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Quan Y, Wang Y, Gao S, Yuan S, Song S, Liu B, Wang Y. Breaking the fortress: a mechanistic review of meningitis-causing bacteria breaching tactics in blood brain barrier. Cell Commun Signal 2025; 23:235. [PMID: 40399897 PMCID: PMC12096492 DOI: 10.1186/s12964-025-02248-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2025] [Accepted: 05/13/2025] [Indexed: 05/23/2025] Open
Abstract
The blood-brain barrier is a physiological protective barrier around blood vessels in the brain. It prevents most bacteria and harmful substances from entering the brain through the blood. However, when bacterial meningitis occurs, bacteria enter the brain either from the circulation or by direct invasion from neighbouring structures, causing an inflammatory response that in severe cases may lead to death. High morbidity and mortality are prominent features of the disease. Many pathogenic bacteria can break through the blood-brain barrier and cause meningitis, such as Streptococcus pneumoniae, Group B Streptococcus, Streptococcus suis, Neisseria meningitidis, meningitis-associated Escherichia coli, etc. This article reviews the mechanisms by which these bacteria cross the blood-brain barrier when causing meningitis and the interactions between bacteria and host cells to help pathogens invade the brain. Clarifying the mechanism by which pathogens cross the blood-brain barrier can provide new ideas for developing effective treatments for bacterial meningitis.
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Affiliation(s)
- Yingying Quan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yuxin Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Shuji Gao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Shuo Yuan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Shenao Song
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Baobao Liu
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
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Ma J, Wu H, Ma Z, Wu Z. Bacterial and host factors involved in zoonotic Streptococcal meningitis. Microbes Infect 2025; 27:105335. [PMID: 38582147 DOI: 10.1016/j.micinf.2024.105335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/08/2024]
Abstract
Zoonotic streptococci cause several invasive diseases with high mortality rates, especially meningitis. Numerous studies elucidated the meningitis pathogenesis of zoonotic streptococci, some specific to certain bacterial species. In contrast, others are shared among different bacterial species, involving colonization and invasion of mucosal barriers, survival in the bloodstream, breaching the blood-brain and/or blood-cerebrospinal fluid barrier to access the central nervous system, and triggering inflammation of the meninges. This review focuses on the recent advancements in comprehending the molecular and cellular events of five major zoonotic streptococci responsible for causing meningitis in humans or animals, including Streptococcus agalactiae, Streptococcus equi subspecies zooepidemicus, Streptococcus suis, Streptococcus dysgalactiae, and Streptococcus iniae. The underlying mechanism was summarized into four themes, including 1) bacterial survival in blood, 2) brain microvascular endothelial cell adhesion and invasion, 3) penetration of the blood-brain barrier, and 4) activation of the immune system and inflammatory reaction within the brain. This review may contribute to developing therapeutics to prevent or mitigate injury of streptococcal meningitis and improve risk stratification.
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Affiliation(s)
- Jiale Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Huizhen Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Zhe Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China; Guangdong Provincial Key Laboratory of Research on the Technology of Pig-breeding and Pig-disease Prevention, Guangzhou 511400, China.
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Imran M, Abida, Kamal M, Al Fares MA, Hazazi A, Sabour AA, Alshiekheid MA, Sulaiman T, Abdulkhaliq AA, Al Kaabi NA, Alfaresi M, Rabaan AA. Non-coding RNAs in meningitis: Key regulators of immune response and inflammation. Pathol Res Pract 2024; 263:155626. [PMID: 39353323 DOI: 10.1016/j.prp.2024.155626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2024] [Revised: 09/11/2024] [Accepted: 09/26/2024] [Indexed: 10/04/2024]
Abstract
Non-coding RNAs (ncRNAs) contain circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and micro-ribonucleic acids (miRNAs). These RNAs receive good functionality in modulation of gene expressions & cellular roles. Recent research is shedding light on their pivotal roles in the pathophysiology of inflammatory meningitis, such as viral, fungal, or bacterial infections. This review addresses the intricate roles of non-coding RNAs (ncRNAs) that transcribe code-independent mRNA and other biological elements that control inflammation and immunological events extant during meningitis. ncRNAs, acting on a myriad of immune cell development, cytokine production, pathogen recognition, and so forth, finely orchestrate the host's immune response. Although lncRNAs and circRNAs are associated with gene networks regulating immune responses, miRNAs can precisely modulate the expression of pro- and anti-inflammatory cytokines. Moreover, ncRNAs have unique expression patterns in disease states and are stable in bio-fluids; therefore, they can serve as specific molecular biomarkers for meningitis concerning the diagnosis and prognosis. It might also be helpful to target ncRNAs as a therapeutic strategy to impact immune regulation and inflammation. Here, we review the current knowledge of how ncRNAs function in meningitis and discuss adopted approaches and perspectives and their implications for therapeutic strategies.
