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Tan YJ, Jin Y, Zhou J, Yang YF. Lipid droplets in pathogen infection and host immunity. Acta Pharmacol Sin 2024; 45:449-464. [PMID: 37993536 PMCID: PMC10834987 DOI: 10.1038/s41401-023-01189-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/30/2023] [Indexed: 11/24/2023] Open
Abstract
As the hub of cellular lipid metabolism, lipid droplets (LDs) have been linked to a variety of biological processes. During pathogen infection, the biogenesis, composition, and functions of LDs are tightly regulated. The accumulation of LDs has been described as a hallmark of pathogen infection and is thought to be driven by pathogens for their own benefit. Recent studies have revealed that LDs and their subsequent lipid mediators contribute to effective immunological responses to pathogen infection by promoting host stress tolerance and reducing toxicity. In this comprehensive review, we delve into the intricate roles of LDs in governing the replication and assembly of a wide spectrum of pathogens within host cells. We also discuss the regulatory function of LDs in host immunity and highlight the potential for targeting LDs for the diagnosis and treatment of infectious diseases.
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Affiliation(s)
- Yan-Jie Tan
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, 250014, China
| | - Yi Jin
- Research Center of Translational Medicine, Central Hospital Affiliated to Shandong First Medical University, Jinan, 250013, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, 250014, China.
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin, 300071, China.
| | - Yun-Fan Yang
- Department of Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, 250012, China.
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2
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Prado LG, Camara NOS, Barbosa AS. Cell lipid biology in infections: an overview. Front Cell Infect Microbiol 2023; 13:1148383. [PMID: 37868347 PMCID: PMC10587689 DOI: 10.3389/fcimb.2023.1148383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 09/22/2023] [Indexed: 10/24/2023] Open
Abstract
Lipids are a big family of molecules with a vast number of functions in the cell membranes, within the cytoplasm, and extracellularly. Lipid droplets (LDs) are the most common storage organelles and are present in almost every tissue type in the body. They also have structural functions serving as building blocks of cellular membranes and may be precursors of other molecules such as hormones, and lipoproteins, and as messengers in signal transduction. Fatty acids (FAs), such as sterol esters and triacylglycerols, are stored in LDs and are used in β-oxidation as fuel for tricarboxylic acid cycle (TCA) and adenosine triphosphate (ATP) generation. FA uptake and entrance in the cytoplasm are mediated by membrane receptors. After a cytoplasmic round of α- and β-oxidation, FAs are guided into the mitochondrial matrix by the L-carnitine shuttle system, where they are fully metabolized, and enter the TCA cycle. Pathogen infections may lead to impaired lipid metabolism, usage of membrane phospholipids, and LD accumulation in the cytoplasm of infected cells. Otherwise, bacterial pathogens may use lipid metabolism as a carbon source, thus altering the reactions and leading to cellular and organelles malfunctioning. This review aims to describe cellular lipid metabolism and alterations that occur upon infections.
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Affiliation(s)
- Luan Gavião Prado
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, Brazil
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Niels Olsen Saraiva Camara
- Laboratório de Imunobiologia de Transplantes, Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
- Disciplina de Nefrologia, Departamento de Medicina, Universidade Federal de São Paulo, São Paulo, Brazil
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Safi R, Sánchez-Álvarez M, Bosch M, Demangel C, Parton RG, Pol A. Defensive-lipid droplets: Cellular organelles designed for antimicrobial immunity. Immunol Rev 2023; 317:113-136. [PMID: 36960679 DOI: 10.1111/imr.13199] [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: 03/25/2023]
Abstract
Microbes have developed many strategies to subvert host organisms, which, in turn, evolved several innate immune responses. As major lipid storage organelles of eukaryotes, lipid droplets (LDs) are an attractive source of nutrients for invaders. Intracellular viruses, bacteria, and protozoan parasites induce and physically interact with LDs, and the current view is that they "hijack" LDs to draw on substrates for host colonization. This dogma has been challenged by the recent demonstration that LDs are endowed with a protein-mediated antibiotic activity, which is upregulated in response to danger signals and sepsis. Dependence on host nutrients could be a generic "Achilles' heel" of intracellular pathogens and LDs a suitable chokepoint harnessed by innate immunity to organize a front-line defense. Here, we will provide a brief overview of the state of the conflict and discuss potential mechanisms driving the formation of the 'defensive-LDs' functioning as hubs of innate immunity.
