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Zhou Q, Liu J, Yan J, Guo Z, Zhang F. Magnetic microspheres mimicking certain functions of macrophages: Towards precise antibacterial potency for bone defect healing. Mater Today Bio 2023; 20:100651. [PMID: 37206878 PMCID: PMC10189291 DOI: 10.1016/j.mtbio.2023.100651] [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: 02/23/2023] [Revised: 04/27/2023] [Accepted: 04/29/2023] [Indexed: 05/21/2023] Open
Abstract
A variety of novel biomaterials have recently been developed to promote bone regeneration. However, the current biomaterials cannot accurately and effectively resist bacterial invasion. In this study, we constructed microspheres that mimic certain functions of macrophages as additives to bone repair materials, which can be manipulated as demanded to resist bacteria effectively and protect bone defect healing. Firstly, we prepared gelatin microspheres (GMSs) by an emulsion-crosslinking method, which were subsequently coated with polydopamine (PDA). Then, amino antibacterial nanoparticles obtained by a nanoprecipitation-self-assembly method and commercial amino magnetic nanoparticles were modified onto these PDA-coated GMSs to construct the functionalized microspheres (FMSs). The results showed that the FMSs possessed a rough topography and could be manipulated by a 100-400 mT static magnetic field to migrate directionally in unsolidified hydrogels. Moreover, in vitro experiments with near-infrared (NIR) showed that the FMSs had a sensitive and recyclable photothermal performance and could capture and kill Porphyromonas gingivalis by releasing reactive oxygen species. Finally, the FMSs were mixed with osteogenic hydrogel precursor, injected into the Sprague-Dawley rat periodontal bone defect of maxillary first molar (M1), and subsequently driven by magnetism to the cervical surface of M1 and the outer surface of the gel system for targeted sterilization under NIR, thus protecting the bone defect healing. In conclusion, the FMSs had excellent manipulation and antimicrobial performances. This provided us with a promising strategy to construct light-magnetism-responsive antibacterial materials to build a beneficial environment for bone defect healing.
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Affiliation(s)
- Qiao Zhou
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029, China
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, 210029, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, 210029, China
| | - Jun Liu
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, 210029, China
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, 210008, China
| | - Jia Yan
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029, China
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, 210029, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, 210029, China
| | - Zhaobin Guo
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Feimin Zhang
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, 210029, China
- Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, 210029, China
- Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, 210029, China
- Corresponding author. Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University; Department of Prosthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, 210029, China.
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2
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Okugbeni N, du Toit A, Cole-Holman V, Johnson G, Loos B, Kinnear C. Measurement of Autophagy Activity Reveals Time-Dependent, Bacteria-Specific Turnover during Mycobacterium tuberculosis Infection. Pathogens 2022; 12:pathogens12010024. [PMID: 36678372 PMCID: PMC9864524 DOI: 10.3390/pathogens12010024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
The intracellular pathogen, Mycobacterium tuberculosis (M. tb) uses various mechanisms to evade its killing. One of such is phagosomal damage and cytosolic translocation which is then targeted by the host's bactericidal autophagy pathway. It is suggested that cytosolic translocation of M. tb is time-dependent, occurring at later time points of 48 to 72 h post-infection. It is, however, not known whether increased autophagic targeting correlates with these time points of infection. We investigated the time-dependent profile of autophagy activity through the course of M. tb infection in mammalian macrophages. Autophagy activity was inferred by the turnover measurement of autophagy markers and M. tb bacilli in THP-1 and RAW 264.7 macrophages. Over a period of 4 to 72 h, we observed highest autophagy turnover at 48 h of infection in M. tb-containing cells. This was evident by the highest turnover levels of p62 and intracellular M. tb. This supports observations of phagosomal damage mostly occurring at this time point and reveal the correlation of increased autophagy activity. The findings support the preservation of autophagy activity despite M. tb infection while also highlighting time-dependent differences in M. tb-infected macrophages. Future studies may explore time-dependent exogenous autophagy targeting towards host-directed anti-tuberculosis therapy.
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Affiliation(s)
- Naomi Okugbeni
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, US/SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
- South African Medical Research Council Genomics Centre, Tygerberg 7505, South Africa
| | - André du Toit
- Neuro Research Group, Department of Physiological Sciences, Faculty of Sciences, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Victoria Cole-Holman
- South African Medical Research Council Genomics Centre, Tygerberg 7505, South Africa
| | - Glynis Johnson
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, US/SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
| | - Ben Loos
- Neuro Research Group, Department of Physiological Sciences, Faculty of Sciences, Stellenbosch University, Stellenbosch 7602, South Africa
| | - Craig Kinnear
- DSI-NRF Centre of Excellence for Biomedical Tuberculosis Research, US/SAMRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg 7505, South Africa
- South African Medical Research Council Genomics Centre, Tygerberg 7505, South Africa
- Correspondence:
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3
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Akt Inhibition Promotes Autophagy and Clearance of Group B Streptococcus from the Alveolar Epithelium. Pathogens 2022; 11:pathogens11101134. [PMID: 36297190 PMCID: PMC9611837 DOI: 10.3390/pathogens11101134] [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: 08/03/2022] [Revised: 09/24/2022] [Accepted: 09/27/2022] [Indexed: 12/04/2022] Open
Abstract
Group B Streptococcus (GBS) is a gram-positive bacterium that is harmless for healthy individuals but may provoke invasive disease in young infants and immunocompromised hosts. GBS invades the epithelial barriers to enter the bloodstream, and thus strategies that enhance epithelial cell responses may hamper GBS invasion. In the present study, we sought to investigate whether the inhibition of Akt, a kinase that regulates host inflammatory responses and autophagy via suppression of mTOR, can enhance the response of non-phagocytic alveolar epithelial cells against GBS. Treatment of the alveolar epithelial cell line A549 with the Akt inhibitor MK-2206 resulted in the enhanced production of reactive oxygen species and inflammatory mediators in response to GBS. Additionally, Akt inhibition via MK-2206 resulted in elevated LC3II/I ratios and increased autophagic flux in alveolar epithelial cells. Importantly, the inhibition of Akt promoted GBS clearance both in alveolar epithelial cells in vitro and in lung tissue in vivo in a murine model of GBS pneumonia. The induction of autophagy was essential for GBS clearance in MK-2206 treated cells, as knockdown of ATG5, a critical component of autophagy, abrogated the effect of Akt inhibition on GBS clearance. Our findings highlight the role of Akt kinase inhibition in promoting autophagy and GBS clearance in the alveolar epithelium. The inhibition of Akt may serve as a promising measure to strengthen epithelial barriers and prevent GBS invasion in susceptible hosts.
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Abstract
Micro-/nanorobots (MNRs) can be autonomously propelled on demand in complex biological environments and thus may bring revolutionary changes to biomedicines. Fluorescence has been widely used in real-time imaging, chemo-/biosensing, and photo-(chemo-) therapy. The integration of MNRs with fluorescence generates fluorescent MNRs with unique advantages of optical trackability, on-the-fly environmental sensitivity, and targeting chemo-/photon-induced cytotoxicity. This review provides an up-to-date overview of fluorescent MNRs. After the highlighted elucidation about MNRs of various propulsion mechanisms and the introductory information on fluorescence with emphasis on the fluorescent mechanisms and materials, we systematically illustrate the design and preparation strategies to integrate MNRs with fluorescent substances and their biomedical applications in imaging-guided drug delivery, intelligent on-the-fly sensing and photo-(chemo-) therapy. In the end, we summarize the main challenges and provide an outlook on the future directions of fluorescent MNRs. This work is expected to attract and inspire researchers from different communities to advance the creation and practical application of fluorescent MNRs on a broad horizon.
