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Zheng S, Jiang L, Qiu L. The effects of fine particulate matter on the blood-testis barrier and its potential mechanisms. REVIEWS ON ENVIRONMENTAL HEALTH 2024; 39:233-249. [PMID: 36863426 DOI: 10.1515/reveh-2022-0204] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 11/13/2022] [Indexed: 02/17/2024]
Abstract
With the rapid expansion of industrial scale, an increasing number of fine particulate matter (PM2.5) has bringing health concerns. Although exposure to PM2.5 has been clearly associated with male reproductive toxicity, the exact mechanisms are still unclear. Recent studies demonstrated that exposure to PM2.5 can disturb spermatogenesis through destroying the blood-testis barrier (BTB), consisting of different junction types, containing tight junctions (TJs), gap junctions (GJs), ectoplasmic specialization (ES) and desmosomes. The BTB is one of the tightest blood-tissue barriers among mammals, which isolating germ cells from hazardous substances and immune cell infiltration during spermatogenesis. Therefore, once the BTB is destroyed, hazardous substances and immune cells will enter seminiferous tubule and cause adversely reproductive effects. In addition, PM2.5 also has shown to cause cells and tissues injury via inducing autophagy, inflammation, sex hormones disorder, and oxidative stress. However, the exact mechanisms of the disruption of the BTB, induced by PM2.5, are still unclear. It is suggested that more research is required to identify the potential mechanisms. In this review, we aim to understand the adverse effects on the BTB after exposure to PM2.5 and explore its potential mechanisms, which provides novel insight into accounting for PM2.5-induced BTB injury.
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Affiliation(s)
- Shaokai Zheng
- School of Public Health, Nantong University, Nantong, P. R. China
| | - Lianlian Jiang
- School of Public Health, Nantong University, Nantong, P. R. China
| | - Lianglin Qiu
- School of Public Health, Nantong University, Nantong, P. R. China
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2
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Burstyn-Cohen T, Fresia R. TAM receptors in phagocytosis: Beyond the mere internalization of particles. Immunol Rev 2023; 319:7-26. [PMID: 37596991 DOI: 10.1111/imr.13267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 07/18/2023] [Indexed: 08/21/2023]
Abstract
TYRO3, AXL, and MERTK constitute the TAM family of receptor tyrosine kinases, activated by their ligands GAS6 and PROS1. TAMs are necessary for adult homeostasis in the immune, nervous, reproductive, skeletal, and vascular systems. Among additional cellular functions employed by TAMs, phagocytosis is central for tissue health. TAM receptors are dominant in providing phagocytes with the molecular machinery necessary to engulf diverse targets, including apoptotic cells, myelin debris, and portions of live cells in a phosphatidylserine-dependent manner. Simultaneously, TAMs drive the release of anti-inflammatory and tissue repair molecules. Disruption of the TAM-driven phagocytic pathway has detrimental consequences, resulting in autoimmunity, male infertility, blindness, and disrupted vascular integrity, and which is thought to contribute to neurodegenerative diseases. Although structurally and functionally redundant, the TAM receptors and ligands underlie complex signaling cascades, of which several key aspects are yet to be elucidated. We discuss similarities and differences between TAMs and other phagocytic pathways, highlight future directions and how TAMs can be harnessed therapeutically to modulate phagocytosis.
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Affiliation(s)
- Tal Burstyn-Cohen
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
| | - Roberta Fresia
- The Institute for Biomedical and Oral Research, Faculty of Dental Medicine, The Hebrew University, Jerusalem, Israel
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3
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Bhat EA, Ali T, Sajjad N, Kumar R, Bron P. Insights into the structure, functional perspective, and pathogenesis of ZIKV: an updated review. Biomed Pharmacother 2023; 165:115175. [PMID: 37473686 DOI: 10.1016/j.biopha.2023.115175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/04/2023] [Accepted: 07/12/2023] [Indexed: 07/22/2023] Open
Abstract
Zika virus (ZIKV) poses a serious threat to the entire world. The rapid spread of ZIKV and recent outbreaks since 2007 have caused worldwide concern about the virus. Diagnosis is complicated because of the cross-reactivity of the virus with other viral antibodies. Currently, the virus is diagnosed by molecular techniques such as RT-PCR and IgM-linked enzyme immunoassays (MAC-ELISA). Recently, outbreaks and epidemics have been caused by ZIKV, and severe clinical symptoms and congenital malformations have also been associated with the virus. Although most ZIKV infections present with a subclinical or moderate flu-like course of illness, severe symptoms such as Guillain-Barre syndrome in adults and microcephaly in children of infected mothers have also been reported. Because there is no reliable cure for ZIKV and no vaccine is available, the public health response has focused primarily on preventing infection, particularly in pregnant women. A comprehensive approach is urgently needed to combat this infection and stop its spread and imminent threat. In view of this, this review aims to present the current structural and functional viewpoints, structure, etiology, clinical prognosis, and measures to prevent this transmission based on the literature and current knowledge. Moreover, we provide thorough description of the current understanding about ZIKV interaction with receptors, and a comparative examination of its similarities and differences with other viruses.
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Affiliation(s)
- Eijaz Ahmed Bhat
- CBS (Centre de Biologie Structurale), Univ. Montpellier, CNRS, INSERM, 29 rue de Navacelles, 34090 Montpellier, France.
| | - Tufail Ali
- Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Nasreena Sajjad
- Department of Biochemistry, University of Kashmir, Hazratbal, Jammu and Kashmir 190006, India
| | - Rohit Kumar
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India
| | - Patrick Bron
- CBS (Centre de Biologie Structurale), Univ. Montpellier, CNRS, INSERM, 29 rue de Navacelles, 34090 Montpellier, France.