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Affiliation(s)
- Rémi Safi
- Lipid Trafficking and Disease Group, Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
- Josep Carreras Leukemia Research Institute, Barcelona, Spain
| | - Miguel Sánchez-Álvarez
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Instituto de Investigaciones Biomédicas Alberto Sols (IIB), Madrid, Spain
| | - Marta Bosch
- Lipid Trafficking and Disease Group, Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
- Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain
| | - Caroline Demangel
- Immunobiology and Therapy Unit, Institut Pasteur, Université Paris Cité, INSERM U1224, Paris, France
| | - Robert G Parton
- Institute for Molecular Bioscience (IMB), Brisbane, Queensland, Australia
- Centre for Microscopy and Microanalysis (CMM), University of Queensland, Brisbane, Queensland, Australia
| | - Albert Pol
- Lipid Trafficking and Disease Group, Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
- Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
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4
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Liu Y, Han L, Zhu P, Song M, Zhang Y, Meng L, Zhang W, Zhang C, Zhong M. PTPN2 targets TAK1 for dephosphorylation to improve cellular senescence and promote adipose tissue browning in T2DM. Front Pharmacol 2023; 14:1124633. [PMID: 37251330 PMCID: PMC10213551 DOI: 10.3389/fphar.2023.1124633] [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: 12/15/2022] [Accepted: 04/19/2023] [Indexed: 05/31/2023] Open
Abstract
Introduction: The energy imbalance when energy intake exceeds expenditure acts as an essential factor in the development of insulin resistance (IR). The activity of brown adipose tissue, which is involved in the dissipation of energy via heat expenditure decreases under type 2 diabetic mellitus (T2DM) state when the number of pathological aging adipocytes increases. Protein tyrosine phosphatase non-receptor type 2 (PTPN2) regulates several biological processes by dephosphorylating several cellular substrates; however, whether PTPN2 regulates cellular senescence in adipocytes and the underlying mechanism has not been reported. Methods: We constructed a model of type 2 diabetic mice with PTPN2 overexpression to explore the role of PTPN2 in T2DM. Results: We revealed that PTPN2 facilitated adipose tissue browning by alleviating pathological senescence, thus improving glucose tolerance and IR in T2DM. Mechanistically, we are the first to report that PTPN2 could bind with transforming growth factor-activated kinase 1 (TAK1) directly for dephosphorylation to inhibit the downstream MAPK/NF-κB pathway in adipocytes and regulate cellular senescence and the browning process subsequently. Discussion: Our study revealed a critical mechanism of adipocytes browning progression and provided a potential target for the treatment of related diseases.
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Affiliation(s)
- Yapeng Liu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Lu Han
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
- Department of General Practice, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Ping Zhu
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Ming Song
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Yaoyuan Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Linlin Meng
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Wei Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Cheng Zhang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Ming Zhong
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine, Department of Cardiology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
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Barthelemy J, Bogard G, Wolowczuk I. Beyond energy balance regulation: The underestimated role of adipose tissues in host defense against pathogens. Front Immunol 2023; 14:1083191. [PMID: 36936928 PMCID: PMC10019896 DOI: 10.3389/fimmu.2023.1083191] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/09/2023] [Indexed: 03/06/2023] Open
Abstract
Although the adipose tissue (AT) is a central metabolic organ in the regulation of whole-body energy homeostasis, it is also an important endocrine and immunological organ. As an endocrine organ, AT secretes a variety of bioactive peptides known as adipokines - some of which have inflammatory and immunoregulatory properties. As an immunological organ, AT contains a broad spectrum of innate and adaptive immune cells that have mostly been studied in the context of obesity. However, overwhelming evidence supports the notion that AT is a genuine immunological effector site, which contains all cell subsets required to induce and generate specific and effective immune responses against pathogens. Indeed, AT was reported to be an immune reservoir in the host's response to infection, and a site of parasitic, bacterial and viral infections. In addition, besides AT's immune cells, preadipocytes and adipocytes were shown to express innate immune receptors, and adipocytes were reported as antigen-presenting cells to regulate T-cell-mediated adaptive immunity. Here we review the current knowledge on the role of AT and AT's immune system in host defense against pathogens. First, we will summarize the main characteristics of AT: type, distribution, function, and extraordinary plasticity. Second, we will describe the intimate contact AT has with lymph nodes and vessels, and AT immune cell composition. Finally, we will present a comprehensive and up-to-date overview of the current research on the contribution of AT to host defense against pathogens, including the respiratory viruses influenza and SARS-CoV-2.
