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Tanim K, Holtzhausen A, Thapa A, Huelse JM, Graham DK, Earp HS. MERTK Inhibition as a Targeted Novel Cancer Therapy. Int J Mol Sci 2024; 25:7660. [PMID: 39062902 PMCID: PMC11277220 DOI: 10.3390/ijms25147660] [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: 06/04/2024] [Revised: 07/06/2024] [Accepted: 07/07/2024] [Indexed: 07/28/2024] Open
Abstract
In this issue honoring the contributions of Greg Lemke, the Earp and Graham lab teams discuss several threads in the discovery, action, signaling, and translational/clinical potential of MERTK, originally called c-mer, a member of the TYRO3, AXL, and MERTK (TAM) family of receptor tyrosine kinases. The 30-year history of the TAM RTK family began slowly as all three members were orphan RTKs without known ligands and/or functions when discovered by three distinct alternate molecular cloning strategies in the pre-genome sequencing era. The pace of understanding their physiologic and pathophysiologic roles has accelerated over the last decade. The activation of ligands bridging externalized phosphatidylserine (PtdSer) has placed these RTKs in a myriad of processes including neurodevelopment, cancer, and autoimmunity. The field is ripe for further advancement and this article hopefully sets the stage for further understanding and therapeutic intervention. Our review will focus on progress made through the collaborations of the Earp and Graham labs over the past 30 years.
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Affiliation(s)
- K.M. Tanim
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Alisha Holtzhausen
- Lineburger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
| | - Aashis Thapa
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Justus M. Huelse
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Douglas K. Graham
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Atlanta, GA 30322, USA; (K.M.T.); (A.T.); (J.M.H.)
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - H. Shelton Earp
- Lineburger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Burstyn-Cohen T, Fresia R. TAM receptors in phagocytosis: Beyond the mere internalization of particles. Immunol Rev 2023; 319:7-26. [PMID: 37596991 DOI: 10.1111/imr.13267] [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: 04/17/2023] [Accepted: 07/18/2023] [Indexed: 08/21/2023]
Abstract
TYRO3, AXL, and MERTK constitute the TAM family of receptor tyrosine kinases, activated by their ligands GAS6 and PROS1. TAMs are necessary for adult homeostasis in the immune, nervous, reproductive, skeletal, and vascular systems. Among additional cellular functions employed by TAMs, phagocytosis is central for tissue health. TAM receptors are dominant in providing phagocytes with the molecular machinery necessary to engulf diverse targets, including apoptotic cells, myelin debris, and portions of live cells in a phosphatidylserine-dependent manner. Simultaneously, TAMs drive the release of anti-inflammatory and tissue repair molecules. Disruption of the TAM-driven phagocytic pathway has detrimental consequences, resulting in autoimmunity, male infertility, blindness, and disrupted vascular integrity, and which is thought to contribute to neurodegenerative diseases. Although structurally and functionally redundant, the TAM receptors and ligands underlie complex signaling cascades, of which several key aspects are yet to be elucidated. We discuss similarities and differences between TAMs and other phagocytic pathways, highlight future directions and how TAMs can be harnessed therapeutically to modulate phagocytosis.
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Affiliation(s)
- Tal Burstyn-Cohen
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | - Roberta Fresia
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
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Lei X, Wang Y, Broens C, Borst J, Xiao Y. Immune checkpoints targeting dendritic cells for antibody-based modulation in cancer. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 382:145-179. [PMID: 38225102 DOI: 10.1016/bs.ircmb.2023.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
Dendritic cells (DC) are professional antigen-presenting cells which link innate to adaptive immunity. DC play a central role in regulating antitumor T-cell responses in both tumor-draining lymph nodes (TDLN) and the tumor microenvironment (TME). They modulate effector T-cell responses via immune checkpoint proteins (ICPs) that can be either stimulatory or inhibitory. Functions of DC are often impaired by the suppressive TME leading to tumor immune escape. Therefore, better understanding of the mechanisms of action of ICPs expressed by (tumor-infiltrating) DC will lead to potential new treatment strategies. Genetic manipulation and high-dimensional analyses have provided insight in the interactions between DC and T-cells in TDLN and the TME upon ICP targeting. In this review, we discuss (tumor-infiltrating) DC lineage cells and tumor tissue specific "mature" DC states and their gene signatures in relation to anti-tumor immunity. We also review a number of ICPs expressed by DC regarding their functions in phagocytosis, DC activation, or inhibition and outline position in, or promise for clinical trials in cancer immunotherapy. Collectively, we highlight the critical role of DC and their exact status in the TME for the induction and propagation of T-cell immunity to cancer.
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Affiliation(s)
- Xin Lei
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Yizhi Wang
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Chayenne Broens
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Jannie Borst
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands
| | - Yanling Xiao
- Department of Immunology and Oncode Institute, Leiden University Medical Center, Leiden, The Netherlands.
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Pidkovka N, Belkhiri A. Altered expression of AXL receptor tyrosine kinase in gastrointestinal cancers: a promising therapeutic target. Front Oncol 2023; 13:1079041. [PMID: 37469409 PMCID: PMC10353021 DOI: 10.3389/fonc.2023.1079041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 05/31/2023] [Indexed: 07/21/2023] Open
Abstract
Gastrointestinal (GI) cancers that include all cancers of the digestive tract organs are generally associated with obesity, lack of exercising, smoking, poor diet, and heavy alcohol consumption. Treatment of GI cancers typically involves surgery followed by chemotherapy and/or radiation. Unfortunately, intrinsic or acquired resistance to these therapies underscore the need for more effective targeted therapies that have been proven in other malignancies. The aggressive features of GI cancers share distinct signaling pathways that are connected to each other by the overexpression and activation of AXL receptor tyrosine kinase. Several preclinical and clinical studies involving anti-AXL antibodies and small molecule AXL kinase inhibitors to test their efficacy in solid tumors, including GI cancers, have been recently carried out. Therefore, AXL may be a promising therapeutic target for overcoming the shortcomings of standard therapies in GI cancers.
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Affiliation(s)
- Nataliya Pidkovka
- Department of Health Science, South College, Nashville, TN, United States
| | - Abbes Belkhiri
- Department of Surgery, Vanderbilt University Medical Center, Nashville, TN, United States
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, United States
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TAM receptor signaling dictates lesion location and clinical phenotype during experimental autoimmune encephalomyelitis. J Neuroimmunol 2023; 375:578016. [PMID: 36708633 DOI: 10.1016/j.jneuroim.2023.578016] [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: 10/30/2022] [Revised: 12/22/2022] [Accepted: 01/06/2023] [Indexed: 01/21/2023]
Abstract
Experimental autoimmune encephalomyelitis (EAE), induced by the adoptive transfer of Th17 cells, typically presents with ascending paralysis and inflammatory demyelination of the spinal cord. Brain white matter is relatively spared. Here we show that treatment of Th17 transfer recipients with a highly selective inhibitor to the TAM family of tyrosine kinase receptors results in ataxia associated with a shift of the inflammatory infiltrate to the hindbrain parenchyma. During homeostasis and preclinical EAE, hindbrain microglia express high levels of the TAM receptor Mer. Our data suggest that constitutive TAM receptor signaling in hindbrain microglia confers region-specific protection against Th17 mediated EAE.
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Huang H, Jiang J, Chen R, Lin Y, Chen H, Ling Q. The role of macrophage TAM receptor family in the acute-to-chronic progression of liver disease: From friend to foe? Liver Int 2022; 42:2620-2631. [PMID: 35900248 DOI: 10.1111/liv.15380] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 12/12/2022]
Abstract
Hepatic macrophages, the key cellular components of the liver, emerge as essential players in liver inflammation, tissue repair and subsequent fibrosis, as well as tumorigenesis. Recently, the TAM receptor tyrosine kinase family, consisting of Tyro3, Axl and MerTK, was found to be a pivotal modulator of macrophages. Activation of macrophage TAM receptor signalling promotes the efferocytosis of apoptotic cells and skews the polarization of macrophages. After briefly reviewing the mechanisms of TAM receptor signalling in macrophage polarization, we focus on their role in liver diseases from acute injury to chronic inflammation, fibrosis and then to tumorigenesis. Notably, macrophage TAM receptor signalling seems to be a two-edged sword for liver diseases. On one hand, the activation of TAM receptor signalling inhibits inflammation and facilitates tissue repair during acute liver injury. On the other hand, continuous activation of the signalling contributes to the process of chronic inflammation into fibrosis and tumorigenesis by evoking hepatic stellate cells and inhibiting anti-tumour immunity. Therefore, targeting macrophage TAM receptors and clarifying its downstream pathways will be exciting prospects for the precaution and treatment of liver diseases, particularly at different stages or statuses.
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Affiliation(s)
- Haitao Huang
- Department of Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC Key Laboratory of Combined Multi-Organ Transplantation, Hangzhou, China
| | - Jingyu Jiang
- Department of Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC Key Laboratory of Combined Multi-Organ Transplantation, Hangzhou, China
| | - Ruihan Chen
- Department of Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC Key Laboratory of Combined Multi-Organ Transplantation, Hangzhou, China
| | - Yimou Lin
- Department of Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC Key Laboratory of Combined Multi-Organ Transplantation, Hangzhou, China
| | - Hui Chen
- NHC Key Laboratory of Combined Multi-Organ Transplantation, Hangzhou, China
| | - Qi Ling
- Department of Surgery, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC Key Laboratory of Combined Multi-Organ Transplantation, Hangzhou, China.,Alibaba-Zhejiang University Joint Research Center of Future Digital Healthcare, Hangzhou, China
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Bao J, Zhang X, Li B, Niu M, Wu Z, Song P, Guo X, Husain SZ, Hu G, Li L, Wen L. AXL and MERTK receptor tyrosine kinases inhibition protects against pancreatic necrosis via selectively limiting CXCL2-related neutrophil infiltration. Biochim Biophys Acta Mol Basis Dis 2022; 1868:166490. [PMID: 35841983 DOI: 10.1016/j.bbadis.2022.166490] [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: 04/13/2022] [Revised: 06/27/2022] [Accepted: 07/08/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Acute pancreatitis (AP) was initiated within pancreatic parenchymal cells and sustained by uncontrolled inflammatory responses. AXL and MERTK receptor tyrosine kinases play a crucial role in negatively regulating the innate immunity. Therefore, this study aimed to investigate the role and underlying mechanism of AXL and MERTK in AP. METHODS Experimental AP was induced by ten hourly intraperitoneal administration of caerulein in global, hematopoietic- and pancreas-specific Axl and Mertk deficient mice. Pancreatitis severity was assessed biochemically and histologically. Pancreatic transcriptomics and pancreatic infiltrating immune cells were profiled. Some mice were given R428, an antagonist of AXL and MERTK. AXL and MERTK in peripheral leukocytes were measured by flow cytometry. FINDINGS The levels of AXL and MERTK in pancreatic tissue and pancreatic CD45+ cells were dynamically altered at 6 h and 12 h after the 1st injection of caerulein. Global and hematopoietic-specific, but not pancreas-specific deletion of Axl and Mertk protected against pancreatic necrosis and trypsinogen activation. Pancreatic transcriptomic analysis revealed that differentially expressed gene signatures were mainly related to metabolic and inflammatory pathways. Furthermore, deletion or inhibition of Axl and Mertk selectively inhibited pancreatic neutrophil infiltration, which was primarily related to CXCL2 secreted by pro-inflammatory macrophages. Increased levels of MERTK in peripheral leukocytes were correlated with more severe form of AP. INTERPRETATION Our findings reveal that specific AXL/MERTK antagonist may be a novel and potential early treatment for AP and the levels of MERTK in peripheral leukocytes may be a promising biomarker for predicting pancreatic severity in patients with AP. FUNDING National Natural Science Foundation of China, Shanghai Natural Science Foundation, a Shanghai Young Talent Award and a Shanghai Young Orient Scholar Award. RESEARCH IN CONTEXT Evidence before this study Acute pancreatitis (AP) is a common inflammatory disorder of the exocrine pancreas, the severity of which was determined by the extent of pancreatic necrosis, with no targeted therapy. AP was initiated by signals within pancreatic parenchymal cells and sustained by uncontrolled innate immune responses. One of the three crucial regulatory roles for AXL and MERTK is to negatively regulate innate immune responses. Added value of this study Global and hematopoietic-, but not pancreas-specific Axl and Mertk deficiency protected against pancreatitis, primarily pancreatic necrosis. Deletion of Axl and Mertk selectively inhibited pancreatic neutrophil infiltration that was related to CXCL2 secreted by pro-inflammatory macrophages. AXL and MERTK antagonist similarly reduced pancreatitis severity via limiting CXCL2-mediated pancreatic neutrophil infiltration. Higher levels of MERTK, but not AXL in peripheral leukocytes were correlated with more severe form of acute pancreatitis. Implications of all the available evidence A specific AXL/MERTK antagonist may be a novel and potential early treatment for AP. The level of MERTK on peripheral leukocytes may be a promising biomarker for predicting disease severity in patients with AP.