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4
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Zhang Y, Xu B. Involvement of testicular N-glycoproteome heterogeneity in seasonal spermatogenesis of the American mink (Neovison vison). Front Vet Sci 2022; 9:1001431. [PMID: 36406079 PMCID: PMC9672844 DOI: 10.3389/fvets.2022.1001431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Accepted: 10/11/2022] [Indexed: 11/06/2022] Open
Abstract
Spermatogenesis in the American mink is characterized by an annual cycle of transition involving completely inactive and fully activated stages. N-glycosylation of proteins has emerged as an important regulator as it affects protein folding, secretion, degradation, and activity. However, the function of protein N-glycosylation in seasonal spermatogenesis of the American mink remains unclear. In the present study, we established a proteome-wide stoichiometry of N-glycosylation in mink testes at various phases of spermatogenesis using N-linked glycosylated-peptide enrichment in combination with liquid chromatography-tandem mass spectrometry analysis. A total of 532 N-glycosylated sites matching the canonical Asn-X-Ser/Thr motif were identified in 357 testicular proteins. Both the number of glycoproteins and the sites of N-glycosylated proteins in mink testes were highly dynamic at different stages. Functional analyses showed that testicular proteins with different N-glycosylation might play a vital role in spermatogenesis by affecting their folding, distribution, stability, and activity. Overall, our data suggest that the dynamics of N-glycosylation of testicular proteins are involved in seasonal spermatogenesis in the American mink.
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5
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Immune homeostasis and disorder in the testis —roles of Sertoli cells. J Reprod Immunol 2022; 152:103625. [DOI: 10.1016/j.jri.2022.103625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/05/2022] [Accepted: 04/13/2022] [Indexed: 01/19/2023]
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6
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Atli MO, Hitit M, Özbek M, Köse M, Bozkaya F. Cell-Specific Expression Pattern of Toll-Like Receptors and Their Roles in Animal Reproduction. Handb Exp Pharmacol 2022; 276:65-93. [PMID: 35434748 DOI: 10.1007/164_2022_584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Toll-like receptors (TLRs), a part of the innate immune system, have critical roles in protection against infections and involve in basic pathology and physiology. Secreted molecules from the body or pathogens could be a ligand for induction of the TLR system. There are many immune and non-immune types of cells that express at a least single TLR on their surface or cytoplasm. Those cells may be a player in a defense system or in the physiological regulation mechanisms. Reproductive tract and organs contain different types of cells that have essential functions such as hormone production, providing an environment for embryo/fetus, germ cell production, etc. Although lower parts of reproductive organs are in a relationship with outsider contaminants (bacteria, viruses, etc.), upper parts should be sterile to provide a healthy pregnancy and germ cell production. In those areas, TLRs bear controller or regulator roles. In this chapter, we will provide current information about physiological functions of TLR in the cells of the reproductive organs and tract, and especially about their roles in follicle selection, maturation, follicular atresia, ovulation, corpus luteum (CL) formation and regression, establishment and maintenance of pregnancy, sperm production, maturation, capacitation as well as the relationship between TLR polymorphism and reproduction in domestic animals. We will also discuss pathogen-associated molecular patterns (PAMPs)-induced TLRs that involve in reproductive inflammation/pathology.
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Affiliation(s)
- Mehmet Osman Atli
- Department of Reproduction, Faculty of Veterinary Medicine, Harran University, Şanlıurfa, Turkey.
| | - Mustafa Hitit
- Department of Genetics, Faculty of Veterinary Medicine, Kastamonu University, Kastamonu, Turkey
| | - Mehmet Özbek
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Mehmet Akif Ersoy University, Burdur, Turkey
| | - Mehmet Köse
- Department of Obstetrics and Gynecology, Faculty of Veterinary Medicine, Dicle University, Diyarbakır, Turkey
| | - Faruk Bozkaya
- Department of Genetics, Faculty of Veterinary Medicine, Harran University, Sanlıurfa, Turkey
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7
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Xiong H, Chen Z, Zhao J, Li W, Zhang S. TNF-α/ENO1 signaling facilitates testicular phagocytosis by directly activating Elmo1 gene expression in mouse Sertoli cells. FEBS J 2021; 289:2809-2827. [PMID: 34919331 DOI: 10.1111/febs.16326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 10/10/2021] [Accepted: 12/15/2021] [Indexed: 11/27/2022]
Abstract
Phagocytic clearance of apoptotic germ cells (GCs), as well as residual bodies (RBs) released from developing spermatids, is critical for Sertoli cells (SCs) to maintain inner environment homeostasis within testis. However, the molecular mechanisms controlling the phagocytosis are ill defined. Here, we identify a new role for alpha-enolase (ENO1), a key enzyme during glycolysis, as a molecule that facilitates testicular phagocytosis via transactivation of the engulfment and cell motility 1 (Elmo1) gene. Using immunohistochesmitry and double-labeling immunofluorescence, ENO1 was observed to be expressed exclusively in the nuclei of SCs and its expression correlated with the completion of Sertoli cell differentiation. By incubating TM4 cells with different pharmacological inhibitors and establishing TM4Tnfr1-/- cells, we demonstrated that Sertoli cell-specific expression of ENO1 was under a delicate paracrine control from apoptotic GCs. In turn, persistent blockade of ENO1 expression by a validated siRNA protocol resulted in the disturbance of spermatogenesis and impairment of male fertility. Furthermore, using chromatin immunoprecipitation, electrophoretic mobility shift assay and luciferase reporter assay, we showed that in the presence of apoptotic GCs, ENO1 binds to the distal region of the Elmo1 promoter and facilitates transactivation of the Elmo1 gene. In agreement, overexpression of ELMO1 ameliorated ENO1 deficiency-induced impairment of phagocytosis in TM4 cells. These data reveal a novel role for Sertoli cell-specific expression of ENO1 in regulating phagocytosis in testis, identify TNF-α and ELMO1 as critical upstream and downstream factors in mediating ENO1 action, and have important implications for understanding paracrine control of Sertoli cell function by adjacent GCs.
