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Deng H, Jia G, Li P, Tang Y, Zhao L, Yang Q, Zhao J, Wang J, Tu Y, Yong X, Zhang S, Mo X, Billadeau DD, Su Z, Jia D. The WDR11 complex is a receptor for acidic-cluster-containing cargo proteins. Cell 2024; 187:4272-4288.e20. [PMID: 39013469 PMCID: PMC11316641 DOI: 10.1016/j.cell.2024.06.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Revised: 05/06/2024] [Accepted: 06/18/2024] [Indexed: 07/18/2024]
Abstract
Vesicle trafficking is a fundamental process that allows for the sorting and transport of specific proteins (i.e., "cargoes") to different compartments of eukaryotic cells. Cargo recognition primarily occurs through coats and the associated proteins at the donor membrane. However, it remains unclear whether cargoes can also be selected at other stages of vesicle trafficking to further enhance the fidelity of the process. The WDR11-FAM91A1 complex functions downstream of the clathrin-associated AP-1 complex to facilitate protein transport from endosomes to the TGN. Here, we report the cryo-EM structure of human WDR11-FAM91A1 complex. WDR11 directly and specifically recognizes a subset of acidic clusters, which we term super acidic clusters (SACs). WDR11 complex assembly and its binding to SAC-containing proteins are indispensable for the trafficking of SAC-containing proteins and proper neuronal development in zebrafish. Our studies thus uncover that cargo proteins could be recognized in a sequence-specific manner downstream of a protein coat.
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Affiliation(s)
- Huaqing Deng
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Guowen Jia
- State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610044, China
| | - Ping Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Yingying Tang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Lin Zhao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Qin Yang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Jia Zhao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Jinrui Wang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Yingfeng Tu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Xin Yong
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Sitao Zhang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China
| | - Xianming Mo
- Department of Pediatric Surgery and Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Daniel D Billadeau
- Division of Oncology Research and Schulze Center for Novel Therapeutics, Mayo Clinic, Rochester, MN 55905, USA
| | - Zhaoming Su
- State Key Laboratory of Biotherapy, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610044, China.
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu 610041, China.
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2
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Ma Z, Sun Y, Yu Y, Xiao W, Xiao Z, Zhong T, Xiang X, Li Z. Extracellular vesicles containing MFGE8 from colorectal cancer facilitate macrophage efferocytosis. Cell Commun Signal 2024; 22:295. [PMID: 38802814 PMCID: PMC11131254 DOI: 10.1186/s12964-024-01669-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Accepted: 05/18/2024] [Indexed: 05/29/2024] Open
Abstract
BACKGROUND Colorectal cancer (CRC) commonly exhibits tolerance to cisplatin treatment, but the underlying mechanisms remain unclear. Within the tumor microenvironment, macrophages play a role in resisting the cytotoxic effects of chemotherapy by engaging in efferocytosis to clear apoptotic cells induced by chemotherapeutic agents. The involvement of extracellular vesicles (EVs), an intercellular communicator within the tumor microenvironment, in regulating the efferocytosis for the promotion of drug resistance has not been thoroughly investigated. METHODS We constructed GFP fluorescent-expressing CRC cell lines (including GFP-CT26 and GFP-MC38) to detect macrophage efferocytosis through flow cytometric analysis. We isolated and purified CRC-secreted EVs using a multi-step ultracentrifugation method and identified them through electron microscopy and nanoflow cytometry. Proteomic analysis was conducted to identify the protein molecules carried by CRC-EVs. MFGE8 knockout CRC cell lines were constructed using CRISPR-Cas9, and their effects were validated through in vitro and in vivo experiments using Western blotting, immunofluorescence, and flow cytometric analysis, confirming that these EVs activate the macrophage αvβ3-Src-FAK-STAT3 signaling pathway, thereby promoting efferocytosis. RESULTS In this study, we found that CRC-derived EVs (CRC-EVs) enhanced macrophage efferocytosis of cisplatin-induced apoptotic CRC cells. Analysis of The Cancer Genome Atlas (TCGA) database revealed a high expression of the efferocytosis-associated gene MFGE8 in CRC patients, suggesting a poorer prognosis. Additionally, mass spectrometry-based proteomic analysis identified a high abundance of MFGE8 protein in CRC-EVs. Utilizing CRISPR-Cas9 gene edition system, we generated MFGE8-knockout CRC cells, demonstrating that their EVs fail to upregulate macrophage efferocytosis in vitro and in vivo. Furthermore, we demonstrated that MFGE8 in CRC-EVs stimulated macrophage efferocytosis by increasing the expression of αvβ3 on the cell surface, thereby activating the intracellular Src-FAK-STAT3 signaling pathway. CONCLUSIONS Therefore, this study highlighted a mechanism in CRC-EVs carrying MFGE8 activated the macrophage efferocytosis. This activation promoted the clearance of cisplatin-induced apoptotic CRC cells, contributing to CRC resistance against cisplatin. These findings provide novel insights into the potential synergistic application of chemotherapy drugs, EVs inhibitors, and efferocytosis antagonists for CRC treatment.