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Affiliation(s)
- Jingpiao Bao
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiuli Zhang
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin Li
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengya Niu
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zengkai Wu
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Pengli Song
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiaoyu Guo
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Department of Pancreatic and Biliary Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
| | - Sohail Z Husain
- Division of Pediatric Gastroenterology, Department of Pediatrics, Stanford University, Palo Alto, CA, United States
| | - Guoyong Hu
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Liang Li
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Li Wen
- Department of Gastroenterology and Shanghai Key Laboratory of Pancreatic Disease, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, China.
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Aria H, Ghaedrahmati F, Ganjalikhani-Hakemi M. Cutting edge: Metabolic immune reprogramming, reactive oxygen species, and cancer. J Cell Physiol 2021; 236:6168-6189. [PMID: 33561318 DOI: 10.1002/jcp.30303] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/09/2021] [Accepted: 01/19/2021] [Indexed: 02/05/2023]
Abstract
A recently proposed term "immunometabolism" points to the functional intracellular metabolic changes that occur within different immune cells. Recent findings suggest that immune responses can be determined by the metabolic status of immune cells and metabolic reprogramming is an important feature of immune cell activation. Metabolic reprogramming is also well known for cancer cells and has been suggested as a major sign of cancer progression. Metabolic reprogramming of immune cells is also seen in the tumor microenvironment. In the past decade, immunometabolism has progressively become an extraordinarily vibrant and productive area of study in immunology because of its importance for immunotherapy. Understanding the immunometabolic situation of T cells and other immune cells along with the metabolic behavior of cancer cells can help us design new therapeutic approaches against cancers. Here, we have the aim to review the cutting-edge findings on the immunometabolic situation in immune and tumor cells. We discuss new findings on signaling pathways during metabolic reprogramming, its regulation, and the participation of reactive oxygen species in these processes.
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Affiliation(s)
- Hamid Aria
- Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Farhoodeh Ghaedrahmati
- Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Abstract
Tyro3, Axl and Mertk are members of the TAM family of tyrosine kinase receptors. TAMs are activated by two structurally homologous ligands GAS6 and PROS1. TAM receptors and ligands are widely distributed and often co-expressed in the same cells allowing diverse functions across many systems including the immune, reproductive, vascular, and the developing as well as adult nervous systems. This review will focus specifically on TAM signaling in the nervous system, highlighting the essential roles this pathway fulfills in maintaining cell survival and homeostasis, cellular functions such as phagocytosis, immunity and tissue repair. Dysfunctional TAM signaling can cause complications in development, disruptions in homeostasis which can rouse autoimmunity, neuroinflammation and neurodegeneration. The development of therapeutics modulating TAM activities in the nervous system has great prospects, however, foremost we need a complete understanding of TAM signaling pathways.
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Affiliation(s)
- Tal Burstyn-Cohen
- Institute for Dental Sciences, Faculty of Dental Medicine, The Hebrew University-Hadassah, Jerusalem, Israel
| | - Arielle Hochberg
- Institute for Dental Sciences, Faculty of Dental Medicine, The Hebrew University-Hadassah, Jerusalem, Israel
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Lin TY, Lin FH, Hung CC, Liu CL, Hsiao YC, Lee CH, Wang NC. Growth arrest-specific 6 protein in HIV-infected patients: Determination of plasma level and different antiretroviral regimens. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2021; 54:926-933. [PMID: 34210628 DOI: 10.1016/j.jmii.2021.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 04/11/2021] [Accepted: 05/06/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND/PURPOSE Growth arrest-specific 6 (Gas6) protein is involved in cell proliferation, differentiation, adhesion, migration in response to inflammatory processes. Human immunodeficiency virus (HIV) infection induces a chronic inflammatory condition and combination of antiretroviral therapy improves immune function and decreases the inflammatory state. The aim of this study was to assess the implications of Gas6 in chronic inflammation status of HIV-infected patients undergoing different third regimens of antiretroviral therapy. The Gas6 may be a marker of chronic inflammation of HIV-infected patients. METHODS A total of 356 adult males, including 258 HIV-infected patients and 98 healthy controls, were recruited. The demographic and clinical characteristics of the patients were collected. Laboratory assessment included hemogram, CD4 count, plasma HIV RNA load (PVL), hepatitis B and C viruses, and serum biochemistry. Plasma Gas6 concentrations were determined. RESULTS The values of Gas6 were lower in HIV patients compared to healthy subjects (14.3 ± 6.4 vs 21.5 ± 15.2, p = 0.01). HIV patients that received antiviral regimen with abacavir had similar Gas6 level than those who received antiviral regimens with tenofovir (14.3 ± 6.5 vs 13.8 ± 5.9, p = 0.99). HIV patients that received antiviral regimen with protease inhibitors (PIs) had lower Gas6 level (13.1 ± 3.5 vs 14.2 ± 6.6 vs 14.6 ± 6.5, p = 0.03) than those who received antiviral regimens with non-nucleoside reverse transcriptase inhibitors (nNRTIs) and integrase inhibitors (INSTIs), respectively. CONCLUSIONS Decreased plasma Gas6 concentrations were observed in HIV patients. Gas6 levels are associated with different third regimen of highly active antiretroviral therapy. Gas6 may represent a unique marker for assessing the chronic inflammation state difference among cART regimens in HIV patients.
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Affiliation(s)
- Te-Yu Lin
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Fu-Huang Lin
- School of Public Health, National Defense Medical Center, Taipei, Taiwan
| | - Ching-Ching Hung
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chang-Lin Liu
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Chun Hsiao
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chien-Hsing Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Ning-Chi Wang
- Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan.
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Maimon A, Levi-Yahid V, Ben-Meir K, Halpern A, Talmi Z, Priya S, Mizraji G, Mistriel-Zerbib S, Berger M, Baniyash M, Loges S, Burstyn-Cohen T. Myeloid cell-derived PROS1 inhibits tumor metastasis by regulating inflammatory and immune responses via IL-10. J Clin Invest 2021; 131:126089. [PMID: 33848267 DOI: 10.1172/jci126089] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 04/07/2021] [Indexed: 12/11/2022] Open
Abstract
Stimulation of TAM (TYRO3, AXL, and MERTK) receptor tyrosine kinases promotes tumor progression through numerous cellular mechanisms. TAM cognate ligands GAS6 and PROS1 (for TYRO3 and MERTK) are secreted by host immune cells, an interaction which may support tumor progression. Here, we revealed an unexpected antimetastatic role for myeloid-derived PROS1: suppressing metastatic potential in lung and breast tumor models. Pros1 deletion in myeloid cells led to increased lung metastasis, independent of primary tumor infiltration. PROS1-cKO bone marrow-derived macrophages (BMDMs) led to elevated TNF-α, IL-6, Nos2, and IL-10 via modulation of the Socs3/NF-κB pathway. Conditioned medium from cKO BMDMs enhanced EMT, ERK, AKT, and STAT3 activation within tumor cells and promoted IL-10-dependent invasion and survival. Macrophages isolated from metastatic lungs modulated T cell proliferation and function, as well as expression of costimulatory molecules on DCs in a PROS1-dependent manner. Inhibition of MERTK kinase activity blocked PROS1-mediated suppression of TNF-α and IL-6 but not IL-10. Overall, using lung and breast cancer models, we identified the PROS1/MERTK axis within BMDMs as a potent regulator of adaptive immune responses with a potential to suppress metastatic seeding and revealed IL-10 regulation by PROS1 to deviate from that of TNF-α and IL-6.
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Affiliation(s)
- Avi Maimon
- The Institute for Dental Sciences, Faculty of Dental Medicine and
| | | | - Kerem Ben-Meir
- The Lautenberg Center for Immunology and Cancer Research, Israel-Canada Medical Research Institute, Faculty of Medicine, the Hebrew University, Jerusalem, Israel
| | - Amit Halpern
- The Institute for Dental Sciences, Faculty of Dental Medicine and
| | - Ziv Talmi
- The Institute for Dental Sciences, Faculty of Dental Medicine and
| | - Shivam Priya
- The Institute for Dental Sciences, Faculty of Dental Medicine and
| | - Gabriel Mizraji
- The Institute for Dental Sciences, Faculty of Dental Medicine and
| | - Shani Mistriel-Zerbib
- The Lautenberg Center for Immunology and Cancer Research, Israel-Canada Medical Research Institute, Faculty of Medicine, the Hebrew University, Jerusalem, Israel
| | - Michael Berger
- The Lautenberg Center for Immunology and Cancer Research, Israel-Canada Medical Research Institute, Faculty of Medicine, the Hebrew University, Jerusalem, Israel
| | - Michal Baniyash
- The Lautenberg Center for Immunology and Cancer Research, Israel-Canada Medical Research Institute, Faculty of Medicine, the Hebrew University, Jerusalem, Israel
| | - Sonja Loges
- Division of Personalized Medical Oncology (A420), German Cancer Research Center (DKFZ), Heidelberg, Germany.,Department of Personalized Oncology, University Hospital Mannheim, Mannheim, Germany
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Post SM, Andreeff M, DiNardo C, Khoury JD, Ruvolo PP. TAM kinases as regulators of cell death. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2021; 1868:118992. [PMID: 33647320 DOI: 10.1016/j.bbamcr.2021.118992] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Revised: 02/19/2021] [Accepted: 02/22/2021] [Indexed: 01/16/2023]
Abstract
Receptor Tyrosine Kinases are critical regulators of signal transduction that support cell survival, proliferation, and differentiation. Dysregulation of normal Receptor Tyrosine Kinase function by mutation or other activity-altering event can be oncogenic or can impact the transformed malignant cell so it becomes particularly resistant to stress challenge, have increased proliferation, become evasive to immune surveillance, and may be more prone to metastasis of the tumor to other organ sites. The TAM family of Receptor Tyrosine Kinases (TYRO3, AXL, MERTK) is emerging as important components of malignant cell survival in many cancers. The TAM kinases are important regulators of cellular homeostasis and proper cell differentiation in normal cells as receptors for their ligands GAS6 and Protein S. They also are critical to immune and inflammatory processes. In malignant cells, the TAM kinases can act as ligand independent co-receptors to mutant Receptor Tyrosine Kinases and in some cases (e.g. FLT3-ITD mutant) are required for their function. They also have a role in immune checkpoint surveillance. At the time of this review, the Covid-19 pandemic poses a global threat to world health. TAM kinases play an important role in host response to many viruses and it is suggested the TAM kinases may be important in aspects of Covid-19 biology. This review will cover the TAM kinases and their role in these processes.
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Affiliation(s)
- Sean M Post
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Michael Andreeff
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America; Section of Molecular Hematology and Therapy, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Courtney DiNardo
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Joseph D Khoury
- Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America
| | - Peter P Ruvolo
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America; Section of Molecular Hematology and Therapy, The University of Texas MD Anderson Cancer Center, Houston, TX, United States of America.
