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Gudgeon J, Marín-Rubio JL, Trost M. The role of macrophage scavenger receptor 1 (MSR1) in inflammatory disorders and cancer. Front Immunol 2022; 13:1012002. [PMID: 36325338 PMCID: PMC9618966 DOI: 10.3389/fimmu.2022.1012002] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 09/28/2022] [Indexed: 08/27/2023] Open
Abstract
Macrophage scavenger receptor 1 (MSR1), also named CD204, holds key inflammatory roles in multiple pathophysiologic processes. Present primarily on the surface of various types of macrophage, this receptor variably affects processes such as atherosclerosis, innate and adaptive immunity, lung and liver disease, and more recently, cancer. As highlighted throughout this review, the role of MSR1 is often dichotomous, being either host protective or detrimental to the pathogenesis of disease. We will discuss the role of MSR1 in health and disease with a focus on the molecular mechanisms influencing MSR1 expression, how altered expression affects disease process and macrophage function, the limited cell signalling pathways discovered thus far, the emerging role of MSR1 in tumour associated macrophages as well as the therapeutic potential of targeting MSR1.
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Affiliation(s)
| | - José Luis Marín-Rubio
- Laboratory for Biological Mass Spectrometry, Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Matthias Trost
- Laboratory for Biological Mass Spectrometry, Biosciences Institute, Newcastle University, Newcastle-upon-Tyne, United Kingdom
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2
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Xie Y, Jia Y, Li Z, Hu F. Scavenger receptor A in immunity and autoimmune diseases: Compelling evidence for targeted therapy. Expert Opin Ther Targets 2022; 26:461-477. [PMID: 35510370 DOI: 10.1080/14728222.2022.2072729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Scavenger receptor A (SR-A) is reported to be involved in innate and adaptive immunity and in recent years, the soluble form of SR-A has also been identified. Intriguingly, SR-A displays double-edged sword features in different diseases. Moreover, targeted therapy on SR-A, including genetic modulation, small molecule inhibitor, inhibitory peptides, fucoidan, and blocking antibodies, provides potential strategies for treatment. Currently, therapeutics targeting SR-A are in preclinical studies and clinical trials, revealing great perspectives in future immunotherapy. AREAS COVERED Through searching PubMed (January 1979-March 2022) and clinicaltrials.gov, we review most of the research and clinical trials involving SR-A. This review briefly summarizes recent study advances on SR-A, with particular concern on its role in immunity and autoimmune diseases. EXPERT OPINION Given the emerging evidence of SR-A in immunity, its targeted therapy has been studied in various diseases, especially autoimmune diseases. However, many challenges still remain to be overcome, such as the double-sworded effects and the specific isoform targeting. For further clinical success of SR-A targeted therapy, the crystal structure illustration and the dual function discrimination of SR-A should be further investigated. Nevertheless, although challenging, targeting SR-A would be a potential effective strategy in the treatment of autoimmune diseases and other immune-related diseases.
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Affiliation(s)
- Yang Xie
- Department of Rheumatology and Immunology, Peking University People's Hospital & Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, Peking, China
| | - Yuan Jia
- Department of Rheumatology and Immunology, Peking University People's Hospital & Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, Peking, China
| | - Zhanguo Li
- Department of Rheumatology and Immunology, Peking University People's Hospital & Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, Peking, China.,State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, Peking, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, Peking, China
| | - Fanlei Hu
- Department of Rheumatology and Immunology, Peking University People's Hospital & Beijing Key Laboratory for Rheumatism Mechanism and Immune Diagnosis (BZ0135), Beijing, Peking, China.,State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, Peking, China.,Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University, Beijing, Peking, China
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3
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Linares-Alcántara E, Mendlovic F. Scavenger Receptor A1 Signaling Pathways Affecting Macrophage Functions in Innate and Adaptive Immunity. Immunol Invest 2022; 51:1725-1755. [PMID: 34986758 DOI: 10.1080/08820139.2021.2020812] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
First discovered on macrophages by Goldstein and Brown in 1979, Scavenger Receptors have since been shown to participate in a diverse number of cell functions; equally diverse are their structures and the ligands they bind. Macrophage activation is crucial in the outcome of an immune response. SR-A1 is highly abundant on macrophages and recognizes both host- and microorganism-derived molecules that impact processes that are initiated, perpetuated, or modified. This review summarizes the involvement of SR-A1 in both inflammatory and anti-inflammatory responses, the multiple-ligand internalization mechanisms and the diversity of signaling pathways that impact macrophage function and activation. Engagement of SR-A1 results in the stimulation of differential signaling pathways and patterns of cytokine expression, kinetics, magnitude of response and activation status. SR-A1 plays essential roles in phagocytosis and efferocytosis, interacting with other receptors and promoting tolerance in response to apoptotic cell uptake. In cell adhesion, tissue remodeling, and cell migration, SR-A1 signals through different pathways engaging different cytoplasmic motifs. We describe the role of SR-A1 during innate and adaptive immune responses, such as participation in macrophage polarization and interaction with other innate receptors, as well as in antigen uptake, processing, and presentation, regulating T and B cell activation. The dichotomous contribution of SR-A1 on macrophage functions is discussed. A better understanding of the role SR-A1 plays through molecular mechanisms and crosstalk with other receptors may provide insights into developing novel therapeutic strategies to modulate immune responses and immunopathologies.
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Affiliation(s)
- Elizabeth Linares-Alcántara
- Facultad de Ciencias, UNAM, Av. Universidad 3000, Col. Copilco-Universidad, Ciudad de Mexico, Mexico.,Departamento de Microbiología y Parasitología, Facultad de Medicina, UNAM, Av. Universidad 3000, Col. Copilco-Universidad, Ciudad de Mexico, Mexico
| | - Fela Mendlovic
- Departamento de Microbiología y Parasitología, Facultad de Medicina, UNAM, Av. Universidad 3000, Col. Copilco-Universidad, Ciudad de Mexico, Mexico.,Facultad de Ciencias de la Salud, Universidad Anahuac Mexico Norte, Huixquilucan, Mexico
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4
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Qiao O, Ji H, Zhang Y, Zhang X, Zhang X, Liu N, Huang L, Liu C, Gao W. New insights in drug development for Alzheimer's disease based on microglia function. Biomed Pharmacother 2021; 140:111703. [PMID: 34083109 DOI: 10.1016/j.biopha.2021.111703] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/29/2021] [Accepted: 05/05/2021] [Indexed: 12/26/2022] Open
Abstract
One of the biggest challenges in drug development for Alzheimer's disease (AD) is how to effectively remove deposits of amyloid-beta (Aβ). Recently, the relationship between microglia and Aβ has become a research hotspot. Emerging evidence suggests that Aβ-induced microglia-mediated neuroinflammation further aggravates the decline of cognitive function, while microglia are also involved in the process of Aβ clearance. Hence, microglia have become a potential therapeutic target for the treatment or prevention of AD. An in-depth understanding of the role played by microglia in the development of AD will help us to broaden therapeutic strategies for AD. In this review, we provide an overview of the dual roles of microglia in AD progression: the positive effect of phagocytosis of Aβ and its negative effect on neuroinflammation after over-activation. With the advantages of novel structure, high efficiency, and low toxicity, small-molecule compounds as modulators of microglial function have attracted considerable attention in the therapeutic areas of AD. In this review, we also summarize the therapeutic potential of small molecule compounds (SMCs) and their structure-activity relationship for AD treatment through modulating microglial phagocytosis and inhibiting neuroinflammation. For example, the position and number of phenolic hydroxyl groups on the B ring are the key to the activity of flavonoids, and the substitution of hydroxyl groups on the benzene ring enhances the anti-inflammatory activity of phenolic acids. This review is expected to be useful for developing effective modulators of microglial function from SMCs for the amelioration and treatment of AD.
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Affiliation(s)
- Ou Qiao
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Weijin Road, Tianjin 300072, China
| | - Haixia Ji
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Weijin Road, Tianjin 300072, China
| | - Yi Zhang
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Weijin Road, Tianjin 300072, China
| | - Xinyu Zhang
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Weijin Road, Tianjin 300072, China
| | - Xueqian Zhang
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Weijin Road, Tianjin 300072, China
| | - Na Liu
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Weijin Road, Tianjin 300072, China
| | - Luqi Huang
- Chinese Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Changxiao Liu
- The State Key Laboratories of Pharmacodynamics and Pharmacokinetics, Tianjin 300193, China
| | - Wenyuan Gao
- Tianjin Key Laboratory for Modern Drug Delivery and High-Efficiency, School of Pharmaceutical Science and Technology, Tianjin University, Weijin Road, Tianjin 300072, China.
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5
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Umemura K, Ohtsuki S, Nagaoka M, Kusamori K, Inoue T, Takahashi Y, Takakura Y, Nishikawa M. Critical contribution of macrophage scavenger receptor 1 to the uptake of nanostructured DNA by immune cells. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2021; 34:102386. [PMID: 33774131 DOI: 10.1016/j.nano.2021.102386] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 02/27/2021] [Accepted: 02/28/2021] [Indexed: 11/28/2022]
Abstract
Despite the efficient uptake of polypod-like nanostructured DNA, or polypodna, by macrophage-like RAW264.7 and other immune cells, the detailed mechanism has not been fully elucidated. Our previous study using HEK-Blue hTLR9 cells showed that transfection of macrophage scavenger receptor 1 (MSR1) increased the uptake of tetrapod-like structured DNA. Here, we investigated the involvement of MSR1 in the structure-dependent uptake of polypodna. Transfection of MSR1 to HEK-Blue hTLR9 cells pod number-dependently increased the uptake of polypodna, and its knockout in RAW264.7 cells reduced the uptake and subsequent cytokine release. To examine the binding of DNA with MSR1, biotinylated DNA added to RAW264.7 cells was cross-linked with cell surface proteins. Then, MSR1 cross-linked with polypodna, but not with single-stranded DNA. Similar results were obtained with murine primary immune cells. Taken together, MSR1 discriminates between simple and nanostructured DNAs and plays a dominant role in the efficient uptake of polypodna by immune cells.
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Affiliation(s)
- Keisuke Umemura
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Shozo Ohtsuki
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Makoto Nagaoka
- Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Kosuke Kusamori
- Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan
| | - Takao Inoue
- Division of Cellular and Gene Therapy Products, National Institute of Health Sciences, Kawasaki, Kanagawa, Japan
| | - Yuki Takahashi
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Yoshinobu Takakura
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Makiya Nishikawa
- Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan; Laboratory of Biopharmaceutics, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan.