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Affiliation(s)
| | | | - Isabelle Wolowczuk
- Univ. Lille, Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (Inserm), Centre Hospitalier Universitaire de Lille (CHU Lille), Institut Pasteur de Lille, U1019 - UMR 9017 - Center for Infection and Immunity of Lille (CIIL), Lille, France
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6
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Zhang W, Zhang Y, Zhu Q. Cigarette smoke extract-mediated FABP4 upregulation suppresses viability and induces apoptosis, inflammation and oxidative stress of bronchial epithelial cells by activating p38 MAPK/MK2 signaling pathway. J Inflamm (Lond) 2022; 19:7. [PMID: 35706027 PMCID: PMC9202166 DOI: 10.1186/s12950-022-00304-z] [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: 09/10/2021] [Accepted: 06/06/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Long-term inhalation of cigarette smoke is considered to be one of the main causes of bronchial epithelioid cell damage, but its underlying mechanism has to be further clarified.
Methods
Gene expression at mRNA level and protein levels were detected by qRT-PCR and western blot analysis respectively. CCK-8, TUNEL assays, ELISA, western blot analysis and commercial kits were utilized to test cell viability, apoptosis inflammatory response and oxidative stress. The correlation between fatty acid binding protein 4 (FABP4) and the p38 mitogen-activated protein kinase (MAPK)/MAPK activated kinase 2 (MK2) signaling pathway was verified by western blot analysis and rescue assays.
Results
Cigarette smoke extract (CSE) exposure decreased viability, induced apoptosis and inflammatory response in 16HBE cells. Moreover, the expression of FABP4 in CSE-treated 16HBE cells was up-regulated in a time and dose-dependent manner. Ablation of FABP4 in 16HBE cells significantly protected against CSE-mediated cell viability decline and apoptosis. Further, FABP4 knockdown suppressed inflammatory response by down-regulating the elevated levels of cellular inflammatory factors including TNF-α, IL-1β, IL-6, Cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNOS) in CSE-treated 16HBE cells. The oxidative stress induced by CSE in 16HBE cells was also inhibited by FABP4 silence as evidence by reduced ROS and MDA level but increased SOD activity caused by FABP4 silence. Finally, all the above effects of FABP4 silence on CSE-treated 16HBE cells were reversed by asiatic acid, an agonist of p38 mitogen-activated protein kinase (MAPK).
Conclusions
The up-regulation of FABP4 expression mediated by CSE exerted pro-inflammatory, pro-oxidative stress and pro-apoptotic effects on bronchial epithelial cells by activating the p38 MAPK/MK2 signaling pathway. Our findings help to further understand the underlying mechanism of cigarette smoke-induced bronchial inflammation.
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López-Ortega O, Moreno-Corona NC, Cruz-Holguin VJ, Garcia-Gonzalez LD, Helguera-Repetto AC, Romero-Valdovinos M, Arevalo-Romero H, Cedillo-Barron L, León-Juárez M. The Immune Response in Adipocytes and Their Susceptibility to Infection: A Possible Relationship with Infectobesity. Int J Mol Sci 2022; 23:ijms23116154. [PMID: 35682832 PMCID: PMC9181511 DOI: 10.3390/ijms23116154] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/25/2022] [Accepted: 05/27/2022] [Indexed: 02/01/2023] Open
Abstract
The current obesity pandemic has been expanding in both developing and developed countries. This suggests that the factors contributing to this condition need to be reconsidered since some new factors are arising as etiological causes of this disease. Moreover, recent clinical and experimental findings have shown an association between the progress of obesity and some infections, and the functions of adipose tissues, which involve cell metabolism and adipokine release, among others. Furthermore, it has recently been reported that adipocytes could either be reservoirs for these pathogens or play an active role in this process. In addition, there is abundant evidence indicating that during obesity, the immune system is exacerbated, suggesting an increased susceptibility of the patient to the development of several forms of illness or death. Thus, there could be a relationship between infection as a trigger for an increase in adipose cells and the impact on the metabolism that contributes to the development of obesity. In this review, we describe the findings concerning the role of adipose tissue as a mediator in the immune response as well as the possible role of adipocytes as infection targets, with both roles constituting a possible cause of obesity.
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Affiliation(s)
- Orestes López-Ortega
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, 75015 Paris, France;
| | - Nidia Carolina Moreno-Corona
- Laboratory of Human Lymphohematopoiesis, Imagine Institute, INSERM UMR 1163, Université de Paris, 75015 Paris, France;
| | - Victor Javier Cruz-Holguin
- Departamento de Immunobioquímica, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Ciudad de México 11000, Mexico; (V.J.C.-H.); (L.D.G.-G.); (A.C.H.-R.)