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Affiliation(s)
- Manyi Yang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Xia Guo
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Fangzhi Mou
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
| | - Jianguo Guan
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, International School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, P. R. China
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5
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Deng J, Wang R, Huang S, Ding J, Zhou W. Macrophages-regulating nanomedicines for sepsis therapy. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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6
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Bhattacharya A, Ghosh P, Singh A, Ghosh A, Bhowmick A, Sinha DK, Ghosh A, Sen P. Delineating the complex mechanistic interplay between NF-κβ driven mTOR depedent autophagy and monocyte to macrophage differentiation: A functional perspective. Cell Signal 2021; 88:110150. [PMID: 34547324 DOI: 10.1016/j.cellsig.2021.110150] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/30/2021] [Accepted: 09/13/2021] [Indexed: 12/24/2022]
Abstract
Autophagy is an extremely essential cellular process aimed to clear redundant and damaged materials, namely organelles, protein aggregates, invading pathogens, etc. through the formation of autophagosomes which are ultimately targeted to lysosomal degradation. In this study, we demonstrated that mTOR dependent classical autophagy is ubiquitously triggered in differentiating monocytes. Moreover, autophagy plays a decisive role in sustaining the process of monocyte to macrophage differentiation. We have delved deeper into understanding the underlying mechanistic complexities that trigger autophagy during differentiation. Intrigued by the significant difference between the protein profiles of monocytes and macrophages, we investigated to learn that autophagy directs monocyte differentiation via protein degradation. Further, we delineated the complex cross-talk between autophagy and cell-cycle arrest in differentiating monocytes. This study also inspects the contribution of adhesion on various steps of autophagy and its ultimate impact on monocyte differentiation. Our study reveals new mechanistic insights into the process of autophagy associated with monocyte differentiation and would undoubtedly help to understand the intricacies of the process better for the effective design of therapeutics as autophagy and autophagy-related processes have enormous importance in human patho-physiology.
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Affiliation(s)
- Anindita Bhattacharya
- School of Biological Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Purnam Ghosh
- School of Biological Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Arpana Singh
- School of Biological Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Arnab Ghosh
- School of Biological Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India
| | - Arghya Bhowmick
- Department of Biochemistry, Centenary Campus, Bose Institute, P-1/12 C.I.T. Scheme VII-M, Kolkata 700054, India
| | - Deepak Kumar Sinha
- Department of Biochemistry, Centenary Campus, Bose Institute, P-1/12 C.I.T. Scheme VII-M, Kolkata 700054, India
| | - Abhrajyoti Ghosh
- Department of Biochemistry, Centenary Campus, Bose Institute, P-1/12 C.I.T. Scheme VII-M, Kolkata 700054, India
| | - Prosenjit Sen
- School of Biological Sciences, Indian Association for the Cultivation of Science, Kolkata 700032, India.
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7
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Li Y, Yong YL, Yang M, Wang W, Qu X, Dang X, Shang D, Shao Y, Liu J, Chang Y. Fine particulate matter inhibits phagocytosis of macrophages by disturbing autophagy. FASEB J 2020; 34:16716-16735. [PMID: 33124742 DOI: 10.1096/fj.202000657r] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/25/2020] [Accepted: 10/14/2020] [Indexed: 01/22/2023]
Abstract
Mounting evidence from epidemiological and clinical studies has revealed marked correlations between the air pollutant fine particulate matter (FPM) and respiratory diseases. FPM reaches distal airways and deposits in alveolar regions where it can act directly on alveolar macrophages. However, the detailed effect of FPM on the physiological function of alveolar macrophages and the underlying mechanisms remain unclear. In this study, we showed that exposing THP-1-derived macrophages to FPM led to autophagy dysfunction. FPM activated the extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway, which promoted the expression of autophagy-related 2A (ATG2A) and reactive oxygen species generation. The overexpression of ATG2A enhanced the synthesis of autophagic membranes, and the excessive production of reactive oxygen species caused autophagy flux inhibition through disrupting the lysosomal activity. More importantly, FPM impaired the phagocytic ability of macrophages on Escherichia coli and apoptotic neutrophils. Finally, we showed that restoring autophagy rescued the impairment of phagocytic ability induced by FPM. In summary, these results reveal the molecular mechanism of autophagy dysfunction caused by FPM and provide a novel approach to resolve the impaired function of macrophages in respiratory diseases induced by FPM.
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Affiliation(s)
- Ying Li
- Center for Translational Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Yu-Le Yong
- National Translational Science Center for Molecular Medicine, Department of Cell Biology, Fourth Military Medical University, Xi'an, China
| | - Menglin Yang
- Center for Translational Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Weijia Wang
- Center for Translational Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Xiaoyan Qu
- Center for Translational Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Xiaomin Dang
- Department of Respiration, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Dong Shang
- Department of Respiration, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an, China
| | - Yongping Shao
- Center for Translational Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Jiankang Liu
- Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
| | - Ying Chang
- Center for Translational Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, China
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8
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Yu Y, Sun B. Autophagy-mediated regulation of neutrophils and clinical applications. BURNS & TRAUMA 2020; 8:tkz001. [PMID: 32341923 PMCID: PMC7175771 DOI: 10.1093/burnst/tkz001] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/07/2019] [Indexed: 12/16/2022]
Abstract
Autophagy, an adaptive catabolic process, plays a cytoprotective role in enabling cellular homeostasis in the innate and adaptive immune systems. Neutrophils, the most abundant immune cells in circulation, are professional killers that orchestrate a series of events during acute inflammation. The recent literature indicates that autophagy has important roles in regulating neutrophil functions, including differentiation, degranulation, metabolism and neutrophil extracellular trap formation, that dictate neutrophil fate. It is also becoming increasingly clear that autophagy regulation is critical for neutrophils to exert their immunological activity. However, evidence regarding the systematic communication between neutrophils and autophagy is insufficient. Here, we provide an updated overview of the function of autophagy as a regulator of neutrophils and discuss its clinical relevance to provide novel insight into potentially relevant treatment strategies.
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Affiliation(s)
- Yao Yu
- Department of Burns and Plastic Surgery, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou 215002, Jiangsu Province, China
| | - Bingwei Sun
- Department of Burns and Plastic Surgery, the Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou 215002, Jiangsu Province, China
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9
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Padhi A, Pattnaik K, Biswas M, Jagadeb M, Behera A, Sonawane A. Mycobacterium tuberculosisLprE Suppresses TLR2-Dependent Cathelicidin and Autophagy Expression to Enhance Bacterial Survival in Macrophages. THE JOURNAL OF IMMUNOLOGY 2019; 203:2665-2678. [DOI: 10.4049/jimmunol.1801301] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 09/15/2019] [Indexed: 12/20/2022]
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10
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de Sousa JR, Da Costa Vasconcelos PF, Quaresma JAS. Functional aspects, phenotypic heterogeneity, and tissue immune response of macrophages in infectious diseases. Infect Drug Resist 2019; 12:2589-2611. [PMID: 31686866 PMCID: PMC6709804 DOI: 10.2147/idr.s208576] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/05/2019] [Indexed: 12/13/2022] Open
Abstract
Macrophages are a functionally heterogeneous group of cells with specialized functions depending not only on their subgroup but also on the function of the organ or tissue in which the cells are located. The concept of macrophage phenotypic heterogeneity has been investigated since the 1980s, and more recent studies have identified a diverse spectrum of phenotypic subpopulations. Several types of macrophages play a central role in the response to infectious agents and, along with other components of the immune system, determine the clinical outcome of major infectious diseases. Here, we review the functions of various macrophage phenotypic subpopulations, the concept of macrophage polarization, and the influence of these cells on the evolution of infections. In addition, we emphasize their role in the immune response in vivo and in situ, as well as the molecular effectors and signaling mechanisms used by these cells. Furthermore, we highlight the mechanisms of immune evasion triggered by infectious agents to counter the actions of macrophages and their consequences. Our aim here is to provide an overview of the role of macrophages in the pathogenesis of critical transmissible diseases and discuss how elucidation of this relationship could enhance our understanding of the host-pathogen association in organ-specific immune responses.
