Medical University, Taipei, 110, Taiwan
- * E-mail:
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Abstract
Studies over the past two decades have identified ceramide as a multifunctional central molecule in the sphingolipid biosynthetic pathway. Given its diverse tumor suppressive activities, molecular understanding of ceramide action will produce fundamental insights into processes that limit tumorigenesis and may identify key molecular targets for therapeutic intervention. Ceramide can be activated by a diverse array of stresses such as heat shock, genotoxic damage, oxidative stress and anticancer drugs. Ceramide triggers a variety of tumor suppressive and anti-proliferative cellular programs such as apoptosis, autophagy, senescence, and necroptosis by activating or repressing key effector molecules. Defects in ceramide generation and metabolism in cancer contribute to tumor cell survival and resistance to chemotherapy. The potent and versatile anticancer activity profile of ceramide has motivated drug development efforts to (re-)activate ceramide in established tumors. This review focuses on our current understanding of the tumor suppressive functions of ceramide and highlights the potential downstream targets of ceramide which are involved in its tumor suppressive action.
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The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) protects cells against cold-shock-induced apoptosis by maintaining phosphorylation of protein kinase B (AKT). J Neurovirol 2015; 21:568-75. [PMID: 26071090 DOI: 10.1007/s13365-015-0361-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/20/2015] [Accepted: 06/01/2015] [Indexed: 10/23/2022]
Abstract
The herpes simplex virus type 1 (HSV-1) latency-associated transcript (LAT) blocks apoptosis and inhibits caspase-3 activation. We previously showed that serum starvation (removal of serum from tissue culture media), which takes several days to induce apoptosis, results in decreased levels of both AKT (protein kinase B) and phosphorylated AKT (pAKT) in cells not expressing LAT. In contrast in mouse neuroblastoma cells expressing LAT, AKT, and pAKT levels remained high. AKT is a serine/threonine protein kinase that promotes cell survival. To examine the effect of LAT on AKT-pAKT using a different and more rapid method of inducing apoptosis, a stable cell line expressing LAT was compared to non-LAT expressing cells as soon as 15 min following recovery from cold-shock-induced apoptosis. Expression of LAT appeared to inhibit dephosphorylation of pAKT. This protection correlated with blocking numerous pro-apoptotic events that are inhibited by pAKT. These results support the hypothesis that inhibiting dephosphorylation of pAKT may be one of the pathways by which LAT protects cells against apoptosis.
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Ceramides in Alzheimer's Disease: Key Mediators of Neuronal Apoptosis Induced by Oxidative Stress and Aβ Accumulation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:346783. [PMID: 26090071 PMCID: PMC4458271 DOI: 10.1155/2015/346783] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 11/17/2022]
Abstract
Alzheimer's disease (AD), the most common chronic and progressive neurodegenerative disorder, is characterized by extracellular deposits of amyloid β-peptides (Aβ) and intracellular deposits of hyperphosphorylated tau (phospho-tau) protein. Ceramides, the major molecules of sphingolipid metabolism and lipid second messengers, have been associated with AD progression and pathology via Aβ generation. Enhanced levels of ceramides directly increase Aβ through stabilization of β-secretase, the key enzyme in the amyloidogenic processing of Aβ precursor protein (APP). As a positive feedback loop, the generated oligomeric and fibrillar Aβ induces a further increase in ceramide levels by activating sphingomyelinases that catalyze the catabolic breakdown of sphingomyelin to ceramide. Evidence also supports important role of ceramides in neuronal apoptosis. Ceramides may initiate a cascade of biochemical alterations, which ultimately leads to neuronal death by diverse mechanisms, including depolarization and permeabilization of mitochondria, increased production of reactive oxygen species (ROS), cytochrome c release, Bcl-2 depletion, and caspase-3 activation, mainly by modulating intracellular signalling, particularly along the pathways related to Akt/PKB kinase and mitogen-activated protein kinases (MAPKs). This review summarizes recent findings related to the role of ceramides in oxidative stress-driven neuronal apoptosis and interplay with Aβ in the cascade of events ending in neuronal degeneration.
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Zhao L, Liu P, Guo G, Wang L. Combination of cytokinin and auxin induces apoptosis, cell cycle progression arrest and blockage of the Akt pathway in HeLa cells. Mol Med Rep 2015; 12:719-27. [PMID: 25738331 DOI: 10.3892/mmr.2015.3420] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 01/15/2015] [Indexed: 11/06/2022] Open
Abstract
Plant cytokinins and auxins have recently been proposed as novel cancer therapies, which proceed via different mechanisms; however, their combined use has not been investigated. To the best of our knowledge, the present study was the first to show that the cytokinin ortho-methoxytopolin-riboside (MeoTR) strongly inhibited the proliferation of HeLa cells, the effect of which was synergistically enhanced by auxin indole-3-acetic acid (IAA), while IAA demonstrated to have no cytotoxic effects on cells. MeoTR was found to activate intrinsic and extrinsic caspase-dependent pathways, and IAA potentiated this activation. In addition, these effects were blocked by Z-Val-Ala-Asp-fluoromethylketone (Z-VAD-FMK), a pan-specific-caspase-inhibitor. IAA increased the MeoTR- induced inhibition of B cell lymphoma 2 (Bcl-2) and survivin, whereas IAA-only decreased Bcl-2 expression. MeoTR downregulated phosphorylated (p)-pyruvate dehydrogenase kinase 1, p-Akt and p-glycogen synthase kinase 3β, the effect of which was more potent in combination with IAA, despite the weak effect of IAA alone. LY294002, an Akt-inhibitor, was able to increase the inhibition of p-Akt through MeoTR and combination treatment. IAA and MeoTR increased the proportion of cells in S phase independently. However, the combination treatment induced a further increase. In addition, IAA and MeoTR treatment downregulated protein levels of cyclin A, cyclin-dependent kinase 2 (CDK2) and p-CDK2, and upregulated protein levels of p21 and p27. Furthermore, the combination treatment enhanced these effects, indicating that IAA potentiated the inhibitory effect of MeoTR on HeLa cells via cell cycle progression arrest and accumulation in S phase, coupled with the negative regulation of Bcl-2. In conclusion, the results of the present study suggested that treatment with these two phytohormones in combination, may offer a novel therapeutic strategy for the treatment of malignant cervical cancer.
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Affiliation(s)
- Liwei Zhao
- Department of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Peng Liu
- Department of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Guangqin Guo
- Department of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
| | - Li Wang
- Department of Cell Biology, School of Life Sciences, Lanzhou University, Lanzhou 730000, P.R. China
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