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Affiliation(s)
- Hu Xiong
- Reproductive Medicine Center, Department of Gynecology and Obstetrics, Tangdu Hospital, Air Force Medical University, Xi'an, 710038, P.R.China
| | - Zhenzhen Chen
- Department of Human Anatomy, Histology and Embryology, Air Force Medical University, Xi'an, 710032, P.R.China
| | - Jie Zhao
- Department of Human Anatomy, Histology and Embryology, Air Force Medical University, Xi'an, 710032, P.R.China
| | - Wei Li
- Department of Human Anatomy, Histology and Embryology, Air Force Medical University, Xi'an, 710032, P.R.China
| | - Shun Zhang
- Reproductive Medicine Center, Department of Gynecology and Obstetrics, Tangdu Hospital, Air Force Medical University, Xi'an, 710038, P.R.China
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Physiological Roles of Apoptotic Cell Clearance: Beyond Immune Functions. Life (Basel) 2021; 11:life11111141. [PMID: 34833017 PMCID: PMC8621940 DOI: 10.3390/life11111141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/24/2021] [Accepted: 10/25/2021] [Indexed: 11/16/2022] Open
Abstract
The clearance of apoptotic cells is known to be a critical step in maintaining tissue and organism homeostasis. This process is rapidly/promptly mediated by recruited or resident phagocytes. Phagocytes that engulf apoptotic cells have been closely linked to the release of anti-inflammatory cytokines to eliminate inflammatory responses. Defective clearance of apoptotic cells can cause severe inflammation and autoimmune responses due to secondary necrosis of apoptotic cells. Recently accumulated evidence indicates that apoptotic cells and their clearance have important physiological roles in addition to immune-related functions. Herein, we review the current understanding of the mechanisms and fundamental roles of apoptotic cell clearance and the beneficial roles of apoptotic cells in physiological processes such as differentiation and development.
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Du X, Hou Y, Huang J, Pang Y, Ruan C, Wu W, Xu C, Zhang H, Yin L, He W. Cytosolic delivery of the immunological adjuvant Poly I:C and cytotoxic drug crystals via a carrier-free strategy significantly amplifies immune response. Acta Pharm Sin B 2021; 11:3272-3285. [PMID: 34729315 PMCID: PMC8546930 DOI: 10.1016/j.apsb.2021.03.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/15/2021] [Accepted: 01/29/2021] [Indexed: 02/07/2023] Open
Abstract
Co-delivery of chemotherapeutics and immunostimulant or chemoimmunotherapy is an emerging strategy in cancer therapy. The precise control of the targeting and release of agents is critical in this methodology. This article proposes the asynchronous release of the chemotherapeutic agents and immunostimulants to realize the synergistic effect between chemotherapy and immunotherapy. To obtain a proof-of-concept, a co-delivery system was prepared via a drug-delivering-drug (DDD) strategy for cytosolic co-delivery of Poly I:C, a synthetic dsRNA analog to activate RIG-I signaling, and PTX, a commonly used chemotherapeutics, in which pure PTX nanorods were sequentially coated with Poly I:C and mannuronic acid via stimulating the RIG-I signaling axis. The co-delivery system with a diameter of 200 nm enables profound immunogenicity of cancer cells, exhibiting increased secretion of cytokines and chemokines, pronounced immune response in vivo, and significant inhibition of tumor growth. Also, we found that intracellularly sustained release of cytotoxic agents could elicit the immunogenicity of cancer cells. Overall, the intracellular asynchronous release of chemotherapeutics and immunomodulators is a promising strategy to promote the immunogenicity of cancer cells and augment the antitumor immune response.
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Affiliation(s)
- Xiaoqing Du
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Yuqi Hou
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Jia Huang
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Yan Pang
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Chenlu Ruan
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Wei Wu
- Key Laboratory of Smart Drug Delivery of Ministry of Education of China, School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Chenjie Xu
- Department of Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Hongwei Zhang
- Department of Pharmaceutical Sciences, School of Pharmacy–Boston, MCPHS University, Boston, MA 02115, USA
| | - Lifang Yin
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
| | - Wei He
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 211198, China
- Corresponding author.
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10
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Fang Y, Su Y, Xu J, Hu Z, Zhao K, Liu C, Zhang H. Varicocele-Mediated Male Infertility: From the Perspective of Testicular Immunity and Inflammation. Front Immunol 2021; 12:729539. [PMID: 34531872 PMCID: PMC8438154 DOI: 10.3389/fimmu.2021.729539] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 08/16/2021] [Indexed: 01/14/2023] Open
Abstract
Background Varicocele (VC) is present in 35 - 40% of men with infertility. However, current surgical and antioxidant treatments are not completely effective. In addition to oxidative stress, it is likely that other factors such as testicular immune microenvironment disorder contribute to irreversible testicular. Evidence suggests that VC is associated with anti-sperm antibodies (ASAs), spermatogenesis and testosterone secretion abnormalities, and testicular cytokine production. Moreover, inhibition of inflammation can alleviate VC-mediated pathogenesis. The normal function of the testis depends on its immune tolerance mechanism. Testicular immune regulation is complex, and many infectious or non-infectious diseases may damage this precision system. Results The testicular immune microenvironment is composed of common immune cells and other cells involved in testicular immunity. The former includes testicular macrophages, T cells, dendritic cells (DCs), and mast cells, whereas the latter include Leydig cells and Sertoli cells (SCs). In animal models and in patients with VC, most studies have revealed an abnormal increase in the levels of ASAs and pro-inflammatory cytokines such as interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha in the seminal plasma, testicular tissue, and even peripheral blood. It is also involved in the activation of potential inflammatory pathways, such as the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing (NLRP)-3 pathway. Finally, the development of VC-mediated infertility (VMI) may be facilitated by abnormal permeability of proteins, such as claudin-11, that constitute the blood-testis barrier (BTB). Conclusions The testicular immune response, including the production of ASAs and inflammatory factors, activation of inflammatory pathways, and destruction of the BTB may be involved in the pathogenesis of VMI it is necessary to further explore how patient outcomes can be improved through immunotherapy.