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Affiliation(s)
- Zhixin Ma
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Yu Sun
- Guangdong Provincial Key Laboratory of Digestive Cancer Research, Digestive Diseases Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Yang Yu
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Wenjun Xiao
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Zhijie Xiao
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Tianyu Zhong
- Department of Laboratory Medicine, First Affiliated Hospital of Gannan Medical University, Ganzhou, 341004, China
| | - Xi Xiang
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China
| | - Zhigang Li
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen, 518107, China.
- Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research, Shenzhen, 518107, China.
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Joshi S, López L, Morosi LG, Amadio R, Pachauri M, Bestagno M, Ogar IP, Giacca M, Piperno GM, Vorselen D, Benvenuti F. Tim4 enables large peritoneal macrophages to cross-present tumor antigens at early stages of tumorigenesis. Cell Rep 2024; 43:114096. [PMID: 38607919 DOI: 10.1016/j.celrep.2024.114096] [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: 09/14/2023] [Revised: 02/20/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Receptors controlling the cross-presentation of tumor antigens by macrophage subsets in cancer tissues are poorly explored. Here, we show that TIM4+ large peritoneal macrophages efficiently capture and cross-present tumor-associated antigens at early stages of peritoneal infiltration by ovarian cancer cells. The phosphatidylserine (PS) receptor TIM4 promotes maximal uptake of dead cells or PS-coated artificial targets and triggers inflammatory and metabolic gene programs in combination with cytoskeletal remodeling and upregulation of transcriptional signatures related to antigen processing. At the cellular level, TIM4-mediated engulfment induces nucleation of F-actin around nascent phagosomes, delaying the recruitment of vacuolar ATPase, acidification, and cargo degradation. In vivo, TIM4 deletion blunts induction of early anti-tumoral effector CD8 T cells and accelerates the progression of ovarian tumors. We conclude that TIM4-mediated uptake drives the formation of specialized phagosomes that prolong the integrity of ingested antigens and facilitate cross-presentation, contributing to immune surveillance of the peritoneum.
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Affiliation(s)
- Sonal Joshi
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Lucía López
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Luciano Gastón Morosi
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Roberto Amadio
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Manendra Pachauri
- Department of Medical, Surgical, and Health Sciences, University of Trieste and International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Marco Bestagno
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Ironya Paul Ogar
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy; Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medical Sciences, University of Calabar, P.M.B. 1115 Calabar, Cross River State, Nigeria
| | - Mauro Giacca
- Department of Medical, Surgical, and Health Sciences, University of Trieste and International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy; King's College London, British Heart Foundation Center of Research Excellence, School of Cardiovascular Medicine & Sciences, London, UK
| | - Giulia Maria Piperno
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy
| | - Daan Vorselen
- Department of Cell Biology & Immunology, Wageningen University & Research, 6708 PD Wageningen, the Netherlands
| | - Federica Benvenuti
- Cellular Immunology, International Center for Genetic Engineering and Biotechnology (ICGEB), Trieste, Italy.