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13
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Msaouel P, Genovese G, Gao J, Sen S, Tannir NM. TAM kinase inhibition and immune checkpoint blockade- a winning combination in cancer treatment? Expert Opin Ther Targets 2021; 25:141-151. [PMID: 33356674 DOI: 10.1080/14728222.2021.1869212] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Introduction: Immune checkpoint inhibitors (ICI) have shown great promise in a wide spectrum of malignancies. However, responses are not always durable, and this mode of treatment is only effective in a subset of patients. As such, there exists an unmet need for novel approaches to bolster ICI efficacy.Areas covered: We review the role of the Tyro3, Axl, and Mer (TAM) receptor tyrosine kinases in promoting tumor-induced immune suppression and discuss the benefits that may be derived from combining ICI with TAM kinase-targeted tyrosine kinase inhibitors. We searched the MEDLINE Public Library of Medicine (PubMed) and EMBASE databases and referred to ClinicalTrials.gov for relevant ongoing studies.Expert opinion: Targeting of TAM kinases may improve the efficacy of immune checkpoint blockade. However, it remains to be determined whether this effect will be better achieved by the selective targeting of each TAM receptor, depending on the context, or by multi-receptor TAM inhibitors. Triple inhibition of all TAM receptors is more likely to be associated with an increased risk for adverse events. Clinical trial designs should use high-resolution clinical endpoints and proper control arms to determine the synergistic effects of combining TAM inhibition with immune checkpoint blockade.
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Affiliation(s)
- Pavlos Msaouel
- Department of Genitourinary Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Giannicola Genovese
- Department of Genitourinary Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jianjun Gao
- Department of Genitourinary Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Nizar M Tannir
- Department of Genitourinary Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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14
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Huelse J, Fridlyand D, Earp S, DeRyckere D, Graham DK. MERTK in cancer therapy: Targeting the receptor tyrosine kinase in tumor cells and the immune system. Pharmacol Ther 2020; 213:107577. [PMID: 32417270 PMCID: PMC9847360 DOI: 10.1016/j.pharmthera.2020.107577] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The receptor tyrosine kinase MERTK is aberrantly expressed in numerous human malignancies, and is a novel target in cancer therapeutics. Physiologic roles of MERTK include regulation of tissue homeostasis and repair, innate immune control, and platelet aggregation. However, aberrant expression in a wide range of liquid and solid malignancies promotes neoplasia via growth factor independence, cell cycle progression, proliferation and tumor growth, resistance to apoptosis, and promotion of tumor metastases. Additionally, MERTK signaling contributes to an immunosuppressive tumor microenvironment via induction of an anti-inflammatory cytokine profile and regulation of the PD-1 axis, as well as regulation of macrophage, myeloid-derived suppressor cell, natural killer cell and T cell functions. Various MERTK-directed therapies are in preclinical development, and clinical trials are underway. In this review we discuss MERTK inhibition as an emerging strategy for cancer therapy, focusing on MERTK expression and function in neoplasia and its role in mediating resistance to cytotoxic and targeted therapies as well as in suppressing anti-tumor immunity. Additionally, we review preclinical and clinical pharmacological strategies to target MERTK.
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Affiliation(s)
- Justus Huelse
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Diana Fridlyand
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Shelton Earp
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC
| | - Deborah DeRyckere
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
| | - Douglas K. Graham
- Aflac Cancer and Blood Disorders Center, Children’s Healthcare of Atlanta, Department of Pediatrics, Emory University, Atlanta, Georgia
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15
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Gas6 Induces Myelination through Anti-Inflammatory IL-10 and TGF-β Upregulation in White Matter and Glia. Cells 2020; 9:cells9081779. [PMID: 32722558 PMCID: PMC7465828 DOI: 10.3390/cells9081779] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/16/2020] [Accepted: 07/24/2020] [Indexed: 02/07/2023] Open
Abstract
The Gas6–TAM (Tyro3, Axl, Mer) ligand–receptor system is believed to promote central nervous system (CNS) (re)myelination and glial cell development. An additional important function of Gas6–TAM signalling appears to be the regulation of immunity and inflammation, which remains to be fully elucidated in the CNS. Here, we characterised the expression of TAM receptors and ligands in individual CNS glial cell types, observing high expression of Gas6 and the TAM receptors, Mer and Axl, in microglia, and high expression of Tyro3 in astrocytes. We also investigated the effect of Gas6 on the inflammatory cytokine response in the optic nerve and in mixed glial cell cultures from wildtype and single TAM receptor knockout mice. In wildtype and Mer-deficient cultures, Gas6 significantly stimulated the expression of the anti-inflammatory/pro-repair cytokines interleukin 10 (IL-10) and transforming growth factor β (TGF-β), whereas this effect was absent in either Tyro3 or Axl knockout cultures. Furthermore, Gas6 caused upregulation of myelin basic protein (MBP) expression in optic nerves, which was blocked by a neutralising antibody against IL-10. In conclusion, our data show that microglia are both a major source of Gas6 as well as an effector of Gas6 action in the CNS through the upregulation of anti-inflammatory and pro-repair mediators. Furthermore, the presence of both Axl and Tyro3 receptors appears to be necessary for these effects of Gas6. In addition, IL-10, alongside suppressing inflammation and immunity, mediates the pro-myelinating mechanism of Gas6 action in the optic nerve. Therefore, Gas6 may present an attractive target for novel therapeutic interventions for demyelinating as well as neuroinflammatory disorders of the CNS.
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16
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Wang X, Liu Y, Zhang S, Ouyang X, Wang Y, Jiang Y, An N. Crosstalk between Akt and NF-κB pathway mediates inhibitory effect of gas6 on monocytes-endothelial cells interactions stimulated by P. gingivalis-LPS. J Cell Mol Med 2020; 24:7979-7990. [PMID: 32462812 PMCID: PMC7348146 DOI: 10.1111/jcmm.15430] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 05/01/2020] [Accepted: 05/07/2020] [Indexed: 02/06/2023] Open
Abstract
Correlation between periodontitis and atherosclerosis is well established, and the inherent mechanisms responsible for this relationship remain unclear. The biological function of growth arrest‐specific 6 (gas6) has been discovered in both atherosclerosis and inflammation. Inhibitory effects of gas6 on the expression of inflammatory factors in human umbilical vein endothelial cells (HUVECs) stimulated by Porphyromonas gingivalis lipopolysaccharide (P. gingivalis‐LPS) were reported in our previous research. Herein, the effects of gas6 on monocytes‐endothelial cells interactions in vitro and their probable mechanisms were further investigated. Gas6 protein in HUVECs was knocked down with siRNA or overexpressed with plasmids. Transwell inserts and co‐culturing system were introduced to observe chemotaxis and adhering affinity between monocytes and endothelial cells in vitro. Expression of gas6 was decreased in inflammatory periodontal tissues and HUVECs challenged with P. gingivalis‐LPS. The inhibitory effect of gas6 on chemotaxis and adhesion affinity between monocytes and endothelial cells was observed, and gas6 promoted Akt phosphorylation and inhibited NF‐κB phosphorylation. To our best knowledge, we are first to report that gas6 inhibit monocytes‐endothelial cells interactions in vitro induced by P. gingivalis‐LPS via Akt/NF‐κB pathway. Additionally, inflammation‐mediated inhibition of gas6 expression is through LncRNA GAS6‐AS2, rather than GAS6‐AS1, which is also newly reported.
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Affiliation(s)
- Xuekui Wang
- Department of General Dentistry II, Peking University School and Hospital of Stomatology, Beijing, China.,Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Peking University School and Hospital of Stomatology, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yingjun Liu
- Department of General Dentistry II, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Peking University School and Hospital of Stomatology, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Shengnan Zhang
- Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Peking University School and Hospital of Stomatology, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Xiangying Ouyang
- Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Peking University School and Hospital of Stomatology, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yuguang Wang
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Peking University School and Hospital of Stomatology, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Yong Jiang
- Department of General Dentistry II, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Peking University School and Hospital of Stomatology, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China
| | - Na An
- Department of General Dentistry II, Peking University School and Hospital of Stomatology, Beijing, China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, Peking University School and Hospital of Stomatology, Beijing, China.,National Clinical Research Center for Oral Diseases, Peking University School and Hospital of Stomatology, Beijing, China.,Beijing Key Laboratory of Digital Stomatology, Peking University School and Hospital of Stomatology, Beijing, China
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17
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Zheng G, Li LF, Zhang Y, Qu L, Wang W, Li M, Yu S, Zhou M, Luo Y, Sun Y, Munir M, Li S, Qiu HJ. MERTK is a host factor that promotes classical swine fever virus entry and antagonizes innate immune response in PK-15 cells. Emerg Microbes Infect 2020; 9:571-581. [PMID: 32172658 PMCID: PMC7144274 DOI: 10.1080/22221751.2020.1738278] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Classical swine fever virus (CSFV) is a member of the genus Pestivirus in the Flaviviridae family. To date, the host factors required for CSFV entry remain poorly characterized. To identify the functional membrane protein(s) involved in CSFV infection, we analyzed the transcriptomic data from previous studies describing gene expression profiles for CSFV, and found twelve novel candidate proteins. One of these proteins, MERTK, significantly reduced CSFV protein expression by RNA interference screening using a recombinant CSFV that contains a luciferase reporter to measure CSFV protein expression. Furthermore, our results demonstrated that either anti-MERTK antibodies or soluble MERTK ectodomain could reduce CSFV infection in PK-15 cells in a dose-dependent manner. Mechanistically, MERTK interacted with the E2 protein of CSFV and facilitated virus entry. After virus entry, MERTK downregulates of mRNA expression of IFN-β and promotes CSFV infection. Interestingly, the soluble MERTK ectodomain could also reduce the infection of bovine viral diarrhea virus (BVDV), another pestivirus. Taken together, our results suggested that MERTK is a CSFV entry factor that synergistically dampens innate immune responses in PK-15 cells and is also involved in BVDV infection.
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Affiliation(s)
- Guanglai Zheng
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Lian-Feng Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Yuexiu Zhang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Liang Qu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Wenjing Wang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Miao Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Shaoxiong Yu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Mo Zhou
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Yuzi Luo
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Yuan Sun
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Muhammad Munir
- Division of Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, United Kingdom
| | - Su Li
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
| | - Hua-Ji Qiu
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China
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18
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TAM Receptor Pathways at the Crossroads of Neuroinflammation and Neurodegeneration. DISEASE MARKERS 2019; 2019:2387614. [PMID: 31636733 PMCID: PMC6766163 DOI: 10.1155/2019/2387614] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 06/04/2019] [Accepted: 08/12/2019] [Indexed: 02/07/2023]
Abstract
Increasing evidence suggests that pathogenic mechanisms underlying neurodegeneration are strongly linked with neuroinflammatory responses. Tyro3, Axl, and Mertk (TAM receptors) constitute a subgroup of the receptor tyrosine kinase family, cell surface receptors which transmit signals from the extracellular space to the cytoplasm and nucleus. TAM receptors and the corresponding ligands, Growth Arrest Specific 6 and Protein S, are expressed in different tissues, including the nervous system, playing complex roles in tissue repair, inflammation and cell survival, proliferation, and migration. In the nervous system, TAM receptor signalling modulates neurogenesis and neuronal migration, synaptic plasticity, microglial activation, phagocytosis, myelination, and peripheral nerve repair, resulting in potential interest in neuroinflammatory and neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Multiple Sclerosis. In Alzheimer and Parkinson diseases, a role of TAM receptors in neuronal survival and pathological protein aggregate clearance has been suggested, while in Multiple Sclerosis TAM receptors are involved in myelination and demyelination processes. To better clarify roles and pathways involving TAM receptors may have important therapeutic implications, given the fine modulation of multiple molecular processes which could be reached. In this review, we summarise the roles of TAM receptors in the central nervous system, focusing on the regulation of immune responses and microglial activities and analysing in vitro and in vivo studies regarding TAM signalling involvement in neurodegeneration.
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19
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Abstract
Tissue macrophages rapidly recognize and engulf apoptotic cells. These events require the display of so-called eat-me signals on the apoptotic cell surface, the most fundamental of which is phosphatidylserine (PtdSer). Externalization of this phospholipid is catalysed by scramblase enzymes, several of which are activated by caspase cleavage. PtdSer is detected both by macrophage receptors that bind to this phospholipid directly and by receptors that bind to a soluble bridging protein that is independently bound to PtdSer. Prominent among the latter receptors are the MER and AXL receptor tyrosine kinases. Eat-me signals also trigger macrophages to engulf virus-infected or metabolically traumatized, but still living, cells, and this 'murder by phagocytosis' may be a common phenomenon. Finally, the localized presentation of PtdSer and other eat-me signals on delimited cell surface domains may enable the phagocytic pruning of these 'locally dead' domains by macrophages, most notably by microglia of the central nervous system.