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Affiliation(s)
- Yiwei Fang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yufang Su
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jia Xu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhiyong Hu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kai Zhao
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chunyan Liu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huiping Zhang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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MERTK-Mediated LC3-Associated Phagocytosis (LAP) of Apoptotic Substrates in Blood-Separated Tissues: Retina, Testis, Ovarian Follicles. Cells 2021; 10:cells10061443. [PMID: 34207717 PMCID: PMC8229618 DOI: 10.3390/cells10061443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/05/2021] [Accepted: 06/07/2021] [Indexed: 01/22/2023] Open
Abstract
Timely and efficient elimination of apoptotic substrates, continuously produced during one’s lifespan, is a vital need for all tissues of the body. This task is achieved by cells endowed with phagocytic activity. In blood-separated tissues such as the retina, the testis and the ovaries, the resident cells of epithelial origin as retinal pigmented epithelial cells (RPE), testis Sertoli cells and ovarian granulosa cells (GC) provide phagocytic cleaning of apoptotic cells and cell membranes. Disruption of this process leads to functional ablation as blindness in the retina and compromised fertility in males and females. To ensure the efficient elimination of apoptotic substrates, RPE, Sertoli cells and GC combine various mechanisms allowing maintenance of tissue homeostasis and avoiding acute inflammation, tissue disorganization and functional ablation. In tight cooperation with other phagocytosis receptors, MERTK—a member of the TAM family of receptor tyrosine kinases (RTK)—plays a pivotal role in apoptotic substrate cleaning from the retina, the testis and the ovaries through unconventional autophagy-assisted phagocytosis process LAP (LC3-associated phagocytosis). In this review, we focus on the interplay between TAM RTKs, autophagy-related proteins, LAP, and Toll-like receptors (TLR), as well as the regulatory mechanisms allowing these components to sustain tissue homeostasis and prevent functional ablation of the retina, the testis and the ovaries.
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12
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The Seminiferous Epithelial Cycle of Spermatogenesis: Role of Non-receptor Tyrosine Kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1288:1-20. [PMID: 34453729 DOI: 10.1007/978-3-030-77779-1_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Non-receptor tyrosine kinases (NRTKs) are implicated in various biological processes including cell proliferation, differentiation, survival, and apoptosis, as well as cell adhesion and movement. NRTKs are expressed in all mammals and in different cell types, with extraordinarily high expression in the testis. Their association with the plasma membrane and dynamic subcellular localization are crucial parameters in their activation and function. Many NRTKs are found in endosomal protein trafficking pathways, which suggests a novel mechanism to regulate the timely junction restructuring in the mammalian testis to facilitate spermiation and germ cell transport across the seminiferous epithelium.
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13
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Embryonic Microglia Interact with Hypothalamic Radial Glia during Development and Upregulate the TAM Receptors MERTK and AXL following an Insult. Cell Rep 2021; 34:108587. [PMID: 33406432 DOI: 10.1016/j.celrep.2020.108587] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 09/23/2020] [Accepted: 12/10/2020] [Indexed: 02/07/2023] Open
Abstract
Despite a growing appreciation for microglial influences on the developing brain, the responsiveness of microglia to insults during gestation remains less well characterized, especially in the embryo when microglia themselves are still maturing. Here, we asked if fetal microglia could coordinate an innate immune response to an exogenous insult. Using time-lapse imaging, we showed that hypothalamic microglia actively surveyed their environment by near-constant "touching" of radial glia projections. However, following an insult (i.e., IUE or AAV transduction), this seemingly passive touching became more intimate and long lasting, ultimately resulting in the retraction of radial glial projections and degeneration into small pieces. Mechanistically, the TAM receptors MERTK and AXL were upregulated in microglia following the insult, and Annexin V treatment inhibited radial glia breakage and engulfment by microglia. These data demonstrate a remarkable responsiveness of embryonic microglia to insults during gestation, a critical window for neurodevelopment.
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14
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Abstract
Mammalian spermatogenesis is a carefully orchestrated male germ cell differentiation process by which spermatogonia differentiate to spermatozoa in the testis. A highly organized testicular microenvironment is therefore necessary to support spermatogenesis. Regarding immunologic aspects, the testis adapts a specialized immune environment for the protection of male germ cells and testicular functions. The mammalian testis possesses two immunologic features: (1) it is an immunoprivileged organ where immunogenic germ cells do not induce deleterious immune responses under physiologic conditions; and (2) it creates its own effective innate defense system against microbial infection. Various pathologic conditions may disrupt testicular immune homeostasis, thereby resulting in a detrimental immune response and perturbing testicular functions, one of the etiologic factors of male infertility. Understanding the mechanisms underlying immunoregulation in the testis can aid in establishing strategies for the prevention and therapy of immunologic testicular dysfunction and male infertility. This chapter focuses on the mechanisms underlying immune privilege, local innate immunity, and immunologic diseases of the testis.
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15
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Bhushan S, Theas MS, Guazzone VA, Jacobo P, Wang M, Fijak M, Meinhardt A, Lustig L. Immune Cell Subtypes and Their Function in the Testis. Front Immunol 2020; 11:583304. [PMID: 33101311 PMCID: PMC7554629 DOI: 10.3389/fimmu.2020.583304] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 09/14/2020] [Indexed: 12/20/2022] Open
Abstract
Immunoregulation in the testis is characterized by a balance between immuno-suppression (or immune privilege) and the ability to react to infections and inflammation. In this review, we analyze the phenotypes of the various immune cell subtypes present in the testis, and how their functions change between homeostatic and inflammatory conditions. Starting with testicular macrophages, we explore how this heterogeneous population is shaped by the testicular microenvironment to ensure immune privilege. We then describe how dendritic cells exhibit a tolerogenic status under normal conditions, but proliferate, mature and then stimulate effector T-cell expansion under inflammatory conditions. Finally, we outline the two T-cell populations in the testis: CD4+/CD8+ αβ T cells and CD4+/CD8+ Foxp3+ regulatory T cells and describe the distribution and function of mast cells. All these cells help modulate innate immunity and regulate the immune response. By improving our understanding of immune cell behavior in the testis under normal and inflammatory conditions, we will be better placed to evaluate testis impairment due to immune mechanisms in affected patients.