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Moon B, Yang S, Moon H, Lee J, Park D. After cell death: the molecular machinery of efferocytosis. Exp Mol Med 2023; 55:1644-1651. [PMID: 37612408 PMCID: PMC10474042 DOI: 10.1038/s12276-023-01070-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 08/25/2023] Open
Abstract
Cells constituting a multicellular organism die in a variety of ways throughout life, and most of them die via apoptosis under normal conditions. The occurrence of apoptosis is especially prevalent during development and in tissues with a high cellular turnover rate, such as the thymus and bone marrow. Interestingly, although the number of apoptotic cells produced daily is known to be innumerable in a healthy adult human body, apoptotic cells are rarely observed. This absence is due to the existence of a cellular process called efferocytosis that efficiently clears apoptotic cells. Studies over the past decades have focused on how phagocytes are able to remove apoptotic cells specifically, swiftly, and continuously, resulting in defined molecular and cellular events. In this review, we will discuss the current understanding of the clearance of apoptotic cells at the molecular level.
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Affiliation(s)
- Byeongjin Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Susumin Yang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Hyunji Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Juyeon Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Daeho Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
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5
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Bhattacharya P, Dhawan UK, Hussain MT, Singh P, Bhagat KK, Singhal A, Austin-Williams S, Sengupta S, Subramanian M. Efferocytes release extracellular vesicles to resolve inflammation and tissue injury via prosaposin-GPR37 signaling. Cell Rep 2023; 42:112808. [PMID: 37436891 DOI: 10.1016/j.celrep.2023.112808] [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: 03/06/2023] [Revised: 05/16/2023] [Accepted: 06/27/2023] [Indexed: 07/14/2023] Open
Abstract
Macrophages release soluble mediators following efferocytic clearance of apoptotic cells to facilitate intercellular communication and promote the resolution of inflammation. However, whether inflammation resolution is modulated by extracellular vesicles (EVs) and vesicular mediators released by efferocytes is not known. We report that efferocyte-derived EVs express prosaposin, which binds to macrophage GPR37 to increase expression of the efferocytosis receptor Tim4 via an ERK-AP1-dependent signaling axis, leading to increased macrophage efferocytosis efficiency and accelerated resolution of inflammation. Neutralization and knockdown of prosaposin or blocking GRP37 abrogates the pro-resolution effects of efferocyte-derived EVs in vivo. Administration of efferocyte-derived EVs in a murine model of atherosclerosis is associated with an increase in lesional macrophage efferocytosis efficiency and a decrease in plaque necrosis and lesional inflammation. Thus, we establish a critical role for efferocyte-derived vesicular mediators in increasing macrophage efferocytosis efficiency and accelerating the resolution of inflammation and tissue injury.
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Affiliation(s)
- Purbasha Bhattacharya
- CSIR - Institute of Genomics and Integrative Biology, New Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Umesh Kumar Dhawan
- William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Mohammed Tayab Hussain
- William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Praveen Singh
- CSIR - Institute of Genomics and Integrative Biology, New Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Karran Kiran Bhagat
- William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Aarushi Singhal
- William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Shani Austin-Williams
- William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Shantanu Sengupta
- CSIR - Institute of Genomics and Integrative Biology, New Delhi, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Manikandan Subramanian
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India; William Harvey Research Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, London, UK.
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6
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Yang S, Min C, Moon H, Moon B, Lee J, Jeon J, Kwon H, Jang D, Park D. Internalization of apoptotic cells during efferocytosis requires Mertk-mediated calcium influx. Cell Death Dis 2023; 14:391. [PMID: 37391432 PMCID: PMC10313764 DOI: 10.1038/s41419-023-05925-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/02/2023]
Abstract
Phagocytosis of apoptotic cells, called efferocytosis, requires calcium inside and outside of phagocytes. Due to its necessity, calcium flux is sophisticatedly modulated, and the level of intracellular calcium in phagocytes is ultimately elevated during efferocytosis. However, the role of elevated intracellular calcium in efferocytosis remains elusive. Here, we report that Mertk-mediated intracellular calcium elevation is necessary for internalization of apoptotic cells during efferocytosis. Drastic depletion of intracellular calcium abrogated the internalization step of efferocytosis by delaying phagocytic cup extension and closure. Especially, the defect of phagocytic cup closure for internalization of apoptotic cells was caused by impaired F-actin disassembly and the attenuated interaction of Calmodulin with myosin light chain kinase (MLCK), leading to diminished myosin light chain (MLC) phosphorylation. Genetic and pharmacological impairment of the Calmodulin-MLCK-MLC axis or Mertk-mediated calcium influx also resulted in inefficient efferocytosis due to a defect in internalization of the targets. Taken together, our observations imply that intracellular calcium elevation through Mertk-mediated calcium influx facilitates efferocytosis by inducing myosin II-mediated contraction and F-actin disassembly required for internalization of apoptotic cells.