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Av. Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Mexico City 07360, Mexico;
| | - Luis Didier Garcia-Gonzalez
- Departamento de Immunobioquímica, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Ciudad de México 11000, Mexico; (V.J.C.-H.); (L.D.G.-G.); (A.C.H.-R.)
| | - Addy Cecilia Helguera-Repetto
- Departamento de Immunobioquímica, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Ciudad de México 11000, Mexico; (V.J.C.-H.); (L.D.G.-G.); (A.C.H.-R.)
| | - Mirza Romero-Valdovinos
- Departamento de Biología Molecular e Histocompatibilidad, Hospital General “Dr. Manuel Gea González”, Calzada de Tlalpan 4800, Col. Sección XVI, Ciudad de México 14080, Mexico;
| | - Haruki Arevalo-Romero
- Laboratorio de Inmunología y Microbiología Molecular, División Académica Multidisciplinaria de Jalpa de Méndez, Jalpa de Méndez 86205, Mexico;
| | - Leticia Cedillo-Barron
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Av. Instituto Politécnico Nacional 2508, San Pedro Zacatenco, Mexico City 07360, Mexico;
| | - Moisés León-Juárez
- Departamento de Immunobioquímica, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Ciudad de México 11000, Mexico; (V.J.C.-H.); (L.D.G.-G.); (A.C.H.-R.)
- Correspondence:
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Chlamydia psittaci Induces Autophagy in Human Bronchial Epithelial Cells via PERK and IRE1α, but Not ATF6 Pathway. Infect Immun 2022; 90:e0007922. [PMID: 35435728 DOI: 10.1128/iai.00079-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chlamydia psittaci is an important pathogen that causes chronic and atypical pneumonia in humans. Autophagy and the unfolded protein response (UPR) are important mechanisms for regulating the growth of infectious parasitic pathogens in living cells. Here, we explored whether C. psittaci infection induced autophagy via the UPR and the effect of these cellular responses on the survival and replication of C. psittaci in human bronchial epithelial cells (HBEs). Not only were the numbers of autophagosomes and the expression of LC3-II and Beclin1 increased following C. psittaci infection of HBEs, but also the expression of p62 (also called sequestosome-1) was downregulated. Moreover, after C. psittaci infection, the UPR and UPR sensors PERK/eIF2α and IRE1α/XBP1 were activated, but not the ATF6 pathway. When either Bip siRNA was used to block normal initiation of the UPR, or activation of the PERK and IER1α pathways was blocked with specific inhibitors GSK2606414 and 4μ8C, the level of autophagy caused by C. psittaci infection was significantly inhibited. Furthermore, blocking activation of the UPR and associated pathways significantly reduced the number of C. psittaci inclusions. Our research suggests that the UPR, via the PERK and IRE1α, but not ATF6 signaling pathways, regulates HBE-cell autophagy induced by C. psittaci infection and the replication of C. psittaci.
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Chlamydia pneumoniae Interferes with Macrophage Differentiation and Cell Cycle Regulation to Promote Its Replication. Cell Microbiol 2022. [DOI: 10.1155/2022/9854449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Chlamydia pneumoniae is a ubiquitous intracellular bacterium which infects humans via the respiratory route. The tendency of C. pneumoniae to persist in monocytes and macrophages is well known, but the underlying host-chlamydial interactions remain elusive. In this work, we have described changes in macrophage intracellular signaling pathways induced by C. pneumoniae infection. Label-free quantitative proteome analysis and pathway analysis tools were used to identify changes in human THP-1-derived macrophages upon C. pneumoniae CV6 infection. At 48-h postinfection, pathways associated to nuclear factor κB (NF-κB) regulation were stressed, while negative regulation on cell cycle control was prominent at both 48 h and 72 h. Upregulation of S100A8 and S100A9 calcium binding proteins, osteopontin, and purine nucleoside hydrolase, laccase domain containing protein 1 (LACC1) underlined the proinflammatory consequences of the infection, while elevated NF-κB2 levels in infected macrophages indicates interaction with the noncanonical NF-κB pathway. Infection-induced alteration of cell cycle control was obvious by the downregulation of mini chromosome maintenance (MCM) proteins MCM2-7, and the significance of host cell cycle regulation for C. pneumoniae replication was demonstrated by the ability of a cyclin-dependent kinase (CDK) 4/6 inhibitor Palbociclib to promote C. pneumoniae replication and infectious progeny production. The infection was found to suppress retinoblastoma expression in the macrophages in both protein and mRNA levels, and this change was reverted by treatment with a histone deacetylase inhibitor. The epigenetic suppression of retinoblastoma, along with upregulation of S100A8 and S100A9, indicate host cell changes associated with myeloid-derived suppressor cell (MDSC) phenotype.