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Affiliation(s)
- Sudhanshu Bhushan
- Department of Anatomy and Cell Biology, Justus-Liebig University Giessen, Giessen, Germany.,Hessian Center of Reproductive Medicine, Justus-Leibig-University Giessen, Giessen, Germany
| | - María S Theas
- Departamento de Biología Celular e Histología/Unidad Académica II, Facultad de Medicina, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Medicina, Instituto de Investigaciones Biomédicas (INBIOMED), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - Vanesa A Guazzone
- Departamento de Biología Celular e Histología/Unidad Académica II, Facultad de Medicina, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Medicina, Instituto de Investigaciones Biomédicas (INBIOMED), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - Patricia Jacobo
- Departamento de Biología Celular e Histología/Unidad Académica II, Facultad de Medicina, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Medicina, Instituto de Investigaciones Biomédicas (INBIOMED), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
| | - Ming Wang
- Medical Research Center, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Monika Fijak
- Department of Anatomy and Cell Biology, Justus-Liebig University Giessen, Giessen, Germany.,Hessian Center of Reproductive Medicine, Justus-Leibig-University Giessen, Giessen, Germany
| | - Andreas Meinhardt
- Department of Anatomy and Cell Biology, Justus-Liebig University Giessen, Giessen, Germany.,Hessian Center of Reproductive Medicine, Justus-Leibig-University Giessen, Giessen, Germany
| | - Livia Lustig
- Departamento de Biología Celular e Histología/Unidad Académica II, Facultad de Medicina, Universidad de Buenos Aires (UBA), Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Medicina, Instituto de Investigaciones Biomédicas (INBIOMED), Universidad de Buenos Aires (UBA), Buenos Aires, Argentina
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16
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Qin L, Lin J, Xie X. CircRNA-9119 suppresses poly I:C induced inflammation in Leydig and Sertoli cells via TLR3 and RIG-I signal pathways. Mol Med 2019; 25:28. [PMID: 31195953 PMCID: PMC6567632 DOI: 10.1186/s10020-019-0094-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 05/21/2019] [Indexed: 12/11/2022] Open
Abstract
Background Circular RNAs (circRNAs) contribute to the epigenetic modulation of pathological and physiological conditions. The understanding of the impact of circRNAs on generation of testicular inflammatory reactions is insufficient. Methods Our research adopted a poly I:C-triggered testicular inflammation murine model and cell assays. Results Microarray data and quantitative evaluation revealed the elevation in the concentrations of Toll-like receptor 3 (TLR3), circRNA-9119, and retinoic acid inducible gene-I (RIG-I) and repression in the levels of miR-136 and miR-26a. Inhibition of circRNA-9119 expression impaired the inflammatory reactions in the separated Leydig and Sertoli cells subjected to poly I:C treatment. CircRNA-9119 suppressed the expression of miR-136 and miR-26a by acting as a microRNA sponge. miR-136 and miR-26a repressed the expression of RIG-I and TLR3 through the expected target region in Leydig and Sertoli cells in vitro. Inhibition of miR-136 and miR-26a expression, at least in part, restored the expression of inflammatory cytokines, which were inhibited upon circRNA-9119 expression silencing. Furthermore, the expression of circRNA-9119 was positively associated with RIG-I and TLR3 mRNA and protein levels. The expression of inflammatory genes triggered by poly I:C treatment was noticeably suppressed after RIG-I and TLR3 knockout. Conclusions Our results suggest that circRNA-9119 may serve as a competing endogenous RNA that insulated miR-136 and miR-26a and consequently defended RIG-I and TLR3 mRNAs against miR-26a/miR-136-mediated inhibition of testicular cells. Moreover, RIG-I and TLR3 contributed to the modulation of poly I:C-triggered inflammatory cytokine generation during orchitis in testicular cells. Electronic supplementary material The online version of this article (10.1186/s10020-019-0094-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Le Qin
- Department of Pediatric Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, Wenzhou, China
| | - Jie Lin
- Department of Pediatric Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Zhejiang, Wenzhou, China
| | - Xiaoxiao Xie
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, West College Road, Lucheng District, Wenzhou, 325027, Zhejiang, China.
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17
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Crittenden MR, Baird J, Friedman D, Savage T, Uhde L, Alice A, Cottam B, Young K, Newell P, Nguyen C, Bambina S, Kramer G, Akporiaye E, Malecka A, Jackson A, Gough MJ. Mertk on tumor macrophages is a therapeutic target to prevent tumor recurrence following radiation therapy. Oncotarget 2018; 7:78653-78666. [PMID: 27602953 PMCID: PMC5346667 DOI: 10.18632/oncotarget.11823] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2016] [Accepted: 08/25/2016] [Indexed: 12/19/2022] Open
Abstract
Radiation therapy provides a means to kill large numbers of cancer cells in a controlled location resulting in the release of tumor-specific antigens and endogenous adjuvants. However, by activating pathways involved in apoptotic cell recognition and phagocytosis, irradiated cancer cells engender suppressive phenotypes in macrophages. We demonstrate that the macrophage-specific phagocytic receptor, Mertk is upregulated in macrophages in the tumor following radiation therapy. Ligation of Mertk on macrophages results in anti-inflammatory cytokine responses via NF-kB p50 upregulation, which in turn limits tumor control following radiation therapy. We demonstrate that in immunogenic tumors, loss of Mertk is sufficient to permit tumor cure following radiation therapy. However, in poorly immunogenic tumors, TGFβ inhibition is also required to result in tumor cure following radiation therapy. These data demonstrate that Mertk is a highly specific target whose absence permits tumor control in combination with radiation therapy.