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Affiliation(s)
- Susumin Yang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Chanhyuk Min
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Hyunji Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Byeongjin Moon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Juyeon Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Jaeseon Jeon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Hagyeong Kwon
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Deokyun Jang
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea
| | - Daeho Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
- Cell Mechanobiology Laboratory, Gwangju Institute of Science and Technology, Gwangju, 61005, Korea.
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7
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Hirao H, Kageyama S, Nakamura K, Kadono K, Kojima H, Siyuan Y, Farmer DG, Kaldas FM, Dery KJ, Kupiec-Weglinski JW. Recipient TIM4 signaling regulates ischemia reperfusion-induced ER stress and metabolic responses in liver transplantation: from mouse-to-human. FRONTIERS IN TRANSPLANTATION 2023; 2:1176384. [PMID: 38993869 PMCID: PMC11235257 DOI: 10.3389/frtra.2023.1176384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/17/2023] [Indexed: 07/13/2024]
Abstract
T-cell immunoglobulin and mucin (Tim)4 is expressed on APCs, including macrophages, as one of the main amplifiers in the mechanism of liver ischemia-reperfusion injury (IRI) following orthotopic liver transplantation (OLT). Though donor Tim4 selectively expressed on Kupffer cells serves as a checkpoint regulator of innate immune-driven IRI cascades, its role on cells outside the OLT remains unclear. To dissect the role of donor vs. recipient-specific Tim4 signaling in IR-induced stress and hepatocellular function, we employed a murine OLT model utilizing Tim4-knockout (KO) mice as either donor or recipient (WT → WT, WT → Tim4-KO, Tim4-KO → WT). In the experimental arm, disruption of donor Tim4 attenuated IRI-OLT damage, while recipient Tim4-null mutation aggravated hepatic IRI concomitant with disturbed lipid metabolism, enhanced endoplasmic reticulum stress, and activated pro-apoptotic signaling in the grafts. In the in vitro study, murine hepatocytes co-cultured with Tim4-null adipose tissue showed enhanced C/EBP homologous protein (CHOP) expression pattern and susceptibility to hepatocellular death accompanied by activated caspase cascade in response to TNF-α stimulation. In the clinical arm, liver grafts from forty-one transplant patients with enhanced TIM4 expression showed higher body mass index, augmented hepatic endoplasmic reticulum stress, enhanced pro-apoptotic markers, upregulated innate/adaptive immune responses, exacerbated hepatocellular damage, and inferior graft survival. In conclusion, although TIM4 is considered a principal villain in peri-transplant early tissue injury, recipient TIM4 signaling may serve as a savior of IR-triggered metabolic stress in mouse and human OLT recipients.
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Affiliation(s)
- Hirofumi Hirao
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
| | - Shoichi Kageyama
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery and Transplantation, Kyoto University, Kyoto, Japan
| | - Kojiro Nakamura
- Department of Surgery, Hepato-Biliary-Pancreatic Surgery and Transplantation, Kyoto University, Kyoto, Japan
| | - Kentaro Kadono
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
| | - Hidenobu Kojima
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
| | - Yao Siyuan
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
| | - Douglas G. Farmer
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
| | - Fady M. Kaldas
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
| | - Kenneth J. Dery
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jerzy W. Kupiec-Weglinski
- Dumont-UCLA Transplantation Center, Department of Surgery, Division of Liver and Pancreas Transplantation, University of California, Los Angeles, Los Angeles, CA, United States
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8
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Wang Z, Chen C, Su Y, Ke N. Function and characteristics of TIM‑4 in immune regulation and disease (Review). Int J Mol Med 2022; 51:10. [PMID: 36524355 PMCID: PMC9848438 DOI: 10.3892/ijmm.2022.5213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/23/2022] [Indexed: 12/14/2022] Open
Abstract
T‑cell/transmembrane immunoglobulin and mucin domain containing 4 (TIM‑4) is a phosphatidylserine receptor that is mainly expressed on antigen‑presenting cells and is involved in the recognition and efferocytosis of apoptotic cells. TIM‑4 has been found to be expressed in immune cells such as natural killer T, B and mast cells and to participate in multiple aspects of immune regulation, suggesting that TIM‑4 may be involved in a variety of immune‑related diseases. Recent studies have confirmed that TIM‑4 is also abnormally expressed in a variety of malignant tumor cells and is closely associated with the occurrence and development of tumors and the tumor immune microenvironment. The present study aimed to describe the expression and functional characteristics of TIM‑4 in detail and to comprehensively discuss its role in pathophysiological processes such as infection, allergy, metabolism, autoimmunity and tumor immunity. The current review provided a comprehensive understanding of the functions and characteristics of TIM‑4, as well as novel ideas for the diagnosis and treatment of diseases.