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Affiliation(s)
- Mohd Imran
- Department of Pharmaceutical Chemistry, College of Pharmacy, Northern Border University, Rafha 91911, Saudi Arabia; Center for Health Research, Northern Border University, Arar, Saudi Arabia
| | - Abida
- Department of Pharmaceutical Chemistry, College of Pharmacy, Northern Border University, Rafha 91911, Saudi Arabia.
| | - Mehnaz Kamal
- Department of Pharmaceutical Chemistry, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Mona A Al Fares
- Department of Internal Medicine, King Abdulaziz University Hospital, Jeddah 21589, Saudi Arabia
| | - Ali Hazazi
- Department of Pathology and Laboratory Medicine, Security Forces Hospital Program, Riyadh, Saudi Arabia; College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia
| | - Amal A Sabour
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Maha A Alshiekheid
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Tarek Sulaiman
- Infectious Diseases Section, Medical Specialties Department, King Fahad Medical City, Riyadh 12231, Saudi Arabia
| | - Altaf A Abdulkhaliq
- Department of Biochemistry, Faculty of Medicine, Umm Al-Qura University, Saudi Arabia
| | - Nawal A Al Kaabi
- College of Medicine and Health Science, Khalifa University, Abu Dhabi 127788, United Arab Emirates; Sheikh Khalifa Medical City, Abu Dhabi Health Services Company (SEHA), Abu Dhabi 51900, United Arab Emirates
| | - Mubarak Alfaresi
- Department of Microbiology, National Reference Laboratory, Cleveland Clinic Abu Dhabi, Abu Dhabi 92323, United Arab Emirates; Department of Pathology, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai 505055, United Arab Emirates
| | - Ali A Rabaan
- College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia; Molecular Diagnostic Laboratory, Johns Hopkins Aramco Healthcare, Dhahran 31311, Saudi Arabia; Department of Public Health and Nutrition, The University of Haripur, Haripur 22610, Pakistan
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Yi JX, Sun ZY, Liu P, Wang YH, Liu H, Lv QY, Kong DC, Huang WH, Ren YH, Li Q, Jiang YQ, Li J, Jiang H. Unveiling the crucial role of ferroptosis in host resistance to streptococcus agalactiae infection. Cell Death Discov 2024; 10:423. [PMID: 39353913 PMCID: PMC11445261 DOI: 10.1038/s41420-024-02189-8] [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: 03/18/2024] [Revised: 09/10/2024] [Accepted: 09/20/2024] [Indexed: 10/03/2024] Open
Abstract
IL-1β represents an important inflammatory factor involved in the host response against GBS infection. Prior research has suggested a potential involvement of IL-1β in the process of ferroptosis. However, the relationship between IL-1β and ferroptosis in the context of anti-GBS infection remains uncertain. This research demonstrates that the occurrence of ferroptosis is essential for the host's defense against GBS infection in a mouse model of abdominal infection, with peritoneal macrophages identified as the primary cells undergoing ferroptosis. Further research indicates that IL-1β induces lipid oxidation in macrophages through the upregulation of pathways related to lipid oxidation. Concurrently, IL-1β is not only involved in the initiation of ferroptosis in macrophages, but its production is intricately linked to the onset of ferroptosis. Ultimately, we posit that ferroptosis acts as a crucial initiating factor in the host response to GBS infection, with IL-1β playing a significant role in the resistance to infection by serving as a key inducer of ferroptosis.