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Affiliation(s)
- Jorge Rodrigues de Sousa
- Tropical Medicine Center, Federal University of Pará, Belém, PA, Brazil
- Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, Brazil
| | - Pedro Fernando Da Costa Vasconcelos
- Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, Brazil
- Center of Biological and Health Sciences, State University of Pará, Belém, PA, Brazil
| | - Juarez Antonio Simões Quaresma
- Tropical Medicine Center, Federal University of Pará, Belém, PA, Brazil
- Evandro Chagas Institute, Ministry of Health, Ananindeua, PA, Brazil
- Center of Biological and Health Sciences, State University of Pará, Belém, PA, Brazil
- School of Medicine, São Paulo University, São Paulo, SP, Brazil
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11
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Xiong W, Wen Q, Du X, Wang J, He W, Wang R, Hu S, Zhou X, Yang J, Gao Y, Ma L. Novel Function of Cyclooxygenase-2: Suppressing Mycobacteria by Promoting Autophagy via the Protein Kinase B/Mammalian Target of Rapamycin Pathway. J Infect Dis 2019; 217:1267-1279. [PMID: 29373690 DOI: 10.1093/infdis/jiy033] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/18/2018] [Indexed: 12/22/2022] Open
Abstract
In Mycobacterium tuberculosis-infected macrophages, cyclooxygenase-2 (COX-2) expression considerably increases to defend the body against mycobacteria by regulating adaptive immunity and restoring the mitochondrial inner membrane. Moreover, in cancer cells, COX-2 enhances the autophagy machinery, an important bactericidal mechanism. However, the association between M. tuberculosis-induced COX-2 and autophagy-mediated antimycobacterial response has not been explored. Here, COX-2 expression silencing reduced the autophagy and bactericidal activity against intracellular M. tuberculosis, while COX-2 overexpression reversed the above effects. In addition, enhancement of bactericidal activity was suppressed by inhibiting autophagy in COX-2-overexpressing cells, indicating that COX-2 accelerated mycobacterial elimination by promoting autophagy. Furthermore, the regulatory effects of COX-2 on autophagy were mediated by its catalytic products, which functioned through inhibiting the protein kinase B/mammalian target of rapamycin pathway. Thus, COX-2 contributes to host defense against mycobacterial infection by promoting autophagy, establishing the basis for development of novel therapeutic agents against tuberculosis by targeting COX-2.
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Affiliation(s)
- Wenjing Xiong
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Qian Wen
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Xialin Du
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Jinli Wang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Wenting He
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Ruining Wang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Shengfeng Hu
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Xinying Zhou
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Jiahui Yang
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Yuchi Gao
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
| | - Li Ma
- Institute of Molecular Immunology, School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, China
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12
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Dai Y, Gao C, Chen L, Chang W, Yu W, Ma X, Li J. Heterogeneous Vancomycin-Intermediate Staphylococcus aureus Uses the VraSR Regulatory System to Modulate Autophagy for Increased Intracellular Survival in Macrophage-Like Cell Line RAW264.7. Front Microbiol 2019; 10:1222. [PMID: 31214151 PMCID: PMC6554704 DOI: 10.3389/fmicb.2019.01222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 05/16/2019] [Indexed: 12/14/2022] Open
Abstract
The VraSR two-component system is a vancomycin resistance-associated sensor/regulator that is upregulated in vancomycin-intermediate Staphylococcus aureus (VISA) and heterogeneous VISA (hVISA) strains. VISA/hVISA show reduced susceptibility to vancomycin and an increased ability to evade host immune responses, resulting in enhanced clinical persistence. However, the underlying mechanism remains unclear. Recent studies have reported that S. aureus strains have developed some strategies to survive within the host cell by using autophagy processes. In this study, we confirmed that clinical isolates with high vraR expression showed increased survival in murine macrophage-like RAW264.7 cells. We constructed isogenic vraSR deletion strain Mu3ΔvraSR and vraSR-complemented strain Mu3ΔvraSR-C to ascertain whether S. aureus uses the VraSR system to modulate autophagy for increasing intracellular survival in RAW264.7. Overall, the survival of Mu3ΔvraSR in RAW264.7 cells was reduced at all infection time points compared with that of the Mu3 wild-type strain. Mu3ΔvraSR-infected RAW264.7 cells also showed decreased transcription of autophagy-related genes Becn1 and Atg5, decreased LC3-II turnover and increased p62 degradation, and fewer visible punctate LC3 structures. In addition, we found that inhibition of autophagic flux significantly increased the survival of Mu3ΔvraSR in RAW264.7 cells. Together, these results demonstrate that S. aureus uses the VraSR system to modulate host-cell autophagy processes for increasing its own survival within macrophages. Our study provides novel insights into the impact of VraSR on bacterial infection and will help to further elucidate the relationship between bacteria and the host immune response. Moreover, understanding the autophagic pathway in vraSR associated immunity has potentially important implications for preventing or treating VISA/hVISA infection.
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Affiliation(s)
- Yuanyuan Dai
- Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei, China.,Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Caihong Gao
- Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei, China.,Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Li Chen
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Wenjiao Chang
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Wenwei Yu
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Xiaoling Ma
- Department of Clinical Laboratory, First Affiliated Hospital of University of Science and Technology of China, Hefei, China
| | - Jiabin Li
- Department of Infectious Diseases, First Affiliated Hospital of Anhui Medical University, Hefei, China.,Anhui Center for Surveillance of Bacterial Resistance, Hefei, China.,Department of Infectious Diseases, Chaohu Hospital of Anhui Medical University, Hefei, China
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13
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The role of autophagy in colitis-associated colorectal cancer. Signal Transduct Target Ther 2018; 3:31. [PMID: 30510778 PMCID: PMC6265276 DOI: 10.1038/s41392-018-0031-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/04/2018] [Accepted: 10/17/2018] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an evolutionarily conserved catabolic process that eliminates harmful components through lysosomal degradation. In addition to its role in maintaining cellular homeostasis, autophagy is critical to pathological processes, such as inflammation and cancer. Colitis-associated colorectal cancer (CAC) is a specific type of colorectal cancer that develops from long-standing colitis in inflammatory bowel disease (IBD) patients. Accumulating evidence indicates that autophagy of microenvironmental cells plays different but vital roles during tumorigenesis and CAC development. Herein, after summarizing the recent advances in understanding the role of autophagy in regulating the tumor microenvironment during different CAC stages, we draw the following conclusions: autophagy in intestinal epithelial cells inhibits colitis and CAC initiation but promotes CAC progression; autophagy in macrophages inhibits colitis, but its function on CAC is currently unclear; autophagy in neutrophils and cancer-associated fibroblasts (CAFs) promotes both colitis and CAC; autophagy in dendritic cells (DCs) and T cells represses both colitis and CAC; autophagy in natural killer cells (NKs) inhibits colitis, but promotes CAC; and autophagy in endothelial cells plays a controversial role in colitis and CAC. Understanding the role of autophagy in specific compartments of the tumor microenvironment during different stages of CAC may provide insight into malignant transformation, tumor progression, and combination therapy strategies for CAC.