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Affiliation(s)
- Ziyao Wang
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China
| | - Chen Chen
- Department of Radiology, The First People's Hospital of Chengdu, Chengdu, Sichuan 610095, P.R. China
| | - Yingzhen Su
- Kunming University School of Medicine, Kunming University School, Kunming, Yunnan 650124, P.R. China
| | - Nengwen Ke
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China,Correspondence to: Professor Nengwen Ke, Department of Pancreatic Surgery, West China Hospital, Sichuan University, 37 Guoxue Lane, Chengdu, Sichuan 610041, P.R. China, E-mail:
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9
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Abstract
The daily removal of billions of apoptotic cells in the human body via the process of efferocytosis is essential for homeostasis. To allow for this continuous efferocytosis, rapid phenotypic changes occur in the phagocytes enabling them to engulf and digest the apoptotic cargo. In addition, efferocytosis is actively anti-inflammatory and promotes resolution. Owing to its ubiquitous nature and the sheer volume of cell turnover, efferocytosis is a point of vulnerability. Aberrations in efferocytosis are associated with numerous inflammatory pathologies, including atherosclerosis, cancer and infections. The recent exciting discoveries defining the molecular machinery involved in efferocytosis have opened many avenues for therapeutic intervention, with several agents now in clinical trials.
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Affiliation(s)
- Parul Mehrotra
- Unit for Cell Clearance in Health and Disease, VIB Center for Inflammation Research, Ghent, Belgium
| | - Kodi S Ravichandran
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.
- The Center for Cell Clearance, University of Virginia, Charlottesville, VA, USA.
- Division of Immunobiology, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.
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10
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Yang Y, Wang Y, Guo L, Gao W, Tang TL, Yan M. Interaction between macrophages and ferroptosis. Cell Death Dis 2022; 13:355. [PMID: 35429990 PMCID: PMC9013379 DOI: 10.1038/s41419-022-04775-z] [Citation(s) in RCA: 106] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/17/2022] [Accepted: 03/25/2022] [Indexed: 02/06/2023]
Abstract
Abstract Ferroptosis, a newly discovered iron-dependent cell death pathway, is characterized by lipid peroxidation and GSH depletion mediated by iron metabolism and is morphologically, biologically and genetically different from other programmed cell deaths. Besides, ferroptosis is usually found accompanied by inflammatory reactions. So far, it has been found participating in the development of many kinds of diseases. Macrophages are a group of immune cells that widely exist in our body for host defense and play an important role in tissue homeostasis by mediating inflammation and regulating iron, lipid and amino acid metabolisms through their unique functions like phagocytosis and efferocytosis, cytokines secretion and ROS production under different polarization. According to these common points in ferroptosis characteristics and macrophages functions, it’s obvious that there must be relationship between macrophages and ferroptosis. Therefore, our review aims at revealing the interaction between macrophages and ferroptosis concerning three metabolisms and integrating the application of certain relationship in curing diseases, mostly cancer. Finally, we also provide inspirations for further studies in therapy for some diseases by targeting certain resident macrophages in distinct tissues to regulate ferroptosis. Facts Ferroptosis is considered as a newly discovered form characterized by its nonapoptotic and iron-dependent lipid hydroperoxide, concerning iron, lipid and amino acid metabolisms. Ferroptosis has been widely found playing a crucial part in various diseases, including hepatic diseases, neurological diseases, cancer, etc. Macrophages are phagocytic immune cells, widely existing and owning various functions such as phagocytosis and efferocytosis, cytokines secretion and ROS production. Macrophages are proved to participate in mediating metabolisms and initiating immune reactions to maintain balance in our body. Recent studies try to treat cancer by altering macrophages’ polarization which damages tumor microenvironment and induces ferroptosis of cancer cells.