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Affiliation(s)
- Greg Lemke
- Molecular Neurobiology Laboratory, Immunobiology and Microbial Pathogenesis Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.
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20
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Li Y, Wan YY, Zhu B. Immune Cell Metabolism in Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1011:163-196. [PMID: 28875490 DOI: 10.1007/978-94-024-1170-6_5] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Tumor microenvironment (TME) is composed of tumor cells, immune cells, cytokines, extracellular matrix, etc. The immune system and the metabolisms of glucose, lipids, amino acids, and nucleotides are integrated in the tumorigenesis and development. Cancer cells and immune cells show metabolic reprogramming in the TME, which intimately links immune cell functions and edits tumor immunology. Recent findings in immune cell metabolism hold the promising possibilities toward clinical therapeutics for treating cancer. This chapter introduces the updated understandings of metabolic reprogramming of immune cells in the TME and suggests new directions in manipulation of immune responses for cancer diagnosis and therapy.
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Affiliation(s)
- Yongsheng Li
- Institute of Cancer, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Yisong Y Wan
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Bo Zhu
- Institute of Cancer, Xinqiao Hospital, Third Military Medical University, Chongqing, China.
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21
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Saha S, Shalova IN, Biswas SK. Metabolic regulation of macrophage phenotype and function. Immunol Rev 2018; 280:102-111. [PMID: 29027220 DOI: 10.1111/imr.12603] [Citation(s) in RCA: 146] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Studies in the last 20 years have given us a remarkable insight into the functional and phenotypic diversity of macrophages which reflects their integral role in host defence, homeostasis and pathogenesis. Mouse genetics, transcriptomic and epigenetic studies have provided an ontogenic and molecular perspective to the phenotypic diversity of these cells. Recently, metabolic studies have revealed the crucial role of metabolism and metabolites in shaping the phenotype and function of macrophages. Evidence pertaining to this aspect will be reviewed here.
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Affiliation(s)
- Shilpi Saha
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A*STAR), Singapore
| | - Irina N Shalova
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A*STAR), Singapore
| | - Subhra K Biswas
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A*STAR), Singapore
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22
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Shafit-Zagardo B, Gruber RC, DuBois JC. The role of TAM family receptors and ligands in the nervous system: From development to pathobiology. Pharmacol Ther 2018. [PMID: 29514053 DOI: 10.1016/j.pharmthera.2018.03.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tyro3, Axl, and Mertk, referred to as the TAM family of receptor tyrosine kinases, are instrumental in maintaining cell survival and homeostasis in mammals. TAM receptors interact with multiple signaling molecules to regulate cell migration, survival, phagocytosis and clearance of metabolic products and cell debris called efferocytosis. The TAMs also function as rheostats to reduce the expression of proinflammatory molecules and prevent autoimmunity. All three TAM receptors are activated in a concentration-dependent manner by the vitamin K-dependent growth arrest-specific protein 6 (Gas6). Gas6 and the TAMs are abundantly expressed in the nervous system. Gas6, secreted by neurons and endothelial cells, is the sole ligand for Axl. ProteinS1 (ProS1), another vitamin K-dependent protein functions mainly as an anti-coagulant, and independent of this function can activate Tyro3 and Mertk, but not Axl. This review will focus on the role of the TAM receptors and their ligands in the nervous system. We highlight studies that explore the function of TAM signaling in myelination, the visual cortex, neural cancers, and multiple sclerosis (MS) using Gas6-/- and TAM mutant mice models.
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Affiliation(s)
- Bridget Shafit-Zagardo
- Albert Einstein College of Medicine, Department of Pathology, 1300 Morris Park Avenue, Bronx, NY 10461, United States.
| | - Ross C Gruber
- Sanofi, Neuroinflammation and MS Research, 49 New York Ave, Framingham, MA 01701, United States
| | - Juwen C DuBois
- Albert Einstein College of Medicine, Department of Pathology, 1300 Morris Park Avenue, Bronx, NY 10461, United States
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23
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Chang CF, Goods BA, Askenase MH, Hammond MD, Renfroe SC, Steinschneider AF, Landreneau MJ, Ai Y, Beatty HE, da Costa LHA, Mack M, Sheth KN, Greer DM, Huttner A, Coman D, Hyder F, Ghosh S, Rothlin CV, Love JC, Sansing LH. Erythrocyte efferocytosis modulates macrophages towards recovery after intracerebral hemorrhage. J Clin Invest 2017; 128:607-624. [PMID: 29251628 DOI: 10.1172/jci95612] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 11/07/2017] [Indexed: 02/03/2023] Open
Abstract
Macrophages are a source of both proinflammatory and restorative functions in damaged tissue through complex dynamic phenotypic changes. Here, we sought to determine whether monocyte-derived macrophages (MDMs) contribute to recovery after acute sterile brain injury. By profiling the transcriptional dynamics of MDMs in the murine brain after experimental intracerebral hemorrhage (ICH), we found robust phenotypic changes in the infiltrating MDMs over time and demonstrated that MDMs are essential for optimal hematoma clearance and neurological recovery. Next, we identified the mechanism by which the engulfment of erythrocytes with exposed phosphatidylserine directly modulated the phenotype of both murine and human MDMs. In mice, loss of receptor tyrosine kinases AXL and MERTK reduced efferocytosis of eryptotic erythrocytes and hematoma clearance, worsened neurological recovery, exacerbated iron deposition, and decreased alternative activation of macrophages after ICH. Patients with higher circulating soluble AXL had poor 1-year outcomes after ICH onset, suggesting that therapeutically augmenting efferocytosis may improve functional outcomes by both reducing tissue injury and promoting the development of reparative macrophage responses. Thus, our results identify the efferocytosis of eryptotic erythrocytes through AXL/MERTK as a critical mechanism modulating macrophage phenotype and contributing to recovery from ICH.
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Affiliation(s)
- Che-Feng Chang
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Brittany A Goods
- Department of Biological Engineering, Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Michael H Askenase
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Matthew D Hammond
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Stephen C Renfroe
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Margaret J Landreneau
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Youxi Ai
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Hannah E Beatty
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Luís Henrique Angenendt da Costa
- Department of Neurosciences and Behavioral Sciences, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, Brazil
| | - Matthias Mack
- Department of Internal Medicine (Nephrology), University of Regensburg, Regensburg, Germany
| | - Kevin N Sheth
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - David M Greer
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Daniel Coman
- Department of Diagnostic Radiology and Biomedical Engineering
| | - Fahmeed Hyder
- Department of Diagnostic Radiology and Biomedical Engineering
| | - Sourav Ghosh
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Pharmacology, and
| | - Carla V Rothlin
- Department of Pharmacology, and.,Department of Immunobiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - J Christopher Love
- Chemical Engineering, Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Lauren H Sansing
- Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, USA
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24
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Increased Circulating and Urinary Levels of Soluble TAM Receptors in Diabetic Nephropathy. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:1971-1983. [PMID: 28668213 DOI: 10.1016/j.ajpath.2017.05.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 04/29/2017] [Accepted: 05/02/2017] [Indexed: 01/25/2023]
Abstract
TAM receptors (Tyro3, Axl, and Mer) have been implicated in innate immunity. Circulating TAM receptor soluble forms (sTyro3, sAxl, sMer) are related to autoimmune disorders. We investigated TAM and their ligand protein S in patients with diabetes. Urinary and plasma levels of protein S, sTyro3, sAxl, and sMer were determined in 126 patients with diabetes assigned to a normoalbuminuric or macroalbuminuric (urinary albumin excretion <30 mg/24 hours and >300 mg/24 hours, respectively) study group and 18 healthy volunteers. TAM and protein S immunostaining was performed on kidney biopsy specimens from patients with diabetic nephropathy (n = 9) and controls (n = 6). TAM expression and shedding by tubular epithelial cells were investigated by PCR and enzyme-linked immunosorbent assay in an in vitro diabetes model. Patients with macroalbuminuria diabetes had higher circulating levels of sMer and more urinary sTyro3 and sMer than normoalbuminuric diabetics. Increased clearance of sTyro3 and sMer was associated with loss of tubular Tyro3 and Mer expression in diabetic nephropathy tissue and glomerular depositions of protein S. During in vitro diabetes, human kidney cells had down-regulation of Tyro3 and Mer mRNA and increased shedding of sTyro3 and sMer. Renal injury in diabetes is associated with elevated systemic and urine levels of sMer and sTyro3. This is the first study reporting excretion of sTAM receptors in urine, identifying the kidney as a source of sTAM.
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25
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Growth Arrest-Specific 6 Enhances the Suppressive Function of CD4 +CD25 + Regulatory T Cells Mainly through Axl Receptor. Mediators Inflamm 2017; 2017:6848430. [PMID: 28270700 PMCID: PMC5320320 DOI: 10.1155/2017/6848430] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/07/2016] [Accepted: 12/05/2016] [Indexed: 11/17/2022] Open
Abstract
Background. Growth arrest-specific (Gas) 6 is one of the endogenous ligands of TAM receptors (Tyro3, Axl, and Mertk), and its role as an immune modulator has been recently emphasized. Naturally occurring CD4+CD25+ regulatory T cells (Tregs) are essential for the active suppression of autoimmunity. The present study was designed to investigate whether Tregs express TAM receptors and the potential role of Gas6-TAM signal in regulating the suppressive function of Tregs. Methods. The protein and mRNA levels of TAM receptors were determined by using Western blot, immunofluorescence, flow cytometry, and RT-PCR. Then, TAM receptors were silenced using targeted siRNA or blocked with specific antibody. The suppressive function of Tregs was assessed by using a CFSE-based T cell proliferation assay. Flow cytometry was used to determine the expression of Foxp3 and CTLA4 whereas cytokines secretion levels were measured by ELISA assay. Results. Tregs express both Axl and Mertk receptors. Gas6 increases the suppressive function of Tregs in vitro and in mice. Both Foxp3 and CTLA-4 expression on Tregs are enhanced after Gas6 stimulation. Gas6 enhances the suppressive activity of Tregs mainly through Axl receptor. Conclusion. Gas6 has a direct effect on the functions of CD4+CD25+Tregs mainly through its interaction with Axl receptor.
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Davra V, Kimani SG, Calianese D, Birge RB. Ligand Activation of TAM Family Receptors-Implications for Tumor Biology and Therapeutic Response. Cancers (Basel) 2016; 8:cancers8120107. [PMID: 27916840 PMCID: PMC5187505 DOI: 10.3390/cancers8120107] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 11/16/2016] [Accepted: 11/26/2016] [Indexed: 12/21/2022] Open
Abstract
The TAM family of receptors (i.e., Tyro3, Axl, and Mertk), and their ligands Growth arrest specific factor 6 (Gas6) and Protein S (Pros1) contribute to several oncogenic processes, such as cell survival, invasion, migration, chemo-resistance, and metastasis, whereby expression often correlates with poor clinical outcomes. In recent years, there has been great interest in the study of TAM receptors in cancer, stemming both from their roles as oncogenic signaling receptors, as well as their roles in tumor immunology. As a result, several classes of TAM inhibitors that include small molecule tyrosine kinase inhibitors, monoclonal antibodies, decoy receptors, as well as novel strategies to target TAM ligands are being developed. This paper will review the biology of TAM receptors and their ligands with a focus on cancer, as well as evidence-based data for the continued pursuit of TAM/Gas6 inhibitors in clinical practice.
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Affiliation(s)
- Viralkumar Davra
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07103, USA.
| | - Stanley G Kimani
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07103, USA.
| | - David Calianese
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07103, USA.
| | - Raymond B Birge
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07103, USA.
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27
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The Gas6/TAM System and Multiple Sclerosis. Int J Mol Sci 2016; 17:ijms17111807. [PMID: 27801848 PMCID: PMC5133808 DOI: 10.3390/ijms17111807] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/22/2016] [Accepted: 10/26/2016] [Indexed: 01/25/2023] Open
Abstract
Growth arrest specific 6 (Gas6) is a multimodular circulating protein, the biological actions of which are mediated by the interaction with three transmembrane tyrosine kinase receptors: Tyro3, Axl, and MerTK, collectively named TAM. Over the last few decades, many progresses have been done in the understanding of the biological activities of this highly pleiotropic system, which plays a role in the regulation of immune response, inflammation, coagulation, cell growth, and clearance of apoptotic bodies. Recent findings have further related Gas6 and TAM receptors to neuroinflammation in general and, specifically, to multiple sclerosis (MS). In this paper, we review the biology of the Gas6/TAM system and the current evidence supporting its potential role in the pathogenesis of MS.