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6
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Pulkkinen HH, Kiema M, Lappalainen JP, Toropainen A, Beter M, Tirronen A, Holappa L, Niskanen H, Kaikkonen MU, Ylä-Herttuala S, Laakkonen JP. BMP6/TAZ-Hippo signaling modulates angiogenesis and endothelial cell response to VEGF. Angiogenesis 2021; 24:129-144. [PMID: 33021694 PMCID: PMC7921060 DOI: 10.1007/s10456-020-09748-4] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 09/18/2020] [Indexed: 12/12/2022]
Abstract
The BMP/TGFβ-Smad, Notch and VEGF signaling guides formation of endothelial tip and stalk cells. However, the crosstalk of bone morphogenetic proteins (BMPs) and vascular endothelial growth factor receptor 2 (VEGFR2) signaling has remained largely unknown. We demonstrate that BMP family members regulate VEGFR2 and Notch signaling, and act via TAZ-Hippo signaling pathway. BMPs were found to be regulated after VEGF gene transfer in C57/Bl6 mice and in a porcine myocardial ischemia model. BMPs 2/4/6 were identified as endothelium-specific targets of VEGF. BMP2 modulated VEGF-mediated endothelial sprouting via Delta like Canonical Notch Ligand 4 (DLL4). BMP6 modulated VEGF signaling by regulating VEGFR2 expression and acted via Hippo signaling effector TAZ, known to regulate cell survival/proliferation, and to be dysregulated in cancer. In a matrigel plug assay in nude mice BMP6 was further demonstrated to induce angiogenesis. BMP6 is the first member of BMP family found to directly regulate both Hippo signaling and neovessel formation. It may thus serve as a target in pro/anti-angiogenic therapies.
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Affiliation(s)
- H H Pulkkinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - M Kiema
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - J P Lappalainen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- Department of Clinical Chemistry, University of Eastern Finland and Eastern Finland Laboratory Centre, Kuopio, Finland
| | - A Toropainen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - M Beter
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - A Tirronen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - L Holappa
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - H Niskanen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - M U Kaikkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - S Ylä-Herttuala
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
- Science Service Center, Kuopio University Hospital, Kuopio, Finland
- Gene Therapy Unit, Kuopio University Hospital, Kuopio, Finland
| | - Johanna P Laakkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
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7
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Danger-Sensing/Patten Recognition Receptors and Neuroinflammation in Alzheimer's Disease. Int J Mol Sci 2020; 21:ijms21239036. [PMID: 33261147 PMCID: PMC7731137 DOI: 10.3390/ijms21239036] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 02/06/2023] Open
Abstract
Fibrillar aggregates and soluble oligomers of both Amyloid-β peptides (Aβs) and hyperphosphorylated Tau proteins (p-Tau-es), as well as a chronic neuroinflammation are the main drivers causing progressive neuronal losses and dementia in Alzheimer’s disease (AD). However, the underlying pathogenetic mechanisms are still much disputed. Several endogenous neurotoxic ligands, including Aβs, and/or p-Tau-es activate innate immunity-related danger-sensing/pattern recognition receptors (PPRs) thereby advancing AD’s neuroinflammation and progression. The major PRR families involved include scavenger, Toll-like, NOD-like, AIM2-like, RIG-like, and CLEC-2 receptors, plus the calcium-sensing receptor (CaSR). This quite intricate picture stresses the need to identify the pathogenetically topmost Aβ-activated PRR, whose signaling would trigger AD’s three main drivers and their intra-brain spread. In theory, the candidate might belong to any PRR family. However, results of preclinical studies using in vitro nontumorigenic human cortical neurons and astrocytes and in vivo AD-model animals have started converging on the CaSR as the pathogenetically upmost PRR candidate. In fact, the CaSR binds both Ca2+ and Aβs and promotes the spread of both Ca2+ dyshomeostasis and AD’s three main drivers, causing a progressive neurons’ death. Since CaSR’s negative allosteric modulators block all these effects, CaSR’s candidacy for topmost pathogenetic PRR has assumed a growing therapeutic potential worth clinical testing.
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8
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Spartalis M, Spartalis E, Athanasiou A, Paschou SA, Kontogiannis C, Georgiopoulos G, Iliopoulos DC, Voudris V. The Role of the Endothelium in Premature Atherosclerosis: Molecular Mechanisms. Curr Med Chem 2020; 27:1041-1051. [PMID: 31544711 DOI: 10.2174/0929867326666190911141951] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/29/2019] [Accepted: 04/28/2019] [Indexed: 12/22/2022]
Abstract
Atherosclerotic disease is still one of the leading causes of mortality. Atherosclerosis is a complex progressive and systematic artery disease that involves the intima of the large and middle artery vessels. The inflammation has a key role in the pathophysiological process of the disease and the infiltration of the intima from monocytes, macrophages and T-lymphocytes combined with endothelial dysfunction and accumulated oxidized low-density lipoprotein (LDL) are the main findings of atherogenesis. The development of atherosclerosis involves multiple genetic and environmental factors. Although a large number of genes, genetic polymorphisms, and susceptible loci have been identified in chromosomal regions associated with atherosclerosis, it is the epigenetic process that regulates the chromosomal organization and genetic expression that plays a critical role in the pathogenesis of atherosclerosis. Despite the positive progress made in understanding the pathogenesis of atherosclerosis, the knowledge about the disease remains scarce.
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Affiliation(s)
- Michael Spartalis
- Division of Cardiology, Onassis Cardiac Surgery Center, 17674 Athens, Greece
| | - Eleftherios Spartalis
- Laboratory of Experimental Surgery and Surgical Research, University of Athens, Medical School, Athens, Greece
| | - Antonios Athanasiou
- Laboratory of Experimental Surgery and Surgical Research, University of Athens, Medical School, Athens, Greece
| | - Stavroula A Paschou
- Division of Endocrinology and Diabetes, "Aghia Sophia" Hospital, Medical School, National and Kapodistrian University of Athens, 11527 Athens, Greece
| | - Christos Kontogiannis
- Department of Clinical Therapeutics, "Alexandra" Hospital, University of Athens, 11528 Athens, Greece
| | - Georgios Georgiopoulos
- Department of Clinical Therapeutics, "Alexandra" Hospital, University of Athens, 11528 Athens, Greece
| | - Dimitrios C Iliopoulos
- Laboratory of Experimental Surgery and Surgical Research, University of Athens, Medical School, Athens, Greece
| | - Vassilis Voudris
- Division of Cardiology, Onassis Cardiac Surgery Center, 17674 Athens, Greece
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9
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Xiang X, Zhang Y, Li Q, Wei J, Liu K, Shao D, Li B, Olszewski MA, Ma Z, Qiu Y. Expression profile of porcine scavenger receptor A and its role in bacterial phagocytosis by macrophages. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 104:103534. [PMID: 31689452 PMCID: PMC7796722 DOI: 10.1016/j.dci.2019.103534] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/31/2019] [Accepted: 10/31/2019] [Indexed: 06/10/2023]
Abstract
Expression of scavenger receptor A (SRA) in macrophages plays key role in macrophage mediated uptake of microbes. However, little is known about the role of porcine scavenger receptor A (pSRA) in phagocytic function of macrophages in swine species. In this study, polyclonal antibody against pSRA was generated by using recombinant proteins to study expression and function of pSRA. We report broad expression of pSRA in different tissues. In the lungs, pSRA is mainly expressed by alveolar macrophages. Blockade of class A scavenger receptor by fucoidan treatment demonstrates that pSRA has role in bacterial phagocytosis by macrophages. Furthermore, importance of SRA-mediated bacterial phagocytosis has been shown using CHO cell line expressing pSRA. In summary, these findings reveal that pSRA, which is predominantly expressed in alveolar macrophages is likely to be an important receptor mediating recognition and uptake of bacteria in pig lungs.
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Affiliation(s)
- Xiao Xiang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China
| | - Yanbing Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China
| | - Qianqian Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China
| | - Jianchao Wei
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China
| | - Ke Liu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China
| | - Donghua Shao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China
| | - Beibei Li
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China
| | - Michal A Olszewski
- Division of Pulmonary & Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, USA; Research Service, Ann Arbor VA Health System, Department of Veterans Affairs Health System, USA
| | - Zhiyong Ma
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China.
| | - Yafeng Qiu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, China.
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10
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Novakowski KE, Yap NVL, Yin C, Sakamoto K, Heit B, Golding GB, Bowdish DME. Human-Specific Mutations and Positively Selected Sites in MARCO Confer Functional Changes. Mol Biol Evol 2019; 35:440-450. [PMID: 29165618 DOI: 10.1093/molbev/msx298] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Macrophage Receptor with COllagenous structure (MARCO) is a class A scavenger receptor that binds, phagocytoses, and modifies inflammatory responses to bacterial pathogens. Multiple candidate gene approach studies have shown that polymorphisms in MARCO are associated with susceptibility or resistance to Mycobacterium tuberculosis infection, but how these variants alter function is not known. To complement candidate gene approach studies, we previously used phylogenetic analyses to identify a residue, glutamine 452 (Q452), within the ligand-binding Scavenger Receptor Cysteine Rich domain as undergoing positive selection in humans. Herein, we show that Q452 is found in Denisovans, Neanderthals, and extant humans, but all other nonprimate, terrestrial, and aquatic mammals possess an aspartic acid (D452) residue. Further analysis of hominoid sequences of MARCO identified an additional human-specific mutation, phenylalanine 282 (F282), within the collagenous domain. We show that residue 282 is polymorphic in humans, but only 17% of individuals (rs6761637) possess the ancestral serine residue at position 282. We show that rs6761637 is in linkage disequilibrium with MARCO polymorphisms that have been previously linked to susceptibility to pulmonary tuberculosis. To assess the functional importance of sites Q452 and F282 in humans, we cloned the ancestral residues and loss-of-function mutations and investigated the role of these residues in binding and internalizing polystyrene microspheres and Escherichia coli. Herein, we show that the residues at sites 452 and 282 enhance receptor function.
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Affiliation(s)
- Kyle E Novakowski
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
| | - Nicholas V L Yap
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Charles Yin
- Department of Microbiology and Immunology and The Centre for Human Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - Kaori Sakamoto
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA
| | - Bryan Heit
- Department of Microbiology and Immunology and The Centre for Human Immunology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - G Brian Golding
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Dawn M E Bowdish
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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11
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Jakubowski H. Homocysteine Modification in Protein Structure/Function and Human Disease. Physiol Rev 2019; 99:555-604. [PMID: 30427275 DOI: 10.1152/physrev.00003.2018] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epidemiological studies established that elevated homocysteine, an important intermediate in folate, vitamin B12, and one carbon metabolism, is associated with poor health, including heart and brain diseases. Earlier studies show that patients with severe hyperhomocysteinemia, first identified in the 1960s, exhibit neurological and cardiovascular abnormalities and premature death due to vascular complications. Although homocysteine is considered to be a nonprotein amino acid, studies over the past 2 decades have led to discoveries of protein-related homocysteine metabolism and mechanisms by which homocysteine can become a component of proteins. Homocysteine-containing proteins lose their biological function and acquire cytotoxic, proinflammatory, proatherothrombotic, and proneuropathic properties, which can account for the various disease phenotypes associated with hyperhomocysteinemia. This review describes mechanisms by which hyperhomocysteinemia affects cellular proteostasis, provides a comprehensive account of the biological chemistry of homocysteine-containing proteins, and discusses pathophysiological consequences and clinical implications of their formation.