Open questions How do macrophages regulate ferroptosis of other tissue cells specifically? Can we use the interaction between macrophages and ferroptosis in treating diseases other than cancer? What can we do to treat diseases related to ferroptosis by targeting macrophages? Is the use of the relationship between macrophages and ferroptosis more effective than other therapies when treating diseases?
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Affiliation(s)
- Yan Yang
- Department of Pharmacy, Second Xiangya Hospital, Central South University, Changsha, China
| | - Yu Wang
- Department of Pharmacy, Second Xiangya Hospital, Central South University, Changsha, China.,Xiangya School of Medicine, Central South University, Changsha, China
| | - Lin Guo
- Department of Pharmacy, Second Xiangya Hospital, Central South University, Changsha, China
| | - Wen Gao
- Department of Pharmacy, Second Xiangya Hospital, Central South University, Changsha, China.,Xiangya School of Medicine, Central South University, Changsha, China
| | - Ting-Li Tang
- Department of Pharmacy, Second Xiangya Hospital, Central South University, Changsha, China
| | - Miao Yan
- Department of Pharmacy, Second Xiangya Hospital, Central South University, Changsha, China.
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11
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Wang J, Yu C, Zhuang J, Qi W, Jiang J, Liu X, Zhao W, Cao Y, Wu H, Qi J, Zhao RC. The role of phosphatidylserine on the membrane in immunity and blood coagulation. Biomark Res 2022; 10:4. [PMID: 35033201 PMCID: PMC8760663 DOI: 10.1186/s40364-021-00346-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/01/2021] [Indexed: 12/17/2022] Open
Abstract
The negatively charged aminophospholipid, phosphatidylserine (PtdSer), is located in the inner leaflet of the plasma membrane in normal cells, and may be exposed to the outer leaflet under some immune and blood coagulation processes. Meanwhile, Ptdser exposed to apoptotic cells can be recognized and eliminated by various immune cells, whereas on the surface of activated platelets Ptdser interacts with coagulation factors prompting enhanced production of thrombin which significantly facilitates blood coagulation. In the case where PtdSer fails in exposure or mistakenly occurs, there are occurrences of certain immunological and haematological diseases, such as the Scott syndrome and Systemic lupus erythematosus. Besides, viruses (e.g., Human Immunodeficiency Virus (HIV), Ebola virus (EBOV)) can invade host cells through binding the exposed PtdSer. Most recently, the Corona Virus Disease 2019 (COVID-19) has been similarly linked to PtdSer or its receptors. Therefore, it is essential to comprehensively understand PtdSer and its functional characteristics. Therefore, this review summarizes Ptdser, its eversion mechanism; interaction mechanism, particularly with its immune receptors and coagulation factors; recognition sites; and its function in immune and blood processes. This review illustrates the potential aspects for the underlying pathogenic mechanism of PtdSer-related diseases, and the discovery of new therapeutic strategies as well.
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Affiliation(s)
- Jiao Wang
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.
| | - Changxin Yu
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Junyi Zhuang
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Wenxin Qi
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Jiawen Jiang
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Xuanting Liu
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Wanwei Zhao
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Yiyang Cao
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Hao Wu
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Jingxuan Qi
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Robert Chunhua Zhao
- School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.
- Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, No. 5 Dongdansantiao, Beijing, 100005, China.
- Centre of Excellence in Tissue Engineering, Chinese Academy of Medical Sciences, Beijing, China.
- Beijing Key Laboratory of New Drug Development and Clinical Trial of Stem Cell Therapy (BZ0381), Beijing, China.