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Goudarzi S, Rivera A, Butt AM, Hafizi S. Gas6 Promotes Oligodendrogenesis and Myelination in the Adult Central Nervous System and After Lysolecithin-Induced Demyelination. ASN Neuro 2016; 8:8/5/1759091416668430. [PMID: 27630207 PMCID: PMC5027908 DOI: 10.1177/1759091416668430] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/11/2016] [Indexed: 01/24/2023] Open
Abstract
A key aim of therapy for multiple sclerosis (MS) is to promote the regeneration of oligodendrocytes and remyelination in the central nervous system (CNS). The present study provides evidence that the vitamin K-dependent protein growth arrest specific 6 (Gas6) promotes such repair in in vitro cultures of mouse optic nerve and cerebellum. We first determined expression of Gas6 and TAM (Tyro3, Axl, Mer) receptors in the mouse CNS, with all three TAM receptors increasing in expression through postnatal development, reaching maximal levels in the adult. Treatment of cultured mouse optic nerves with Gas6 resulted in significant increases in oligodendrocyte numbers as well as expression of myelin basic protein (MBP). Gas6 stimulation also resulted in activation of STAT3 in optic nerves as well as downregulation of multiple genes involved in MS development, including matrix metalloproteinase-9 (MMP9), which may decrease the integrity of the blood-brain barrier and is found upregulated in MS lesions. The cytoprotective effects of Gas6 were examined in in vitro mouse cerebellar slice cultures, where lysolecithin was used to induce demyelination. Cotreatment of cerebellar slices with Gas6 significantly attenuated demyelination as determined by MBP immunostaining, and Gas6 activated Tyro3 receptor through its phosphorylation. In conclusion, these results demonstrate that Gas6/TAM signaling stimulates the generation of oligodendrocytes and increased myelin production via Tyro3 receptor in the adult CNS, including repair after demyelinating injury. Furthermore, the effects of Gas6 on STAT3 signaling and matrix MMP9 downregulation indicate potential glial cell repair and immunoregulatory roles for Gas6, indicating that Gas6-TAM signaling could be a potential therapeutic target in MS and other neuropathologies.
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Affiliation(s)
- Salman Goudarzi
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
| | - Andrea Rivera
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
| | - Arthur M Butt
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
| | - Sassan Hafizi
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Science, University of Portsmouth, UK
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Biswas SK. Metabolic Reprogramming of Immune Cells in Cancer Progression. Immunity 2016; 43:435-49. [PMID: 26377897 DOI: 10.1016/j.immuni.2015.09.001] [Citation(s) in RCA: 435] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 08/25/2015] [Accepted: 08/31/2015] [Indexed: 11/25/2022]
Abstract
Immune cells play a key role in host defense against infection and cancer. Upon encountering danger signals, these cells undergo activation leading to a modulation in their immune functions. However, recent studies reveal that immune cells upon activation also show distinct metabolic changes that impact their immune functions. Such metabolic reprogramming and its functional effects are well known for cancer cells. Given that immune cells have emerged as crucial players in cancer progression, it is important to understand whether immune cells also undergo metabolic reprogramming in tumors and how this might affect their contribution in cancer progression. This emerging aspect of tumor-associated immune cells is reviewed here, discussing metabolic reprogramming of different immune cell types, the key pathways involved, and its impact on tumor progression.
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Affiliation(s)
- Subhra K Biswas
- Singapore Immunology Network (SIgN), Agency for Science, Technology & Research (A(∗)STAR), #04-06 Immunos, 8A Biomedical Grove, Singapore 138648, Singapore.
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30
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Sunbul M, Cagman Z, Gerin F, Ozgen Z, Durmus E, Seckin D, Ahmad S, Uras F, Agirbasli M. Growth arrest-specific 6 and cardiometabolic risk factors in patients with psoriasis. Cardiovasc Ther 2015; 33:56-61. [PMID: 25752901 DOI: 10.1111/1755-5922.12112] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVES An increased risk for cardiovascular disease with psoriasis has been reported. Growth Arrest-Specific 6 (GAS6) amplifies pro-inflammatory endothelial cell activation via TAM receptors. However, it also inhibits inflammation by multiple mechanisms including phagocytosis. The objective of this study was to investigate whether plasma GAS6 levels are associated with conventional cardiometabolic (CM) risk factors in patients with psoriasis. METHODS Forty patients diagnosed with psoriasis (22 male, mean age: 43.3 ± 13.8 years) and 40 age-/sex-matched healthy controls (22 male, mean age: 39.3 ± 8.9 years) were included in the study. CM risk factors (hypertension, hyperlipidemia, diabetes mellitus, and cigarette smoking) were identified. GAS6 levels were measured by ELISA. RESULTS There were no significant differences between the plasma GAS6 levels of patients with psoriasis compared to the control group (6.6 ± 2.0 ng/mL, 7.6 ± 2.8 ng/mL, respectively, P > 0.05). However, GAS6 levels of patients with psoriasis having a smoking history (n = 11) were significantly lower than both patients with psoriasis who had no smoking history (n = 29) and controls (5.5 ± 1.7 ng/mL, 6.9 ± 1.9 ng/mL, 7.6 ± 2.8 ng/mL, respectively, P < 0.05). Similarly, psoriasis patients with at least one CM risk factor showed lower GAS6 levels compared to subjects without any CM risk factor (5.7 ± 1.7 ng/mL, 7.3 ± 2.0 ng/mL, P < 0.01). There was no correlation between the GAS6 level, disease duration or PASI score (r = 0.150, -0.150, and P = 0.310, 0.398, respectively). CONCLUSIONS This pilot study provides the first evidence in humans for an association between low plasma GAS6 levels and conventional risk factors in psoriasis. Further large scale, prospective studies are needed to confirm these results.
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Affiliation(s)
- Murat Sunbul
- Department of Cardiology, Faculty of Medicine, Marmara University, Istanbul, Turkey
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Chen CH, Chen HC, Chang CC, Peng YJ, Lee CH, Shieh YS, Hung YJ, Lin YF. Growth Arrest-Specific 6 Protein in Patients with Sjögren Syndrome: Determination of the Plasma Level and Expression in the Labial Salivary Gland. PLoS One 2015; 10:e0139955. [PMID: 26445266 PMCID: PMC4596882 DOI: 10.1371/journal.pone.0139955] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 09/18/2015] [Indexed: 01/21/2023] Open
Abstract
Aims Growth arrest-specific protein 6 (Gas6) is a vitamin K-dependent protein expressed by endothelial cells and leukocytes that are involved in cell survival, migration, and proliferation in response to inflammatory processes. The aim of this study was to assess the implications of Gas6 in Sjögren syndrome (SS) and its expression in the labial salivary gland. Methods and Results A total of 254 adults, including 159 with primary Sjögren syndrome (pSS), 34 with secondary Sjögren syndrome (sSS), and 61 normal controls, were recruited. Plasma Gas6 concentrations were determined, and Gas6 expressions in labial salivary gland (LSG) tissues from controls and pSS and sSS patients were also evaluated. Plasma Gas6 concentrations were significantly lower among patients with pSS than normal controls (13.5 ± 8.6 vs. 19.9 ± 13.4 ng/ml, p < 0.001). There were, however, no significant differences in plasma Gas6 levels between pSS and sSS patients (13.5 ± 8.6 vs. 16.9 ± 11.2 ng/ml, p = 0.068). In multivariate logistic regression analysis, after adjustment for white blood cell count, hemoglobin level, platelet count, lymphocyte count, and C3 and C4 levels, lower plasma Gas6 concentrations were significantly associated with an increased risk of SS. Moreover, by using a semi-quantitative scale to evaluate Gas6 expression in LSG tissues, Gas6 expression was found to be markedly lower in LSG tissues from pSS patients than in tissues from normal controls. Conclusions Decreased plasma Gas6 concentration and LSG expression were associated with pSS. As such, Gas6 may represent a novel independent risk factor for pSS, with a potential role in salivary gland inflammation and dysfunction.
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Affiliation(s)
- Chen-Hung Chen
- Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan
- Division of Rheumatology, Immunology and Allergy, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, School of Medicine, Tzu Chi University, Hualien, Taiwan
- Division of Rheumatology, Immunology and Allergy, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Hsiang-Cheng Chen
- Division of Rheumatology, Immunology and Allergy, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chi-Ching Chang
- Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan
- Division of Rheumatology, Immunology and Allergy, Department of Internal Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Yi-Jen Peng
- Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chien-Hsing Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Shing Shieh
- School of Dentistry, National Defense Medical Center, Department of Oral Diagnosis and Pathology, Tri-Service General Hospital, Taipei, Taiwan
| | - Yi-Jen Hung
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yuh-Feng Lin
- Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan
- Division of Nephrology, Department of Medicine, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
- * E-mail:
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Wu X, Liu X, Koul S, Lee CY, Zhang Z, Halmos B. AXL kinase as a novel target for cancer therapy. Oncotarget 2015; 5:9546-63. [PMID: 25337673 PMCID: PMC4259419 DOI: 10.18632/oncotarget.2542] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/29/2014] [Indexed: 12/12/2022] Open
Abstract
The AXL receptor tyrosine kinase and its major ligand, GAS6 have been demonstrated to be overexpressed and activated in many human cancers (such as lung, breast, and pancreatic cancer) and have been correlated with poor prognosis, promotion of increased invasiveness/metastasis, the EMT phenotype and drug resistance. Targeting AXL in different model systems with specific small molecule kinase inhibitors or antibodies alone or in combination with other drugs can lead to inactivation of AXL-mediated signaling pathways and can lead to regained drug sensitivity and improved therapeutic efficacy, defining AXL as a promising novel target for cancer therapeutics. This review highlights the data supporting AXL as a novel treatment candidate in a variety of cancers as well as the current status of drug development targeting the AXL/GAS6 axis and future perspectives in this emerging field.
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Affiliation(s)
- Xiaoliang Wu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Xuewen Liu
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China. Division of Hematology/Oncology, Herbert Irving Comprehensive Cancer Center, New York Presbyterian Hospital-Columbia University Medical Center, New York, NY, USA
| | - Sanjay Koul
- Division of Hematology/Oncology, Herbert Irving Comprehensive Cancer Center, New York Presbyterian Hospital-Columbia University Medical Center, New York, NY, USA
| | - Chang Youl Lee
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Chuncheon Sacred Heart Hospital Hallym University Medical Center, Chuncheon-si Gangwon-do 200-704 Republic of Korea
| | - Zhenfeng Zhang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Balazs Halmos
- Division of Hematology/Oncology, Herbert Irving Comprehensive Cancer Center, New York Presbyterian Hospital-Columbia University Medical Center, New York, NY, USA
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Ji R, Meng L, Li Q, Lu Q. TAM receptor deficiency affects adult hippocampal neurogenesis. Metab Brain Dis 2015; 30:633-44. [PMID: 25487541 PMCID: PMC4414696 DOI: 10.1007/s11011-014-9636-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 11/17/2014] [Indexed: 10/24/2022]
Abstract
The Tyro3, Axl and Mertk (TAM) subfamily of receptor protein tyrosine kinases functions in cell growth, differentiation, survival, and most recently found, in the regulation of immune responses and phagocytosis. All three receptors and their ligands, Gas6 (growth arrest-specific gene 6) and protein S, are expressed in the central nervous system (CNS). TAM receptors play pivotal roles in adult hippocampal neurogenesis. Loss of these receptors causes a comprised neurogenesis in the dentate gyrus of adult hippocampus. TAM receptors have a negative regulatory effect on microglia and peripheral antigen-presenting cells, and play a critical role in preventing overproduction of pro-inflammatory cytokines detrimental to the proliferation, differentiation, and survival of adult neuronal stem cells (NSCs). Besides, these receptors also play an intrinsic trophic function in supporting NSC survival, proliferation, and differentiation into immature neurons. All these events collectively ensure a sustained neurogenesis in adult hippocampus.