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Affiliation(s)
- Jia-Xuan Yi
- College of Biological Science and Food Engineering, Southwest Forestry University, Kunming, Yunnan, China
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Ze-Yu Sun
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Peng Liu
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Yu-Hang Wang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Hui Liu
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Qing-Yu Lv
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - De-Cong Kong
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Wen-Hua Huang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Yu-Hao Ren
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Qian Li
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China
| | - Yong-Qiang Jiang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China.
| | - Jing Li
- College of Biological Science and Food Engineering, Southwest Forestry University, Kunming, Yunnan, China.
| | - Hua Jiang
- State Key Laboratory of Pathogen and Biosecurity, Academy of Military Medical Sciences, Beijing, China.
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Huang G, Yang S, Long T, Gao Y, Lin G. Proteomic analysis of brain tissue from ducks with meningitis caused by Riemerella anatipestifer infection. Poult Sci 2024; 103:104059. [PMID: 39068696 PMCID: PMC11338091 DOI: 10.1016/j.psj.2024.104059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 06/27/2024] [Accepted: 06/27/2024] [Indexed: 07/30/2024] Open
Abstract
Riemerella anatipestifer is a Gram-negative, rod-shaped bacterium that is flagellated, non-budded, and encapsulated, measuring approximately 0.4 μm × 0.7 μm. After infecting ducklings with R. anatipestifer, the hosts exhibited pathological changes, such as bacterial meningitis, fibrinous pericarditis, and fibrinous peripheral hepatitis. The pathogenesis of meningitis caused by R. anatipestifer has not yet been elucidated. To investigate the key molecules or proteins involved in R. anatipestifer's penetration of the blood-brain barrier (BBB) and the subsequent development of duck meningitis, a duck meningitis model was established and characterized. Duckling brain tissues were collected and analyzed using 4D label-free proteomic technology. Differentially expressed proteins were analyzed using a series of bioinformatics methods and verified using RT-qPCR and Western-Blot. The results showed that the differentially expressed proteins were primarily related to intracellular transport, transport protein activity, and transmembrane transport protein activity, and were mainly enriched in pathways associated with reducing intercellular connections and adhesion and increasing cell migration and apoptosis. Thus, it is suggested that R. anatipestifer may penetrate the BBB via transcellular and paracellular pathways, causing neurological diseases such as meningitis. This study is the first to analyze R. anatipestifer-infected duckling brain tissue using proteomics, thus providing a direction for further research into the mechanisms of R. anatipestifer's penetration of the BBB.
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Affiliation(s)
- Guoliang Huang
- Life Science and Engineering College, Northwest Minzu University, Lanzhou 730030, China
| | - Shengmei Yang
- Life Science and Engineering College, Northwest Minzu University, Lanzhou 730030, China
| | - Ting Long
- Life Science and Engineering College, Northwest Minzu University, Lanzhou 730030, China
| | - Yuhan Gao
- Life Science and Engineering College, Northwest Minzu University, Lanzhou 730030, China
| | - Guozhen Lin
- Life Science and Engineering College, Northwest Minzu University, Lanzhou 730030, China.