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12
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Apoptotic Cells Trigger Calcium Entry in Phagocytes by Inducing the Orai1-STIM1 Association. Cells 2021; 10:cells10102702. [PMID: 34685684 PMCID: PMC8534458 DOI: 10.3390/cells10102702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 09/30/2021] [Accepted: 10/08/2021] [Indexed: 11/30/2022] Open
Abstract
Swift and continuous phagocytosis of apoptotic cells can be achieved by modulation of calcium flux in phagocytes. However, the molecular mechanism by which apoptotic cells modulate calcium flux in phagocytes is incompletely understood. Here, using biophysical, biochemical, pharmaceutical, and genetic approaches, we show that apoptotic cells induced the Orai1-STIM1 interaction, leading to store-operated calcium entry (SOCE) in phagocytes through the Mertk-phospholipase C (PLC) γ1-inositol 1,4,5-triphosphate receptor (IP3R) axis. Apoptotic cells induced calcium release from the endoplasmic reticulum, which led to the Orai1-STIM1 association and, consequently, SOCE in phagocytes. This association was attenuated by masking phosphatidylserine. In addition, the depletion of Mertk, which indirectly senses phosphatidylserine on apoptotic cells, reduced the phosphorylation levels of PLCγ1 and IP3R, resulting in attenuation of the Orai1-STIM1 interaction and inefficient SOCE upon apoptotic cell stimulation. Taken together, our observations uncover the mechanism of how phagocytes engulfing apoptotic cells elevate the calcium level.
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Bohan D, Maury W. Enveloped RNA virus utilization of phosphatidylserine receptors: Advantages of exploiting a conserved, widely available mechanism of entry. PLoS Pathog 2021; 17:e1009899. [PMID: 34555126 PMCID: PMC8459961 DOI: 10.1371/journal.ppat.1009899] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Dana Bohan
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Immunology Graduate Program, University of Iowa, Iowa City, Iowa, United States of America
| | - Wendy Maury
- Department of Microbiology and Immunology, University of Iowa, Iowa City, Iowa, United States of America
- Interdisciplinary Immunology Graduate Program, University of Iowa, Iowa City, Iowa, United States of America
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EphA2 Interacts with Tim-4 through Association between Its FN3 Domain and the IgV Domain of Tim-4. Cells 2021; 10:cells10061290. [PMID: 34067457 PMCID: PMC8224564 DOI: 10.3390/cells10061290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/13/2021] [Accepted: 05/21/2021] [Indexed: 11/22/2022] Open
Abstract
Tim-4 promotes the engulfment of apoptotic cells or exogenous particles by securing them on phagocytes. It is unable to transduce signals by itself but helps other engulfment receptors sense and internalize them. However, the identity of the engulfment receptors collaborating with Tim-4 is still incompletely understood. In this study, we searched for a candidate transmembrane protein with a FN3 domain, important for interaction with Tim-4, in silico and investigated whether it indeed interacts with Tim-4 and is involved in Tim-4-mediated phagocytosis. We found that EphA2 containing a FN3 domain in the extracellular region interacted with Tim-4, which was mediated by the IgV domain of Tim-4 and the FN3 domain of EphA2. Nevertheless, we found that EphA2 expression failed to alter Tim-4-mediated phagocytosis of apoptotic cells or polystyrene beads. Taken together, our findings suggest that EphA2, a new Tim-4 interacting protein, may intervene in a Tim-4-mediated cellular event even if it is not phagocytosis of endogenous or exogenous particles and vice versa.
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15
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Zhou L, Matsushima GK. Tyro3, Axl, Mertk receptor-mediated efferocytosis and immune regulation in the tumor environment. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 361:165-210. [PMID: 34074493 DOI: 10.1016/bs.ircmb.2021.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Three structurally related tyrosine receptor cell surface kinases, Tyro3, Axl, and Mertk (TAM) have been recognized to modulate immune function, tissue homeostasis, cardiovasculature, and cancer. The TAM receptor family appears to operate in adult mammals across multiple cell types, suggesting both widespread and specific regulation of cell functions and immune niches. TAM family members regulate tissue homeostasis by monitoring the presence of phosphatidylserine expressed on stressed or apoptotic cells. The detection of phosphatidylserine on apoptotic cells requires intermediary molecules that opsonize the dying cells and tether them to TAM receptors on phagocytes. This complex promotes the engulfment of apoptotic cells, also known as efferocytosis, that leads to the resolution of inflammation and tissue healing. The immune mechanisms dictating these processes appear to fall upon specific family members or may involve a complex of different receptors acting cooperatively to resolve and repair damaged tissues. Here, we focus on the role of TAM receptors in triggering efferocytosis and its consequences in the regulation of immune responses in the context of inflammation and cancer.