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10
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Wang XW, Sun YJ, Chen X, Zhang WZ. Interleukin-4-induced FABP4 promotes lipogenesis in human skeletal muscle cells by activating the PPAR γ signaling pathway. Cell Biochem Biophys 2022; 80:355-366. [PMID: 35122221 DOI: 10.1007/s12013-022-01063-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 01/26/2022] [Indexed: 11/03/2022]
Abstract
Chronic low back pain (CLBP) is a common symptom of lumbar degenerative disease. Degeneration of the lumbar paravertebral muscles causes a loss of muscle mass and strength, which is a vital factor causing CLBP and often accompanied by lipid infiltration. Tandem mass spectrometry (TMT) was used to identify differentially expressed proteins in lipid-infiltrated and normal muscles. The results show that fatty acid binding protein 4 (FABP4) participated in the peroxisome proliferator-activated receptor-γ (PPAR γ) signaling pathway as an up-regulated protein, which is related to lipogenesis in diverse cells. In addition, chronic inflammation is believed to be involved in lumbar muscle degeneration and lipogenesis, with interleukin-4 (IL-4) considered as the predominant contributor. In present study, we investigate the effect of FABP4 on lipogenesis in human skeletal muscle cells (HSMCs) stimulated by Interleukin-4 (IL-4) and explore the mechanistic basis. We found expression level of FABP4 in lipid-infiltrated muscles was significantly higher than that in normal muscles. Lipogenesis in HSMCs could be increased by IL-4 treatment, as well as by FABP4 overexpression. FABP4 inhibition suppressed IL-4-mediated lipogenesis in HSMCs, whereas the PPAR γ inhibitor alleviated lipogenesis in both IL-4-treated and FABP4-overexpressed HSMCs. Collectively, the results indicate that FABP4 induces lipogenesis in HSMCs stimulated with IL-4 via activating the PPAR γ signaling pathway. Our study offers a detailed perspective on the pathogenesis of muscle lipid infiltration and provides a potential target for the clinical treatment strategy of muscle lipid infiltration and CLBP.
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Affiliation(s)
- Xin-Wen Wang
- Spine Center, Department of Orthopedics, Provincial Hospital Affiliated to Anhui Medical University, Hefei, 230001, China
| | - Yong-Jin Sun
- Spine Center, Department of Orthopedics, Provincial Hospital Affiliated to Anhui Medical University, Hefei, 230001, China
| | - Xiao Chen
- Spine Center, Department of Orthopedics, Provincial Hospital Affiliated to Anhui Medical University, Hefei, 230001, China
| | - Wen-Zhi Zhang
- Spine Center, Department of Orthopedics, Provincial Hospital Affiliated to Anhui Medical University, Hefei, 230001, China.
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11
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Allen PE, Noland RC, Martinez JJ. Rickettsia conorii survival in THP-1 macrophages involves host lipid droplet alterations and active rickettsial protein production. Cell Microbiol 2021; 23:e13390. [PMID: 34464019 DOI: 10.1111/cmi.13390] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 08/25/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022]
Abstract
Rickettsia conorii is a Gram-negative, cytosolic intracellular bacterium that has classically been investigated in terms of endothelial cell infection. However, R. conorii and other human pathogenic Rickettsia species have evolved mechanisms to grow in various cell types, including macrophages, during mammalian infection. During infection of these phagocytes, R. conorii shifts the host cell's overall metabolism towards an anti-inflammatory M2 response, metabolically defined by an increase in host lipid metabolism and oxidative phosphorylation. Lipid metabolism has more recently been identified as a key regulator of host homeostasis through modulation of immune signalling and metabolism. Intracellular pathogens have adapted mechanisms of hijacking host metabolic pathways including host lipid catabolic pathways for various functions required for growth and survival. In the present study, we hypothesised that alterations of host lipid droplets initiated by lipid catabolic pathways during R. conorii infection is important for bacterial survival in macrophages. Herein, we determined that host lipid droplet modulation is initiated early during R. conorii infection, and these alterations rely on active bacteria and lipid catabolic pathways. We also find that these lipid catabolic pathways are essential for efficient bacterial survival. Unlike the mechanisms used by other intracellular pathogens, the catabolism of lipid droplets induced by R. conorii infection is independent of upstream host peroxisome proliferator-activated receptor-alpha (PPARα) signalling. Inhibition of PPARɣ signalling and lipid droplet accumulation in host cells cause a significant decrease in R. conorii survival suggesting a negative correlation with lipid droplet production and R. conorii survival. Together, these results strongly suggest that the modulation of lipid droplets in macrophage cells infected by R. conorii is an important and underappreciated aspect of the infection process. TAKE AWAYS: Host lipid droplets are differentially altered in early and replicative stages of THP-1 macrophage infection with R. conorii. Lipid droplet alterations are initiated in a bacterial-dependent manner and do not require host peroxisome proliferator-activated receptors α or ɣ activation. Pharmacological inhibition of host lipid catabolic processes during R. conorii infection indicates a requirement of lipid catabolism for bacterial survival and initiation of lipid droplet modulation. A significant increase in host lipid droplets during infection has a negative impact on R. conorii survival in THP-1 macrophages.
