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Shannon BA, Hurst JR, Flannagan RS, Craig HC, Rishi A, Kasper KJ, Tuffs SW, Heinrichs DE, McCormick JK. Streptolysin S is required for Streptococcus pyogenes nasopharyngeal and skin infection in HLA-transgenic mice. PLoS Pathog 2024; 20:e1012072. [PMID: 38452154 PMCID: PMC10950238 DOI: 10.1371/journal.ppat.1012072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/19/2024] [Accepted: 02/25/2024] [Indexed: 03/09/2024] Open
Abstract
Streptococcus pyogenes is a human-specific pathogen that commonly colonizes the upper respiratory tract and skin, causing a wide variety of diseases ranging from pharyngitis to necrotizing fasciitis and toxic shock syndrome. S. pyogenes has a repertoire of secreted virulence factors that promote infection and evasion of the host immune system including the cytolysins streptolysin O (SLO) and streptolysin S (SLS). S. pyogenes does not naturally infect the upper respiratory tract of mice although mice transgenic for MHC class II human leukocyte antigens (HLA) become highly susceptible. Here we used HLA-transgenic mice to assess the role of both SLO and SLS during both nasopharyngeal and skin infection. Using S. pyogenes MGAS8232 as a model strain, we found that an SLS-deficient strain exhibited a 100-fold reduction in bacterial recovery from the nasopharynx and a 10-fold reduction in bacterial burden in the skin, whereas an SLO-deficient strain did not exhibit any infection defects in these models. Furthermore, depletion of neutrophils significantly restored the bacterial burden of the SLS-deficient bacteria in skin, but not in the nasopharynx. In mice nasally infected with the wildtype S. pyogenes, there was a marked change in localization of the tight junction protein ZO-1 at the site of infection, demonstrating damage to the nasal epithelia that was absent in mice infected with the SLS-deficient strain. Overall, we conclude that SLS is required for the establishment of nasopharyngeal infection and skin infection in HLA-transgenic mice by S. pyogenes MGAS8232 and provide evidence that SLS contributes to nasopharyngeal infection through the localized destruction of nasal epithelia.
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Affiliation(s)
- Blake A. Shannon
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Jacklyn R. Hurst
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Ronald S. Flannagan
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Heather C. Craig
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Aanchal Rishi
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Katherine J. Kasper
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - Stephen W. Tuffs
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - David E. Heinrichs
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
| | - John K. McCormick
- Department of Microbiology and Immunology, University of Western Ontario, London, Ontario, Canada
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Yamada T, Yamamori Y, Matsuda N, Nagamune H, Ohkura K, Tomoyasu T, Tabata A. Streptolysin S induces pronounced calcium-ion influx-dependent expression of immediate early genes encoding transcription factors. Sci Rep 2023; 13:13720. [PMID: 37608082 PMCID: PMC10444759 DOI: 10.1038/s41598-023-40981-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/19/2023] [Indexed: 08/24/2023] Open
Abstract
Anginosus group streptococci (AGS) are opportunistic human pathogens of the oral cavity. The β-hemolytic subgroup of Streptococcus anginosus subsp. anginosus secretes streptolysin S (SLS) and exhibits not only hemolytic activity but also cytotoxicity toward cultured human cell lines. However, the detailed mechanism of action of SLS and the cellular responses of host cells have not yet been fully clarified. To determine the pathogenic potential of SLS-producing β-hemolytic S. anginosus subsp. anginosus, the SLS-dependent response induced in the human oral squamous cell carcinoma HSC-2 cells was investigated to determine the pathogenic potential of SLS-producing β-hemolytic S. anginosus subsp. anginosus. This study revealed that the Ca2+ influx and the expression of immediate early genes (IEGs) encoding transcription factors such as early growth responses (EGRs) and activator protein-1 (AP-1) were greatly increased in HSC-2 cells incubated with the culture supernatant of SLS-producing β-hemolytic S. anginosus subsp. anginosus. Moreover, this SLS-dependent increase in expression was significantly suppressed by Ca2+ chelation, except for jun. These results suggest that SLS caused Ca2+ influx into the cells following greatly enhanced expression of IEG-encoding transcription factors. The results of this study may help in understanding the pathogenicity of SLS-producing AGS.
