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Huang B, Ma J, Xu W, Cui J, Chen J, Qu Y, Zhao Y, Han Y, Liu Y, Wang W, Wang X. A newly identified scallop MyD88 interacts with TLR and functions in innate immunity. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109697. [PMID: 38871139 DOI: 10.1016/j.fsi.2024.109697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 06/02/2024] [Accepted: 06/11/2024] [Indexed: 06/15/2024]
Abstract
Myeloid differentiation factor-88 (MyD88) is a key adaptor of the toll-like receptor (TLR) signaling pathway and plays a crucial role in innate immune signal transduction in animals. However, the MyD88-mediated signal transduction mechanism in shellfish has not been well studied. In this study, a new MyD88 gene, CfMyD88-2, was identified in the Zhikong scallop, Chlamys farreri. The 1779 bp long open reading frame encodes 592 amino acids. The N-terminus of CfMyD88-2 contains a conserved death domain (DD), followed by a TIR (TLR/Interleukin-1 Receptor) domain. The results of the multi-sequence comparison showed that the TIR domain sequences were highly conserved. Phylogenetic analysis revealed that CfMyD88-2 was first associated with Mizuhopecten yessoensis MyD88-4 and Argopecten irradians MyD88-4. CfMyD88-2 mRNA was expressed in all scallop tissues, as detected by qRT-PCR, and the expression level was the highest in the mantle and hepatopancreas. In addition, CfMyD88-2 mRNA expression significantly increased after pathogen-associated molecular patterns (PAMPs, such as lipopolysaccharide, peptidoglycan, or polyinosinic-polycytidylic acid) stimulation. The results of the co-immunoprecipitation experiments in HEK293T cells showed that both CfMyD88-1 and CfMyD88-2 interacted with the TLR protein of scallops, suggesting the existence of more than one functional TLR-MyD88 signaling axis in scallops. Dual luciferase reporter gene assays indicated that the overexpressed CfMyD88-2 in HEK293T cells activated interferon (IFN) α, IFN-β, IFN-γ, and NF-κB reporter genes, indicating that the protein has multiple functions. The results of the subcellular localization experiment uncovered that CfMyD88-2 was mainly localized in the cytoplasm of human cells. In summary, the novel identified CfMyD88-2 can respond to the challenge of PAMPs, participate in TLR immune signaling, and may activate downstream effector genes such as NF-κB gene. These research results will be useful in advancing the theory of innate immunity in invertebrates and provide a reference for the selection of disease-resistant scallops in the future.
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Affiliation(s)
- Baoyu Huang
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Jilv Ma
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Wenwen Xu
- School of Agriculture, Ludong University, Yantai, 264025, China; Rushan Marine Economy and Development Center, Rushan, 264599, China
| | - Jie Cui
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Jiwen Chen
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Yifan Qu
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Yue Zhao
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Yijing Han
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Yaqiong Liu
- School of Agriculture, Ludong University, Yantai, 264025, China
| | - Weizhong Wang
- Shandong Blue Ocean Technology Co., Ltd., Yantai, 261413, China.
| | - Xiaotong Wang
- School of Agriculture, Ludong University, Yantai, 264025, China.
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A New Protocol of Computer-Assisted Image Analysis Highlights the Presence of Hemocytes in the Regenerating Cephalic Tentacles of Adult Pomacea canaliculata. Int J Mol Sci 2021; 22:ijms22095023. [PMID: 34065143 PMCID: PMC8126035 DOI: 10.3390/ijms22095023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/27/2021] [Accepted: 05/05/2021] [Indexed: 12/27/2022] Open
Abstract
In humans, injuries and diseases can result in irreversible tissue or organ loss. This well-known fact has prompted several basic studies on organisms capable of adult regeneration, such as amphibians, bony fish, and invertebrates. These studies have provided important biological information and helped to develop regenerative medicine therapies, but important gaps concerning the regulation of tissue and organ regeneration remain to be elucidated. To this aim, new models for studying regenerative biology could prove helpful. Here, the description of the cephalic tentacle regeneration in the adult of the freshwater snail Pomacea canaliculata is presented. In this invasive mollusk, the whole tentacle is reconstructed within 3 months. Regenerating epithelial, connective, muscular and neural components are already recognizable 72 h post-amputation (hpa). Only in the early phases of regeneration, several hemocytes are retrieved in the forming blastema. In view of quantifying the hemocytes retrieved in regenerating organs, granular hemocytes present in the tentacle blastema at 12 hpa were counted, with a new and specific computer-assisted image analysis protocol. Since it can be applied in absence of specific cell markers and after a common hematoxylin-eosin staining, this protocol could prove helpful to evidence and count the hemocytes interspersed among regenerating tissues, helping to unveil the role of immune-related cells in sensory organ regeneration.