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15
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Wang XY, Liu WL. Mechanism of autophagy in liver fibrosis. Shijie Huaren Xiaohua Zazhi 2018; 26:1415-1422. [DOI: 10.11569/wcjd.v26.i23.1415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Autophagy is an evolutionarily conserved lysosome-dependent catabolic process which degrades cell components, including proteins and lipids, in order to recycle substrates to exert optimally and adapt to tough circumstances. It is an important mechanism for the body to maintain the homeostasis of the internal environment. Liver fibrosis refers to the excessive proliferation and abnormal deposition of extracellular matrix components in the liver tissue, resulting in pathological changes in liver structure and function abnormalities, which is seen in chronic liver diseases of many different causes. In this article, we summarizes the role of autophagy in hepatic fibrosis as well as the relevant signaling pathways to reveal the mechanism of autophagy in hepatic fibrosis.
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Affiliation(s)
- Xin-Yan Wang
- School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Wen-Lan Liu
- School of Traditional Chinese Medicine, Capital Medical University, Beijing 100069, China
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16
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Lou J, Wang Y, Zheng X, Qiu W. TRIM22 regulates macrophage autophagy and enhances Mycobacterium tuberculosis clearance by targeting the nuclear factor-multiplicity κB/beclin 1 pathway. J Cell Biochem 2018; 119:8971-8980. [PMID: 30011088 DOI: 10.1002/jcb.27153] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 05/18/2018] [Indexed: 12/19/2022]
Abstract
Autophagy is a crucial host-defense mechanism against Mycobacterium tuberculosis (Mtb) infection by spanning innate and adaptive immune functions. TRIM22 is a member of tripartite motif family protein which involved in innate immunity and autophagy process. However, its role in the modulation of bacterial infection has not been investigated. Here, we demonstrated that TRIM22 is upregulated in a dose-dependent and time-dependent manner during Mtb infection of THP-1 cells. Downregulation of TRIM22 significantly decreased light chain 3 (LC3)-II protein level and the formation of LC3 puncta, while it markedly increased SQSTM1, a marker of autophagic degradation, in Mtb-infected THP-1 cells. What is more, enhanced bacterial survival was observed in TRIM22 knockdown THP-1 cells, while rapamycin abrogated this effect. In the presence of vector containing TRIM22 in THP-1 cells prior to infection, the survival of Mtb was decreased, while BafA restored this effect. Further study demonstrated that TRIM22 expression was regulated by MicroRNA-20b, and that TRIM22 regulates Mtb-infected THP-1 autophagy via the nuclear factor-κB/beclin 1 pathway. Using a nuclear factor-κB inhibitor BAY 11-7082, we found that TRIM22-induced high expression of LC3-II and the formation of LC3 was substantially attenuated, while the TRIM22-induced low expression of SQSTM1 was markedly increased in BAY 11-7082-treatment cells. In addition, the bacterial survival reduced by TRIM22 was significantly reversed by BAY 11-7082. Overall, these results suggest that TRIM22-augmented autophagy prevents intracellular Mtb to evade autophagic clearance, thereby inhibiting the persistence of Mtb infections.
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Affiliation(s)
- Jun Lou
- Department of Clinical Laboratory, Zhumadian Central Hospital, Zhumadian, China
| | - Yongli Wang
- Department of the Neonatal Intensive Care Unit, Zhumadian Central Hospital, Zhumadian, China
| | - Ximing Zheng
- Department of Clinical Laboratory, Zhumadian Central Hospital, Zhumadian, China
| | - Weiqiang Qiu
- Department of Clinical Laboratory, Zhumadian Central Hospital, Zhumadian, China
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17
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Cheng MI, Chen C, Engström P, Portnoy DA, Mitchell G. Actin-based motility allows Listeria monocytogenes to avoid autophagy in the macrophage cytosol. Cell Microbiol 2018; 20:e12854. [PMID: 29726107 DOI: 10.1111/cmi.12854] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 04/03/2018] [Accepted: 04/23/2018] [Indexed: 12/23/2022]
Abstract
Listeria monocytogenes grows in the host cytosol and uses the surface protein ActA to promote actin polymerisation and mediate actin-based motility. ActA, along with two secreted bacterial phospholipases C, also mediates avoidance from autophagy, a degradative process that targets intracellular microbes. Although it is known that ActA prevents autophagic recognition of L. monocytogenes in epithelial cells by masking the bacterial surface with host factors, the relative roles of actin polymerisation and actin-based motility in autophagy avoidance are unclear in macrophages. Using pharmacological inhibition of actin polymerisation and a collection of actA mutants, we found that actin polymerisation prevented the colocalisation of L. monocytogenes with polyubiquitin, the autophagy receptor p62, and the autophagy protein LC3 during macrophage infection. In addition, the ability of L. monocytogenes to stimulate actin polymerisation promoted autophagy avoidance and growth in macrophages in the absence of phospholipases C. Time-lapse microscopy using green fluorescent protein-LC3 macrophages and a probe for filamentous actin showed that bacteria undergoing actin-based motility moved away from LC3-positive membranes. Collectively, these results suggested that although actin polymerisation protects the bacterial surface from autophagic recognition, actin-based motility allows escape of L. monocytogenes from autophagic membranes in the macrophage cytosol.
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Affiliation(s)
- Mandy I Cheng
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Chen Chen
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Patrik Engström
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Daniel A Portnoy
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.,School of Public Health, University of California, Berkeley, CA, USA
| | - Gabriel Mitchell
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
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Wulandari DN, Nugraha J, Soedarsono S. THE DIFFERENCE OF MAP1LC3 LEVEL AS MACROPHAGE AUTOPHAGY MARKER BETWEEN RESISTANT AND SENSITIVE TUBERCULOSIS PATIENTS ON RIFAMPICIN. INDONESIAN JOURNAL OF TROPICAL AND INFECTIOUS DISEASE 2018. [DOI: 10.20473/ijtid.v7i1.6024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
M. tuberculosis (MTB) is an intracelular bacteria that live in the host macrophage cells. Several organs can be affected by tuberculosis but most major illnesses are lung diseases. Immediately after infection, MTB will be phagocytosed by the alveolar macrophage cells and can survive in the phagosome. The macrophage plays a role in innate immunity towards an infection using autophagy by removing the microbe directly via phagocytosis. When bacteria phagocytosized, vacuole membrane formed double membranes called autophagosome, and followed by degradation by lysosome, which known as autolysosome. Induction of autophagy can be observed on the formation of microtubule-associated proteins 1B lightchain 3B (MAP1LC3B/LC3). MAP1LC3B is protein that have role at autophagic way for selection autophagy substrate and biogenesis. In this study we are used serum from patients TB with rifampicin resistant and rifampicin sensitive as control. Samples were divided using gene expert to differentiate between resistant and sensitive rifampicin.This research aims to compare MAP1LC3B levels in resistant and sensitive rifampicin to study macrophages respond in autophagic way in tuberculosis patients, and give information for define therapy plan to improve therapy for MDR-TB patients. Type of this research is a case control study design with cross sectional research with each groups sample is 19 from age 18-65 years old. Result, MAP1LC3B serum levels on the rifampicin resistant group are lower compared to rifampicin sensitive group. This occur because MTB is able to hide and evade innate immune defense mechanisms. MTB can maintain intracellular growth inside the phagosome by inhibiting phagolysosome formation in autophagy process especially inhibit MAP1LC3B formation by PDIM.