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Affiliation(s)
- Paige E Allen
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, Louisiana, USA
| | - Robert C Noland
- Skeletal Muscle Metabolism Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA
| | - Juan J Martinez
- Vector Borne Disease Laboratories, Department of Pathobiological Sciences, LSU School of Veterinary Medicine, Baton Rouge, Louisiana, USA
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Allen PE, Martinez JJ. Modulation of Host Lipid Pathways by Pathogenic Intracellular Bacteria. Pathogens 2020; 9:pathogens9080614. [PMID: 32731350 PMCID: PMC7460438 DOI: 10.3390/pathogens9080614] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 07/17/2020] [Accepted: 07/25/2020] [Indexed: 12/22/2022] Open
Abstract
Lipids are a broad group of molecules required for cell maintenance and homeostasis. Various intracellular pathogens have developed mechanisms of modulating and sequestering host lipid processes for a large array of functions for both bacterial and host cell survival. Among the host cell lipid functions that intracellular bacteria exploit for infection are the modulation of host plasma membrane microdomains (lipid rafts) required for efficient bacterial entry; the recruitment of specific lipids for membrane integrity of intracellular vacuoles; and the utilization of host lipid droplets for the regulation of immune responses and for energy production through fatty acid β-oxidation and oxidative phosphorylation. The majority of published studies on the utilization of these host lipid pathways during infection have focused on intracellular bacterial pathogens that reside within a vacuole during infection and, thus, have vastly different requirements for host lipid metabolites when compared to those intracellular pathogens that are released into the host cytosol upon infection. Here we summarize the mechanisms by which intracellular bacteria sequester host lipid species and compare the modulation of host lipid pathways and metabolites during host cell infection by intracellular pathogens residing in either a vacuole or within the cytosol of infected mammalian cells. This review will also highlight common and unique host pathways necessary for intracellular bacterial growth that could potentially be targeted for therapeutic intervention.
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13
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Evaluation of the Relationship between Adipose Metabolism Patterns and Secretion of Appetite-Related Endocrines on Chicken. Animals (Basel) 2020; 10:ani10081282. [PMID: 32727133 PMCID: PMC7460314 DOI: 10.3390/ani10081282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 12/22/2022] Open
Abstract
Simple Summary The weight of an animal conforms to a certain growth pattern. Among others, feed, environment, and body composition, in addition to genetics, affect the animal’s feed consumption and body weight. Under normal circumstances, the body weight of an animal is mainly affected by feed intake, and body composition may significantly influence feed intake. Therefore, this report sets out the effects of fat accumulation on lipid metabolism and appetite, and finally introduces the effects of feeding patterns on animal feed intake. Abstract In addition to the influence of genes, the quality of poultry products is mainly controlled by the rearing environment or feed composition during rearing, and has to meet human use and economical needs. As the only source of energy for poultry, feed considerably affects the metabolic pattern of poultry and further affects the regulation of appetite-related endocrine secretion in poultry. Under normal circumstances, the accumulation of lipid in adipose reduces feed intake in poultry and increases the rate of adipose metabolism. When the adipose content in cells decreases, endocrines that promote food intake are secreted and increase nutrient concentrations in serum and cells. By regulating the balance between appetite and adipose metabolism, the poultry’s growth and posture can maintain a balanced state. In addition, increasing fiber composition in feed can effectively increase poultry welfare, body weight, lean composition and antioxidant levels in poultry. According to this, the concept that proper fiber content should be added to feed should be considered for better economic benefits, poultry welfare and meat productivity.