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Debuque RJ, Nowoshilow S, Chan KE, Rosenthal NA, Godwin JW. Distinct toll-like receptor signaling in the salamander response to tissue damage. Dev Dyn 2021; 251:988-1003. [PMID: 33797128 DOI: 10.1002/dvdy.340] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/10/2021] [Accepted: 03/29/2021] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Efficient wound healing or pathogen clearance both rely on balanced inflammatory responses. Inflammation is essential for effective innate immune-cell recruitment; however, excessive inflammation will result in local tissue destruction, pathogen egress, and ineffective pathogen clearance. Sterile and nonsterile inflammation operate with competing functional priorities but share common receptors and overlapping signal transduction pathways. In regenerative organisms such as the salamander, whole limbs can be replaced after amputation while exposed to a nonsterile environment. In mammals, exposure to sterile-injury Damage Associated Molecular Patterns (DAMPS) alters innate immune-cell responsiveness to secondary Pathogen Associated Molecular Pattern (PAMP) exposure. RESULTS Using new phospho-flow cytometry techniques to measure signaling in individual cell subsets we compared mouse to salamander inflammation. These studies demonstrated evolutionarily conserved responses to PAMP ligands through toll-like receptors (TLRs) but identified key differences in response to DAMP ligands. Co-exposure of macrophages to DAMPs/PAMPs suppressed MAPK signaling in mammals, but not salamanders, which activate sustained MAPK stimulation in the presence of endogenous DAMPS. CONCLUSIONS These results reveal an alternative signal transduction network compatible with regeneration that may ultimately lead to the promotion of enhanced tissue repair in mammals.
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Affiliation(s)
- Ryan J Debuque
- Australian Regenerative Medicine Institute (ARMI), Monash University, Melbourne, Victoria, Australia
| | - Sergej Nowoshilow
- The Research Institute of Molecular Pathology (IMP), Vienna, Austria
| | | | | | - James W Godwin
- Australian Regenerative Medicine Institute (ARMI), Monash University, Melbourne, Victoria, Australia.,The Jackson Laboratory, Bar Harbour, Maine, USA.,The MDI Biological Laboratory (MDIBL), Salisbury Cove, Maine, USA
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Zong X, Fu J, Xu B, Wang Y, Jin M. Interplay between gut microbiota and antimicrobial peptides. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2020; 6:389-396. [PMID: 33364454 PMCID: PMC7750803 DOI: 10.1016/j.aninu.2020.09.002] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/09/2020] [Accepted: 09/14/2020] [Indexed: 12/19/2022]
Abstract
The gut microbiota is comprised of a diverse array of microorganisms that interact with immune system and exert crucial roles for the health. Changes in the gut microbiota composition and functionality are associated with multiple diseases. As such, mobilizing a rapid and appropriate antimicrobial response depending on the nature of each stimulus is crucial for maintaining the balance between homeostasis and inflammation in the gut. Major players in this scenario are antimicrobial peptides (AMP), which belong to an ancient defense system found in all organisms and participate in a preservative co-evolution with a complex microbiome. Particularly increasing interactions between AMP and microbiota have been found in the gut. Here, we focus on the mechanisms by which AMP help to maintain a balanced microbiota and advancing our understanding of the circumstances of such balanced interactions between gut microbiota and host AMP. This review aims to provide a comprehensive overview on the interplay of diverse antimicrobial responses with enteric pathogens and the gut microbiota, which should have therapeutic implications for different intestinal disorders.