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Affiliation(s)
- Rui Ji
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Lingbin Meng
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Qiutang Li
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA
| | - Qingxian Lu
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, KY 40202, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, KY 40202, USA
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Tang Y, Wu S, Liu Q, Xie J, Zhang J, Han D, Lu Q, Lu Q. Mertk deficiency affects macrophage directional migration via disruption of cytoskeletal organization. PLoS One 2015; 10:e0117787. [PMID: 25617898 PMCID: PMC4305281 DOI: 10.1371/journal.pone.0117787] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Accepted: 12/30/2014] [Indexed: 01/17/2023] Open
Abstract
Mertk belongs to the Tyro3, Axl and Mertk (TAM) family of receptor tyrosine kinases, and plays a pivotal role in regulation of cytoskeletal rearrangement during phagocytosis. Phagocytosis by either professional or non-professional phagocytes is impaired in the Mertk deficient individual. In the present study, we further investigated the effects of Mertk mutation on peritoneal macrophage morphology, attachment, spreading and movement. Mertk-mutated macrophages exhibited decreased attachment, weak spreading, loss of spindle-like body shape and lack of clear leading and trailing edges within the first few hours of culture, as observed by environmental scanning electron microscopy. Time-lapse video photography recording showed that macrophage without Mertk conducted mainly random movement with oscillating swing around the cell body, and lost the directional migration action seen on the WT cells. Western blotting showed a decreased phosphorylation of focal adhesion kinase (FAK). Immunocytochemistry revealed that actin filaments and dynamic protein myosin II failed to concentrate in the leading edge of migrating cells. Microtubules were localized mainly in one side of mutant cell body, with no clear MTOC and associated radially-distributed microtubule bundles, which were clearly evident in the WT cells. Our results suggest that Mertk deficiency affects not only phagocytosis but also cell shape and migration, likely through a common regulatory mechanism on cytoskeletons.
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Affiliation(s)
- Yong Tang
- Beijing Institute of Ophthalmology, Beijing Tong-Ren Hospital, Capital Medical University, Beijing 100069, China
| | - Shen Wu
- Beijing Tong-Ren Eye Center, Beijing Tong-Ren Hospital, Capital Medical University, Beijing 100069, China
- Beijing Ophthalmology and Visual Science Key Laboratory. Beijing 100069, China
| | - Qian Liu
- Beijing Tong-Ren Eye Center, Beijing Tong-Ren Hospital, Capital Medical University, Beijing 100069, China
- Beijing Ophthalmology and Visual Science Key Laboratory. Beijing 100069, China
| | - Jiayi Xie
- National Center for Nanoscience and Technology, Beijing 100190, China
| | - Jingxue Zhang
- Beijing Tong-Ren Eye Center, Beijing Tong-Ren Hospital, Capital Medical University, Beijing 100069, China
- Beijing Ophthalmology and Visual Science Key Laboratory. Beijing 100069, China
| | - Dong Han
- National Center for Nanoscience and Technology, Beijing 100190, China
| | - Qingxian Lu
- Beijing Institute of Ophthalmology, Beijing Tong-Ren Hospital, Capital Medical University, Beijing 100069, China
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd, Louisville, KY 40202, United States of America
- * E-mail: (Qingjun Lu); (Qingxian Lu)
| | - Qingjun Lu
- Beijing Institute of Ophthalmology, Beijing Tong-Ren Hospital, Capital Medical University, Beijing 100069, China
- Beijing Tong-Ren Eye Center, Beijing Tong-Ren Hospital, Capital Medical University, Beijing 100069, China
- Beijing Ophthalmology and Visual Science Key Laboratory. Beijing 100069, China
- * E-mail: (Qingjun Lu); (Qingxian Lu)
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Axl phosphorylates Elmo scaffold proteins to promote Rac activation and cell invasion. Mol Cell Biol 2015; 35:76-87. [PMID: 25332238 PMCID: PMC4295393 DOI: 10.1128/mcb.00764-14] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The receptor tyrosine kinase Axl contributes to cell migration and invasion. Expression of Axl correlates with metastatic progression in cancer patients, yet the specific signaling events promoting invasion downstream of Axl are poorly defined. Herein, we report Elmo scaffolds to be direct substrates and binding partners of Axl. Elmo proteins are established to interact with Dock family guanine nucleotide exchange factors to control Rac-mediated cytoskeletal dynamics. Proteomics and mutagenesis studies reveal that Axl phosphorylates Elmo1/2 on a conserved carboxyl-terminal tyrosine residue. Upon Gas6-dependent activation of Axl, endogenous Elmo2 becomes phosphorylated on Tyr-713 and enters into a physical complex with Axl in breast cancer cells. Interfering with Elmo2 expression prevented Gas6-induced Rac1 activation in breast cancer cells. Similarly to blocking of Axl, Elmo2 knockdown or pharmacological inhibition of Dock1 abolishes breast cancer cell invasion. Interestingly, Axl or Elmo2 knockdown diminishes breast cancer cell proliferation. Rescue of Elmo2 knockdown cells with the wild-type protein but not with Elmo2 harboring Tyr-713-Phe mutations restores cell invasion and cell proliferation. These results define a new mechanism by which Axl promotes cell proliferation and invasion and identifies inhibition of the Elmo-Dock pathway as a potential therapeutic target to stop Axl-induced metastases.
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Abstract
The control of cellular growth and proliferation is key to the maintenance of homeostasis. Survival, proliferation, and arrest are regulated, in part, by Growth Arrest Specific 6 (Gas6) through binding to members of the TAM receptor tyrosine kinase family. Activation of the TAM receptors leads to downstream signaling through common kinases, but the exact mechanism within each cellular context varies and remains to be completely elucidated. Deregulation of the TAM family, due to its central role in mediating cellular proliferation, has been implicated in multiple diseases. Axl was cloned as the first TAM receptor in a search for genes involved in the progression of chronic to acute-phase leukemia, and has since been established as playing a critical role in the progression of cancer. The oncogenic nature of Axl is demonstrated through its activation of signaling pathways involved in proliferation, migration, inhibition of apoptosis, and therapeutic resistance. Despite its recent discovery, significant progress has been made in the development of effective clinical therapeutics targeting Axl. In order to accurately define the role of Axl in normal and diseased processes, it must be analyzed in a cell type-specific context.
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Lew ED, Oh J, Burrola PG, Lax I, Zagórska A, Través PG, Schlessinger J, Lemke G. Differential TAM receptor-ligand-phospholipid interactions delimit differential TAM bioactivities. eLife 2014; 3. [PMID: 25265470 PMCID: PMC4206827 DOI: 10.7554/elife.03385] [Citation(s) in RCA: 197] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 09/28/2014] [Indexed: 12/22/2022] Open
Abstract
The TAM receptor tyrosine kinases Tyro3, Axl, and Mer regulate key features of cellular physiology, yet the differential activities of the TAM ligands Gas6 and Protein S are poorly understood. We have used biochemical and genetic analyses to delineate the rules for TAM receptor–ligand engagement and find that the TAMs segregate into two groups based on ligand specificity, regulation by phosphatidylserine, and function. Tyro3 and Mer are activated by both ligands but only Gas6 activates Axl. Optimal TAM signaling requires coincident TAM ligand engagement of both its receptor and the phospholipid phosphatidylserine (PtdSer): Gas6 lacking its PtdSer-binding ‘Gla domain’ is significantly weakened as a Tyro3/Mer agonist and is inert as an Axl agonist, even though it binds to Axl with wild-type affinity. In two settings of TAM-dependent homeostatic phagocytosis, Mer plays a predominant role while Axl is dispensable, and activation of Mer by Protein S is sufficient to drive phagocytosis. DOI:http://dx.doi.org/10.7554/eLife.03385.001 Cells send out and receive signals to communicate with other cells. Detecting these signals is largely carried out by proteins called receptors that span the cell surface membrane. These proteins typically have extracellular domains outside of the cell that can bind to specific signaling molecules and an intracellular domain inside the cell that relays the information inwards to trigger a response. Three such receptor proteins are collectively known as the TAM receptors. Each day, many billions of cells in the human body die and are engulfed by other cells and broken down so that their building blocks can be reused. TAM receptors are required for this process; and the TAM receptors also help prevent the immune system from going out of control, which would damage the body's own tissues. Two different signaling proteins, called Gas6 and Protein S, can bind to and activate TAM receptors. Both of the signaling proteins can also bind to a phospholipid molecule that is found on the surface membrane of dead cells. However, it is not known if all three TAM receptors bind to both signaling proteins equally, and the importance of the phospholipid-binding domain in the signaling proteins remains unclear. To shed light on the workings of these receptors, Lew et al. created mouse cells that each only express one out of the three TAM receptors. These cells were then exposed to intact Gas6 and Protein S, or shortened versions that lacked the phospholipid-binding domain. Lew et al. found that Gas6 could trigger a response through all three TAM receptors but that Protein S was specific for only two out of the three receptors. Signaling proteins with or without their phospholipid-binding domains bound equally well to the receptors, but the maximum level of response was only triggered when both signaling proteins were intact and the phospholipid molecule was present. This is important since the phospholipid can be thought of as an ‘eat-me’ signal by which the dead cells are recognized by the TAM receptor-expressing cells that will engulf them. Using mice that only produce a TAM receptor called Mer, Lew et al. show that Protein S alone can trigger the process that engulfs and breaks down cells in a living organism. These data and previous work suggest that two TAM receptors—including Mer—are involved in the daily engulfment of dying cells, whereas the third mediates this process during infection and tissue damage. Molecules that inhibit or activate the function of TAM receptors are currently being developed to treat cancer and other diseases. By revealing which receptors respond to which signaling molecules, the findings of Lew et al. will serve to guide these efforts. DOI:http://dx.doi.org/10.7554/eLife.03385.002
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Affiliation(s)
- Erin D Lew
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, United States
| | - Jennifer Oh
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, United States
| | - Patrick G Burrola
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, United States
| | - Irit Lax
- Department of Pharmacology, Yale University School of Medicine, New Haven, United States
| | - Anna Zagórska
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, United States
| | - Paqui G Través
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, United States
| | - Joseph Schlessinger
- Department of Pharmacology, Yale University School of Medicine, New Haven, United States
| | - Greg Lemke
- Molecular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, United States
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Bhattacharyya S, Zagórska A, Lew ED, Shrestha B, Rothlin CV, Naughton J, Diamond MS, Lemke G, Young JAT. Enveloped viruses disable innate immune responses in dendritic cells by direct activation of TAM receptors. Cell Host Microbe 2014; 14:136-47. [PMID: 23954153 DOI: 10.1016/j.chom.2013.07.005] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Revised: 05/21/2013] [Accepted: 06/14/2013] [Indexed: 01/21/2023]
Abstract
Upon activation by the ligands Gas6 and Protein S, Tyro3/Axl/Mer (TAM) receptor tyrosine kinases promote phagocytic clearance of apoptotic cells and downregulate immune responses initiated by Toll-like receptors and type I interferons (IFNs). Many enveloped viruses display the phospholipid phosphatidylserine on their membranes, through which they bind Gas6 and Protein S and engage TAM receptors. We find that ligand-coated viruses activate TAM receptors on dendritic cells (DCs), dampen type I IFN signaling, and thereby evade host immunity and promote infection. Upon virus challenge, TAM-deficient DCs display type I IFN responses that are elevated in comparison to wild-type cells. As a consequence, TAM-deficient DCs are relatively resistant to infection by flaviviruses and pseudotyped retroviruses, but infection can be restored with neutralizing type I IFN antibodies. Correspondingly, a TAM kinase inhibitor antagonizes the infection of wild-type DCs. Thus, TAM receptors are engaged by viruses in order to attenuate type I IFN signaling and represent potential therapeutic targets.