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Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, International Center for Public Health , Newark, New Jersey ; and Department of Biochemistry and Biotechnology, Poznań University of Life Sciences , Poznań , Poland
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12
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Gupta RK, Gupta K, Sharma A, Das M, Ansari IA, Dwivedi PD. Maillard reaction in food allergy: Pros and cons. Crit Rev Food Sci Nutr 2017; 58:208-226. [PMID: 26980434 DOI: 10.1080/10408398.2016.1152949] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Food allergens have a notable potential to induce various health concerns in susceptible individuals. The majority of allergenic foods are usually subjected to thermal processing prior to their consumption. However, during thermal processing and long storage of foods, Maillard reaction (MR) often takes place. The MR is a non-enzymatic glycation reaction between the carbonyl group of reducing sugars and compounds having free amino groups. MR may sometimes be beneficial by damaging epitope of allergens and reducing allergenic potential, while exacerbation in allergic reactions may also occur due to changes in the motifs of epitopes or neoallergen generation. Apart from these modulations, non-enzymatic glycation can also modify the food protein(s) with various type of advance glycation end products (AGEs) such as Nϵ-(carboxymethyl-)lysine (CML), pentosidine, pyrraline, and methylglyoxal-H1 derived from MR. These Maillard products may act as immunogen by inducing the activation and proliferation of various immune cells. Literature is available to understand pathogenesis of glycation in the context of various diseases but there is hardly any review that can provide a thorough insight on the impact of glycation in food allergy. Therefore, present review explores the pathogenesis with special reference to food allergy caused by non-enzymatic glycation as well as AGEs.
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Affiliation(s)
- Rinkesh Kumar Gupta
- a Food, Drug and Chemical Toxicology Group, Indian Institute of Toxicology Research , Lucknow -, India.,b Department of Biosciences , Integral University , Lucknow , India
| | - Kriti Gupta
- a Food, Drug and Chemical Toxicology Group, Indian Institute of Toxicology Research , Lucknow -, India
| | - Akanksha Sharma
- a Food, Drug and Chemical Toxicology Group, Indian Institute of Toxicology Research , Lucknow -, India.,c Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Capmus , Lucknow , India
| | - Mukul Das
- a Food, Drug and Chemical Toxicology Group, Indian Institute of Toxicology Research , Lucknow -, India
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Gene-expression profiling of different arms of lymphatic vasculature identifies candidates for manipulation of cell traffic. Proc Natl Acad Sci U S A 2016; 113:10643-8. [PMID: 27601677 DOI: 10.1073/pnas.1602357113] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Afferent lymphatic vessels bring antigens and diverse populations of leukocytes to draining lymph nodes, whereas efferent lymphatics allow only lymphocytes and antigens to leave the nodes. Despite the fundamental importance of afferent vs. efferent lymphatics in immune response and cancer spread, the molecular characteristics of these different arms of the lymphatic vasculature are largely unknown. The objective of this work was to explore molecular differences behind the distinct functions of afferent and efferent lymphatic vessels, and find possible molecules mediating lymphocyte traffic. We used laser-capture microdissection and cell sorting to isolate lymphatic endothelial cells (LECs) from the subcapsular sinus (SS, afferent) and lymphatic sinus (LS, efferent) for transcriptional analyses. The results reveal marked differences between afferent and efferent LECs and identify molecules on lymphatic vessels. Further characterizations of Siglec-1 (CD169) and macrophage scavenger receptor 1 (MSR1/CD204), show that they are discriminatively expressed on lymphatic endothelium of the SS but not on lymphatic vasculature of the LS. In contrast, endomucin (EMCN) is present on the LS endothelium and not on lymphatic endothelium of the SS. Moreover, both murine and human MSR1 on lymphatic endothelium of the SS bind lymphocytes and in in vivo studies MSR1 regulates entrance of lymphocytes from the SS to the lymph node parenchyma. In conclusion, this paper reports surprisingly distinct molecular profiles for afferent and efferent lymphatics and a function for MSR1. These results may open avenues to explore some of the now-identified molecules as targets to manipulate the function of lymphatic vessels.
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Scavenger receptor class-A plays diverse role in innate immunity, cell signaling and different pathologies. ASIAN PACIFIC JOURNAL OF TROPICAL DISEASE 2016. [DOI: 10.1016/s2222-1808(16)61088-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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15
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Aluganti Narasimhulu C, Fernandez-Ruiz I, Selvarajan K, Jiang X, Sengupta B, Riad A, Parthasarathy S. Atherosclerosis--do we know enough already to prevent it? Curr Opin Pharmacol 2016; 27:92-102. [PMID: 26974701 DOI: 10.1016/j.coph.2016.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 02/12/2016] [Indexed: 01/07/2023]
Abstract
In this review, we have briefly summarized the characteristics of lipids and lipoproteins and the atherosclerotic process. The development of atherosclerosis is a continuous process that involves numerous cellular and acellular processes that influence the behavior of each other. These include oxidative stress, lipoprotein modifications, macrophage polarization, macrophage lipid accumulation, generation of pro- and anti-inflammatory components, calcification, cellular growth and proliferation, and plaque rupture. The precise role(s) of many of these are unknown. Understanding the events at each particular stage might shed more light onto the process as a whole and could potentially reveal targets for intervention. Therapeutic modalities that work at one stage may have little to no influence on other stages of the disease.
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Affiliation(s)
| | - Irene Fernandez-Ruiz
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, United States
| | - Krithika Selvarajan
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, United States
| | - Xeuting Jiang
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, United States
| | - Bhaswati Sengupta
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, United States
| | - Aladdin Riad
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, United States
| | - Sampath Parthasarathy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, United States.
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Novakowski KE, Huynh A, Han S, Dorrington MG, Yin C, Tu Z, Pelka P, Whyte P, Guarné A, Sakamoto K, Bowdish DME. A naturally occurring transcript variant of MARCO reveals the SRCR domain is critical for function. Immunol Cell Biol 2016; 94:646-55. [PMID: 26888252 PMCID: PMC4980223 DOI: 10.1038/icb.2016.20] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 02/08/2016] [Accepted: 02/10/2016] [Indexed: 12/26/2022]
Abstract
Macrophage receptor with collagenous structure (MARCO) is a Class A Scavenger Receptor (cA-SR) that recognizes and phagocytoses of a wide variety of pathogens. Most cA-SRs that contain a C-terminal Scavenger Receptor Cysteine Rich (SRCR) domain use the proximal collagenous domain to bind ligands. In contrast, for the role of the SRCR domain of MARCO in phagocytosis, adhesion and pro-inflammatory signalling is less clear. The discovery of a naturally-occurring transcript variant lacking the SRCR domain, MARCOII, provided the opportunity to study the role of the SRCR domain of MARCO. We tested whether the SRCR domain is required for ligand binding, promoting downstream signalling, and enhancing cellular adhesion. Unlike cells expressing full-length MARCO, ligand binding was abolished in MARCOII-expressing cells. Furthermore, co-expression of MARCO and MARCOII impaired phagocytic function, indicating that MARCOII acts as a dominant negative variant. Unlike MARCO, expression of MARCOII did not enhance Toll-Like Receptor 2 (TLR2)-mediated pro-inflammatory signalling in response to bacterial stimulation. MARCO-expressing cells were more adherent and exhibited a dendritic-like phenotype, while MARCOII-expressing cells were less adherent and did not exhibit changes in morphology. These data suggest the SRCR domain of MARCO is the key domain in modulating ligand binding, enhancing downstream pro-inflammatory signalling, and MARCO-mediated cellular adhesion.
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Affiliation(s)
- Kyle E Novakowski
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Angela Huynh
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - SeongJun Han
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Michael G Dorrington
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Charles Yin
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Zhongyuan Tu
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Peter Pelka
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Peter Whyte
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Alba Guarné
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Kaori Sakamoto
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - Dawn M E Bowdish
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
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Tsay HJ, Huang YC, Chen YJ, Lee YH, Hsu SM, Tsai KC, Yang CN, Huang FL, Shie FS, Lee LC, Shiao YJ. Identifying N-linked glycan moiety and motifs in the cysteine-rich domain critical for N-glycosylation and intracellular trafficking of SR-AI and MARCO. J Biomed Sci 2016; 23:27. [PMID: 26892079 PMCID: PMC4758095 DOI: 10.1186/s12929-016-0244-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/03/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The accumulation of soluble oligomeric amyloid-β peptide (oAβ) proceeding the formation of senile plaques contributes to synaptic and memory deficits in Alzheimer's disease. Our previous studies have indentified scavenger receptor A (SR-A), especially SR-A type I (SR-AI), as prominent scavenger receptors on mediating oAβ clearance by microglia while glycan moiety and scavenger receptor cysteine-rich (SRCR) domain may play the critical role. Macrophage receptor with collagenous structure (MARCO), another member of class A superfamily with a highly conserved SRCR domain, may also play the similar role on oAβ internalization. However, the role of N-glycosylation and SRCR domain of SR-AI and MARCO on oAβ internalization remains unclear. RESULT We found that oAβ internalization was diminished in the cells expressing SR-AI harboring mutations of dual N-glycosylation sites (i.e. N120Q-N143Q and N143Q-N184Q) while they were normally surface targeted. Normal oAβ internalization was observed in 10 SR-AI-SRCR and 4 MARCO-SRCR surface targeted mutants. Alternatively, the SRCR mutants at β-sheet and α-helix and on disulfide bone formation obstructed receptor's N-glycosylation and surface targeting. CONCLUSION Our study reveals that N-glycan moiety is more critical than SRCR domain for SR-A-mediated oAβ internalization.
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Affiliation(s)
- Huey-Jen Tsay
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Yung-Cheng Huang
- Department of Physical Medicine and Rehabilitation, Cheng Hsin General Hospital, Taipei, 112, Taiwan, R.O.C.
| | - Yi-Jen Chen
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Yun-Hao Lee
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Shu-Meng Hsu
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Keng-Chang Tsai
- Division of Chinese Materia Medica Development, National Research Institute of Chinese Medicine, Taipei, 11221, Taiwan, R.O.C.
| | - Cheng-Ning Yang
- Institute of Anatomy and Cell Biology, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Fong-Lee Huang
- Institute of Anatomy and Cell Biology, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Feng-Shiun Shie
- Center for Neuropsychiatric Research, National Health Research Institutes, No. 35 Keyan Road, Zhunan Town, Miaoli County, 350, Taiwan, R.O.C.
| | - Lin-Chien Lee
- Department of Physical Medicine and Rehabilitation, Cheng Hsin General Hospital, Taipei, 11220, Taiwan, R.O.C.
| | - Young-Ji Shiao
- Division of Basic Chinese Medicine, National Research Institute of Chinese Medicine, Taipei, 11221, Taiwan, R.O.C. .,Institute of Biopharmaceutical Science, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
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Ben J, Zhu X, Zhang H, Chen Q. Class A1 scavenger receptors in cardiovascular diseases. Br J Pharmacol 2015; 172:5523-30. [PMID: 25651870 DOI: 10.1111/bph.13105] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 01/15/2015] [Accepted: 02/02/2015] [Indexed: 01/03/2023] Open
Abstract
Class A1 scavenger receptors (SR-A1) are membrane glycoproteins that can form homotrimers. This receptor was originally defined by its ability to mediate the accumulation of lipids in macrophages. Subsequent studies reveal that SR-A1 plays critical roles in innate immunity, cell apoptosis and proliferation. This review highlights recent advances in understanding the structure, receptor pathway and regulation of SR-A1. Although its role in atherosclerosis is disputable, recent discoveries suggest that SR-A1 function in anti-inflammatory responses by promoting an M2 macrophage phenotype in cardiovascular diseases. Therefore, SR-A1 may be a potential target for therapeutic intervention of cardiovascular diseases.