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Affiliation(s)
- Liwen Zhou
- UNC Neuroscience Center, University of North Carolina-CH, Chapel Hill, NC, United States
| | - Glenn K Matsushima
- UNC Neuroscience Center, University of North Carolina-CH, Chapel Hill, NC, United States; UNC Department of Microbiology & Immunology, University of North Carolina-CH, Chapel Hill, NC, United States; UNC Integrative Program for Biological & Genome Sciences, University of North Carolina-CH, Chapel Hill, NC, United States.
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16
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Lee SA, Lee J, Kim K, Moon H, Min C, Moon B, Kim D, Yang S, Park H, Lee G, Park R, Park D. The Peroxisomal Localization of Hsd17b4 Is Regulated by Its Interaction with Phosphatidylserine. Mol Cells 2021; 44:214-222. [PMID: 33935042 PMCID: PMC8112170 DOI: 10.14348/molcells.2021.2217] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/20/2021] [Accepted: 04/05/2021] [Indexed: 12/28/2022] Open
Abstract
Phosphatidylserine (PS), a negatively charged phospholipid exclusively located in the inner leaflet of the plasma membrane, is involved in various cellular processes such as blood coagulation, myoblast fusion, mammalian fertilization, and clearance of apoptotic cells. Proteins that specifically interact with PS must be identified to comprehensively understand the cellular processes involving PS. However, only a limited number of proteins are known to associate with PS. To identify PS-associating proteins, we performed a pulldown assay using streptavidin-coated magnetic beads on which biotin-linked PS was immobilized. Using this approach, we identified Hsd17b4, a peroxisomal protein, as a PS-associating protein. Hsd17b4 strongly associated with PS, but not with phosphatidylcholine or sphingomyelin, and the Scp-2-like domain of Hsd17b4 was responsible for this association. The association was disrupted by PS in liposomes, but not by free PS or the components of PS. In addition, translocation of PS to the outer leaflet of the plasma membrane enriched Hsd17b4 in peroxisomes. Collectively, this study suggests an unexpected role of PS as a regulator of the subcellular localization of Hsd17b4.
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Affiliation(s)
- Sang-Ah Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Juyeon Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Kwanhyeong Kim
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Hyunji Moon
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Chanhyuk Min
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Byeongjin Moon
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Deokhwan Kim
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Susumin Yang
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Hyunjin Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Gwangrog Lee
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
| | - Raekil Park
- Department of Biomedical Science and Engineering, GIST, Gwangju 61005, Korea
| | - Daeho Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
- Center for Cell Mechanobiology, GIST, Gwangju 61005, Korea
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Gadiyar V, Patel G, Davra V. Immunological role of TAM receptors in the cancer microenvironment. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 357:57-79. [PMID: 33234245 DOI: 10.1016/bs.ircmb.2020.09.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
TAM receptors belong to the family of receptor tyrosine kinases, comprising of Tyro3, Axl and Mertk receptors (TAMs) and are important homeostatic regulators of inflammation in higher eukaryotes. Along with their ligands, Gas6 and ProteinS, TAMs acts as receptors to phosphatidylserine (PtdSer), an anionic phospholipid that becomes externalized on the surface of apoptotic and stressed cells. TAM receptors, specially Mertk, have been well established to play a role in the process of efferocytosis, the engulfment of dying cells. Besides being efferocytic receptors, TAMs are pleiotropic immune modulators as the lack of TAM receptors in various mouse models lead to chronic inflammation and autoimmunity. Owing to their immune modulatory role, the PtdSer-TAM receptor signaling axis has been well characterized as a global immune-suppressive signal, and in cancers, and emerging literature implicates TAM receptors in cancer immunology and anti-tumor therapeutics. In the tumor microenvironment, immune-suppressive signals, such as ones that originate from TAM receptor signaling can be detrimental to anti-tumor therapy. In this chapter, we discuss immune modulatory functions of TAM receptors in the tumor microenvironment as well role of differentially expressed TAM receptors and their interactions with immune and tumor cells. Finally, we describe current strategies being utilized for targeting TAMs in several cancers and their implications in immunotherapy.
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Affiliation(s)
- Varsha Gadiyar
- Rutgers New Jersey Medical School, Newark, NJ, United States
| | - Gopi Patel
- Rutgers New Jersey Medical School, Newark, NJ, United States
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