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6
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Dernovics Á, Seprényi G, Rázga Z, Ayaydin F, Veréb Z, Megyeri K. Phenol-Soluble Modulin α3 Stimulates Autophagy in HaCaT Keratinocytes. Biomedicines 2023; 11:3018. [PMID: 38002017 PMCID: PMC10669503 DOI: 10.3390/biomedicines11113018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/30/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND Phenol-soluble modulins (PSMs) are pore-forming toxins (PFTs) produced by staphylococci. PSMs exert diverse cellular effects, including lytic, pro-apoptotic, pro-inflammatory and antimicrobial actions. Since the effects of PSMs on autophagy have not yet been reported, we evaluated the autophagic activity in HaCaT keratinocytes treated with recombinant PSMα3. METHODS The autophagic flux and levels of autophagic marker proteins were determined using Western blot analysis. Subcellular localization of LC3B and Beclin-1 was investigated using an indirect immunofluorescence assay. The ultrastructural features of control and PSMα3-treated cells were evaluated via transmission electron microscopy. Cytoplasmic acidification was measured via acridine orange staining. Phosphorylation levels of protein kinases, implicated in autophagy regulation, were studied using a phospho-kinase array and Western blot analysis. RESULTS PSMα3 facilitated the intracellular redistribution of LC3B, increased the average number of autophagosomes per cell, promoted the development of acidic vesicular organelles, elevated the levels of LC3B-II, stimulated autophagic flux and triggered a significant decrease in the net autophagic turnover rate. PSMα3 induced the accumulation of autophagosomes/autolysosomes, amphisomes and multilamellar bodies at the 0.5, 6 and 24 h time points, respectively. The phospho-Akt1/2/3 (T308 and S473), and phospho-mTOR (S2448) levels were decreased, whereas the phospho-Erk1/2 (T202/Y204 and T185/Y187) level was increased in PSMα3-treated cells. CONCLUSIONS In HaCaT keratinocytes, PSMα3 stimulates autophagy. The increased autophagic activity elicited by sub-lytic PSM concentrations might be an integral part of the cellular defense mechanisms protecting skin homeostasis.
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Affiliation(s)
- Áron Dernovics
- Department of Medical Microbiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary;
| | - György Seprényi
- Department of Anatomy, Histology and Embryology, Albert Szent-Györgyi Medical School, University of Szeged, Kossuth L. sgt. 40., H-6724 Szeged, Hungary;
| | - Zsolt Rázga
- Department of Pathology, University of Szeged, Állomás u. 2, H-6720 Szeged, Hungary;
| | - Ferhan Ayaydin
- Hungarian Centre of Excellence for Molecular Medicine (HCEMM) Nonprofit Ltd., Római krt. 21., H-6723 Szeged, Hungary;
- Laboratory of Cellular Imaging, Biological Research Centre, Eötvös Loránd Research Network, Temesvári krt. 62., H-6726 Szeged, Hungary
| | - Zoltán Veréb
- Regenerative Medicine and Cellular Pharmacology Laboratory, Department of Dermatology and Allergology, University of Szeged, Korányi Fasor 6, H-6720 Szeged, Hungary;
- Biobank, University of Szeged, H-6720 Szeged, Hungary
- Interdisciplinary Research Development and Innovation Center of Excellence, University of Szeged, H-6720 Szeged, Hungary
| | - Klára Megyeri
- Department of Medical Microbiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary;
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Cheng Z, Zheng Y, Yang W, Sun H, Zhou F, Huang C, Zhang S, Song Y, Liang Q, Yang N, Li M, Liu B, Feng L, Wang L. Pathogenic bacteria exploit transferrin receptor transcytosis to penetrate the blood-brain barrier. Proc Natl Acad Sci U S A 2023; 120:e2307899120. [PMID: 37733740 PMCID: PMC10523449 DOI: 10.1073/pnas.2307899120] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 08/23/2023] [Indexed: 09/23/2023] Open
Abstract
The human blood-brain barrier (BBB) comprises a single layer of brain microvascular endothelial cells (HBMECs) protecting the brain from bloodborne pathogens. Meningitis is among the most serious diseases, but the mechanisms by which major meningitis-causing bacterial pathogens cross the BBB to reach the brain remain poorly understood. We found that Streptococcus pneumoniae, group B Streptococcus, and neonatal meningitis Escherichia coli commonly exploit a unique vesicle fusion mechanism to hitchhike on transferrin receptor (TfR) transcytosis to cross the BBB and illustrated the details of this process in human BBB model in vitro and mouse model. Toll-like receptor signals emanating from bacteria-containing vesicles (BCVs) trigger K33-linked polyubiquitination at Lys168 and Lys181 of the innate immune regulator TRAF3 and then activate the formation of a protein complex containing the guanine nucleotide exchange factor RCC2, the small GTPase RalA and exocyst subcomplex I (SC I) on BCVs. The distinct function of SEC6 in SC I, interacting directly with RalA on BCVs and the SNARE protein SNAP23 on TfR vesicles, tethers these two vesicles and initiates the fusion. Our results reveal that innate immunity triggers a unique modification of TRAF3 and the formation of the HBMEC-specific protein complex on BCVs to authenticate the precise recognition and selection of TfR vesicles to fuse with and facilitate bacterial penetration of the BBB.