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Affiliation(s)
- Jingjing Ben
- Atherosclerosis Research Center, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, 210029, China
| | - Xudong Zhu
- Atherosclerosis Research Center, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, 210029, China
| | - Hanwen Zhang
- Atherosclerosis Research Center, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, 210029, China
| | - Qi Chen
- Atherosclerosis Research Center, Key Laboratory of Cardiovascular Disease and Molecular Intervention, Nanjing Medical University, Nanjing, 210029, China
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Homocysteine thiolactone and N-homocysteinylated protein induce pro-atherogenic changes in gene expression in human vascular endothelial cells. Amino Acids 2015; 47:1319-39. [PMID: 25802182 PMCID: PMC4458266 DOI: 10.1007/s00726-015-1956-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 03/04/2015] [Indexed: 12/11/2022]
Abstract
Genetic or nutritional deficiencies in homocysteine (Hcy) metabolism lead to hyperhomocysteinemia (HHcy) and cause endothelial dysfunction, a hallmark of atherosclerosis. In addition to Hcy, related metabolites accumulate in HHcy but their role in endothelial dysfunction is unknown. Here, we examine how Hcy-thiolactone, N-Hcy-protein, and Hcy affect gene expression and molecular pathways in human umbilical vein endothelial cells. We used microarray technology, real-time quantitative polymerase chain reaction, and bioinformatic analysis with PANTHER, DAVID, and Ingenuity Pathway Analysis (IPA) resources. We identified 47, 113, and 30 mRNAs regulated by N-Hcy-protein, Hcy-thiolactone, and Hcy, respectively, and found that each metabolite induced a unique pattern of gene expression. Top molecular pathways affected by Hcy-thiolactone were chromatin organization, one-carbon metabolism, and lipid-related processes [−log(P value) = 20–31]. Top pathways affected by N-Hcy-protein and Hcy were blood coagulation, sulfur amino acid metabolism, and lipid metabolism [−log(P value)] = 4–11; also affected by Hcy-thiolactone, [−log(P value) = 8–14]. Top disease related to Hcy-thiolactone, N-Hcy-protein, and Hcy was ‘atherosclerosis, coronary heart disease’ [−log(P value) = 9–16]. Top-scored biological networks affected by Hcy-thiolactone (score = 34–40) were cardiovascular disease and function; those affected by N-Hcy-protein (score = 24–35) were ‘small molecule biochemistry, neurological disease,’ and ‘cardiovascular system development and function’; and those affected by Hcy (score = 25–37) were ‘amino acid metabolism, lipid metabolism,’ ‘cellular movement, and cardiovascular and nervous system development and function.’ These results indicate that each Hcy metabolite uniquely modulates gene expression in pathways important for vascular homeostasis and identify new genes and pathways that are linked to HHcy-induced endothelial dysfunction and vascular disease.
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Huang FL, Shiao YJ, Hou SJ, Yang CN, Chen YJ, Lin CH, Shie FS, Tsay HJ. Cysteine-rich domain of scavenger receptor AI modulates the efficacy of surface targeting and mediates oligomeric Aβ internalization. J Biomed Sci 2013; 20:54. [PMID: 23915271 PMCID: PMC3750411 DOI: 10.1186/1423-0127-20-54] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 07/30/2013] [Indexed: 11/13/2022] Open
Abstract
Background Insufficient clearance of soluble oligomeric amyloid-β peptide (oAβ) in the central nervous system leads to the synaptic and memory deficits in Alzheimer's disease (AD). Previously we have identified scavenger receptor class A (SR-A) of microglia mediates oligomeric amyloid-β peptide (oAβ) internalization by siRNA approach. SR-A is a member of cysteine-rich domain (SRCR) superfamily which contains proteins actively modulating the innate immunity and host defense, however the functions of the SRCR domain remain unclear. Whether the SRCR domain of SR-AI modulates the receptor surface targeting and ligand internalization was investigated by expressing truncated SR-A variants in COS-7 cells. Surface targeting of SR-A variants was examined by live immunostaining and surface biotinylation assays. Transfected COS-7 cells were incubated with fluorescent oAβ and acetylated LDL (AcLDL) to assess their ligand-internalization capabilities. Result Genetic ablation of SR-A attenuated the internalization of oAβ and AcLDL by microglia. Half of oAβ-containing endocytic vesicles was SR-A positive in both microglia and macrophages. Clathrin and dynamin in SR-AI-mediated oAβ internalization were involved. The SRCR domain of SR-AI is encoded by exons 10 and 11. SR-A variants with truncated exon 11 were intracellularly retained, whereas SR-A variants with further truncations into exon 10 were surface-targeted. The fusion of exon 11 to the surface-targeted SR-A variant lacking the SRCR domain resulted in the intracellular retention and the co-immunoprecipitation of Bip chaperon of the endoplasmic reticulum. Surface-targeted variants were N-glycosylated, whereas intracellularly-retained variants retained in high-mannose states. In addition to the collagenous domain, the SRCR domain is a functional binding domain for oAβ and AcLDL. Our data suggest that inefficient folding of SR-AI variants with truncated SRCR domain was recognized by the endoplasmic reticulum associated degradation which leads to the immature N- glycosylation and intracellular retention. Conclusion The novel functions of the SRCR domain on regulating the efficacy of receptor trafficking and ligand binding may lead to possible approaches on modulating the innate immunity in Alzheimer’s disease and atherosclerosis.
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Affiliation(s)
- Fong-Lee Huang
- Institute of Anatomy and Cell Biology, National Yang-Ming University, Taipei11221, Taiwan
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21
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Qiu R, Sun BG, Li J, Liu X, Sun L. Identification and characterization of a cell surface scavenger receptor cysteine-rich protein of Sciaenops ocellatus: bacterial interaction and its dependence on the conserved structural features of the SRCR domain. FISH & SHELLFISH IMMUNOLOGY 2013; 34:810-818. [PMID: 23291106 DOI: 10.1016/j.fsi.2012.12.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/11/2012] [Accepted: 12/11/2012] [Indexed: 06/01/2023]
Abstract
The scavenger receptor cysteine-rich (SRCR) proteins are secreted or membrane-bound receptors with one or multiple SRCR domains. Members of the SRCR superfamily are known to have diverse functions that include pathogen recognition and immunoregulation. In teleost, although protein sequences with SRCR structure have been identified in some species, very little functional investigation has been carried out. In this study, we identified and characterized a teleost SRCR protein from red drum Sciaenops ocellatus. The protein was named S. ocellatus SRCR1 (SoSRCRP1). SoSRCRP1 is 410-residue in length and was predicted to be a transmembrane protein, with the extracellular region containing a collagen triple helix repeat and a SRCR domain. The SRCR domain has six conserved cysteines, of which, C338 and C399, C351 and C409, and C379 and C389 were predicted to form three disulfide bonds. SoSRCRP1 expression was detected mainly in immune-relevant tissues and upregulated by bacterial and viral infection. In head kidney leukocytes, bacterial infection stimulated the expression of SoSRCRP1, and the expressed SoSRCRP1 was localized on cell surface. Recombinant SoSRCRP1 (rSoSRCRP1) corresponding to the SRCR domain was purified from Escherichia coli and found to be able to bind Gram-negative and Gram-positive bacteria. To examine the structure-function relationship of SoSRCRP1, the mutant proteins SoSRCRP1M1, SoSRCRP1M2, SoSRCRP1M3, and SoSRCRP1M4 were created, which bear C351S and C409S, C338S, C379S, and R325A mutations respectively. Compared to rSoSRCRP1, all mutants were significantly reduced in the ability of bacterial interaction, with the highest reduction observed with SoSRCRP1M4. Taken together, these results indicate that SoSRCRP1 is a cell surface-localized SRCR protein that binds bacterial ligands in a manner that depends on the conserved structural features of the SRCR domain.
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Affiliation(s)
- Reng Qiu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, PR China
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He M, Chen P, Arnovitz S, Li Y, Huang H, Neilly MB, Wei M, Rowley JD, Chen J, Li Z. Two isoforms of HOXA9 function differently but work synergistically in human MLL-rearranged leukemia. Blood Cells Mol Dis 2012; 49:102-6. [PMID: 22633751 DOI: 10.1016/j.bcmd.2012.05.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 05/01/2012] [Indexed: 02/07/2023]
Abstract
HOXA9 plays a critical role in both normal hematopoiesis and leukemogenesis, particularly in the development and maintenance of mixed lineage leukemia (MLL)-rearranged leukemia. Through reverse transcription-polymerase chain reaction (RT-PCR) analysis of HOXA9 transcripts in human leukemia and normal bone marrow samples, we identified a truncated isoform of HOXA9, namely HOXA9T, and found that both HOXA9T and canonical HOXA9 were highly expressed in leukemia cell lines bearing MLL rearrangements, relative to human normal bone marrow cells or other subtypes of leukemia cells. A frameshift in HOXA9T in exon I causes a premature stop codon upstream of the PBX-binding domain and the homeodomain, which leads to the generation of a non-homeodomain-containing protein. Unlike the canonical HOXA9, HOXA9T alone cannot transform normal bone marrow progenitor cells. Moreover, HOXA9T cannot cooperate with MEIS1 to transform cells, despite the presence of a MEIS1-binding domain. Remarkably, although the truncated isoforms of many proteins function as dominant-negative competitors or inhibitors of their full-length counterparts, this is not the case for HOXA9T; instead, HOXA9T synergized with HOXA9 in transforming mouse normal bone marrow progenitor cells through promoting self-renewal and proliferation of the cells. Collectively, our data indicate that both truncated and full-length forms of HOXA9 are highly expressed in human MLL-rearranged leukemia, and the truncated isoform of HOXA9 might also play an oncogenic role by cooperating with canonical HOXA9 in cell transformation and leukemogenesis.
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Affiliation(s)
- Miao He
- Section of Hematology/Oncology, Department of Medicine, University of Chicago, Chicago, IL, USA
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Segers FME, Yu H, Molenaar TJM, Prince P, Tanaka T, van Berkel TJC, Biessen EAL. Design and validation of a specific scavenger receptor class AI binding peptide for targeting the inflammatory atherosclerotic plaque. Arterioscler Thromb Vasc Biol 2012; 32:971-8. [PMID: 22282357 DOI: 10.1161/atvbaha.111.235358] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Scavenger receptor A (SR-A) is abundantly expressed by macrophage and plays a critical role in foam cell formation and atherogenesis. In search of selective SR-AI antagonists, we have used affinity selection of a phage displayed peptide library on the synthetic extracellular domain of SR-AI. METHODS AND RESULTS Phage selection led to an almost 1,000-fold enrichment of SR-AI binding phage, which bound avidly to human THP-1 cells. A 15-mer corresponding to the peptide insert of the major SR-AI binding phage (PP1) displaced phage binding to SR-AI. Peptides, docked to a streptavidin scaffold, were effectively internalized by macrophages in an SR-AI-dependent manner. The enriched phage pool and streptavidin bound PP1 exhibited marked uptake by hepatic macrophages in mice. Importantly, PP1 significantly increased streptavidin as well as particulate accumulation in advanced aortic plaques, and in particular intraplaque macrophage, of apolipoprotein E(-/-) mice. CONCLUSIONS We have identified a novel peptide antagonist selective for SR-AI; this antagonist could be a valuable tool in SR-AI targeted imaging of atherosclerotic lesions.