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Affiliation(s)
- Marka R Crittenden
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA.,The Oregon Clinic, Portland OR, USA
| | - Jason Baird
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - David Friedman
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Talicia Savage
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Lauren Uhde
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Alejandro Alice
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Benjamin Cottam
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Kristina Young
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA.,The Oregon Clinic, Portland OR, USA
| | - Pippa Newell
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA.,Providence Hepatobiliary and Pancreatic Cancer Program, Providence Portland Medical Center, Portland OR, USA
| | - Cynthia Nguyen
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Shelly Bambina
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Gwen Kramer
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Emmanuel Akporiaye
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
| | - Anna Malecka
- Host-Tumour Interactions Group, Division of Cancer and Stem Cells, University of Nottingham, UK
| | - Andrew Jackson
- Host-Tumour Interactions Group, Division of Cancer and Stem Cells, University of Nottingham, UK
| | - Michael J Gough
- Earle A. Chiles Research Institute, Robert W. Franz Cancer Center, Providence Portland Medical Center, Portland OR, USA
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18
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Rethinking Phagocytes: Clues from the Retina and Testes. Trends Cell Biol 2018; 28:317-327. [PMID: 29454661 DOI: 10.1016/j.tcb.2018.01.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 01/13/2018] [Accepted: 01/16/2018] [Indexed: 01/30/2023]
Abstract
Specialized phagocytes are a newly appreciated classification of phagocyte that currently encompasses Sertoli cells (SCs) of the testes and the retinal pigment epithelial cells (RPE) of the retina. While these cells support very different tissues, they have a striking degree of similarity both as phagocytes and in ways that go beyond cell clearance. The clearance of apoptotic germ cells, cell debris, and used photoreceptor outer segments are critical functions of these cells, and the unique nature of their clearance events make specialized phagocytes uniquely suited for studying the larger implications of cell clearance in vivo. The shared functions of specialized phagocytes could provide novel insights into how phagocytosis impacts tissue homeostasis and immune modulation. In this review, we examine the remarkable similarities between SCs and RPE as specialized phagocytes and the physiological effects of cell clearance within a tissue.
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19
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Shi X, Shiao SL. The role of macrophage phenotype in regulating the response to radiation therapy. Transl Res 2018; 191:64-80. [PMID: 29175267 PMCID: PMC6018060 DOI: 10.1016/j.trsl.2017.11.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2017] [Revised: 10/23/2017] [Accepted: 11/11/2017] [Indexed: 12/14/2022]
Abstract
Increasing experimental and clinical evidence has revealed a critical role for myeloid cells in the development and progression of cancer. The ability of monocytes and macrophages to regulate inflammation allows them to manipulate the tumor microenvironment to support the growth and development of malignant cells. Recent studies have shown that macrophages can exist in several functional states depending on the microenvironment they encounter in the tissue. These functional phenotypes influence not only the genesis and propagation of tumors, but also the efficacy of cancer therapies, particularly radiation. Early classification of the macrophage phenotypes, or "polarization states," identified 2 major states, M1 and M2, that have cytotoxic and wound repair capacity, respectively. In the context of tumors, classically activated or M1 macrophages driven by interferon-gamma support antitumor immunity while alternatively activated or M2 macrophages generated in part from interleukin-4 exposure hinder antitumor immunity by suppressing cytotoxic responses against a tumor. In this review, we discuss the role that the functional phenotype of a macrophage population plays in tumor development. We will then focus specifically on how macrophages and myeloid cells regulate the tumor response to radiation therapy.
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Affiliation(s)
- Xiaoshan Shi
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Stephen L Shiao
- Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, CA.
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20
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Chen Q, Deng T, Han D. Testicular immunoregulation and spermatogenesis. Semin Cell Dev Biol 2016; 59:157-165. [DOI: 10.1016/j.semcdb.2016.01.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/14/2016] [Accepted: 01/14/2016] [Indexed: 12/22/2022]
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21
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The Role of TAM Family Receptors in Immune Cell Function: Implications for Cancer Therapy. Cancers (Basel) 2016; 8:cancers8100097. [PMID: 27775650 PMCID: PMC5082387 DOI: 10.3390/cancers8100097] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 01/30/2023] Open
Abstract
The TAM receptor protein tyrosine kinases-Tyro3, Axl, and Mer-are essential regulators of immune homeostasis. Guided by their cognate ligands Growth arrest-specific gene 6 (Gas6) and Protein S (Pros1), these receptors ensure the resolution of inflammation by dampening the activation of innate cells as well as by restoring tissue function through promotion of tissue repair and clearance of apoptotic cells. Their central role as negative immune regulators is highlighted by the fact that deregulation of TAM signaling has been linked to the pathogenesis of autoimmune, inflammatory, and infectious diseases. Importantly, TAM receptors have also been associated with cancer development and progression. In a cancer setting, TAM receptors have a dual regulatory role, controlling the initiation and progression of tumor development and, at the same time, the associated anti-tumor responses of diverse immune cells. Thus, modulation of TAM receptors has emerged as a potential novel strategy for cancer treatment. In this review, we discuss our current understanding of how TAM receptors control immunity, with a particular focus on the regulation of anti-tumor responses and its implications for cancer immunotherapy.