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Affiliation(s)
- Takuya Yamada
- Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8506, Japan
| | - Yugo Yamamori
- Faculty of Bioscience and Bioindustry, Bioengineering Course, Tokushima University, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan
| | - Nanami Matsuda
- Faculty of Bioscience and Bioindustry, Bioengineering Course, Tokushima University, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan
| | - Hideaki Nagamune
- Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8506, Japan
- Faculty of Bioscience and Bioindustry, Bioengineering Course, Tokushima University, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan
| | - Kazuto Ohkura
- Division of Clinical Pharmacy and Pharmaceutical Sciences, Graduate School of Pharmaceutical Sciences, Suzuka University of Medical Science, 3500-3 Minamitamagaki-Cho, Suzuka, Mie, 513-8670, Japan
| | - Toshifumi Tomoyasu
- Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8506, Japan
- Faculty of Bioscience and Bioindustry, Bioengineering Course, Tokushima University, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan
| | - Atsushi Tabata
- Department of Biological Science and Technology, Life System, Institute of Technology and Science, Tokushima University Graduate School, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8506, Japan.
- Faculty of Bioscience and Bioindustry, Bioengineering Course, Tokushima University, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan.
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, 2-1 Minamijousanjima-Cho, Tokushima, Tokushima, 770-8513, Japan.
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3
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Alves-Barroco C, Botelho AMN, Américo MA, Fracalanzza SEL, de Matos APA, Guimaraes MA, Ferreira-Carvalho BT, Figueiredo AMS, Fernandes AR. Assessing in vivo and in vitro biofilm development by Streptococcus dysgalactiae subsp. dysgalactiae using a murine model of catheter-associated biofilm and human keratinocyte cell. Front Cell Infect Microbiol 2022; 12:874694. [PMID: 35928206 PMCID: PMC9343579 DOI: 10.3389/fcimb.2022.874694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
Streptococcus dysgalactiae subsp. dysgalactiae (SDSD) is an important agent of bovine mastitis. This infection causes an inflammatory reaction in udder tissue, being the most important disease-causing significant impact on the dairy industry. Therefore, it leads to an increase in dairy farming to meet commercial demands. As a result, there is a major impact on both the dairy industry and the environment including global warming. Recurrent mastitis is often attributed to the development of bacterial biofilms, which promote survival of sessile cells in hostile environments, and resistance to the immune system defense and antimicrobial therapy. Recently, we described the in vitro biofilm development on abiotic surfaces by bovine SDSD. In that work we integrated microbiology, imaging, and computational methods to evaluate the biofilm production capability of SDSD isolates on abiotic surfaces. Additionally, we reported that bovine SDSD can adhere and internalize human cells, including human epidermal keratinocyte (HEK) cells. We showed that the adherence and internalization rates of bovine SDSD isolates in HEK cells are higher than those of a SDSD DB49998-05 isolated from humans. In vivo, bovine SDSD can cause invasive infections leading to zebrafish morbidity and mortality. In the present work, we investigated for the first time the capability of bovine SDSD to develop biofilm in vivo using a murine animal model and ex-vivo on human HEK cells. Bovine SDSD isolates were selected based on their ability to form weak, moderate, or strong biofilms on glass surfaces. Our results showed that SDSD isolates displayed an increased ability to form biofilms on the surface of catheters implanted in mice when compared to in vitro biofilm formation on abiotic surface. A greater ability to form biofilm in vitro after animal passage was observed for the VSD45 isolate, but not for the other isolates tested. Besides that, in vitro scanning electron microscopy demonstrated that SDSD biofilm development was visible after 4 hours of SDSD adhesion to HEK cells. Cell viability tests showed an important reduction in the number of HEK cells after the formation of SDSD biofilms. In this study, the expression of genes encoding BrpA-like (biofilm regulatory protein), FbpA (fibronectin-binding protein A), HtrA (serine protease), and SagA (streptolysin S precursor) was higher for biofilm grown in vivo than in vitro, suggesting a potential role for these virulence determinants in the biofilm-development, host colonization, and SDSD infections. Taken together, these results demonstrate that SDSD can develop biofilms in vivo and on the surface of HEK cells causing important cellular damages. As SDSD infections are considered zoonotic diseases, our data contribute to a better understanding of the role of biofilm accumulation during SDSD colonization and pathogenesis not only in bovine mastitis, but they also shed some lights on the mechanisms of prosthesis-associated infection and cellulitis caused by SDSD in humans, as well.