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Affiliation(s)
- Filip M E Segers
- Department of General Surgery, Maastricht University, the Netherlands.
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24
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Selvarajan K, Moldovan L, Chandrakala AN, Litvinov D, Parthasarathy S. Peritoneal macrophages are distinct from monocytes and adherent macrophages. Atherosclerosis 2011; 219:475-83. [PMID: 21982410 DOI: 10.1016/j.atherosclerosis.2011.09.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 09/06/2011] [Accepted: 09/07/2011] [Indexed: 10/17/2022]
Abstract
OBJECTIVE Peritoneal macrophages are used in many studies related to atherosclerosis. In situ, they are non-adherent and upon culturing, they adhere and function as scavengers of modified lipoproteins and dead apoptotic cells. They also produce growth factors, suggesting that they may provide life-supporting function as well. In this study, we propose that macrophage adherence plays a major role in their function and propose a novel concept that non-adherent macrophages are poor scavengers and may delay the process of apoptosis by secretion of growth factors. METHODS AND RESULTS We analyzed non-adherent and adherent macrophages for changes in receptor expression, growth factor production and function by microarrays, real-time PCR, and western blot analyses. Our results indicate that adherent macrophages have increased expression of scavenger receptors as compared to fresh peritoneal cells. While genes for many growth factors were expressed in both non-adherent and adherent macrophages, the milk fat globule-epidermal growth factor 8 protein (MFG-E8) that recognizes and takes up apoptotic cells was specifically enhanced in non-adherent cells. Furthermore, early apoptotic endothelial cells demonstrated signs of delayed apoptosis when incubated in the presence of peritoneal lavage fluid that was shown to contain MFG-E8. Functional arrays indicated that peritoneal non-adherent macrophages represent a class of macrophages, distinct from either blood monocytes or adherent cultured macrophages. CONCLUSIONS These results suggest that the adherence status of macrophages may play a major role in their functions.
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Affiliation(s)
- Krithika Selvarajan
- Division of Cardiothoracic Surgery, The Ohio State University Medical Center, Columbus, OH 43210, USA
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Martínez VG, Moestrup SK, Holmskov U, Mollenhauer J, Lozano F. The conserved scavenger receptor cysteine-rich superfamily in therapy and diagnosis. Pharmacol Rev 2011; 63:967-1000. [PMID: 21880988 DOI: 10.1124/pr.111.004523] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The scavenger receptor cysteine-rich (SRCR) superfamily of soluble or membrane-bound protein receptors is characterized by the presence of one or several repeats of an ancient and highly conserved protein module, the SRCR domain. This superfamily (SRCR-SF) has been in constant and progressive expansion, now up to more than 30 members. The study of these members is attracting growing interest, which parallels that in innate immunity. No unifying function has been described to date for the SRCR domains, this being the result of the limited knowledge still available on the physiology of most members of the SRCR-SF, but also of the sequence versatility of the SRCR domains. Indeed, involvement of SRCR-SF members in quite different functions, such as pathogen recognition, modulation of the immune response, epithelial homeostasis, stem cell biology, and tumor development, have all been described. This has brought to us new information, unveiling the possibility that targeting or supplementing SRCR-SF proteins could result in diagnostic and/or therapeutic benefit for a number of physiologic and pathologic states. Recent research has provided structural and functional insight into these proteins, facilitating the development of means to modulate the activity of SRCR-SF members. Indeed, some of these approaches are already in use, paving the way for a more comprehensive use of SRCR-SF members in the clinic. The present review will illustrate some available evidence on the potential of well known and new members of the SRCR-SF in this regard.
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Affiliation(s)
- Vanesa Gabriela Martínez
- Center Esther Koplowitz, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
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Stephen SL, Freestone K, Dunn S, Twigg MW, Homer-Vanniasinkam S, Walker JH, Wheatcroft SB, Ponnambalam S. Scavenger receptors and their potential as therapeutic targets in the treatment of cardiovascular disease. Int J Hypertens 2010; 2010:646929. [PMID: 20981357 PMCID: PMC2958427 DOI: 10.4061/2010/646929] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 07/07/2010] [Indexed: 12/12/2022] Open
Abstract
Scavenger receptors act as membrane-bound and soluble proteins that bind to macromolecular complexes and pathogens. This diverse supergroup of proteins mediates binding to modified lipoprotein particles which regulate the initiation and progression of atherosclerotic plaques. In vascular tissues, scavenger receptors are implicated in regulating intracellular signaling, lipid accumulation, foam cell development, and cellular apoptosis or necrosis linked to the pathophysiology of atherosclerosis. One approach is using gene therapy to modulate scavenger receptor function in atherosclerosis. Ectopic expression of membrane-bound scavenger receptors using viral vectors can modify lipid profiles and reduce the incidence of atherosclerosis. Alternatively, expression of soluble scavenger receptors can also block plaque initiation and progression. Inhibition of scavenger receptor expression using a combined gene therapy and RNA interference strategy also holds promise for long-term therapy. Here we review our current understanding of the gene delivery by viral vectors to cells and tissues in gene therapy strategies and its application to the modulation of scavenger receptor function in atherosclerosis.
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Affiliation(s)
- Sam L Stephen
- Endothelial Cell Biology Unit, Institute of Molecular & Cellular Biology, LIGHT Laboratories, University of Leeds, Clarendon Way, Leeds LS2 9JT, UK
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Levitan I, Volkov S, Subbaiah PV. Oxidized LDL: diversity, patterns of recognition, and pathophysiology. Antioxid Redox Signal 2010; 13:39-75. [PMID: 19888833 PMCID: PMC2877120 DOI: 10.1089/ars.2009.2733] [Citation(s) in RCA: 308] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Revised: 10/09/2009] [Accepted: 11/02/2009] [Indexed: 02/06/2023]
Abstract
Oxidative modification of LDL is known to elicit an array of pro-atherogenic responses, but it is generally underappreciated that oxidized LDL (OxLDL) exists in multiple forms, characterized by different degrees of oxidation and different mixtures of bioactive components. The variable effects of OxLDL reported in the literature can be attributed in large part to the heterogeneous nature of the preparations employed. In this review, we first describe the various subclasses and molecular composition of OxLDL, including the variety of minimally modified LDL preparations. We then describe multiple receptors that recognize various species of OxLDL and discuss the mechanisms responsible for the recognition by specific receptors. Furthermore, we discuss the contentious issues such as the nature of OxLDL in vivo and the physiological oxidizing agents, whether oxidation of LDL is a prerequisite for atherogenesis, whether OxLDL is the major source of lipids in foam cells, whether in some cases it actually induces cholesterol depletion, and finally the Janus-like nature of OxLDL in having both pro- and anti-inflammatory effects. Lastly, we extend our review to discuss the role of LDL oxidation in diseases other than atherosclerosis, including diabetes mellitus, and several autoimmune diseases, such as lupus erythematosus, anti-phospholipid syndrome, and rheumatoid arthritis.
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Affiliation(s)
- Irena Levitan
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA.
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Haisma HJ, Boesjes M, Beerens AM, van der Strate BWA, Curiel DT, Plüddemann A, Gordon S, Bellu AR. Scavenger receptor A: a new route for adenovirus 5. Mol Pharm 2009; 6:366-74. [PMID: 19227971 DOI: 10.1021/mp8000974] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Adenoviruses are common pathogens associated with respiratory diseases, gastrointestinal illnesses and/or conjunctivitis. Currently, this virus is used as a vector in gene therapy trials. The promise of viral gene therapy applications is substantially reduced because the virus is cleared by liver macrophages upon systemic administration. The mechanism underlying adenoviral tropism to and degradation in macrophages is poorly understood. We identified a new adenoviral receptor, the scavenger receptor A (SR-A), responsible for uptake of the virus in macrophages. CHO cells expressing SR-A showed increased viral transgene expression when compared with wild type cells. Preincubation of J774 macrophage cells with SR-A ligands decreased significantly adenoviral uptake. Electron-microscopy analysis of infected J774 cells showed activation of a viral degradation pathway. Infection of mice with adenovirus resulted in a substantial decrease of the virus in liver macrophages when SR-A was blocked. Our data provide a basis for understanding of the adenoviral uptake and degradation mechanism in macrophages in vitro and in vivo. Inhibition of adenoviral SR-A uptake can be utilized in gene therapy applications to increase its efficiency and efficacy.
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Affiliation(s)
- Hidde J Haisma
- Department of Therapeutic Gene Modulation, Groningen University Institute for Drug Exploration, University of Groningen, The Netherlands
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Bowdish DME, Gordon S. Conserved domains of the class A scavenger receptors: evolution and function. Immunol Rev 2009; 227:19-31. [PMID: 19120472 DOI: 10.1111/j.1600-065x.2008.00728.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The class A scavenger receptors are phagocytic pattern recognition receptors that are well represented in vertebrate genomes. The high level of conservation among vertebrates implies that this is an evolutionarily conserved family of receptors and indicates the presence of a common ancestral gene. The identity of this ancestral gene is not clear, as it appears that many of the domains of the scavenger receptors (e.g. collagenous, scavenger receptor cysteine rich) originated early in evolutionary history and are found in many combinations, often in genes of unknown function. These early receptors may function in cell-cell recognition, aggregation, or lipid recognition, and their involvement in pattern recognition, phagocytosis, and homeostasis may have been adaptations of such conserved patterns. Herein, we reclassify the class A scavenger receptors based on recent discoveries of new members of this family, describe the evolution of the various domains of the class A scavenger receptors, and discuss the appearance and function of these domains through evolutionary history.