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Chandramani-Shivalingappa P, Bhandari M, Wiechert SA, Gilbertie J, Jones DE, Sponseller BA. Induction of Reactive Intermediates and Autophagy-Related Proteins upon Infection of Macrophages with Rhodococcus equi. SCIENTIFICA 2017; 2017:8135737. [PMID: 29230347 PMCID: PMC5688232 DOI: 10.1155/2017/8135737] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 10/01/2017] [Indexed: 06/07/2023]
Abstract
Rhodococcus equi (R. equi) is an intracellular macrophage-tropic pathogen with potential for causing fatal pyogranulomatous pneumonia in foals between 1 and 6 months of age. In this study, we sought to determine whether infection of macrophages with R. equi could lead to the induction of autophagy. Murine bone marrow derived macrophages (BMDM) were infected with R. equi for various time intervals and analyzed for upregulation of autophagy proteins and accumulation of autophagosomes relative to uninfected controls. Western blot analysis showed a progressive increase in LC3-II and Beclin1 levels in a time-dependent manner. The functional accumulation of autophagosomes detected with monodansylcadaverine further supported the enhanced induction of autophagy in BMDM infected with R. equi. In addition, infection of BMDM with R. equi induced generation of reactive oxygen species (ROS) in a time-dependent manner. These data are consistent with reports documenting the role of ROS in induction of autophagy and indicate that the infection of macrophages by R. equi elicits innate host defense mechanisms.
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Affiliation(s)
- Prashanth Chandramani-Shivalingappa
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
- Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mahesh Bhandari
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Sarah A. Wiechert
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Jessica Gilbertie
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Douglas E. Jones
- Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
| | - Brett A. Sponseller
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA
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20
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Pahari S, Khan N, Aqdas M, Negi S, Kaur J, Agrewala JN. Infergen Stimulated Macrophages Restrict Mycobacterium tuberculosis Growth by Autophagy and Release of Nitric Oxide. Sci Rep 2016; 6:39492. [PMID: 28000752 PMCID: PMC5175149 DOI: 10.1038/srep39492] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 11/24/2016] [Indexed: 12/22/2022] Open
Abstract
IFN alfacon-1 (Infergen) is a synthetic form of Interferon (IFN)-α2b. Infergen has immunomodulatory activity and is effective against hepatitis C virus. However, the effect of Infergen (IFG) on Mycobacterium tuberculosis (Mtb) has not yet been reported. Therefore, for the first time, we have studied the influence of IFG in constraining the survival of Mtb in human macrophages. We observed that IFG significantly enhanced the maturation and activation of macrophages. Further, it substantially augmented the secretion of IL-6, nitric oxide (NO) and antigen uptake. Moreover, macrophages exhibited remarkably higher bactericidal activity, as evidenced by reduction in the Mtb growth. Infergen-mediated mechanism was different from the type-1 interferons; since it worked through the activation of NF-κB, phosphorylation of STAT-3 and Akt-PI3K that improved the bactericidal activity through autophagy and NO release. In future, IFG immunotherapy can be a novel strategy for treating patients and controlling TB.
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Affiliation(s)
- Susanta Pahari
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, 160036, India
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India
| | - Nargis Khan
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, 160036, India
| | - Mohammad Aqdas
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, 160036, India
| | - Shikha Negi
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, 160036, India
| | - Jagdeep Kaur
- Department of Biotechnology, Panjab University, Chandigarh, 160014, India
| | - Javed N. Agrewala
- Immunology Laboratory, CSIR-Institute of Microbial Technology, Chandigarh, 160036, India
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21
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Wu SY, Wang LD, Li JL, Xu GM, He ML, Li YY, Huang R. Salmonella spv locus suppresses host innate immune responses to bacterial infection. FISH & SHELLFISH IMMUNOLOGY 2016; 58:387-396. [PMID: 27666190 DOI: 10.1016/j.fsi.2016.09.042] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 09/14/2016] [Accepted: 09/22/2016] [Indexed: 06/06/2023]
Abstract
Salmonella enterica serovar typhimurium (S. typhimurium) is globally distributed and causes massive morbidity and mortality in humans and animals. S. typhimurium carries Salmonella plasmid virulence (spv) locus, which is highly conserved and closely related to bacterial pathogenicity, while its exact role in host immune responses during infection remains to be elucidated. To counteract the invaders, the host has evolved numerous strategies, among which the innate immunity and autophagy act as the first defense. Recently, zebrafish has been universally accepted as a valuable and powerful vertebrate model in analyzing bacteria-host interactions. To investigate whether spv locus enhances the virulence of Salmonella by exerting an effect on the host early defense, zebrafish larvae were employed in this study. LD50 of S. typhimurium to zebrafish larvae and bacterial dissemination were analyzed. Sudan black B and neutral red staining were performed to detect the responses of neutrophils and macrophages to Salmonella infection. Autophagy agonist Torin1 and inhibitor Chloroquine were used to interfere in autophagic flux, and the protein level of Lc3 and p62 were measured by western blotting. Results indicated that spv locus could decrease the LD50 of S. typhimurium to zebrafish larvae, accelerate the reproduction and dissemination of bacteria by inhibiting the function of neutrophils and macrophages. Moreover, spv locus restrained the formation of autophagosomes in the earlier stage of autophagy. These findings suggested the virulence of spv locus involving in suppressing host innate immune responses for the first time, which shed new light on the role of spv operon in Salmonella pathogenicity.
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Affiliation(s)
- Shu-Yan Wu
- Medical College of Soochow University, Department of Medical Microbiology, No. 199, Ren Ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Li-Dan Wang
- Medical College of Soochow University, Department of Medical Microbiology, No. 199, Ren Ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Jin-Ling Li
- Medical College of Soochow University, Department of Medical Microbiology, No. 199, Ren Ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Guang-Mei Xu
- Medical College of Soochow University, Department of Medical Microbiology, No. 199, Ren Ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Mei-Ling He
- Medical College of Soochow University, Department of Medical Microbiology, No. 199, Ren Ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Yuan-Yuan Li
- Medical College of Soochow University, Department of Medical Microbiology, No. 199, Ren Ai Road, Suzhou, Jiangsu, 215123, PR China
| | - Rui Huang
- Medical College of Soochow University, Department of Medical Microbiology, No. 199, Ren Ai Road, Suzhou, Jiangsu, 215123, PR China.