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Affiliation(s)
- Cinthia Alves-Barroco
- UCIBIO - Applied Molecular Biosciences Unit, Dept. Ciências da Vida, NOVA School of Science and Technology, Caparica, Portugal
- i4HB, Associate Laboratory - Institute for Health and Bioeconomy, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
| | - Ana Maria Nunes Botelho
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marco Antonio Américo
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - António P. Alves de Matos
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Egas Moniz - Cooperativa de Ensino Superior CRL, Quinta da Granja, Portugal
| | - Márcia Aparecida Guimaraes
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Agnes Marie Sá Figueiredo
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- *Correspondence: Alexandra R. Fernandes, ; Agnes Marie Sá Figueiredo,
| | - Alexandra R. Fernandes
- UCIBIO - Applied Molecular Biosciences Unit, Dept. Ciências da Vida, NOVA School of Science and Technology, Caparica, Portugal
- i4HB, Associate Laboratory - Institute for Health and Bioeconomy, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Caparica, Portugal
- *Correspondence: Alexandra R. Fernandes, ; Agnes Marie Sá Figueiredo,
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Ulhuq FR, Mariano G. Bacterial pore-forming toxins. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001154. [PMID: 35333704 PMCID: PMC9558359 DOI: 10.1099/mic.0.001154] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/03/2022] [Indexed: 12/11/2022]
Abstract
Pore-forming toxins (PFTs) are widely distributed in both Gram-negative and Gram-positive bacteria. PFTs can act as virulence factors that bacteria utilise in dissemination and host colonisation or, alternatively, they can be employed to compete with rival microbes in polymicrobial niches. PFTs transition from a soluble form to become membrane-embedded by undergoing large conformational changes. Once inserted, they perforate the membrane, causing uncontrolled efflux of ions and/or nutrients and dissipating the protonmotive force (PMF). In some instances, target cells intoxicated by PFTs display additional effects as part of the cellular response to pore formation. Significant progress has been made in the mechanistic description of pore formation for the different PFTs families, but in several cases a complete understanding of pore structure remains lacking. PFTs have evolved recognition mechanisms to bind specific receptors that define their host tropism, although this can be remarkably diverse even within the same family. Here we summarise the salient features of PFTs and highlight where additional research is necessary to fully understand the mechanism of pore formation by members of this diverse group of protein toxins.
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Affiliation(s)
- Fatima R. Ulhuq
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Giuseppina Mariano
- Microbes in Health and Disease Theme, Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, UK
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5
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Sura T, Surabhi S, Maaß S, Hammerschmidt S, Siemens N, Becher D. The global proteome and ubiquitinome of bacterial and viral co-infected bronchial epithelial cells. J Proteomics 2022; 250:104387. [PMID: 34600154 DOI: 10.1016/j.jprot.2021.104387] [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] [Received: 06/16/2021] [Revised: 08/26/2021] [Accepted: 09/22/2021] [Indexed: 12/13/2022]
Abstract
Viral infections facilitate bacterial trafficking to the lower respiratory tract resulting in bacterial-viral co-infections. Bacterial dissemination to the lower respiratory tract is enhanced by influenza A virus induced epithelial cell damage and dysregulation of immune responses. Epithelial cells act as a line of defense and detect pathogens by a high variety of pattern recognition receptors. The post-translational modification ubiquitin is involved in almost every cellular process. Moreover, ubiquitination contributes to the regulation of host immune responses, influenza A virus uncoating and transport within host cells. We applied proteomics with a special focus on ubiquitination to assess the impact of single bacterial and viral as well as bacterial-viral co-infections on bronchial epithelial cells. We used Tandem Ubiquitin Binding Entities to enrich polyubiquitinated proteins and assess changes in the ubiquitinome. Infecting 16HBE cells with Streptococcus pyogenes led to an increased abundance of proteins related to mitochondrial translation and energy metabolism in proteome and ubiquitinome. In contrast, influenza A virus infection mainly altered the ubiquitinome. Co-infections had no additional impact on protein abundances or affected pathways. Changes in protein abundance and enriched pathways were assigned to imprints of both infecting pathogens. SIGNIFICANCE: Viral and bacterial co-infections of the lower respiratory tract are a burden for health systems worldwide. Therefore, it is necessary to elucidate the complex interplay between the host and the infecting pathogens. Thus, we analyzed the proteome and the ubiquitinome of co-infected bronchial epithelial cells to elaborate a potential synergism of the two infecting organisms. The results presented in this work can be used as a starting point for further analyses.
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Affiliation(s)
- Thomas Sura
- University of Greifswald, Center for Functional Genomics of Microbes, Institute of Microbiology, Department of Microbial Proteomics, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Surabhi Surabhi
- University of Greifswald, Center for Functional Genomics of Microbes, Interfaculty Institute for Genetics and Functional Genomics, Department of Molecular Genetics and Infection Biology, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Sandra Maaß
- University of Greifswald, Center for Functional Genomics of Microbes, Institute of Microbiology, Department of Microbial Proteomics, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Sven Hammerschmidt
- University of Greifswald, Center for Functional Genomics of Microbes, Interfaculty Institute for Genetics and Functional Genomics, Department of Molecular Genetics and Infection Biology, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Nikolai Siemens
- University of Greifswald, Center for Functional Genomics of Microbes, Interfaculty Institute for Genetics and Functional Genomics, Department of Molecular Genetics and Infection Biology, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany
| | - Dörte Becher
- University of Greifswald, Center for Functional Genomics of Microbes, Institute of Microbiology, Department of Microbial Proteomics, Felix-Hausdorff-Str. 8, 17489 Greifswald, Germany.