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Affiliation(s)
- Xin Zong
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jie Fu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Bocheng Xu
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yizhen Wang
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Mingliang Jin
- Key Laboratory of Molecular Animal Nutrition, Ministry of Education, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
- Key Laboratory of Animal Nutrition and Feed Science in Eastern China, Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
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Silencing TLR4/MyD88/NF-κB Signaling Pathway Alleviated Inflammation of Corneal Epithelial Cells Infected by ISE. Inflammation 2020; 44:633-644. [PMID: 33174138 DOI: 10.1007/s10753-020-01363-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/07/2020] [Accepted: 10/12/2020] [Indexed: 12/16/2022]
Abstract
The regulatory role of toll-like receptor 4 (TLR4) in the inactivate staphylococcus epidermidis (ISE)-induced cornea inflammation is not well investigated. Here, TLR4 silence could decrease inflammatory cytokines in corneal epithelial cells treated with ISE. The mouse corneal epithelial cells were exposed to ISE for 24 h, either alone or with the NF-κB inhibitor, TLR4 lentivirus to bilaterally (knock-down or and overexpression). The expression of TLR4 in mouse corneal epithelial cells was investigated using western blot and qRT-PCR assay. The inflammatory cytokine levels were evaluated by qRT-PCR and ELISA, respectively. The relative impact factors of TLR4-mediated NF-κB signaling detected using western blot assay. Results show the expression levels of TLR4 and some inflammatory cytokines were significantly increased in corneal epithelial cells treated with ISE. TLR4 Silence markedly decreased ISE-induced production of IL12, TNF-α, CCL5, and CCL9 in corneal epithelial cells. Furthermore, the nuclear translocation of NF-κB p65 and myeloid differentiation protein 88 (MyD88) in the cells treated with ISE were further reduced by silencing TLR4. Inhibition of TLR4-mediated NF-κB signaling by using BAY11-7082 also alleviated ISE-induced inflammation. In the rescue experiment, transfected the stable TLR4 silenced corneal epithelial cells with TLR4 overexpression lentivirus, we found that TLR4 overexpression can restore the down-regulation of TLR4 and inflammatory cytokines (IL12, TNF-α, CCL9) caused by TLR4 knocked down. Therefore, ISE-induced cornea inflammation was due to the activation of the TLR4/MyD88/NF-κB signaling pathway, and dramatically stimulated IL12, TNF-α, CCL9 secretion. TLR4 silence presented mitigates damage in corneal epithelial cells treated with ISE.
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Prochazkova P, Roubalova R, Dvorak J, Navarro Pacheco NI, Bilej M. Pattern recognition receptors in annelids. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 102:103493. [PMID: 31499098 DOI: 10.1016/j.dci.2019.103493] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/04/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
The existence of pattern recognition receptors (PRRs) on immune cells was discussed in 1989 by Charles Janeway, Jr., who proposed a general concept of the ability of PRRs to recognize and bind conserved molecular structures of microorganisms known as pathogen-associated molecular patterns (PAMPs). Upon PAMP engagement, PRRs trigger intracellular signaling cascades resulting in the expression of various proinflammatory molecules. These recognition molecules represent an important and efficient innate immunity tool of all organisms. As invertebrates lack the instruments of the adaptive immune system, based on "true" lymphocytes and functional antibodies, the importance of PRRs are even more fundamental. In the present review, the structure, specificity, and expression profiles of PRRs characterized in annelids are discussed, and their role in innate defense is suggested.
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Affiliation(s)
- P Prochazkova
- Laboratory of Cellular and Molecular Immunology, Institute of Microbiology of the Czech Academy of Sciences, v. v. i., Prague, Czech Republic.