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Affiliation(s)
- Suchita Bhattacharyya
- Nomis Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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Subramanian M, Hayes CD, Thome JJ, Thorp E, Matsushima GK, Herz J, Farber DL, Liu K, Lakshmana M, Tabas I. An AXL/LRP-1/RANBP9 complex mediates DC efferocytosis and antigen cross-presentation in vivo. J Clin Invest 2014; 124:1296-308. [PMID: 24509082 DOI: 10.1172/jci72051] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/21/2013] [Indexed: 01/02/2023] Open
Abstract
The phagocytosis of apoptotic cells (ACs), or efferocytosis, by DCs is critical for self-tolerance and host defense. Although many efferocytosis-associated receptors have been described in vitro, the functionality of these receptors in vivo has not been explored in depth. Using a spleen efferocytosis assay and targeted genetic deletion in mice, we identified a multiprotein complex--composed of the receptor tyrosine kinase AXL, LDL receptor-related protein-1 (LRP-1), and RAN-binding protein 9 (RANBP9)--that mediates DC efferocytosis and antigen cross-presentation. We found that AXL bound ACs, but required LRP-1 to trigger internalization, in murine CD8α+ DCs and human-derived DCs. AXL and LRP-1 did not interact directly, but relied on RANBP9, which bound both AXL and LRP-1, to form the complex. In a coculture model of antigen presentation, the AXL/LRP-1/RANBP9 complex was used by DCs to cross-present AC-associated antigens to T cells. Furthermore, in a murine model of herpes simplex virus-1 infection, mice lacking DC-specific LRP-1, AXL, or RANBP9 had increased AC accumulation, defective viral antigen-specific CD8+ T cell activation, enhanced viral load, and decreased survival. The discovery of this multiprotein complex that mediates functionally important DC efferocytosis in vivo may have implications for future studies related to host defense and DC-based vaccines.
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Ji R, Tian S, Lu HJ, Lu Q, Zheng Y, Wang X, Ding J, Li Q, Lu Q. TAM receptors affect adult brain neurogenesis by negative regulation of microglial cell activation. THE JOURNAL OF IMMUNOLOGY 2013; 191:6165-77. [PMID: 24244024 DOI: 10.4049/jimmunol.1302229] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
TAM tyrosine kinases play multiple functional roles, including regulation of the target genes important in homeostatic regulation of cytokine receptors or TLR-mediated signal transduction pathways. In this study, we show that TAM receptors affect adult hippocampal neurogenesis and loss of TAM receptors impairs hippocampal neurogenesis, largely attributed to exaggerated inflammatory responses by microglia characterized by increased MAPK and NF-κB activation and elevated production of proinflammatory cytokines that are detrimental to neuron stem cell proliferation and neuronal differentiation. Injection of LPS causes even more severe inhibition of BrdU incorporation in the Tyro3(-/-)Axl(-/-)Mertk(-/-) triple-knockout (TKO) brains, consistent with the LPS-elicited enhanced expression of proinflammatory mediators, for example, IL-1β, IL-6, TNF-α, and inducible NO synthase, and this effect is antagonized by coinjection of the anti-inflammatory drug indomethacin in wild-type but not TKO brains. Conditioned medium from TKO microglia cultures inhibits neuron stem cell proliferation and neuronal differentiation. IL-6 knockout in Axl(-/-)Mertk(-/-) double-knockout mice overcomes the inflammatory inhibition of neurogenesis, suggesting that IL-6 is a major downstream neurotoxic mediator under homeostatic regulation by TAM receptors in microglia. Additionally, autonomous trophic function of the TAM receptors on the proliferating neuronal progenitors may also promote progenitor differentiation into immature neurons.
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Affiliation(s)
- Rui Ji
- Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, KY 40202
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41
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Lee CH, Shieh YS, Tsai CS, Hung YJ, Tsai YT, Lin CY. Plasma concentrations predict aortic expression of growth-arrest-specific protein 6 in patients undergoing coronary artery bypass grafting. PLoS One 2013; 8:e79452. [PMID: 24236135 PMCID: PMC3827360 DOI: 10.1371/journal.pone.0079452] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Accepted: 09/23/2013] [Indexed: 12/14/2022] Open
Abstract
AIMS The tyrosine kinase receptor Axl is expressed in the vasculature, and growth arrest-specific protein 6 (Gas6) is its ligand. Plasma Gas6 levels have been shown to be associated with endothelial dysfunction markers and cardiovascular events. We set out to determine the plasma Gas6 levels in patients undergoing coronary artery bypass grafting (CABG) and investigate the expression of Gas6 and Axl in the aorta. METHODS AND RESULTS Immunoassays were used to investigate plasma Gas6 levels in CABG patients (n = 19) and control subjects (n = 20). The expression of Gas6 and Axl in the injured aorta were examined by reverse transcription-polymerase chain reactions, real-time reverse transcription-polymerase chain reactions, western blotting, and immunohistochemical staining. Plasma Gas6 levels were significantly lower in CABG patients than in matched control subjects. In CABG patients, plasma Gas6 levels were negatively correlated with fasting glucose, E-selectin, and vascular cell adhesion molecule-1 levels. The levels predicted the operative mortality rate and were positively correlated with plasma soluble Axl (sAxl) levels and Gas6 expression in the aorta. Moreover, Gas6 expression was positively correlated with Axl expression in the aorta. CONCLUSION We concluded that plasma Gas6 is associated with fasting glucose, endothelial dysfunction markers, sAxl values, and vascular Gas6 expression in CABG patients, and it predicts the operative mortality of these patients. These findings suggest that the Gas6/Axl system is crucial in vascular biology.
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Affiliation(s)
- Chien-Hsing Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Shing Shieh
- Department of Oral Diagnosis and Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chien-Sung Tsai
- Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Jen Hung
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Yi-Ting Tsai
- Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Chih-Yuan Lin
- Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
- * E-mail:
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Cook RS, Jacobsen KM, Wofford AM, DeRyckere D, Stanford J, Prieto AL, Redente E, Sandahl M, Hunter DM, Strunk KE, Graham DK, Earp HS. MerTK inhibition in tumor leukocytes decreases tumor growth and metastasis. J Clin Invest 2013; 123:3231-42. [PMID: 23867499 DOI: 10.1172/jci67655] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Accepted: 05/10/2013] [Indexed: 01/14/2023] Open
Abstract
MerTK, a receptor tyrosine kinase (RTK) of the TYRO3/AXL/MerTK family, is expressed in myeloid lineage cells in which it acts to suppress proinflammatory cytokines following ingestion of apoptotic material. Using syngeneic mouse models of breast cancer, melanoma, and colon cancer, we found that tumors grew slowly and were poorly metastatic in MerTK-/- mice. Transplantation of MerTK-/- bone marrow, but not wild-type bone marrow, into lethally irradiated MMTV-PyVmT mice (a model of metastatic breast cancer) decreased tumor growth and altered cytokine production by tumor CD11b+ cells. Although MerTK expression was not required for tumor infiltration by leukocytes, MerTK-/- leukocytes exhibited lower tumor cell-induced expression of wound healing cytokines, e.g., IL-10 and growth arrest-specific 6 (GAS6), and enhanced expression of acute inflammatory cytokines, e.g., IL-12 and IL-6. Intratumoral CD8+ T lymphocyte numbers were higher and lymphocyte proliferation was increased in tumor-bearing MerTK-/- mice compared with tumor-bearing wild-type mice. Antibody-mediated CD8+ T lymphocyte depletion restored tumor growth in MerTK-/- mice. These data demonstrate that MerTK signaling in tumor-associated CD11b+ leukocytes promotes tumor growth by dampening acute inflammatory cytokines while inducing wound healing cytokines. These results suggest that inhibition of MerTK in the tumor microenvironment may have clinical benefit, stimulating antitumor immune responses or enhancing immunotherapeutic strategies.
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Affiliation(s)
- Rebecca S Cook
- Department of Cancer Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Li Q, Lu Q, Lu H, Tian S, Lu Q. Systemic autoimmunity in TAM triple knockout mice causes inflammatory brain damage and cell death. PLoS One 2013; 8:e64812. [PMID: 23840307 PMCID: PMC3688737 DOI: 10.1371/journal.pone.0064812] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 04/18/2013] [Indexed: 12/14/2022] Open
Abstract
The Tyro3, Axl and Mertk (TAM) triply knockout (TKO) mice exhibit systemic autoimmune diseases, with characteristics of increased proinflammatory cytokine production, autoantibody deposition and autoreactive lymphocyte infiltration into a variety of tissues. Here we show that TKO mice produce high level of serum TNF-α and specific autoantibodies deposited onto brain blood vessels. The brain-blood barrier (BBB) in mutant brains exhibited increased permeability for Evans blue and fluorescent-dextran, suggesting a breakdown of the BBB in the mutant brains. Impaired BBB integrity facilitated autoreactive T cells infiltrating into all regions of the mutant brains. Brain autoimmune disorder caused accumulation of the ubiquitin-reactive aggregates in the mutant hippocampus, and early formation of autofluorescent lipofuscins in the neurons throughout the entire brains. Chronic neuroinflammation caused damage of the hippocampal mossy fibers and neuronal apoptotic death. This study shows that chronic systemic inflammation and autoimmune disorders in the TKO mice cause neuronal damage and death.
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MESH Headings
- Animals
- Apoptosis
- Autoantibodies/blood
- Autoimmune Diseases/genetics
- Autoimmune Diseases/immunology
- Autoimmune Diseases/pathology
- Blood-Brain Barrier/metabolism
- Brain Damage, Chronic/genetics
- Brain Damage, Chronic/immunology
- Brain Damage, Chronic/pathology
- CA3 Region, Hippocampal/blood supply
- CA3 Region, Hippocampal/immunology
- CA3 Region, Hippocampal/pathology
- Capillary Permeability/immunology
- Cells, Cultured
- Cytokines/metabolism
- Dentate Gyrus/blood supply
- Dentate Gyrus/immunology
- Dentate Gyrus/pathology
- Endothelial Cells/immunology
- Endothelial Cells/metabolism
- Female
- Gene Knockdown Techniques
- Inclusion Bodies/metabolism
- Inflammation Mediators/metabolism
- Lipopolysaccharides/pharmacology
- Mice
- Mice, 129 Strain
- Mice, Inbred C57BL
- Mice, Knockout
- Microvessels/immunology
- Microvessels/metabolism
- Neurons/physiology
- Proto-Oncogene Proteins/genetics
- Receptor Protein-Tyrosine Kinases/genetics
- T-Lymphocytes/immunology
- Tumor Necrosis Factor-alpha/blood
- Ubiquitinated Proteins/metabolism
- c-Mer Tyrosine Kinase
- Axl Receptor Tyrosine Kinase
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Affiliation(s)
- Qiutang Li
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States of America
- The James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky, United States of America
| | - Qingjun Lu
- School of Basic Medicine and Beijing Tong-Ren Hospital, Beijing Ophthalmology and Visual Science Key Laboratory, Capital Medical University, Beijing, China
| | - Huayi Lu
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States of America
| | - Shifu Tian
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States of America
| | - Qingxian Lu
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States of America
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, Kentucky, United States of America
- The James Graham Brown Cancer Center, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail:
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Qi N, Liu P, Zhang Y, Wu H, Chen Y, Han D. Development of a spontaneous liver disease resembling autoimmune hepatitis in mice lacking tyro3, axl and mer receptor tyrosine kinases. PLoS One 2013; 8:e66604. [PMID: 23799121 PMCID: PMC3684578 DOI: 10.1371/journal.pone.0066604] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 05/07/2013] [Indexed: 12/19/2022] Open
Abstract
Autoimmune hepatitis (AIH) is a severe type of chronic liver disease. The lack of appropriate animal models has resulted in a limited understanding regarding the etiology of AIH. Here, we demonstrated that mice deficient in Tyro3, Axl and Mer (TAM) receptor tyrosine kinases (RTKs) developed persistent inflammatory liver damage resembling AIH. Tyro3−/−Axl−/−Mer−/− triple mutant (TAM−/−) mice exhibited chronic hepatitis, manifested by progressive appearance of interface hepatitis, immune cell infiltrations and elevated inflammatory cytokine levels in the liver. Accordingly, increased levels of transaminases were observed. Moreover, characteristic autoantibodies and high levels of plasma immunoglobulin G for AIH were detected as TAM−/− mice aged. Finally, we provided evidence that the liver damage in TAM−/− mice mainly result from bone marrow-derived cells and could be rescued by transplantation of WT bone marrow cells. Results suggest that TAM RTKs play an important role in maintaining immune tolerance of the liver.