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Affiliation(s)
- Zhihui Cheng
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin300071, China
| | - Yangyang Zheng
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Wen Yang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Hongmin Sun
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Fangyu Zhou
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Chuangjie Huang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Shuwen Zhang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Yingying Song
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Qi’an Liang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin300071, China
| | - Nan Yang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin300071, China
| | - Meifang Li
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin300071, China
| | - Bin Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Lu Feng
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
| | - Lei Wang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin300071, China
- TEDA Institute of Biological Sciences and Biotechnology, Tianjin Key Laboratory of Microbial Functional Genomics, Nankai University, Tianjin300457, China
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Pan F, Zhu M, Liang Y, Yuan C, Zhang Y, Wang Y, Fan H, Waldor MK, Ma Z. Membrane vesicle delivery of a streptococcal M protein disrupts the blood-brain barrier by inducing autophagic endothelial cell death. Proc Natl Acad Sci U S A 2023; 120:e2219435120. [PMID: 37276410 PMCID: PMC10268326 DOI: 10.1073/pnas.2219435120] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/08/2023] [Indexed: 06/07/2023] Open
Abstract
M family proteins are critical virulence determinants of Streptococci. Streptococcus equi subsp. zooepidemicus (SEZ) are Group C streptococci that cause meningitis in animals and humans. SzM, the M protein of SEZ, has been linked to SEZ brain invasion. Here, we demonstrate that SzM is important in SEZ disruption of the blood-brain barrier (BBB). SEZ release SzM-bound membrane vesicles (MVs), and endocytosis of these vesicles by human brain endothelial microvascular cells (hBMECs) results in SzM-dependent cytotoxicity. Furthermore, administration of SzM-bound MVs disrupted the murine BBB. A CRISPR screen revealed that SzM cytotoxicity in hBMECs depends on PTEN-related activation of autophagic cell death. Pharmacologic inhibition of PTEN activity prevented SEZ disruption of the murine BBB and delayed mortality. Our data show that MV delivery of SzM to host cells plays a key role in SEZ pathogenicity and suggests that MV delivery of streptococcal M family proteins is likely a common streptococcal virulence mechanism.