| | - R Roubalova
- Laboratory of Cellular and Molecular Immunology, Institute of Microbiology of the Czech Academy of Sciences, v. v. i., Prague, Czech Republic
| | - J Dvorak
- Laboratory of Cellular and Molecular Immunology, Institute of Microbiology of the Czech Academy of Sciences, v. v. i., Prague, Czech Republic
| | - N I Navarro Pacheco
- Laboratory of Cellular and Molecular Immunology, Institute of Microbiology of the Czech Academy of Sciences, v. v. i., Prague, Czech Republic
| | - M Bilej
- Laboratory of Cellular and Molecular Immunology, Institute of Microbiology of the Czech Academy of Sciences, v. v. i., Prague, Czech Republic
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Brennan JJ, Gilmore TD. Evolutionary Origins of Toll-like Receptor Signaling. Mol Biol Evol 2019; 35:1576-1587. [PMID: 29590394 DOI: 10.1093/molbev/msy050] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Toll-like receptors (TLRs) are transmembrane pattern recognition receptors that are best known for their roles in innate immunity for the detection of and defense against microbial pathogens. However, TLRs also have roles in many nonimmune processes, most notably development. TLRs direct both immune and developmental programs by activation of downstream signaling pathways, often by activation of the NF-κB pathway. There are two primary TLR subtypes: 1) TLRs with multiple cysteine clusters in their ectodomain (mccTLRs) and 2) TLRs with a single cysteine cluster in their ectodomain (sccTLRs). For some time, it has been known that TLRs and the biological processes that they control are conserved in organisms from insects to mammals. However, genome and transcriptome sequencing has revealed that many basal metazoans also have TLRs and downstream NF-κB signaling components. In this review, we discuss what is known about the structure, biological function, and downstream signaling pathways of TLRs found in phyla from Porifera through Annelida. From these analyses, we hypothesize that mccTLRs emerged in the phylum Cnidaria, that sccTLRs evolved in the phylum Mollusca, and that TLRs have dual immune and developmental biological functions in organisms as ancient as cnidarians.
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The medicinal leech as a valuable model for better understanding the role of a TLR4-like receptor in the inflammatory process. Cell Tissue Res 2019; 377:245-257. [PMID: 30919048 DOI: 10.1007/s00441-019-03010-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/26/2019] [Indexed: 12/21/2022]
Abstract
Despite extensive investigation focused on both the molecular characteristics and the expression level of Toll-like receptors (TLRs) during the inflammatory response in vertebrates, few data are available in the literature on the role of these proteins in invertebrate's immune response. Here, we propose the medicinal leech as a valuable model to better elucidate the role of TLR4 and its related products, such as tumor necrosis factor (TNF-α), after activation of the leech peripheral immune system with the endogenous medicinal leech recombinant allograft inflammatory factor-1 (rHmAIF-1) or with an exogenous stimulus, such as lipopolysaccharide (LPS). Our results indicate that activated macrophages (HmAIF-1+) and granulocytes (CD11b+) express both TLR4 and its coreceptor CD14. Moreover, functional studies performed by injecting a cyanobacterium selective TLR4 antagonist CyP demonstrated that only the TLR4 pathway was blocked, while the immune response caused by lipoteichoic acid (LTA) treatment is not affected. These results are consistent with literature on vertebrates, indicating that TLR4 functions as a LPS receptor while the recognition of LTA may involve other pathways.
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Kumar V. Toll-like receptors in the pathogenesis of neuroinflammation. J Neuroimmunol 2019; 332:16-30. [PMID: 30928868 DOI: 10.1016/j.jneuroim.2019.03.012] [Citation(s) in RCA: 207] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/19/2019] [Accepted: 03/19/2019] [Indexed: 12/17/2022]
Abstract
Toll-like receptors (TLRs) are discovered as crucial pattern recognition receptors (PRRs) involved in the recognition of pathogen-associated molecular patterns (PAMPs). Later studies showed their involvement in the recognition of various damage/danger-associated molecular patterns (DAMPs) generated by host itself. Thus, TLRs are capable of recognizing wide-array of patterns/molecules derived from pathogens and host as well and initiating a proinflammatory immune response through the activation of NF-κB and other transcription factors causing synthesis of proinflammatory molecules. The process of neuroinflammation is seen under both sterile and infectious inflammatory diseases of the central nervous system (CNS) and may lead to the development of neurodegeneration. The present article is designed to highlight the importance of TLRs in the pathogenesis of neuroinflammation under diverse conditions. TLRs are expressed by various immune cells present in CNS along with neurons. However out of thirteen TLRs described in mammals, some are present and active in these cells, while some are absent and are described in detail in main text. The role of various immune cells present in the brain and their role in the pathogenesis of neuroinflammation depending on the type of TLR expressed is described. Thereafter the role of TLRs in bacterial meningitis, viral encephalitis, stroke, Alzheimer's disease (AD), Parkinson's disease (PD), and autoimmune disease including multiple sclerosis (MS) is described. The article is designed for both neuroscientists needing information regarding TLRs in neuroinflammation and TLR biologists or immunologists interested in neuroinflammation.