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22
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Wu N, Hong F, Zhou Y, Wang Y. Exacerbation of innate immune response in mouse primary cultured sertoli cells caused by nanoparticulate TiO 2 involves the TAM/TLR3 signal pathway. J Biomed Mater Res A 2016; 105:198-208. [PMID: 27643721 DOI: 10.1002/jbm.a.35906] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 08/31/2016] [Accepted: 09/14/2016] [Indexed: 12/15/2022]
Abstract
Sertoli cells provide appropriate mitogens, differentiation factors and sources of energy for developing germ cells throughout the lifetime of males, and protect these germ cells from harmful agents and from the host's own immune system. Therefore, reductions in the rate and quality of spermatogenesis caused by nanoparticulate titanium dioxide (nano-TiO2 ) may be closely involved in the immunoregulation of Sertoli cells. However, the underlying mechanism of this response is still unclear. To address this issue, we used mouse primary cultured Sertoli cells to examine the toxic effects of nano-TiO2 via alterations in morphology, cell viability, and activation of the TAM/TLR3 signal pathway. The results demonstrated that nano-TiO2 could cross the cytomembrane into the cytoplasm or nucleus, decrease Sertoli cell viability, damage morphology (such as elongated fusiform, cellular and nuclear shrinkage) and induce the expression of various immune mediators and inflammatory cytokines, including TLR3(+0.31-fold to +0.81-fold), IL-lβ(+0.33-fold to +5.0-fold), NF-κB(+0.22-fold to +3.65-fold), IL-6(+0.47-fold to +3.53-fold), TNF-α(+0.14-fold to +2.44-fold), IFN-α(+0.17-fold to +2.27-fold), and IFN-β(+0.09-fold to +2.29-fold), and suppress the expression of Tyro3(-9.33% to -61.93%), Axl(-19.03% to -60.67%), Mer(-8.04% to -59.16%), and IκB(-34.35% to -86.59%) in primary cultured Sertoli cells. These results suggest that testicular innate immune responses to pathogens caused by nano-TiO2 may be involved in the regulatory mechanisms of TAM/TLR3 signaling in testicular Sertoli cells. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 198-208, 2017.
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Affiliation(s)
- Nan Wu
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian, 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University, Huaian, 223300, China
- School of Life Sciences, Huaiyin Normal University, Huaian, 223300, China
| | - Fashui Hong
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian, 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University, Huaian, 223300, China
- School of Life Sciences, Huaiyin Normal University, Huaian, 223300, China
| | - Yingjun Zhou
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian, 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University, Huaian, 223300, China
- School of Life Sciences, Huaiyin Normal University, Huaian, 223300, China
| | - Yajing Wang
- Jiangsu Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huaian, 223300, China
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake, Huaiyin Normal University, Huaian, 223300, China
- School of Life Sciences, Huaiyin Normal University, Huaian, 223300, China
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23
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Mukherjee SK, Wilhelm A, Antoniades CG. TAM receptor tyrosine kinase function and the immunopathology of liver disease. Am J Physiol Gastrointest Liver Physiol 2016; 310:G899-905. [PMID: 26867565 PMCID: PMC4935487 DOI: 10.1152/ajpgi.00382.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 01/28/2016] [Indexed: 01/31/2023]
Abstract
Tyro3, Axl, MERTK (TAM) receptor tyrosine kinases are implicated in the regulation of the innate immune response through clearance of apoptotic cellular debris and control of cytokine signaling cascades. As a result they are pivotal in regulating the inflammatory response to tissue injury. Within the liver, immune regulatory signaling is employed to prevent the overactivation of innate immunity in response to continual antigenic challenge from the gastrointestinal tract. In this review we appraise current understanding of the role of TAM receptor function in the regulation of both innate and adaptive immunity, with a focus on its impact upon hepatic inflammatory pathology.
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Affiliation(s)
- S. K. Mukherjee
- 1Division of Digestive Diseases, Department of Medicine, Imperial College London, London, United Kingdom; and
| | - A. Wilhelm
- 1Division of Digestive Diseases, Department of Medicine, Imperial College London, London, United Kingdom; and
| | - C. G. Antoniades
- 1Division of Digestive Diseases, Department of Medicine, Imperial College London, London, United Kingdom; and ,2Division of Transplantation Immunology & Mucosal Biology, Institute of Liver Sciences, King's College London, London, United Kingdom
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24
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Jiang XH, Bukhari I, Zheng W, Yin S, Wang Z, Cooke HJ, Shi QH. Blood-testis barrier and spermatogenesis: lessons from genetically-modified mice. Asian J Androl 2015; 16:572-80. [PMID: 24713828 PMCID: PMC4104086 DOI: 10.4103/1008-682x.125401] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The blood-testis barrier (BTB) is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferous tubes. It is a compound proteinous structure, composed of several types of cell junctions including tight junctions (TJs), adhesion junctions and gap junctions (GJs). Some of the junctional proteins function as structural proteins of BTB and some have regulatory roles. The deletion or functional silencing of genes encoding these proteins may disrupt the BTB, which may cause immunological or other damages to meiotic and postmeiotic cells and ultimately lead to spermatogenic arrest and infertility. In this review, we will summarize the findings on the BTB structure and function from genetically-modified mouse models and discuss the future perspectives.
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Affiliation(s)
| | | | | | | | | | | | - Qing-Hua Shi
- Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China; Institute of Physics, Chinese Academy of Sciences, Hefei, China,
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25
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Axl receptor tyrosine kinase is a potential therapeutic target in renal cell carcinoma. Br J Cancer 2015; 113:616-25. [PMID: 26180925 PMCID: PMC4647683 DOI: 10.1038/bjc.2015.237] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 06/04/2015] [Accepted: 06/05/2015] [Indexed: 12/01/2022] Open
Abstract
Background: Axl plays multiple roles in tumourigenesis in several cancers. Here we evaluated the expression and biological function of Axl in renal cell carcinoma (RCC). Methods: Axl expression was analysed in a tissue microarray of 174 RCC samples by immunostaining and a panel of 11 normal tumour pairs of human RCC tissues by western blot, as well as in RCC cell lines by both western blot and quantitative PCR. The effects of Axl knockdown in RCC cells on cell growth and signalling were investigated. The efficacy of a humanised Axl targeting monoclonal antibody hMAb173 was tested in histoculture and tumour xenograft. Results: We have determined by immunohistochemistry (IHC) that Axl is expressed in 59% of RCC array samples with moderate to high in 20% but not expressed in normal kidney tissue. Western blot analysis of 11 pairs of tumour and adjacent normal tissue show high Axl expression in 73% of the tumours but not normal tissue. Axl is also expressed in RCC cell lines in which Axl knockdown reduces cell viability and PI3K/Akt signalling. The Axl antibody hMAb173 significantly induced RCC cell apoptosis in histoculture and inhibited the growth of RCC tumour in vivo by 78%. The hMAb173-treated tumours also had significantly reduced Axl protein levels, inhibited PI3K signalling, decreased proliferation, and induced apoptosis. Conclusions: Axl is highly expressed in RCC and critical for RCC cell survival. Targeting Axl is a potential approach for RCC treatment.