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Affiliation(s)
- Nan Qi
- Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Anhui Medical University, Hefei, China
| | - Peipei Liu
- Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Yue Zhang
- Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Hui Wu
- Department of Pathology, Navy General Hospital, Beijing, China
| | - Yongmei Chen
- Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Daishu Han
- Department of Cell Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
- * E-mail:
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Growth arrest specific gene 6 protein concentration in cerebrospinal fluid correlates with relapse severity in multiple sclerosis. Mediators Inflamm 2013; 2013:406483. [PMID: 23781120 PMCID: PMC3678413 DOI: 10.1155/2013/406483] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 04/08/2013] [Accepted: 04/22/2013] [Indexed: 12/23/2022] Open
Abstract
Background. Growth arrest specific gene 6 (Gas6) protein enhances survival of oligodendrocytes and neurons, and it is involved in autoimmunity. Therefore, we aimed to verify whether cerebrospinal-fluid (CSF) Gas6 concentration may represent a biomarker of disease activity in multiple sclerosis. Methods. Sixty-five patients who underwent a spinal tap during relapse of relapsing/remitting multiple sclerosis (RR-MS)(McDonald-criteria) were studied. Forty patients affected by noninflammatory/nonautoimmune neurological diseases served as controls. Relapse was defined according to Schumacher criteria. Symptoms were grouped according to Kurtzke-Functional System (FS). Clinical characteristics of the relapse, duration, Expanded-Disability-Status Scale (EDSS) change, number of FS involved, completeness of recovery, age, steroid therapy, were categorised. Patients were followed at 6-month intervals to assess relapse rate and EDSS progression. Gas6 was measured (CSF, plasma) by in-house-enzyme-linked immunoassay (ELISA). Results. Higher CSF Gas6 concentrations were observed in relapses lasting ≤60 days (8.7 ± 3.9 ng/mL) versus >60 days (6.5 ± 2.6) or controls (6.5 ± 2.4; P = 0.05), with ≤2 FS involved (8.5 ± 3.8) versus >2 FS (5.6 ± 2.5) (P < 0.05) and EDSS change ≤2.5 points (8.8 ± 3.7) versus >2.5 (6.5 ± 3.5) (P = 0.04). Conversely, CSF Gas6 was not predictive of the completeness of recovery. Plasma and CSF concentrations were not related (R2 = 0.0003), and neither were predictive of relapse rate or EDSS progression after first relapse. Conclusions. CSF concentration of Gas6 is inversely correlated with the severity of relapse in RR-MS patients but does not predict the subsequent course of the disease.
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Plasma concentrations of growth arrest specific protein 6 and the soluble form of its tyrosine kinase receptor Axl in patients with systemic lupus erythematosus and Behçets disease. J Clin Immunol 2012; 32:1279-86. [PMID: 22833165 DOI: 10.1007/s10875-012-9743-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 07/16/2012] [Indexed: 12/30/2022]
Abstract
PURPOSE The aim of the present study was to investigate plasma concentrations of Gas6 and its soluble tyrosine kinase receptor sAxl in Systemic lupus erythematosus (SLE) and Behçets disease (BD) patients and to correlate those levels with clinical and laboratory manifestations of the diseases. METHODS The study included 89 female SLE and 49 male BD patients. Twenty-seven age and sex matched healthy volunteers served as controls. All patients were subjected to full clinical examination, laboratory investigations and assessment of disease activity. Plasma concentrations of Gas6 and sAxl were quantified using ELISA technique. RESULTS The level of Gas6 and Axl were significantly altered in the SLE patients (p < 0.001) and in the BD patients (p 0.001 and 0.04 respectively) compared to those of the control. In SLE, the Gas6 was remarkably lower in those with class 1 lupus nephritis and in those with neuropsychiatric manifestations. In the BD patients, the level of Axl was significantly increased in those with neurological disease activity. The number of lymphocytes significantly negatively correlated with the gas6 and Axl levels significantly correlated with the number of neutrophils and negatively with the lymphocytic count in the BD patients. CONCLUSION The plasma concentrations of Gas6 and Axl were significantly altered in SLE and BD patients, suggesting that the Axl receptor shedding is an active process affected by and influences Gas6-mediated Axl-signaling in both diseases. Special attention is required in SLE patients with early lupus nephritis and neuropsychiatric manifestations and BD patients presenting with neurological disease activity. The relation with lymphocytes and neutrophils in BD throws light on the role of gas6 and Axl on their known resistance to cell death. Although the mechanisms responsible for the initiation of BD remain to be clarified, the role of the apoptotic process seems critical throughout the disease.
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Park HJ, Baen JY, Lee YJ, Choi YH, Kang JL. The TAM-family receptor Mer mediates production of HGF through the RhoA-dependent pathway in response to apoptotic cells. Mol Biol Cell 2012; 23:3254-65. [PMID: 22740630 PMCID: PMC3418318 DOI: 10.1091/mbc.e12-01-0029] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The TAM receptor protein tyrosine kinases Tyro3, Axl, and Mer play important roles in macrophage function. We investigated the roles of the TAM receptors in mediating the induction of hepatocyte growth factor (HGF) during the interaction of macrophages with apoptotic cells. Mer-specific neutralizing antibody, small interfering RNA (siRNA), and a recombinant Mer protein (Mer/Fc) inhibited HGF mRNA and protein expression, as well as activation of RhoA, Akt, and specific mitogen-activated protein (MAP) kinases in response to apoptotic cells. Inhibition of Axl or Tyro3 with specific antibodies, siRNA, or Fc-fusion proteins did not prevent apoptotic cell-induced HGF mRNA and protein expression and did not inhibit activation of the postreceptor signaling molecules RhoA and certain MAP kinases, including extracellular signal-regulated protein kinase and c-Jun NH(2)-terminal kinase. However, Axl- and Tyro3-specific blockers did inhibit the activation of Akt and p38 MAP kinase in response to apoptotic cells. In addition, none of the TAM receptors mediated the effects of apoptotic cells on transforming growth factor-β or epidermal growth factor mRNA expression. However, they were involved in the induction of vascular endothelial growth factor mRNA expression. Our data provide evidence that when macrophages interact with apoptotic cells, only Mer of the TAM-family receptors is responsible for mediating transcriptional HGF production through a RhoA-dependent pathway.
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Affiliation(s)
- Hyun-Jung Park
- Department of Physiology, School of Medicine, Ewha Womans University, Seoul, Korea
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48
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Zheng Y, Wang Q, Xiao B, Lu Q, Wang Y, Wang X. Involvement of receptor tyrosine kinase Tyro3 in amyloidogenic APP processing and β-amyloid deposition in Alzheimer's disease models. PLoS One 2012; 7:e39035. [PMID: 22701746 PMCID: PMC3372537 DOI: 10.1371/journal.pone.0039035] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 05/15/2012] [Indexed: 01/11/2023] Open
Abstract
Alzheimer's disease (AD) is the most common progressive neurodegenerative disease known to humankind. It is characterized by brain atrophy, extracellular amyloid plaques, and intracellular neurofibril tangles. β-amyloid cascade is considered the major causative player in AD. Up until now, the mechanisms underlying the process of Aβ generation and accumulation in the brain have not been well understood. Tyro3 receptor belongs to the TAM receptor subfamily of receptor protein tyrosine kinases (RPTKs). It is specifically expressed in the neurons of the neocortex and hippocampus. In this study, we established a cell model stably expressing APPswe mutants and producing Aβ. We found that overexpression of Tyro3 receptor in the cell model significantly decreased Aβ generation and also down-regulated the expression of β-site amyloid precursor protein cleaving enzyme (BACE1). However, the effects of Tyro3 were inhibited by its natural ligand, Gas6, in a concentration-dependent manner. In order to confirm the role of Tyro3 in the progression of AD development, we generated an AD transgenic mouse model accompanied by Tyro3 knockdown. We observed a significant increase in the number of amyloid plaques in the hippocampus in the mouse model. More plaque-associated clusters of astroglia were also detected. The present study may help researchers determine the role of Tyro3 receptor in the neuropathology of AD.
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Affiliation(s)
- Yan Zheng
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Qi Wang
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Bing Xiao
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Qingjun Lu
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Yizheng Wang
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
| | - Xiaomin Wang
- Department of Physiology, Capital Medical University, Key Laboratory for Neurodegenerative Disorders of the Ministry of Education, Beijing, People's Republic of China
- * E-mail:
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Brown JE, Krodel M, Pazos M, Lai C, Prieto AL. Cross-phosphorylation, signaling and proliferative functions of the Tyro3 and Axl receptors in Rat2 cells. PLoS One 2012; 7:e36800. [PMID: 22606290 PMCID: PMC3351477 DOI: 10.1371/journal.pone.0036800] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 04/07/2012] [Indexed: 12/29/2022] Open
Abstract
The dysregulation of receptor protein tyrosine kinase (RPTK) function can result in changes in cell proliferation, cell growth and metastasis leading to malignant transformation. Among RPTKs, the TAM receptor family composed of three members Tyro3, Axl, and Mer has been recognized to have a prominent role in cell transformation. In this study we analyzed the consequences of Tyro3 overexpression on cell proliferation, activation of signaling pathways and its functional interactions with Axl. Overexpression of Tyro3 in the Rat2 cell line that expresses Axl, but not Mer or Tyro3, resulted in a 5 fold increase in cell proliferation. This increase was partially blocked by inhibitors of the mitogen-activated protein kinase (MAPK) signaling pathway but not by inhibitors of the phosphatidylinositol 3-kinase (PI(3)K) signaling pathway. Consistent with these findings, an increase in ERK1/2 phosphorylation was detected with Tyro3 but not with Axl overexpression. In contrast, activation of Axl stimulated the PI(3)K pathway, which was mitigated by co-expression of Tyro3. The overexpression of Tyro3 enhanced Gas6-mediated Axl phosphorylation, which was not detected upon overexpression of a “kinase dead” form of Tyro3 (kdTyro3). In addition, the overexpression of Axl induced kdTyro3 phosphorylation. Co-immunoprecipitation experiments confirmed that the Axl and Tyro3 receptors are closely associated. These findings show that overexpression of Tyro3 in the presence of Axl promotes cell proliferation, and that co-expression of Axl and Tyro3 can affect the outcome of Gas6-initiated signaling. Furthermore, they demonstrate a functional interaction between the members of the TAM receptor family which can shed light on the molecular mechanisms underlying the functional consequences of TAM receptor activation in cell transformation, neural function, immune function, and reproductive function among others.
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Affiliation(s)
- Jessica E. Brown
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
- Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Meredith Krodel
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Mauricio Pazos
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Cary Lai
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Anne L. Prieto
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
- * E-mail:
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Schmidt T, Ben-Batalla I, Schultze A, Loges S. Macrophage-tumor crosstalk: role of TAMR tyrosine kinase receptors and of their ligands. Cell Mol Life Sci 2012; 69:1391-414. [PMID: 22076650 PMCID: PMC11115155 DOI: 10.1007/s00018-011-0863-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2011] [Revised: 10/14/2011] [Accepted: 10/14/2011] [Indexed: 02/07/2023]
Abstract
Ample clinical and preclinical evidence indicates that macrophages interact with tumor cells as well as with virtually all populations of host cells present in the tumor microenvironment. This crosstalk can strongly promote malignancy, but also has in principle the potential to inhibit tumor growth. Thus, it is of the utmost importance to improve our understanding of the mechanisms driving the pro- and antimalignant behavior of tumor-associated macrophages (TAMs) in order to develop better anticancer therapies. In this review, we discuss the biological consequences of reciprocal interactions between TAMs, cancer cells, endothelial cells, fibroblasts and other leukocyte subfractions within tumors. It was recently elucidated that tumors specifically educate macrophages to secrete growth arrest-specific gene 6 (Gas6), the common ligand of the Tyro3, Axl, Mer receptor (TAMR) family. In turn, Gas6 fosters tumor growth by promoting cancer cell proliferation. Therefore, the Gas6-TAMR axis might represent a novel target for disrupting tumor-macrophage crosstalk. We summarize here what is known about TAMR and their ligands in (human) cancer biology. In order to shed more light on the role of macrophages in human cancer, we additionally provide an overview of what is currently known about the prognostic impact of TAMs in human cancer.
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Affiliation(s)
- Thomas Schmidt
- Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany
| | - Isabel Ben-Batalla
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
- Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Alexander Schultze
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
- Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Sonja Loges
- Department of Hematology and Oncology with Sections BMT and Pneumology, Hubertus Wald Tumorzentrum, University Comprehensive Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany
- Institute of Tumor Biology, Center of Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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