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22
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Elshaer D, Begun J. The role of barrier function, autophagy, and cytokines in maintaining intestinal homeostasis. Semin Cell Dev Biol 2016; 61:51-59. [PMID: 27565684 DOI: 10.1016/j.semcdb.2016.08.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/10/2016] [Accepted: 08/22/2016] [Indexed: 02/06/2023]
Abstract
Intestinal homeostasis is maintained through the interplay of the intestinal mucosa, local and systemic immune factors, and the microbial content of the gut. The cellular processes of autophagy, endoplasmic reticulum stress, the unfolded protein response and regulation of reactive oxygen species production are required to maintain a balance between pro-inflammatory responses against potential pathogens and a tolerogenic response towards commensal bacteria. Intestinally active cytokines regulate innate immune pathways and cellular pathways within the gut mucosa. Disruption of these processes, or alterations in the cytokine milieu, can result in an improper response to the commensal gut microbial community leading to inappropriate inflammation characteristic of conditions such as inflammatory bowel disease.
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Affiliation(s)
- Dana Elshaer
- Immunity, Infection and Inflammation Program, Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia.
| | - Jakob Begun
- Immunity, Infection and Inflammation Program, Mater Research Institute - University of Queensland, Translational Research Institute, Woolloongabba, Queensland, Australia; University of Queensland School of Medicine, Brisbane, Queensland, Australia.
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23
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Patel U, Rajasingh S, Samanta S, Cao T, Dawn B, Rajasingh J. Macrophage polarization in response to epigenetic modifiers during infection and inflammation. Drug Discov Today 2016; 22:186-193. [PMID: 27554801 DOI: 10.1016/j.drudis.2016.08.006] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 07/14/2016] [Accepted: 08/12/2016] [Indexed: 12/17/2022]
Abstract
Macrophages are a heterogeneous population of phagocytic cells present in all tissues. Recently, several drugs that target the epigenetic machinery have emerged as attractive molecules for treating infection and inflammation by modulating macrophages. Treatment of lipopolysaccharide (LPS)-challenged macrophages with epigenetic modifiers leads to phenotype switching. This could provide stimulatory/destructive (M1) or suppressive/protective (M2) therapeutic strategies, which are crucial in the cytokine milieu in which the macrophages reside. In this review, we provide an overview of macrophage functional diversity during various diseases, including infection, as well as the current status in the development and clinical utility of epigenetic modifiers.
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Affiliation(s)
- Urmi Patel
- Department of Internal Medicine, Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Sheeja Rajasingh
- Department of Internal Medicine, Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Saheli Samanta
- Department of Internal Medicine, Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Thuy Cao
- Department of Internal Medicine, Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Buddhadeb Dawn
- Department of Internal Medicine, Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Johnson Rajasingh
- Department of Internal Medicine, Cardiovascular Research Institute, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
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24
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Chandra V, Bhagyaraj E, Nanduri R, Ahuja N, Gupta P. NR1D1 ameliorates Mycobacterium tuberculosis clearance through regulation of autophagy. Autophagy 2015; 11:1987-1997. [PMID: 26390081 PMCID: PMC4824569 DOI: 10.1080/15548627.2015.1091140] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 08/19/2015] [Accepted: 09/01/2015] [Indexed: 01/07/2023] Open
Abstract
NR1D1 (nuclear receptor subfamily 1, group D, member 1), an adopted orphan nuclear receptor, is widely known to orchestrate the expression of genes involved in various biological processes such as adipogenesis, skeletal muscle differentiation, and lipid and glucose metabolism. Emerging evidence suggests that various members of the nuclear receptor superfamily perform a decisive role in the modulation of autophagy. Recently, NR1D1 has been implicated in augmenting the antimycobacterial properties of macrophages and providing protection against Mycobacterium tuberculosis infection by downregulating the expression of the IL10 gene in human macrophages. This antiinfective property of NR1D1 suggests the need for an improved understanding of its role in other host-associated antimycobacterial pathways. The results presented here demonstrate that in human macrophages either ectopic expression of NR1D1 or treatment with its agonist, GSK4112, enhanced the number of acidic vacuoles as well as the level of MAP1LC3-II, a signature molecule for determination of autophagy progression, in a concentration- and time-dependent manner. Conversely, a decrease in NR1D1 in knockdown cells resulted in the reduced expression of lysosomal-associated membrane protein 1, LAMP1, commensurate with a decrease in the level of transcription factor EB, TFEB. This is indicative of that NR1D1 may have a regulatory role in lysosome biogenesis. NR1D1 being a repressor, its positive regulation on LAMP1 and TFEB is suggestive of an indirect byzantine mechanism of action. Its role in the modulation of autophagy and lysosome biogenesis together with its ability to repress IL10 gene expression supports the theory that NR1D1 has a pivotal antimycobacterial function in human macrophages.
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Affiliation(s)
- Vemika Chandra
- CSIR- Institute of Microbial Technology; Chandigarh, India
| | - Ella Bhagyaraj
- CSIR- Institute of Microbial Technology; Chandigarh, India
| | | | - Nancy Ahuja
- CSIR- Institute of Microbial Technology; Chandigarh, India
| | - Pawan Gupta
- CSIR- Institute of Microbial Technology; Chandigarh, India
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25
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Liu PF, Cheng JS, Sy CL, Huang WC, Yang HC, Gallo RL, Huang CM, Shu CW. IsaB Inhibits Autophagic Flux to Promote Host Transmission of Methicillin-Resistant Staphylococcus aureus. J Invest Dermatol 2015; 135:2714-2722. [PMID: 26134948 PMCID: PMC4641007 DOI: 10.1038/jid.2015.254] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Accepted: 06/17/2015] [Indexed: 12/19/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a major nosocomial pathogen that is widespread in both health-care facilities and in the community at large, as a result of direct host-to-host transmission. Several virulence factors are associated with pathogen transmission to naive hosts. Immunodominant surface antigen B (IsaB) is a virulence factor that helps Staphylococcus aureus to evade the host defense system. However, the mechanism of IsaB on host transmissibility remains unclear. We found that IsaB expression was elevated in transmissible MRSA. Wild-type isaB strains inhibited autophagic flux to promote bacterial survival and elicit inflammation in THP-1 cells and mouse skin. MRSA isolates with increased IsaB expression showed decreased autophagic flux, and the MRSA isolate with the lowest IsaB expression showed increased autophagic flux. In addition, recombinant IsaB rescued the virulence of the isaB deletion strain and increased the group A streptococcus (GAS) virulence in vivo. Together, these results reveal that IsaB diminishes autophagic flux, thereby allowing MRSA to evade host degradation. These findings suggest that IsaB is a suitable target for preventing or treating MRSA infection.