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Affiliation(s)
- Fei Pan
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Mingli Zhu
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Ying Liang
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Chen Yuan
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Yu Zhang
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Yuchang Wang
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
| | - Hongjie Fan
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou225009, China
| | - Matthew K. Waldor
- HHMI, Boston, MA02115
- Brigham and Women’s HospitalDivision of Infectious Diseases, Boston, MA02115
- Department of Microbiology, Harvard Medical School, Boston, MA02115
| | - Zhe Ma
- Ministry of Agriculture Key Laboratory of Animal Bacteriology, the International Joint Laboratory of Animal Health and Food Safety, and College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, Jiangsu210095, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou225009, China
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Srivastava P, Kim KS. Membrane Vesicles Derived from Gut Microbiota and Probiotics: Cutting-Edge Therapeutic Approaches for Multidrug-Resistant Superbugs Linked to Neurological Anomalies. Pharmaceutics 2022; 14:2370. [PMID: 36365188 PMCID: PMC9692612 DOI: 10.3390/pharmaceutics14112370] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 11/06/2022] Open
Abstract
Multidrug-resistant (MDR) superbugs can breach the blood-brain barrier (BBB), leading to a continuous barrage of pro-inflammatory modulators and induction of severe infection-related pathologies, including meningitis and brain abscess. Both broad-spectrum or species-specific antibiotics (β-lactamase inhibitors, polymyxins, vancomycin, meropenem, plazomicin, and sarecycline) and biocompatible poly (lactic-co-glycolic acid) (PLGA) nanoparticles have been used to treat these infections. However, new therapeutic platforms with a broad impact that do not exert off-target deleterious effects are needed. Membrane vesicles or extracellular vesicles (EVs) are lipid bilayer-enclosed particles with therapeutic potential owing to their ability to circumvent BBB constraints. Bacteria-derived EVs (bEVs) from gut microbiota are efficient transporters that can penetrate the central nervous system. In fact, bEVs can be remodeled via surface modification and CRISPR/Cas editing and, thus, represent a novel platform for conferring protection against infections breaching the BBB. Here, we discuss the latest scientific research related to gut microbiota- and probiotic-derived bEVs, and their therapeutic modifications, in terms of regulating neurotransmitters and inhibiting quorum sensing, for the treatment of neurodegenerative diseases, such as Parkinson's and Alzheimer's diseases. We also emphasize the benefits of probiotic-derived bEVs to human health and propose a novel direction for the development of innovative heterologous expression systems to combat BBB-crossing pathogens.
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Affiliation(s)
| | - Kwang-sun Kim
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 46241, Korea
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10
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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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11
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Bergmann R, Gulotta G, Andreoni F, Sumitomo T, Kawabata S, Zinkernagel AS, Chhatwal GS, Nizet V, Rohde M, Uchiyama S. The group A Streptococcus interleukin-8 protease SpyCEP promotes bacterial intracellular survival by evasion of autophagy. INFECTIOUS MICROBES & DISEASES 2022; 4:116-123. [PMID: 37333426 PMCID: PMC10275413 DOI: 10.1097/im9.0000000000000098] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Autophagy serves an innate immune function in defending the host against invading bacteria, including group A Streptococcus (GAS). Autophagy is regulated by numerous host proteins, including the endogenous negative regulator calpain, a cytosolic protease. Globally disseminated serotype M1T1 GAS strains associated with high invasive disease potential express numerous virulence factors and resist autophagic clearance. Upon in vitro infection of human epithelial cell lines with representative wild-type GAS M1T1 strain 5448 (M1.5448), we observed increased calpain activation linked to a specific GAS virulence factor, the IL-8 protease SpyCEP. Calpain activation inhibited autophagy and decreased capture of cytosolic GAS in autophagosomes. In contrast, the serotype M6 GAS strain JRS4 (M6.JRS4), which is highly susceptible to host autophagy-mediated killing, expresses low levels of SpyCEP and does not activate calpain. Overexpression of SpyCEP in M6.JRS4 stimulated calpain activation, inhibited autophagy and significantly decreased bacterial capture in autophagosomes. These paired loss- and gain-of-function studies reveal a novel role for the bacterial protease SpyCEP in enabling GAS M1 evasion of autophagy and host innate immune clearance.