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Affiliation(s)
- Dawn M E Bowdish
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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Bowdish DME, Sakamoto K, Kim MJ, Kroos M, Mukhopadhyay S, Leifer CA, Tryggvason K, Gordon S, Russell DG. MARCO, TLR2, and CD14 are required for macrophage cytokine responses to mycobacterial trehalose dimycolate and Mycobacterium tuberculosis. PLoS Pathog 2009; 5:e1000474. [PMID: 19521507 PMCID: PMC2688075 DOI: 10.1371/journal.ppat.1000474] [Citation(s) in RCA: 219] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2008] [Accepted: 05/14/2009] [Indexed: 01/21/2023] Open
Abstract
Virtually all of the elements of Mycobacterium tuberculosis (Mtb) pathogenesis, including pro-inflammatory cytokine production, granuloma formation, cachexia, and mortality, can be induced by its predominant cell wall glycolipid, trehalose 6,6′-dimycolate (TDM/cord factor). TDM mediates these potent inflammatory responses via interactions with macrophages both in vitro and in vivo in a myeloid differentiation factor 88 (MyD88)-dependent manner via phosphorylation of the mitogen activated protein kinases (MAPKs), implying involvement of toll-like receptors (TLRs). However, specific TLRs or binding receptors for TDM have yet to be identified. Herein, we demonstrate that the macrophage receptor with collagenous structure (MARCO), a class A scavenger receptor, is utilized preferentially to “tether” TDM to the macrophage and to activate the TLR2 signaling pathway. TDM-induced signaling, as measured by a nuclear factor-kappa B (NF-κB)-luciferase reporter assay, required MARCO in addition to TLR2 and CD14. MARCO was used preferentially over the highly homologous scavenger receptor class A (SRA), which required TLR2 and TLR4, as well as their respective accessory molecules, in order for a slight increase in NF-κB signaling to occur. Consistent with these observations, macrophages from MARCO−/− or MARCO−/−SRA−/− mice are defective in activation of extracellular signal-related kinase 1/2 (ERK1/2) and subsequent pro-inflammatory cytokine production in response to TDM. These results show that MARCO-expressing macrophages secrete pro-inflammatory cytokines in response to TDM by cooperation between MARCO and TLR2/CD14, whereas other macrophage subtypes (e.g. bone marrow–derived) may rely somewhat less effectively on SRA, TLR2/CD14, and TLR4/MD2. Macrophages from MARCO−/− mice also produce markedly lower levels of pro-inflammatory cytokines in response to infection with virulent Mtb. These observations identify the scavenger receptors as essential binding receptors for TDM, explain the differential response to TDM of various macrophage populations, which differ in their expression of the scavenger receptors, and identify MARCO as a novel component required for TLR signaling. The causative agent of tuberculosis, Mycobacterium tuberculosis, has a lipid-rich cell wall that contains a high percentage of mycolic acids. These mycolic acids contribute to both the impermeable nature of the cell wall and to the immunostimulatory properties of the bacterium. Indeed, it has been known for over 50 years that trehalose 6,6′-dimycolate (TDM/cord factor) is the major immunogenic lipid of M. tuberculosis, which induces potent pro-inflammatory responses from macrophages, although the receptor has not been identified. We have demonstrated that the toll-like receptor (TLR) pathway is required for pro-inflammatory cytokine production in response to TDM; however, the TLRs alone, or in conjunction with known co-receptors, are not sufficient to induce a response. We demonstrate that the macrophage receptor MARCO, a scavenger receptor, is utilized preferentially to “tether” TDM to the macrophage and activate the TLR2 signaling pathway, and is used preferentially over the related SRA. Macrophages from MARCO−/− mice are defective in activation of TDM-induced signaling and subsequent pro-inflammatory cytokine production in response to both TDM-coated beads and virulent M. tuberculosis. By identifying the macrophage receptors involved in initial recognition we can now explain variable responses to TDM between different macrophage populations (which differ in scavenger receptor expression), and have identified a novel co-receptor that may be involved in lipid presentation to TLRs.
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Affiliation(s)
- Dawn M. E. Bowdish
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Kaori Sakamoto
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - Mi-Jeong Kim
- Department of Microbiology and Immunology, Veterinary Medical Center, Cornell University, Ithaca, New York, United States of America
| | - Mariliis Kroos
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | | | - Cynthia A. Leifer
- Department of Microbiology and Immunology, Veterinary Medical Center, Cornell University, Ithaca, New York, United States of America
| | - Karl Tryggvason
- Division of Matrix Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Siamon Gordon
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
- * E-mail:
| | - David G. Russell
- Department of Microbiology and Immunology, Veterinary Medical Center, Cornell University, Ithaca, New York, United States of America
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Macrophage scavenger receptors and host-derived ligands. Methods 2008; 43:207-17. [PMID: 17920517 DOI: 10.1016/j.ymeth.2007.06.004] [Citation(s) in RCA: 223] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Accepted: 06/25/2007] [Indexed: 02/07/2023] Open
Abstract
The scavenger receptors are a large family of molecules that are structurally diverse and have been implicated in a range of functions. They are expressed by myeloid cells, selected endothelial cells and some epithelial cells and recognise many different ligands, including microbial pathogens as well as endogenous and modified host-derived molecules. This review will focus on the eight classes of scavenger receptors (class A-H) in terms of their structure, expression and recognition of host-derived ligands. Scavenger receptors have been implicated in a range of physiological and pathological processes, such as atherosclerosis and Alzheimer's disease, and function in adhesion and tissue maintenance. More recently, some of the scavenger receptors have been shown to mediate binding and endocytosis of chaperone proteins, such as the heat shock proteins, thereby playing an important role in antigen cross-presentation.
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Plüddemann A, Neyen C, Gordon S, Peiser L. A sensitive solid-phase assay for identification of class A macrophage scavenger receptor ligands using cell lysate. J Immunol Methods 2007; 329:167-75. [PMID: 17996889 DOI: 10.1016/j.jim.2007.10.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 07/16/2007] [Accepted: 10/04/2007] [Indexed: 10/22/2022]
Abstract
In order for macrophages to perform their numerous homeostatic, immunological and tissue remodeling functions they are required to express a broad repertoire of cell-surface receptors. These receptors are particularly important for their host-defense functions in the recognition of foreign pathogens. Delineation of the particular functions of specific receptors requires the identification of ligands recognized by the receptor. We have developed a sensitive, high throughput, solid-phase assay for the detection of ligands for the class A macrophage scavenger receptor (SR-A). Post-nuclear cell lysate from murine bone marrow-derived macrophages is used as a source of receptor and specific ligand binding to SR-A is detected with a monoclonal antibody for SR-A. This assay has been used effectively to identify protein ligands for SR-A on the surface of the bacterium Neisseria meningitidis (Peiser, L. et al. [Peiser, L., Makepeace, K., Pluddemann, A., Savino, S., Wright, J.C., Pizza, M., Rappuoli, R., Moxon, E.R., Gordon, S., 2006. Identification of Neisseria meningitidis nonlipopolysaccharide ligands for class A macrophage scavenger receptor by using a novel assay. Infect. Immun. 74, 5191-5199]). In this paper we describe the method in detail and define the specific variables governing the assay.
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Affiliation(s)
- Annette Plüddemann
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK
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33
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Facciponte JG, Wang XY, Subjeck JR. Hsp110 and Grp170, members of the Hsp70 superfamily, bind to scavenger receptor-A and scavenger receptor expressed by endothelial cells-I. Eur J Immunol 2007; 37:2268-79. [PMID: 17615582 DOI: 10.1002/eji.200737127] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Heat shock protein 110 (hsp110) and glucose-regulated protein (grp170) act as anti-cancer vaccines when complexed to tumor antigens by heat shock. It has been proposed that receptors on antigen-presenting cells contribute to HSP-mediated immune responses. Here, we show that hsp110 binds in a receptor-mediated manner to RAW264.7 macrophages, as does grp170. This hsp110/grp170 binding is inhibited by scavenger receptor ligands, suggesting a role for scavenger receptors as binding structures. We examined scavenger receptor class A (SR-A) and scavenger receptor expressed by endothelial cells-I (SREC-I). We show that hsp110/grp170 binds to both SR-A- and SREC-I-expressing CHO cells in a saturable manner and scavenger receptor ligands inhibit binding. Hsp110 also saturably binds mouse bone marrow-derived dendritic cells (bmDC) and is inhibited by scavenger receptor ligands. When an hsp110-rat neu (intracellular domain) heat shock complex vaccine is used to pulse mouse bmDC in vitro, an induction of IFN-gamma secretion is observed by CD8+ T lymphocytes isolated from vaccine-immunized mice. This immune response is inhibited by the application of scavenger receptor ligands to bmDC. Thus, SR-A and SREC-I appear to contribute to the binding of hsp110 and grp170 on APC. Scavenger receptors, in general, contribute to the cross-presentation of hsp110-chaperoned protein antigen.
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Affiliation(s)
- John G Facciponte
- Department of Immunology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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34
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Abstract
The adaptive component of innate immunity occurs during the course of infection when antigen presenting cells alter expression of soluble or surface associated pattern recognition receptors. This results in increased recognition of a broad spectrum of pathogens, enhancement of effector functions and altered regulation of the inflammatory response.
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Engert JC, Lemire M, Faith J, Brisson D, Fujiwara TM, Roslin NM, Brewer CG, Montpetit A, Darmond-Zwaig C, Renaud Y, Doré C, Bailey SD, Verner A, Tremblay G, St-Pierre J, Bétard C, Platko J, Rioux JD, Morgan K, Hudson TJ, Gaudet D. Identification of a chromosome 8p locus for early-onset coronary heart disease in a French Canadian population. Eur J Hum Genet 2007; 16:105-14. [PMID: 17805225 DOI: 10.1038/sj.ejhg.5201920] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Susceptibility to coronary heart disease (CHD) has long been known to exhibit familial aggregation, with heritability estimated to be greater than 50%. The French Canadian population of the Saguenay-Lac Saint-Jean region of Quebec, Canada is descended from a founder population that settled this region 300-400 years ago and this may provide increased power to detect genes contributing to complex traits such as CHD. Probands with early-onset CHD, defined by angiographically determined coronary stenosis, and their relatives were recruited from this population (average sibship size of 6.4). Linkage analysis was performed following a genome-wide microsatellite marker scan on 42 families with 284 individuals. Nonparametric linkage (NPL) analysis provided suggestive evidence for a CHD susceptibility locus on chromosome 8 with an NPL score of 3.14 (P=0.001) at D8S1106. Linkage to this locus was verified by fine mapping in an enlarged sample of 50 families with 320 individuals. This analysis provided evidence of linkage at D8S552 (NPL score=3.53, P=0.0003), a marker that maps to the same location as D8S1106. Candidate genes in this region, including macrophage scavenger receptor 1, farnesyl-diphosphate farnesyltransferase 1, fibrinogen-like 1, and GATA-binding protein 4, were resequenced in all coding exons in both affected and unaffected individuals. Association studies with variants in these and five other genes did not identify a disease-associated mutation. In conclusion, a genome-wide scan and additional fine mapping provide evidence for a locus on chromosome 8 that contributes to CHD in a French Canadian population.
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Affiliation(s)
- James C Engert
- McGill University Health Centre, Montréal, Québec, Canada.
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Schmitz G, Grandl M. Role of redox regulation and lipid rafts in macrophages during Ox-LDL-mediated foam cell formation. Antioxid Redox Signal 2007; 9:1499-518. [PMID: 17600463 DOI: 10.1089/ars.2007.1663] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hyperlipidemias and small dense LDLs in patients with high-triglyceride low-HDL syndromes lead to a prolonged half life of apoB-containing particles. This is associated with reactive oxygen species (ROS) activation and leads to formation of oxidized LDL (Ox-LDL). Generators of ROS in macrophages (MACs) include myeloperoxidase (MPO)-mediated respiratory burst and raft-associated NADPH-oxidase. The intracellular oxidant milieu is involved in cellular signaling pathways, like ion-transport systems, protein phosphorylation, and gene expression. Lipid oxidation through ROS can amplify foam cell formation through Ox-LDL uptake, leading to formation of ceramide (Cer)-rich lipid membrane microdomains, and is associated with expansion of the lysosomal compartment and an upregulation of ABCA1 and other genes of the AP3 secretory pathway. Ox-LDL may also affect cell-surface turnover of Cer-backbone sphingolipids and apoE-mediated uptake by LRP-family members. In contrast, HDL-mediated lipid efflux causes disruption of lipid membrane microdomains and prevents foam cell formation. Oxidation of HDL through MPO leads to a failure of lipid efflux and enhancement of MAC loading. Therefore, lipid rafts and oxidation processes are important in regulation of MAC foam cell formation and atherosclerosis, and the balance between oxidant and antioxidant intracellular systems is critically important for efficient MAC function.
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Affiliation(s)
- Gerd Schmitz
- Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany.