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Affiliation(s)
- Pei-Feng Liu
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
- Department of Medicine, Division of Dermatology, University of California, San Diego, USA
| | - Jin-Shiung Cheng
- Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Cheng-Len Sy
- Department of Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Wei-Chun Huang
- Cardiovascular Medical Center, Kaohsiung Veterans General Hospital, Kaohsiung City
- School of Medicine, National Yang-Ming University, Taipei City
| | - Hsiu-Chen Yang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Richard L. Gallo
- Department of Medicine, Division of Dermatology, University of California, San Diego, USA
- VA San Diego Healthcare Center, San Diego, USA
| | - Chun-Ming Huang
- Department of Medicine, Division of Dermatology, University of California, San Diego, USA
| | - Chih-Wen Shu
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
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26
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Jong CJ, Ito T, Schaffer SW. The ubiquitin-proteasome system and autophagy are defective in the taurine-deficient heart. Amino Acids 2015; 47:2609-22. [PMID: 26193770 DOI: 10.1007/s00726-015-2053-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 07/10/2015] [Indexed: 12/31/2022]
Abstract
Taurine depletion leads to impaired mitochondrial function, as characterized by reduced ATP production and elevated superoxide generation. These defects can fundamentally alter cardiomyocyte function and if left unchanged can result in cell death. To protect against these stresses, cardiomyocytes possess quality control processes, such as the ubiquitin-proteasome system (UPS) and autophagy, which can rejuvenate cells through the degradation of damaged proteins and organelles. Hence, the present study tested the hypothesis that reactive oxygen species generated by damaged mitochondria initiates UPS and autophagy in the taurine-deficient heart. Using transgenic mice lacking the taurine transporter (TauTKO) as a model of taurine deficiency, it was shown that the levels of ubiquitinated protein were elevated, an effect associated with a decrease in ATP-dependent 26S β5 proteasome activity. Treating the TauTKO mouse with the mitochondria-specific antioxidant, mitoTEMPO, largely abolished the increase in ubiquitinated protein content. The TauTKO heart was also associated with impaired autophagy, characterized by an increase in the initiator, Beclin-1, and autophagosome content, but a defect in the generation of active autophagolysosomes. Although mitoTEMPO treatment only restores the oxidative balance within the mitochondria, it appeared to completely disrupt the crosstalk between the damaged mitochondria and the quality control processes. Thus, mitochondrial oxidative stress is the main trigger initiating the quality control systems in the taurine-deficient heart. We conclude that the activation of the UPS and autophagy is another fundamental function of mitochondria.
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Affiliation(s)
- Chian Ju Jong
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, AL, 36688, USA
| | - Takashi Ito
- School of Pharmacy, Hyogo University of Health Sciences, Kobe, Japan
| | - Stephen W Schaffer
- Department of Pharmacology, University of South Alabama College of Medicine, Mobile, AL, 36688, USA.
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27
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Menon MB, Gaestel M. Sep(t)arate or not – how some cells take septin-independent routes through cytokinesis. J Cell Sci 2015; 128:1877-86. [PMID: 25690008 DOI: 10.1242/jcs.164830] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cytokinesis is the final step of cell division, and is a process that requires a precisely coordinated molecular machinery to fully separate the cytoplasm of the parent cell and to establish the intact outer cell barrier of the daughter cells. Among various cytoskeletal proteins involved, septins are known to be essential mediators of cytokinesis. In this Commentary, we present recent observations that specific cell divisions can proceed in the absence of the core mammalian septin SEPT7 and its Drosophila homolog Peanut (Pnut) and that thus challenge the view that septins have an essential role in cytokinesis. In the pnut mutant neuroepithelium, orthogonal cell divisions are successfully completed. Similarly, in the mouse, Sept7-null mutant early embryonic cells and, more importantly, planktonically growing adult hematopoietic cells undergo productive proliferation. Hence, as discussed here, mechanisms must exist that compensate for the lack of SEPT7 and the other core septins in a cell-type-specific manner. Despite there being crucial non-canonical immune-relevant functions of septins, septin depletion is well tolerated by the hematopoietic system. Thus differential targeting of cytokinesis could form the basis for more specific anti-proliferative therapies to combat malignancies arising from cell types that require septins for cytokinesis, such as carcinomas and sarcomas, without impairing hematopoiesis that is less dependent on septin.
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Affiliation(s)
- Manoj B Menon
- Institute of Physiological Chemistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Matthias Gaestel
- Institute of Physiological Chemistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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Proteomic analysis of the action of the Mycobacterium ulcerans toxin mycolactone: targeting host cells cytoskeleton and collagen. PLoS Negl Trop Dis 2014; 8:e3066. [PMID: 25101965 PMCID: PMC4125307 DOI: 10.1371/journal.pntd.0003066] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 06/20/2014] [Indexed: 12/21/2022] Open
Abstract
Buruli ulcer (BU) is a neglected tropical disease caused by Mycobacterium ulcerans. The tissue damage characteristic of BU lesions is known to be driven by the secretion of the potent lipidic exotoxin mycolactone. However, the molecular action of mycolactone on host cell biology mediating cytopathogenesis is not fully understood. Here we applied two-dimensional electrophoresis (2-DE) to identify the mechanisms of mycolactone's cellular action in the L929 mouse fibroblast proteome. This revealed 20 changed spots corresponding to 18 proteins which were clustered mainly into cytoskeleton-related proteins (Dync1i2, Cfl1, Crmp2, Actg1, Stmn1) and collagen biosynthesis enzymes (Plod1, Plod3, P4ha1). In line with cytoskeleton conformational disarrangements that are observed by immunofluorescence, we found several regulators and constituents of both actin- and tubulin-cytoskeleton affected upon exposure to the toxin, providing a novel molecular basis for the effect of mycolactone. Consistent with these cytoskeleton-related alterations, accumulation of autophagosomes as well as an increased protein ubiquitination were observed in mycolactone-treated cells. In vivo analyses in a BU mouse model revealed mycolactone-dependent structural changes in collagen upon infection with M. ulcerans, associated with the reduction of dermal collagen content, which is in line with our proteomic finding of mycolactone-induced down-regulation of several collagen biosynthesis enzymes. Our results unveil the mechanisms of mycolactone-induced molecular cytopathogenesis on exposed host cells, with the toxin compromising cell structure and homeostasis by inducing cytoskeleton alterations, as well as disrupting tissue structure, by impairing the extracellular matrix biosynthesis. Buruli Ulcer (BU) is a neglected tropical disease caused by Mycobacterium ulcerans infection. It has been recognized for many years that BU pathogenesis is mediated by the potent exotoxin mycolactone; however, the molecular action of this toxin on the host cell biology that drives its pathogenesis is not fully understood. Here we present a proteomic-based study that explores the molecular action of mycolactone on host cells biology. Our results provide further molecular evidence for the cytoskeleton-disarrangement induced by mycolactone, and unveil its impact on cytoskeleton-dependent cellular functions. Moreover, we extend the field of action of this toxin to the biosynthesis of collagen, implicating mycolactone on the decrease of dermal collagen found on BU lesions. Given the dependence of M. ulcerans virulence on its toxin, these findings on mycolactone's molecular action on host cells and tissues are of major importance for the understanding of BU pathogenesis.
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Chargui A, El May MV. Autophagy mediates neutrophil responses to bacterial infection. APMIS 2014; 122:1047-58. [PMID: 24735202 DOI: 10.1111/apm.12271] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 02/13/2014] [Indexed: 12/30/2022]
Abstract
Neutrophils constitute the first line of cellular defense against pathogens and autophagy is a fundamental cellular homeostasis pathway that operates with the intracellular degradation/recycling system. Induction of the autophagic process in neutrophils, in response to invading pathogens, constitutes a crucial mechanism in innate immunity. Exploration of autophagy has greatly progressed and diverse strategies have been reported for studying this molecular process in different biological systems; especially in infectious and inflammatory diseases. Furthermore, the role of autophagy in neutrophils, during pathogenic infection, continues to be of interest, due to the role of the cell in immunity function, its recruitment to the site of infection and its implication in inflammatory diseases. This review focuses on the known role of autophagy in neutrophils defence against pathogenic infections. A more detailed discussion will concern the recent findings highlighting the role of autophagy in inflammation and cell death in infected neutrophils.