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6
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Tabata A, Nagamune H. Diversity of β-hemolysins produced by the human opportunistic streptococci. Microbiol Immunol 2021; 65:512-529. [PMID: 34591320 DOI: 10.1111/1348-0421.12936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/17/2021] [Accepted: 08/18/2021] [Indexed: 11/28/2022]
Abstract
The genus Streptococcus infects a broad range of hosts, including humans. Some species, such as S. pyogenes, S. agalactiae, S. pneumoniae, and S. mutans, are recognized as the major human pathogens, and their pathogenicity toward humans has been investigated. However, many of other streptococcal species have been recognized as opportunistic pathogens in humans, and their clinical importance has been underestimated. In our previous study, the Anginosus group streptococci (AGS) and Mitis group streptococci (MGS) showed clear β-hemolysis on blood agar, and the factors responsible for the hemolysis were homologs of two types of β-hemolysins, cholesterol-dependent cytolysin (CDC) and streptolysin S (SLS). In contrast to the regular β-hemolysins produced by streptococci (typical CDCs and SLSs), genetically, structurally, and functionally atypical β-hemolysins have been observed in AGS and MGS. These atypical β-hemolysins are thought to affect and contribute to the pathogenic potential of opportunistic streptococci mainly inhabiting the human oral cavity. In this review, we introduce the diverse characteristics of β-hemolysin produced by opportunistic streptococci, focusing on the species/strains belonging to AGS and MGS, and discuss their pathogenic potential.
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Affiliation(s)
- Atsushi Tabata
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan
| | - Hideaki Nagamune
- Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University Graduate School, Tokushima, Japan
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Kuo CF, Chen WY, Yu HH, Tsai YH, Chang YC, Chang CP, Tsao N. IL-33/ST2 Axis Plays a Protective Effect in Streptococcus pyogenes Infection through Strengthening of the Innate Immunity. Int J Mol Sci 2021; 22:10566. [PMID: 34638904 PMCID: PMC8509005 DOI: 10.3390/ijms221910566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 09/23/2021] [Accepted: 09/26/2021] [Indexed: 12/21/2022] Open
Abstract
Group A Streptococcus (GAS) causes invasive human diseases with the cytokine storm. Interleukin-33 (IL-33)/suppression of tumorigenicity 2 (ST2) axis is known to drive TH2 response, while its effect on GAS infection is unclear. We used an air pouch model to examine the effect of the IL-33/ST2 axis on GAS-induced necrotizing fasciitis. GAS infection induced IL-33 expression in wild-type (WT) C57BL/6 mice, whereas the IL-33- and ST2-knockout mice had higher mortality rates, more severe skin lesions and higher bacterial loads in the air pouches than those of WT mice after infection. Surveys of infiltrating cells in the air pouch of GAS-infected mice at the early stage found that the number and cell viability of infiltrating cells in both gene knockout mice were lower than those of WT mice. The predominant effector cells in GAS-infected air pouches were neutrophils. Absence of the IL-33/ST2 axis enhanced the expression of inflammatory cytokines, but not TH1 or TH2 cytokines, in the air pouch after infection. Using in vitro assays, we found that the IL-33/ST2 axis not only enhanced neutrophil migration but also strengthened the bactericidal activity of both sera and neutrophils. These results suggest that the IL-33/ST2 axis provided the protective effect on GAS infection through enhancing the innate immunity.
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Affiliation(s)
- Chih-Feng Kuo
- School of Medicine, I-Shou University, Kaohsiung City 824005, Taiwan;
- Department of Nursing, College of Medicine, I-Shou University, Kaohsiung City 824005, Taiwan
| | - Wei-Yu Chen
- Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung City 833401, Taiwan;
| | - Hai-Han Yu
- Department of Biological Science and Technology, College of Medical Science and Technology, I-Shou University, Kaohsiung City 824005, Taiwan; (H.-H.Y.); (Y.-H.T.)
| | - Yu-Hsuan Tsai
- Department of Biological Science and Technology, College of Medical Science and Technology, I-Shou University, Kaohsiung City 824005, Taiwan; (H.-H.Y.); (Y.-H.T.)
| | - Ya-Chu Chang
- Department of Medical Laboratory Science, College of Medical Science and Technology, I-Shou University, Kaohsiung City 824005, Taiwan;
| | - Chih-Peng Chang
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan 701401, Taiwan;
- The Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 701401, Taiwan
| | - Nina Tsao
- Department of Biological Science and Technology, College of Medical Science and Technology, I-Shou University, Kaohsiung City 824005, Taiwan; (H.-H.Y.); (Y.-H.T.)