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14
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Walenna NF, Kurihara Y, Chou B, Ishii K, Soejima T, Hiromatsu K. Chlamydia pneumoniae infection-induced endoplasmic reticulum stress causes fatty acid-binding protein 4 secretion in murine adipocytes. J Biol Chem 2020; 295:2713-2723. [PMID: 31992597 DOI: 10.1074/jbc.ra119.010683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 01/23/2020] [Indexed: 12/28/2022] Open
Abstract
Fatty acid-binding protein 4 (FABP4) is predominantly expressed in adipocytes and macrophages and regulates metabolic and inflammatory pathways. FABP4 is secreted from adipocytes during lipolysis, and elevated circulating FABP4 levels are associated with obesity, metabolic disease, and cardiac dysfunction. We previously reported that the bacterial respiratory pathogen Chlamydia pneumoniae infects murine adipocytes and exploits host FABP4 to mobilize fat and replicate within adipocytes. However, whether C. pneumoniae induces FABP4 secretion from adipocytes has not been determined. Here, we show that FABP4 is actively secreted by murine adipocytes upon C. pneumoniae infection. Chemical inhibition of lipase activity and genetic deficiency of hormone-sensitive lipase blocked FABP4 secretion from C. pneumoniae-infected adipocytes. Mechanistically, C. pneumoniae infection induced endoplasmic reticulum (ER) stress and the unfolded protein response (UPR), resulting in elevated levels of mitochondrial reactive oxygen species and cytosolic Ca2+ Of note, exposure to a mitochondrial reactive oxygen species-specific scavenger, MitoTEMPO, reduced FABP4 release from C. pneumoniae-infected adipocytes. Furthermore, treatment with azoramide, which protects cells against ER stress, decreased FABP4 release from C. pneumoniae-infected adipocytes. Using gene silencing of CHOP (C/EBP homologous protein), a central regulator of ER stress, we further validated the role of C. pneumoniae infection-induced ER stress/UPR in promoting FABP4 secretion. Overall, these results indicate that C. pneumoniae infection robustly induces FABP4 secretion from adipocytes by stimulating ER stress/UPR. Our findings shed additional light on the etiological link between C. pneumoniae infection and metabolic syndrome.
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Affiliation(s)
- Nirwana Fitriani Walenna
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan; Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan
| | - Yusuke Kurihara
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Bin Chou
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Kazunari Ishii
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Toshinori Soejima
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan
| | - Kenji Hiromatsu
- Department of Microbiology & Immunology, Fukuoka University Faculty of Medicine, Fukuoka 814-0180, Japan.
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15
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Kumar R, Derbigny WA. TLR3 Deficiency Leads to a Dysregulation in the Global Gene-Expression Profile in Murine Oviduct Epithelial Cells Infected with Chlamydia muridarum. ACTA ACUST UNITED AC 2020; 1:1-13. [PMID: 31891165 PMCID: PMC6937138 DOI: 10.18689/ijmr-1000101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Chlamydia trachomatis replicates primarily in the epithelial cells lining the genital tract and induces the innate immune response by triggering cellular pathogen recognition receptors (PRRs). Our previous studies showed that Toll-like receptor 3 (TLR3) is expressed in murine oviduct epithelial (OE) cells, is the primary PRR triggered by C. muridarum (Cm) early during infection to induce IFN-β synthesis, and that TLR3 signaling regulates the chlamydial induced synthesis of a plethora of other innate inflammatory modulators including IL-6, CXCL10, CXCL16 and CCL5. We also showed that the expression of these cytokines induced by Chlamydia was severely diminished during TLR3 deficiency; however, the replication of Chlamydiain TLR3 deficient OE cells was more robust than in WT cells. These data suggested that TLR3 had a biological impact on the inflammatory response to Chlamydia infection; however, the global effects of TLR3 signaling in the cellular response to Chlamydia infection in murine OE cells has not yet been investigated. To determine the impact of TLR3 signaling on Chlamydia infection in OE cell at the transcriptome level, we infected wild-type (OE-WT) and TLR3-deficient (OE-TLR3KO) cells with Cm, and performed transcriptome analyses using microarray. Genome-wide expression and ingenuity pathway analysis (IPA) identified enhanced expression of host genes encoding for components found in multiple cellular processes encompassing: (1) pro-inflammatory, (2) cell adhesion, (3) chemoattraction, (4) cellular matrix and small molecule transport, (5) apoptosis, and (6) antigen-processing and presentation. These results support a role for TLR3 in modulating the host cellular responses to Cm infection that extend beyond inflammation and fibrosis, and shows that TLR3 could serve a potential therapeutic target for drug and/or vaccine development.