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Affiliation(s)
- Abderrahman Chargui
- Laboratory of Histology, Embryology and Cell Biology, Faculty of Medicine, Tunis, Tunisia; Higher School of Agriculture, Kef, Tunisia
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30
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Autophagy in hepatic fibrosis. BIOMED RESEARCH INTERNATIONAL 2014; 2014:436242. [PMID: 24779010 PMCID: PMC3980865 DOI: 10.1155/2014/436242] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 01/18/2014] [Accepted: 01/21/2014] [Indexed: 02/07/2023]
Abstract
Hepatic fibrosis is a leading cause of morbidity and mortality worldwide. Hepatic fibrosis is usually associated with chronic liver diseases caused by infection, drugs, metabolic disorders, or autoimmune imbalances. Effective clinical therapies are still lacking. Autophagy is a cellular process that degrades damaged organelles or protein aggregation, which participates in many pathological processes including liver diseases. Autophagy participates in hepatic fibrosis by activating hepatic stellate cells and may participate as well through influencing other fibrogenic cells. Besides that, autophagy can induce some liver diseases to develop while it may play a protective role in hepatocellular abnormal aggregates related liver diseases and reduces fibrosis. With a better understanding of the potential effects of autophagy on hepatic fibrosis, targeting autophagy might be a novel therapeutic strategy for hepatic fibrosis in the near future.
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31
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Regulation of autophagy by the Rab GTPase network. Cell Death Differ 2014; 21:348-58. [PMID: 24440914 DOI: 10.1038/cdd.2013.187] [Citation(s) in RCA: 298] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 10/22/2013] [Accepted: 11/21/2013] [Indexed: 01/14/2023] Open
Abstract
Autophagy (macroautophagy) is a highly conserved intracellular and lysosome-dependent degradation process in which autophagic substrates are enclosed and degraded by a double-membrane vesicular structure in a continuous and dynamic vesicle transport process. The Rab protein is a small GTPase that belongs to the Ras-like GTPase superfamily and regulates the vesicle traffic process. Numerous Rab proteins have been shown to be involved in various stages of autophagy. Rab1, Rab5, Rab7, Rab9A, Rab11, Rab23, Rab32, and Rab33B participate in autophagosome formation, whereas Rab9 is required in non-canonical autophagy. Rab7, Rab8B, and Rab24 have a key role in autophagosome maturation. Rab8A and Rab25 are also involved in autophagy, but their role is unknown. Here, we summarize new findings regarding the involvement of Rabs in autophagy and provide insights regarding future research on the mechanisms of autophagy regulation.
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Vural A, Kehrl JH. Autophagy in macrophages: impacting inflammation and bacterial infection. SCIENTIFICA 2014; 2014:825463. [PMID: 24818040 PMCID: PMC4000662 DOI: 10.1155/2014/825463] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 02/28/2014] [Indexed: 05/09/2023]
Abstract
Macrophages are on the front line of host defense. They possess an array of germline-encoded pattern recognition receptors/sensors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) and which activate downstream effectors/pathways to help mediate innate immune responses and host defense. Innate immune responses include the rapid induction of transcriptional networks that trigger the production of cytokines, chemokines, and cytotoxic molecules; the mobilization of cells including neutrophils and other leukocytes; the engulfment of pathogens by phagocytosis and their delivery to lysosome for degradation; and the induction of autophagy. Autophagy is a catabolic process that normally maintains cellular homeostasis in a lysosome-dependent manner, but it also functions as a cytoprotective response that intersects with a variety of general stress-response pathways. This review focuses on the intimately linked molecular mechanisms that help govern the autophagic pathway and macrophage innate immune responses.
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Affiliation(s)
- Ali Vural
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 10, Room 11N214, Center Drive, MSC 1876, Bethesda, MD 20892, USA
| | - John H. Kehrl
- B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Building 10, Room 11N214, Center Drive, MSC 1876, Bethesda, MD 20892, USA
- *John H. Kehrl:
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Eaves-Pyles T, Patel J, Arigi E, Cong Y, Cao A, Garg N, Dhiman M, Pyles RB, Arulanandam B, Miller AL, Popov VL, Soong L, Carlsen ED, Coletta C, Szabo C, Almeida IC. Immunomodulatory and antibacterial effects of cystatin 9 against Francisella tularensis. Mol Med 2013; 19:263-75. [PMID: 23922243 DOI: 10.2119/molmed.2013.00081] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 08/01/2013] [Indexed: 12/26/2022] Open
Abstract
Cystatin 9 (CST9) is a member of the type 2 cysteine protease inhibitor family, which has been shown to have immunomodulatory effects that restrain inflammation, but its functions against bacterial infections are unknown. Here, we report that purified human recombinant (r)CST9 protects against the deadly bacterium Francisella tularensis (Ft) in vitro and in vivo. Macrophages infected with the Ft human pathogen Schu 4 (S4), then given 50 pg of rCST9 exhibited significantly decreased intracellular bacterial replication and increased killing via preventing the escape of S4 from the phagosome. Further, rCST9 induced autophagy in macrophages via the regulation of the mammalian target of rapamycin (mTOR) signaling pathways. rCST9 promoted the upregulation of macrophage proteins involved in antiinflammation and antiapoptosis, while restraining proinflammatory-associated proteins. Interestingly, the viability and virulence of S4 also was decreased directly by rCST9. In a mouse model of Ft inhalation, rCST9 significantly decreased organ bacterial burden and improved survival, which was not accompanied by excessive cytokine secretion or subsequent immune cell migration. The current report is the first to show the immunomodulatory and antimicrobial functions of rCST9 against Ft. We hypothesize that the attenuation of inflammation by rCST9 may be exploited for therapeutic purposes during infection.
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Affiliation(s)
- Tonyia Eaves-Pyles
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas 77555, USA.
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Deen NS, Huang SJ, Gong L, Kwok T, Devenish RJ. The impact of autophagic processes on the intracellular fate of Helicobacter pylori: more tricks from an enigmatic pathogen? Autophagy 2013; 9:639-52. [PMID: 23396129 DOI: 10.4161/auto.23782] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori is a Gram-negative pathogen that colonizes the gastric epithelium of 50-60% of the world's population. Approximately one-fifth of the infected individuals manifest severe diseases such as peptic ulcers or gastric cancer. H. pylori infection has proven difficult to cure despite intensive antibiotic treatment. One possible reason for the relatively high resistance to antimicrobial therapy is the ability of H. pylori to reside inside host cells. Although considered by most as an extracellular pathogen, H. pylori can invade both gastric epithelial cells and immunocytes to some extent. The intracellular survival of H. pylori has been implicated in its ability to persist in the stomach, evade host immune responses and resist eradication by membrane-impermeable antibiotics. Interestingly, recent evidence suggests that macroautophagy, a cellular self-degradation process characterized by the formation of double-membraned autophagosomes, plays an important role in determining the intracellular fate of H. pylori. Detailed understanding of the interaction between H. pylori and host cell autophagic processes is anticipated to provide novel insights into the molecular mechanisms of macroautophagy and H. pylori pathogenesis, opening new avenues for the therapeutic intervention of autophagy-related and H. pylori-related disorders.
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Affiliation(s)
- Nadia S Deen
- Department of Biochemistry and Molecular Biology, Monash University, Clayton Campus, Victoria, Australia
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