- Department of Medical Laboratory Science, College of Medical Science and Technology, I-Shou University, Kaohsiung City 824005, Taiwan;
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Mechanisms of the Regulation and Dysregulation of Glucagon Secretion. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:3089139. [PMID: 32774668 PMCID: PMC7396046 DOI: 10.1155/2020/3089139] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/11/2020] [Indexed: 02/06/2023]
Abstract
Glucagon, a hormone secreted by pancreatic alpha cells, contributes to the maintenance of normal blood glucose concentration by inducing hepatic glucose production in response to declining blood glucose. However, glucagon hypersecretion contributes to the pathogenesis of type 2 diabetes. Moreover, diabetes is associated with relative glucagon undersecretion at low blood glucose and oversecretion at normal and high blood glucose. The mechanisms of such alpha cell dysfunctions are not well understood. This article reviews the genesis of alpha cell dysfunctions during the pathogenesis of type 2 diabetes and after the onset of type 1 and type 2 diabetes. It unravels a signaling pathway that contributes to glucose- or hydrogen peroxide-induced glucagon secretion, whose overstimulation contributes to glucagon dysregulation, partly through oxidative stress and reduced ATP synthesis. The signaling pathway involves phosphatidylinositol-3-kinase, protein kinase B, protein kinase C delta, non-receptor tyrosine kinase Src, and phospholipase C gamma-1. This knowledge will be useful in the design of new antidiabetic agents or regimens.
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9
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Cho DH, Kim JK, Jo EK. Mitophagy and Innate Immunity in Infection. Mol Cells 2020; 43:10-22. [PMID: 31999918 PMCID: PMC6999710 DOI: 10.14348/molcells.2020.2329] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 01/08/2020] [Accepted: 01/08/2020] [Indexed: 02/08/2023] Open
Abstract
Mitochondria have several quality control mechanisms by which they maintain cellular homeostasis and ensure that the molecular machinery is protected from stress. Mitophagy, selective autophagy of mitochondria, promotes mitochondrial quality control by inducing clearance of damaged mitochondria via the autophagic machinery. Accumulating evidence suggests that mitophagy is modulated by various microbial components in an attempt to affect the innate immune response to infection. In addition, mitophagy plays a key role in the regulation of inflammatory signaling, and mitochondrial danger signals such as mitochondrial DNA translocated into the cytosol can lead to exaggerated inflammatory responses. In this review, we present current knowledge on the functional aspects of mitophagy and its crosstalk with innate immune signaling during infection. A deeper understanding of the role of mitophagy could facilitate the development of more effective therapeutic strategies against various infections.
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Affiliation(s)
- Dong-Hyung Cho
- School of Life Sciences, Kyungpook National University, Daegu 41566,
Korea
| | - Jin Kyung Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 35015,
Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon 35015,
Korea
| | - Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 35015,
Korea
- Infection Control Convergence Research Center, Chungnam National University School of Medicine, Daejeon 35015,
Korea
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10
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Wei S, Peng W, Mai Y, Li K, Wei W, Hu L, Zhu S, Zhou H, Jie W, Wei Z, Kang C, Li R, Liu Z, Zhao B, Cai Z. Outer membrane vesicles enhance tau phosphorylation and contribute to cognitive impairment. J Cell Physiol 2019; 235:4843-4855. [PMID: 31663118 DOI: 10.1002/jcp.29362] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/07/2019] [Indexed: 01/18/2023]
Affiliation(s)
- Shouchao Wei
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Wanjuan Peng
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Yingren Mai
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Kanglan Li
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Wei Wei
- Health Department, Gaomi People's Hospital Weifang Medical University Gaomi China
| | - Li Hu
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Shaoping Zhu
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Haihong Zhou
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Wanxin Jie
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Zhuangsheng Wei
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Chenyao Kang
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Ruikai Li
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Zhou Liu
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Bin Zhao
- Department of Neurology, Guangdong Key Laboratory of Age‐Related Cardiac and Cerebral Diseases, Institute of Neurology Affiliated Hospital of Guangdong Medical University Zhanjiang China
| | - Zhiyou Cai
- Department of Neurology, Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing General Hospital University of Chinese Academy of Sciences Chongqing China
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