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Affiliation(s)
- Ramesh Kumar
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana-46202, USA
| | - Wilbert A Derbigny
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana-46202, USA
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16
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Lipid Droplets: A Significant but Understudied Contributor of Host⁻Bacterial Interactions. Cells 2019; 8:cells8040354. [PMID: 30991653 PMCID: PMC6523240 DOI: 10.3390/cells8040354] [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: 03/10/2019] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 12/13/2022] Open
Abstract
Lipid droplets (LDs) are cytosolic lipid storage organelles that are important for cellular lipid metabolism, energy homeostasis, cell signaling, and inflammation. Several bacterial, viral and protozoal pathogens exploit host LDs to promote infection, thus emphasizing the importance of LDs at the host–pathogen interface. In this review, we discuss the thus far reported relation between host LDs and bacterial pathogens including obligate and facultative intracellular bacteria, and extracellular bacteria. Although there is less evidence for a LD–extracellular bacterial interaction compared to interactions with intracellular bacteria, in this review, we attempt to compare the bacterial mechanisms that target LDs, the host signaling pathways involved and the utilization of LDs by these bacteria. Many intracellular bacteria employ unique mechanisms to target host LDs and potentially obtain nutrients and lipids for vacuolar biogenesis and/or immune evasion. However, extracellular bacteria utilize LDs to either promote host tissue damage or induce host death. We also identify several areas that require further investigation. Along with identifying LD interactions with bacteria besides the ones reported, the precise mechanisms of LD targeting and how LDs benefit pathogens should be explored for the bacteria discussed in the review. Elucidating LD–bacterial interactions promises critical insight into a novel host–pathogen interaction.
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Abstract
Fatty acid-binding proteins (FABPs), a family of lipid chaperones, contribute to systemic metabolic regulation via several lipid signaling pathways. Fatty acid-binding protein 4 (FABP4), known as adipocyte FABP (A-FABP) or aP2, is mainly expressed in adipocytes and macrophages and plays important roles in the development of insulin resistance and atherosclerosis in relation to metabolically driven low-grade and chronic inflammation, referred to as ‘metaflammation’. FABP4 is secreted from adipocytes in a non-classical pathway associated with lipolysis and acts as an adipokine for the development of insulin resistance and atherosclerosis. Circulating FABP4 levels are associated with several aspects of metabolic syndrome and cardiovascular disease. Ectopic expression and function of FABP4 in cells and tissues are also related to the pathogenesis of several diseases. Pharmacological modification of FABP4 function by specific inhibitors, neutralizing antibodies or antagonists of unidentified receptors would be novel therapeutic strategies for several diseases, including obesity, diabetes mellitus, atherosclerosis and cardiovascular disease. Significant roles of FABP4 as a lipid chaperone in physiological and pathophysiological conditions and the possibility of FABP4 being a therapeutic target for metabolic and cardiovascular diseases are discussed in this review.
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Affiliation(s)
- Masato Furuhashi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine
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18
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Kurihara Y, Itoh R, Shimizu A, Walenna NF, Chou B, Ishii K, Soejima T, Fujikane A, Hiromatsu K. Chlamydia trachomatis targets mitochondrial dynamics to promote intracellular survival and proliferation. Cell Microbiol 2018; 21:e12962. [PMID: 30311994 DOI: 10.1111/cmi.12962] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 09/18/2018] [Accepted: 10/04/2018] [Indexed: 11/27/2022]
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that scavenges host metabolic products for its replication. Mitochondria are the power plants of eukaryotic cells and provide most of the cellular ATP via oxidative phosphorylation. Several intracellular pathogens target mitochondria as part of their obligatory cellular reprogramming. This study was designed to analyse the mitochondrial morphological changes in response to C. trachomatis infection in HeLa cells. Mitochondrial elongation and fragmentation were found at the early stages and late stages of C. trachomatis infection, respectively. C. trachomatis infection-induced mitochondrial elongation was associated with the increase of mitochondrial respiratory activity, ATP production, and intracellular growth of C. trachomatis. Silencing mitochondrial fusion mediator proteins abrogated the C. trachomatis infection-induced elevation in the oxygen consumption rate and attenuated chlamydial proliferation. Mechanistically, C. trachomatis induced the elevation of intracellular cAMP at the early phase of infection, followed by the phosphorylation of fission-inactive serine residue 637 (S637) of Drp1, resulting in mitochondrial elongation. Accordingly, treatment with adenylate cyclase inhibitor diminished mitochondrial elongation and bacterial growth in infected cells. Collectively, these results strongly indicate that C. trachomatis promotes its intracellular growth by targeting mitochondrial dynamics to regulate ATP synthesis via inhibition of the fission mediator Drp1.
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Affiliation(s)
- Yusuke Kurihara
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Ryota Itoh
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Akinori Shimizu
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Nirwana Fitriani Walenna
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan.,Faculty of Medicine, Hasanuddin University, Makassar, Indonesia
| | - Bin Chou
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Kazunari Ishii
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Toshinori Soejima
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Aya Fujikane
- General Medicine, Fukuoka University Hospital, Fukuoka, Japan
| | - Kenji Hiromatsu
- Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
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