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26
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Cheng CY. Toxicants target cell junctions in the testis: Insights from the indazole-carboxylic acid model. SPERMATOGENESIS 2015; 4:e981485. [PMID: 26413399 PMCID: PMC4581065 DOI: 10.4161/21565562.2014.981485] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 10/23/2014] [Indexed: 12/31/2022]
Abstract
There are numerous types of junctions in the seminiferous epithelium which are integrated with, and critically dependent on the Sertoli cell cytoskeleton. These include the basal tight junctions between Sertoli cells that form the main component of the blood–testis barrier, the basal ectoplasmic specializations (basal ES) and basal tubulobulbar complexes (basal TBC) between Sertoli cells; as well as apical ES and apical TBC between Sertoli cells and the developing spermatids that orchestrate spermiogenesis and spermiation. These junctions, namely TJ, ES, and TBC interact with actin microfilament-based cytoskeleton, which together with the desmosomal junctions that interact with the intermediate filament-based cytoskeleton plus the highly polarized microtubule-based cytoskeleton are working in concert to move spermatocytes and spermatids between the basal and luminal aspect of the seminiferous epithelium. In short, these various junctions are structurally complexed with the actin- and microtubule-based cytoskeleton or intermediate filaments of the Sertoli cell. Studies have shown toxicants (e.g., cadmium, bisphenol A (BPA), perfluorooctanesulfonate (PFOS), phthalates, and glycerol), and some male contraceptives under development (e.g., adjudin, gamendazole), exert their effects, at least in part, by targeting cell junctions in the testis. The disruption of Sertoli–Sertoli cell and Sertoli–germ cell junctions, results in the loss of germ cells from the seminiferous epithelium. Adjudin, a potential male contraceptive under investigation in our laboratory, produces loss of spermatids from the seminiferous tubules through disruption of the Sertoli cell spermatid junctions and disruption of the Sertoli cell cytoskeleton. The molecular and structural changes associated with adjudin administration are described, to provide an example of the profile of changes caused by disturbance of Sertoli-germ cell and also Sertoli cell-cell junctions.
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Affiliation(s)
- C Yan Cheng
- The Mary M. Wohlford Laboratory for Male Contraceptive Research; Center for Biomedical Research; Population Council ; New York, NY USA
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27
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Mice lacking Axl and Mer tyrosine kinase receptors are susceptible to experimental autoimmune orchitis induction. Immunol Cell Biol 2014; 93:311-20. [PMID: 25403570 DOI: 10.1038/icb.2014.97] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 10/15/2014] [Accepted: 10/16/2014] [Indexed: 02/02/2023]
Abstract
The mammalian testis is an immunoprivileged organ where male germ cell autoantigens are immunologically ignored. Both systemic immune tolerance to autoantigens and local immunosuppressive milieu contribute to the testicular immune privilege. Testicular immunosuppression has been intensively studied, but information on systemic immune tolerance to autoantigens is lacking. In the present study, we aimed to determine the role of Axl and Mer receptor tyrosine kinases in maintaining the systemic tolerance to male germ cell antigens using the experimental autoimmune orchitis (EAO) model. Axl and Mer double-knockout (Axl(-/-)Mer(-/-)) mice developed evident EAO after a single immunization with germ cell homogenates emulsified with complete Freund's adjuvant. EAO was characterized by the accumulation of macrophages and T lymphocytes in the testis. Damage to the seminiferous epithelium was also observed. EAO induction was associated with pro-inflammatory cytokine upregulation in the testes, impaired permeability of the blood-testis barrier and generation of autoantibodies against germ cell antigens in Axl(-/-)Mer(-/-) mice. Immunization also induced mild EAO in Axl or Mer single-gene-knockout mice. By contrast, a single immunization failed to induce EAO in wild-type mice. The results indicate that Axl and Mer receptors cooperatively regulate the systemic immune tolerance to male germ cell antigens.
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28
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Zhao S, Zhu W, Xue S, Han D. Testicular defense systems: immune privilege and innate immunity. Cell Mol Immunol 2014; 11:428-37. [PMID: 24954222 DOI: 10.1038/cmi.2014.38] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 05/03/2014] [Accepted: 05/04/2014] [Indexed: 01/12/2023] Open
Abstract
The mammalian testis possesses a special immunological environment because of its properties of remarkable immune privilege and effective local innate immunity. Testicular immune privilege protects immunogenic germ cells from systemic immune attack, and local innate immunity is important in preventing testicular microbial infections. The breakdown of local testicular immune homeostasis may lead to orchitis, an etiological factor of male infertility. The mechanisms underlying testicular immune privilege have been investigated for a long time. Increasing evidence shows that both a local immunosuppressive milieu and systemic immune tolerance are involved in maintaining testicular immune privilege status. The mechanisms underlying testicular innate immunity are emerging based on the investigation of the pattern recognition receptor-mediated innate immune response in testicular cells. This review summarizes our current understanding of testicular defense mechanisms and identifies topics that merit further investigation.
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