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Affiliation(s)
- V Kumar
- Children Health Clinical Unit, School of Clinical Medicine, Faculty of Medicine, Mater Research, University of Queensland, ST Lucia, Brisbane, Queensland 4078, Australia; School of Biomedical Sciences, Faculty of Medicine, University of Queensland, ST Lucia, Brisbane, Queensland 4078, Australia.
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10
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Nie L, Cai SY, Shao JZ, Chen J. Toll-Like Receptors, Associated Biological Roles, and Signaling Networks in Non-Mammals. Front Immunol 2018; 9:1523. [PMID: 30034391 PMCID: PMC6043800 DOI: 10.3389/fimmu.2018.01523] [Citation(s) in RCA: 178] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 06/19/2018] [Indexed: 01/18/2023] Open
Abstract
The innate immune system is the first line of defense against pathogens, which is initiated by the recognition of pathogen-associated molecular patterns (PAMPs) and endogenous damage-associated molecular patterns (DAMPs) by pattern recognition receptors (PRRs). Among all the PRRs identified, the toll-like receptors (TLRs) are the most ancient class, with the most extensive spectrum of pathogen recognition. Since the first discovery of Toll in Drosophila melanogaster, numerous TLRs have been identified across a wide range of invertebrate and vertebrate species. It seems that TLRs, the signaling pathways that they initiate, or related adaptor proteins are essentially conserved in a wide variety of organisms, from Porifera to mammals. Molecular structure analysis indicates that most TLR homologs share similar domain patterns and that some vital participants of TLR signaling co-evolved with TLRs themselves. However, functional specification and emergence of new signaling pathways, as well as adaptors, did occur during evolution. In addition, ambiguities and gaps in knowledge still exist regarding the TLR network, especially in lower organisms. Hence, a systematic review from the comparative angle regarding this tremendous signaling system and the scenario of evolutionary pattern across Animalia is needed. In the current review, we present overview and possible evolutionary patterns of TLRs in non-mammals, hoping that this will provide clues for further investigations in this field.
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Affiliation(s)
- Li Nie
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, China
| | - Shi-Yu Cai
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, China
| | - Jian-Zhong Shao
- College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jiong Chen
- Laboratory of Biochemistry and Molecular Biology, School of Marine Sciences, Ningbo University, Ningbo, China
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Reins RY, Courson J, Lema C, Redfern RL. MyD88 contribution to ocular surface homeostasis. PLoS One 2017; 12:e0182153. [PMID: 28796783 PMCID: PMC5552092 DOI: 10.1371/journal.pone.0182153] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/13/2017] [Indexed: 12/18/2022] Open
Abstract
The cornea must maintain homeostasis, enabling rapid response to injury and microbial insult, to protect the eye from insult and infection. Toll-like receptors (TLRs) are critical to this innate immune response through the recognition and response to pathogens. Myeloid differentiation primary response (MyD88) is a key signaling molecule necessary for Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R)-mediated immune defense and has been shown to be necessary for corneal defense during infection. Here, we examined the intrinsic role of TLR signaling in ocular surface tissues by determining baseline levels of inflammatory mediators, the response to mechanical stimuli, and corneal infection in MyD88-deficient mice (MyD88-/-). In addition, cytokine, chemokine, and matrix metalloproteinase (MMP) expression was determined in ocular surface cells exposed to a panel of TLR agonists. Compared to wild-type (WT) animals, MyD88-/- mice expressed lower MMP-9 levels in the cornea and conjunctiva. Corneal IL-1α, TNFα, and conjunctival IL-1α, IL-2, IL-6, and IL-9 levels were also significantly reduced. Additionally, CXCL1 and RANTES expression was lower in both MyD88-/- tissues compared to WT and IL-1R-/- mice. Interestingly, MyD88-/- mice had lower corneal sensitivities (1.01±0.31 gm/mm2) than both WT (0.59±0.16 gm/mm2) and IL-1R-/- (0.52±0.08 gm/mm2). Following Pseudomonas aeruginosa challenge, MyD88-/- mice had better clinical scores (0.5±0.0) compared to IL-1R-/- (1.5±0.6) and WT (2.3±0.3) animals, but had significantly more corneal bacterial isolates. However, no signs of infection were detected in inoculated uninjured corneas from either MyD88 or IL-1R-deficient mice. This work furthers our understanding of the importance of TLR signaling in corneal defense and immune homeostasis, showing that a lack of MyD88 may compromise the baseline innate response to insult.