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37
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Arredouani MS, Franco F, Imrich A, Fedulov A, Lu X, Perkins D, Soininen R, Tryggvason K, Shapiro SD, Kobzik L. Scavenger Receptors SR-AI/II and MARCO limit pulmonary dendritic cell migration and allergic airway inflammation. THE JOURNAL OF IMMUNOLOGY 2007; 178:5912-20. [PMID: 17442975 DOI: 10.4049/jimmunol.178.9.5912] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The class A scavenger receptors (SR-A) MARCO and SR-AI/II are expressed on lung macrophages (MPhis) and dendritic cells (DCs) and function in innate defenses against inhaled pathogens and particles. Increased expression of SR-As in the lungs of mice in an OVA-asthma model suggested an additional role in modulating responses to an inhaled allergen. After OVA sensitization and aerosol challenge, SR-AI/II and MARCO-deficient mice exhibited greater eosinophilic airway inflammation and airway hyperresponsiveness compared with wild-type mice. A role for simple SR-A-mediated Ag clearance ("scavenging") by lung MPhis was excluded by the observation of a comparable uptake of fluorescent OVA by wild-type and SR-A-deficient lung MPhis and DCs. In contrast, airway instillation of fluorescent Ag revealed a significantly higher traffic of labeled DCs to thoracic lymph nodes in SR-A-deficient mice than in controls. The increased migration of SR-A-deficient DCs was accompanied by the enhanced proliferation in thoracic lymph nodes of adoptively transferred OVA-specific T cells after airway OVA challenge. The data identify a novel role for SR-As expressed on lung DCs in the down-regulation of specific immune responses to aeroallergens by the reduction of DC migration from the site of Ag uptake to the draining lymph nodes.
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Affiliation(s)
- Mohamed S Arredouani
- Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA
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De Marzo AM, Platz EA, Sutcliffe S, Xu J, Grönberg H, Drake CG, Nakai Y, Isaacs WB, Nelson WG. Inflammation in prostate carcinogenesis. Nat Rev Cancer 2007; 7:256-69. [PMID: 17384581 PMCID: PMC3552388 DOI: 10.1038/nrc2090] [Citation(s) in RCA: 1128] [Impact Index Per Article: 66.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
About 20% of all human cancers are caused by chronic infection or chronic inflammatory states. Recently, a new hypothesis has been proposed for prostate carcinogenesis. It proposes that exposure to environmental factors such as infectious agents and dietary carcinogens, and hormonal imbalances lead to injury of the prostate and to the development of chronic inflammation and regenerative 'risk factor' lesions, referred to as proliferative inflammatory atrophy (PIA). By developing new experimental animal models coupled with classical epidemiological studies, genetic epidemiological studies and molecular pathological approaches, we should be able to determine whether prostate cancer is driven by inflammation, and if so, to develop new strategies to prevent the disease.
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Affiliation(s)
- Angelo M De Marzo
- Johns Hopkins University School of Medicine, Department of Pathology, Baltimore, MD, USA.
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39
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Lin YL, de Villiers WJS, Garvy B, Post SR, Nagy TR, Safadi FF, Faugere MC, Wang G, Malluche HH, Williams JP. The Effect of Class A Scavenger Receptor Deficiency in Bone. J Biol Chem 2007; 282:4653-4660. [PMID: 17166840 DOI: 10.1074/jbc.m608552200] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Class A scavenger receptor (SR-A) is predominantly expressed by macrophages, and because osteoclasts are of monocyte/macrophage lineage, SR-A is of potential interest in osteoclast biology. In addition to modified low density lipoprotein uptake, SR-A is also important in cell attachment and signaling. In this study we evaluated the effect of SR-A deletion on bone. Knock-out animals have 40% greater body weight than wild type. Body composition analyses demonstrated that total lean and fat body mass were greater in knock-out animals, but there was no significant difference in percent fat and lean body mass. Bone mineral density and content were significantly greater in knock-out compared with wild type animals. Micro-computed tomography analyses confirmed that total volume, bone volume as well as trabecular number, thickness, and connectivity were significantly greater in knock-out mice. As expected, trabecular separation was greater in wild type mice. The phenotype appears to be explained by 60% fewer osteoclasts in females and 35% fewer in males compared to wild type mice with a paradoxical increase in nuclei/osteoclast in knock-out animals. Furthermore, there were no differences in adipocyte number and osteoblast number or activity. The addition of the soluble extracellular domain of SR-A to RAW264.7 cells stimulated a concentration-dependent increase in osteoclast differentiation that was receptor activator of nuclear factor-kappaB ligand (RANKL)-dependent. Soluble SR-A had no effect on cell proliferation in the presence of RANKL but stimulated a 40% increase in numbers in the absence of RANKL. We conclude that SR-A plays a role in normal osteoclast differentiation, suggesting a novel role for this receptor in bone biology.
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Affiliation(s)
- Yi-Ling Lin
- College of Dentistry, Department of Internal Medicine, Divisions of University of Kentucky, Lexington, Kentucky 40536
| | - Willem J S de Villiers
- Digestive Diseases and Nutrition and University of Kentucky, Lexington, Kentucky 40536; Lexington Veterans Affairs Medical Center, Lexington, Kentucky 40502
| | - Beth Garvy
- Lexington Veterans Affairs Medical Center, Lexington, Kentucky 40502; Microbiology, Immunology and Molecular Genetics and University of Kentucky, Lexington, Kentucky 40536
| | - Steven R Post
- Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, Kentucky 40536
| | - Tim R Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama 35294, and
| | - Fayez F Safadi
- Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Marie Claude Faugere
- Nephrology, Bone, and Mineral Metabolism, and Departments of University of Kentucky, Lexington, Kentucky 40536
| | - Guodong Wang
- Nephrology, Bone, and Mineral Metabolism, and Departments of University of Kentucky, Lexington, Kentucky 40536
| | - Hartmut H Malluche
- Nephrology, Bone, and Mineral Metabolism, and Departments of University of Kentucky, Lexington, Kentucky 40536
| | - John P Williams
- Lexington Veterans Affairs Medical Center, Lexington, Kentucky 40502; Nephrology, Bone, and Mineral Metabolism, and Departments of University of Kentucky, Lexington, Kentucky 40536.
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40
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Peiser L, Makepeace K, Plüddemann A, Savino S, Wright JC, Pizza M, Rappuoli R, Moxon ER, Gordon S. Identification of Neisseria meningitidis nonlipopolysaccharide ligands for class A macrophage scavenger receptor by using a novel assay. Infect Immun 2006; 74:5191-9. [PMID: 16926412 PMCID: PMC1594824 DOI: 10.1128/iai.00124-06] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Macrophages (Mphi) may play an important role in the pathogenesis of invasive meningococcal infection. Previously, we have shown that the class A Mphi scavenger receptor (SR-A) is a major nonopsonic receptor for Neisseria meningitidis on Mphi. SR-A contributes to host defense by binding proinflammatory polyanionic ligands such as lipopolysaccharide (LPS) and by the uptake and killing of live organisms. SR-A-deficient mouse Mphi display a substantial reduction in the number of meningococci ingested compared to wild-type Mphi, and SR-A is required for meningococcal phagocytosis but not for the release of tumor necrosis factor alpha. Although soluble lipid A and lipid(IV)A are reported as ligands for SR-A, we demonstrated that LPS and LPS expression were not essential for the uptake of whole meningococci. In the present study, we set out to discover protein ligand(s) for SR-A in N. meningitidis lysates and outer membrane vesicles. Using various microbial mutant strains, we determined that molecules comprising the membrane capsule and pili, as well as the abundant surface Opa proteins were not essential for SR-A recognition. We developed a binding assay to detect SR-A ligands and identified three candidate proteins expressed on intact organisms, namely, NMB1220, NMB0278, and NMB0667. Soluble forms of these ligands were shown to block the binding of meningococci to CHO cells stably transfected with SR-A. Furthermore, NMB1220 was endocytosed by SR-A on Mphi and prevented internalization of soluble acetylated low-density lipoprotein. Thus, we have identified novel, unmodified protein ligands for SR-A that are able to inhibit meningococcal interactions with macrophages in vitro.
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Affiliation(s)
- Leanne Peiser
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, United Kingdom
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41
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Moore KJ, Freeman MW. Scavenger receptors in atherosclerosis: beyond lipid uptake. Arterioscler Thromb Vasc Biol 2006; 26:1702-11. [PMID: 16728653 DOI: 10.1161/01.atv.0000229218.97976.43] [Citation(s) in RCA: 396] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Atherosclerotic vascular disease arises as a consequence of the deposition and retention of serum lipoproteins in the artery wall. Macrophages in lesions have been shown to express > or = 6 structurally different scavenger receptors for uptake of modified forms of low-density lipoproteins (LDLs) that promote the cellular accumulation of cholesterol. Because cholesterol-laden macrophage foam cells are the primary component of the fatty streak, the earliest atherosclerotic lesion, lipid uptake by these pathways has long been considered a requisite and initiating event in the pathogenesis of atherosclerosis. Although the removal of proinflammatory modified LDLs from the artery wall via scavenger receptors would seem beneficial, the pathways distal to scavenger receptor uptake that metabolize the modified lipoproteins appear to become overwhelmed, leading to the accumulation of cholesterol-laden macrophages and establishment of a chronic inflammatory setting. These observations have led to the current dogma concerning scavenger receptors, which is that they are proatherogenic molecules. However, recent studies suggest that the effects of scavenger receptors on atherogenesis may be more complex. In addition to modified lipoprotein uptake, these proteins are now known to regulate apoptotic cell clearance, initiate signal transduction, and serve as pattern recognition receptors for pathogens, activities that may contribute both to proinflammatory and anti-inflammatory forces regulating atherogenesis. In this review, we focus on recent advances in our knowledge of scavenger receptor regulation and signal transduction, their roles in sterile inflammation and infection, and the potential impact of these pathways in regulating the balance of lipid accumulation and inflammation in the artery wall.
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Affiliation(s)
- Kathryn J Moore
- Lipid Metabolism Unit, GRJ1328, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Boston, MA 02114, USA.
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42
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Murphy JE, Tedbury PR, Homer-Vanniasinkam S, Walker JH, Ponnambalam S. Biochemistry and cell biology of mammalian scavenger receptors. Atherosclerosis 2006; 182:1-15. [PMID: 15904923 DOI: 10.1016/j.atherosclerosis.2005.03.036] [Citation(s) in RCA: 247] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 03/10/2005] [Accepted: 03/24/2005] [Indexed: 01/14/2023]
Abstract
Scavenger receptors are integral membrane proteins that bind a wide variety of ligands including modified or oxidised low-density lipoproteins, apoptotic cells and pathogens. Modified low-density lipoprotein accumulation is thought to be an early event in vascular disease and thus scavenger receptor function is critical in this context. The scavenger receptor family has at least eight different subclasses (A-H) which bear little sequence homology to each other but recognize common ligands. Here we review our current understanding of the scavenger receptor subclasses with emphasis on their genetics, protein structure, biochemical properties, membrane trafficking, intracellular signalling and links to disease states. We also highlight emerging areas where scavenger receptors play roles in cell and animal physiology.