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Affiliation(s)
- Rose Y. Reins
- The Ocular Surface Institute, College of Optometry, University of Houston, Houston, Texas, United States of America
| | - Justin Courson
- The Ocular Surface Institute, College of Optometry, University of Houston, Houston, Texas, United States of America
| | - Carolina Lema
- The Ocular Surface Institute, College of Optometry, University of Houston, Houston, Texas, United States of America
| | - Rachel L. Redfern
- The Ocular Surface Institute, College of Optometry, University of Houston, Houston, Texas, United States of America
- * E-mail:
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Malagoli D, Ottaviani E. Cross-talk among immune and neuroendocrine systems in molluscs and other invertebrate models. Horm Behav 2017; 88:41-44. [PMID: 27984033 DOI: 10.1016/j.yhbeh.2016.10.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 10/20/2022]
Abstract
The comparison between immune and neuroendocrine systems in vertebrates and invertebrates suggest an ancient origin and a high degree of conservation for the mechanisms underlying the integration between immune and stress responses. This suggests that in both vertebrates and invertebrates the stress response involves the integrated network of soluble mediators (e.g., neurotransmitters, hormones and cytokines) and cell functions (e.g., chemotaxis and phagocytosis), that interact with a common objective, i.e., the maintenance of body homeostasis. During evolution, several changes observed in the stress response of more complex taxa could be the result of new roles of ancestral molecules, such as ancient immune mediators may have been recruited as neurotransmitters and hormones, or vice versa. We review older and recent evidence suggesting that immune and neuro-endocrine functions during the stress response were deeply intertwined already at the dawn of multicellular organisms. These observations found relevant reflections in the demonstration that immune cells can transdifferentiate in olfactory neurons in crayfish and the recently re-proposed neural transdifferentiation in humans.
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Affiliation(s)
- Davide Malagoli
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 213/D, 41125 Modena, Italy
| | - Enzo Ottaviani
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 213/D, 41125 Modena, Italy.
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Tasiemski A, Salzet M. Neuro-immune lessons from an annelid: The medicinal leech. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2017; 66:33-42. [PMID: 27381717 DOI: 10.1016/j.dci.2016.06.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 06/09/2016] [Accepted: 06/30/2016] [Indexed: 06/06/2023]
Abstract
An important question that remains unanswered is how the vertebrate neuroimmune system can be both friend and foe to the damaged nervous tissue. Some of the difficulty in obtaining responses in mammals probably lies in the conflation in the central nervous system (CNS), of the innate and adaptive immune responses, which makes the vertebrate neuroimmune response quite complex and difficult to dissect. An alternative strategy for understanding the relation between neural immunity and neural repair is to study an animal devoid of adaptive immunity and whose CNS is well described and regeneration competent. The medicinal leech offers such opportunity. If the nerve cord of this annelid is crushed or partially cut, axons grow across the lesion and conduction of signals through the damaged region is restored within a few days, even when the nerve cord is removed from the animal and maintained in culture. When the mammalian spinal cord is injured, regeneration of normal connections is more or less successful and implies multiple events that still remain difficult to resolve. Interestingly, the regenerative process of the leech lesioned nerve cord is even more successful under septic than under sterile conditions suggesting that a controlled initiation of an infectious response may be a critical event for the regeneration of normal CNS functions in the leech. Here are reviewed and discussed data explaining how the leech nerve cord sensu stricto (i.e. excluding microglia and infiltrated blood cells) recognizes and responds to microbes and mechanical damages.
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Affiliation(s)
- Aurélie Tasiemski
- Université de Lille, CNRS UMR8198, Unité d'Evolution, Ecologie et Paléontologie (EEP), Species Interactions and Comparative Immunology (SPICI) Team, 59655 Villeneuve d'Ascq, France.
| | - Michel Salzet
- Université de Lille, INSERM U-1192, Laboratoire de Protéomique, Réponse Inflammatoire, Spectrométrie de Masse (PRISM), 59655 Villeneuve d'Ascq, France
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