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Affiliation(s)
- Jane E Murphy
- School of Biochemistry and Microbiology, University of Leeds, Leeds LS2 9JT, UK
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43
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Arredouani MS, Palecanda A, Koziel H, Huang YC, Imrich A, Sulahian TH, Ning YY, Yang Z, Pikkarainen T, Sankala M, Vargas SO, Takeya M, Tryggvason K, Kobzik L. MARCO is the major binding receptor for unopsonized particles and bacteria on human alveolar macrophages. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2005; 175:6058-64. [PMID: 16237101 DOI: 10.4049/jimmunol.175.9.6058] [Citation(s) in RCA: 156] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Alveolar macrophages (AMs) avidly bind and ingest inhaled environmental particles and bacteria. To identify the particle binding receptor(s) on human AMs, we used functional screening of anti-human AM hybridomas and isolated a mAb, PLK-1, which inhibits AM binding of unopsonized particles (e.g., TiO2, latex beads; 63 +/- 5 and 67 +/- 4% inhibition, respectively, measured by flow cytometry; n = 11) and unopsonized bacteria ( approximately 84 and 41% inhibition of Escherichia coli and Staphylococcus aureus binding by mAb PLK-1, respectively). The PLK-1 Ag was identified as the human class A scavenger receptor (SR) MARCO (macrophage receptor with collagenous structure) by observing specific immunolabeling of COS cells transfected with human MARCO (but not SR-AI/II) cDNA and by immunoprecipitation by PLK-1 of a protein of appropriate molecular mass (approximately 70 kDa) from both normal human bronchoalveolar lavage cells (>90% AMs) and human MARCO-transfected COS cells. PLK-1 also specifically inhibited particle binding by COS cells, only after transfection with human MARCO cDNA. Immunostaining showed specific labeling of AMs within human lung tissue, bronchoalveolar lavage samples, as well as macrophages in other sites (e.g., lymph node and liver). Using COS transfectants with different truncated forms of MARCO, allowed epitope mapping for the PLK-1 Ab to MARCO domain V between amino acid residues 420 and 431. A panel of Abs to various SRs identified expression on AMs, but failed to inhibit TiO2 or S. aureus binding. The data support a dominant role for MARCO in the human AM defense against inhaled particles and pathogens.
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van Berkel TJC, Out R, Hoekstra M, Kuiper J, Biessen E, van Eck M. Scavenger receptors: friend or foe in atherosclerosis? Curr Opin Lipidol 2005; 16:525-35. [PMID: 16148537 DOI: 10.1097/01.mol.0000183943.20277.26] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE OF REVIEW Scavenger receptors were originally defined by their ability to bind and internalize modified lipoproteins. Nowadays the family of scavenger receptors is composed of structurally different surface receptors which recognize a broad pattern of common ligands which include, besides modified lipoproteins, apoptotic cells and pathogens. This review focuses on the role of scavenger receptors in the development of atherosclerotic lesions. RECENT FINDINGS Recent studies indicate that scavenger receptor A activity can be regulated by phosphorylation, glucosidases, 8-isoprostane, high glucose and nobiletin. Modulation of these regulatory components may beneficially influence scavenger receptor A's proatherogenic function. It appears that statins do lead to a reduction in CD36 transcription and could modulate in this way CD36-mediated atherosclerotic foam cell formation. Macrophage scavenger receptor BI appears to facilitate the development of small fatty streak lesions, whereas the formation of advanced atherosclerotic lesions is reduced, indicating a unique dual role for macrophage scavenger receptor BI in the pathogenesis of atherosclerosis. SUMMARY It is proposed that the presence of scavenger receptors in macrophages is beneficial because they remove potential deleterious material from the arterial wall. Inadequate handling of the internalized material by the macrophages will lead to foam cell formation. If adequate levels of ATP-binding cassette transporters and accepting HDL are present, however, the macrophage is perfectly able to metabolize and secrete the internalized atherogenic substances whereby HDL facilitates further transport from the arterial wall to the liver, leading to release in bile.
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Affiliation(s)
- Theo J C van Berkel
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, University of Leiden, Gorlaeus Laboratories, Leiden, The Netherlands.
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Yuasa H, Watanabe J. Are novel scavenger-like receptors involved in the hepatic uptake of heparin? Drug Metab Pharmacokinet 2005; 18:273-86. [PMID: 15618747 DOI: 10.2133/dmpk.18.273] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Heparin is an anionic macromolecular drug. It has been widely used as an anticoagulant, and numerous efforts to clarify the mechanism of its disposition in the body have been made to help expand its clinical applications, using its newly found biological activities, as well as to further improve its use in anticoagulant therapy. It has now been shown that heparin is taken up extensively not only by Kupffer cells but also by parenchymal cells in the liver, the major distribution organ, and a receptor-mediated endocytotic mechanism, which is shared by heparin analogs and various anionic macromolecules, is responsible for heparin uptake in both types of cells. Although the characteristics of the receptors for heparin in both cells have lots of similarities to those of scavenger receptors, the receptors in parenchymal cells do not accept acetylated low density lipoprotein (Ac-LDL) as a ligand, which is the only striking difference between them and major scavenger receptors. Although the receptors in Kupffer cells, which accept Ac-LDL as a ligand, may belong to class A scavenger receptors, this remains to be established. We therefore conclude at present that it is likely that novel scavenger-like receptors for heparin (heparin receptors) or unidentified scavenger receptors are responsible for heparin uptake in the liver.
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Affiliation(s)
- Hiroaki Yuasa
- Graduate School of Pharmaceutical Sciences, Nagoya City University, Japan.
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Yoshiizumi K, Nakajima F, Dobashi R, Nishimura N, Ikeda S. 2,4-Bis(octadecanoylamino)benzenesulfonic acid sodium salt as a novel scavenger receptor inhibitor with low molecular weight. Bioorg Med Chem Lett 2005; 14:2791-5. [PMID: 15125934 DOI: 10.1016/j.bmcl.2004.03.082] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Accepted: 03/22/2004] [Indexed: 10/26/2022]
Abstract
In order to investigate the effect of the fixation of the orientations of the two long chains, three types of novel derivatives of scavenger receptor inhibitor 1 were synthesized, and their biological activities were evaluated. Among the novel derivatives, 2,4-bis(octadecanoylamino)benzenesulfonic acid sodium salt (4d) showed the most potent inhibitory activity against the incorporation of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-labeled acetyl-LDL (DiI-acetyl-LDL) into macrophages. 2,5-Bis(octadecanoylamino)benzenesulfonic acid sodium salt (4c), a regioisomer of 4d, did not exhibit as potent an inhibitory activity as 4d, meaning that the substitution pattern of two long chains on the benzene ring must be important. Compound 4d exhibited 10 times more potent inhibitory activity against the binding of 125I-labeled acetyl-LDL to the surface of macrophages than compound 1.
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Affiliation(s)
- Kazuya Yoshiizumi
- R & D Laboratories, Nippon Organon K.K., 1-5-90, Tomobuchi-cho, Miyakojima-ku, Osaka 534-0016, Japan.
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Ricci R, Sumara G, Sumara I, Rozenberg I, Kurrer M, Akhmedov A, Hersberger M, Eriksson U, Eberli FR, Becher B, Borén J, Chen M, Cybulsky MI, Moore KJ, Freeman MW, Wagner EF, Matter CM, Lüscher TF. Requirement of JNK2 for scavenger receptor A-mediated foam cell formation in atherogenesis. Science 2004; 306:1558-61. [PMID: 15567863 DOI: 10.1126/science.1101909] [Citation(s) in RCA: 218] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In vitro studies suggest a role for c-Jun N-terminal kinases (JNKs) in proatherogenic cellular processes. We show that atherosclerosis-prone ApoE-/- mice simultaneously lacking JNK2 (ApoE-/- JNK2-/- mice), but not ApoE-/- JNK1-/- mice, developed less atherosclerosis than do ApoE-/- mice. Pharmacological inhibition of JNK activity efficiently reduced plaque formation. Macrophages lacking JNK2 displayed suppressed foam cell formation caused by defective uptake and degradation of modified lipoproteins and showed increased amounts of the modified lipoprotein-binding and -internalizing scavenger receptor A (SR-A), whose phosphorylation was markedly decreased. Macrophage-restricted deletion of JNK2 was sufficient to decrease atherogenesis. Thus, JNK2-dependent phosphorylation of SR-A promotes uptake of lipids in macrophages, thereby regulating foam cell formation, a critical step in atherogenesis.
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MESH Headings
- Animals
- Aorta/chemistry
- Aorta/pathology
- Apolipoproteins E/genetics
- Arteriosclerosis/metabolism
- Arteriosclerosis/pathology
- Bone Marrow Transplantation
- CD36 Antigens/metabolism
- Cells, Cultured
- Cholesterol/metabolism
- Cholesterol, Dietary/administration & dosage
- Diet, Atherogenic
- Endothelial Cells/physiology
- Foam Cells/metabolism
- Lipoproteins, LDL/metabolism
- Macrophages/metabolism
- Macrophages, Peritoneal/physiology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mitogen-Activated Protein Kinase 8/metabolism
- Mitogen-Activated Protein Kinase 9/genetics
- Mitogen-Activated Protein Kinase 9/metabolism
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/physiology
- Phosphorylation
- Receptors, Immunologic/genetics
- Receptors, Immunologic/metabolism
- Receptors, Scavenger
- Scavenger Receptors, Class A
- T-Lymphocytes/immunology
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Affiliation(s)
- Romeo Ricci
- Cardiovascular Research, Institute of Physiology, and Division of Cardiology, University Hospital Zurich, CH-8057 Zurich, Switzerland.
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Greaves DR, Gordon S. Thematic review series: the immune system and atherogenesis. Recent insights into the biology of macrophage scavenger receptors. J Lipid Res 2004; 46:11-20. [PMID: 15548472 DOI: 10.1194/jlr.r400011-jlr200] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Scavenger receptors were originally defined by their ability to bind and internalize modified lipoproteins. Macrophages express at least six structurally different cell surface receptors for modified forms of LDL that contribute to foam cell formation in atherosclerosis. In addition to their role in the pathology of atherosclerosis, macrophage scavenger receptors, especially SR-A, play critical roles in innate immunity, apoptotic cell clearance, and tissue homeostasis. In this review, we highlight recent advances in understanding the biology of macrophage scavenger receptors as pattern recognition receptors for both infectious nonself (pathogens) and modified self (apoptotic cells and modified LDL). We critically evaluate the potential of scavenger receptors and their ligands as targets for therapeutic intervention in human disease.
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Affiliation(s)
- David R Greaves
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom.
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Mukhopadhyay S, Gordon S. The role of scavenger receptors in pathogen recognition and innate immunity. Immunobiology 2004; 209:39-49. [PMID: 15481139 DOI: 10.1016/j.imbio.2004.02.004] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Scavenger receptors represent a large family of structurally unrelated distinct gene products, expressed by myeloid and selected endothelial cells and able to recognise modified low-density lipoproteins. They also bind and internalise a variety of microbial pathogens, as well as modified or endogenous molecules derived from the host, and contribute to a range of physiological or pathological processes.
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Affiliation(s)
- Subhankar Mukhopadhyay
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford, OX1 3RE, UK.
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50
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Affiliation(s)
- Minghan Wang
- Department of Cardiovascular and Metabolic Diseases, Pharmacia Corporation, 800 North Lindbergh Boulevard, St Louis, Missouri 63167, USA.
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