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Affiliation(s)
- René Bergmann
- Central Unit for Microscopy (ZEIM), Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Giuseppe Gulotta
- Central Unit for Microscopy (ZEIM), Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Federica Andreoni
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland
| | - Tomoko Sumitomo
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, Suita-Osaka, Japan
| | - Shigetada Kawabata
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, Suita-Osaka, Japan
| | - Annelies S. Zinkernagel
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Zurich, Switzerland
| | - Gursharan S. Chhatwal
- Central Unit for Microscopy (ZEIM), Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Victor Nizet
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Manfred Rohde
- Central Unit for Microscopy (ZEIM), Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Satoshi Uchiyama
- Central Unit for Microscopy (ZEIM), Helmholtz Centre for Infection Research, Braunschweig, Germany
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
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12
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Angrand L, Masson JD, Rubio-Casillas A, Nosten-Bertrand M, Crépeaux G. Inflammation and Autophagy: A Convergent Point between Autism Spectrum Disorder (ASD)-Related Genetic and Environmental Factors: Focus on Aluminum Adjuvants. TOXICS 2022; 10:toxics10090518. [PMID: 36136483 PMCID: PMC9502677 DOI: 10.3390/toxics10090518] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/19/2022] [Accepted: 08/25/2022] [Indexed: 05/10/2023]
Abstract
Autism spectrum disorder (ASD), schizophrenia, and bipolar disorder are genetically complex and heterogeneous neurodevelopmental disorders (NDDs) resulting from genetic factors and gene-environment (GxE) interactions for which onset occurs in early brain development. Recent progress highlights the link between ASD and (i) immunogenetics, neurodevelopment, and inflammation, and (ii) impairments of autophagy, a crucial neurodevelopmental process involved in synaptic pruning. Among various environmental factors causing risk for ASD, aluminum (Al)-containing vaccines injected during critical periods have received special attention and triggered relevant scientific questions. The aim of this review is to discuss the current knowledge on the role of early inflammation, immune and autophagy dysfunction in ASD as well as preclinical studies which question Al adjuvant impacts on brain and immune maturation. We highlight the most recent breakthroughs and the lack of epidemiological, pharmacokinetic and pharmacodynamic data constituting a "scientific gap". We propose additional research, such as genetic studies that could contribute to identify populations at genetic risk, improving diagnosis, and potentially the development of new therapeutic tools.
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Affiliation(s)
- Loïc Angrand
- Univ Paris Est Créteil, INSERM, IMRB, F-94010 Créteil, France; (L.A.); (J.-D.M.)
- Ecole Nationale Vétérinaire d’Alfort IMRB, F-94700 Maisons-Alfort, France
- INSERM UMR-S 1270, 75005 Paris, France;
- Sorbonne Université, Campus Pierre et Marie Curie, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Jean-Daniel Masson
- Univ Paris Est Créteil, INSERM, IMRB, F-94010 Créteil, France; (L.A.); (J.-D.M.)
- Ecole Nationale Vétérinaire d’Alfort IMRB, F-94700 Maisons-Alfort, France
| | - Alberto Rubio-Casillas
- Biology Laboratory, Autlán Regional Preparatory School, University of Guadalajara, Autlán 48900, Jalisco, Mexico;
- Autlán Regional Hospital, Health Secretariat, Autlán 48900, Jalisco, Mexico
| | - Marika Nosten-Bertrand
- INSERM UMR-S 1270, 75005 Paris, France;
- Sorbonne Université, Campus Pierre et Marie Curie, 75005 Paris, France
- Institut du Fer à Moulin, 75005 Paris, France
| | - Guillemette Crépeaux
- Univ Paris Est Créteil, INSERM, IMRB, F-94010 Créteil, France; (L.A.); (J.-D.M.)
- Ecole Nationale Vétérinaire d’Alfort IMRB, F-94700 Maisons-Alfort, France
- Correspondence:
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13
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Group B Streptococcus-Induced Macropinocytosis Contributes to Bacterial Invasion of Brain Endothelial Cells. Pathogens 2022; 11:pathogens11040474. [PMID: 35456149 PMCID: PMC9028350 DOI: 10.3390/pathogens11040474] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/12/2022] [Accepted: 04/14/2022] [Indexed: 01/25/2023] Open
Abstract
Bacterial meningitis is defined as serious inflammation of the central nervous system (CNS) in which bacteria infect the blood–brain barrier (BBB), a network of highly specialized brain endothelial cells (BECs). Dysfunction of the BBB is a hallmark of bacterial meningitis. Group B Streptococcus (GBS) is one of the leading organisms that cause bacterial meningitis, especially in neonates. Macropinocytosis is an actin-dependent form of endocytosis that is also tightly regulated at the BBB. Previous studies have shown that inhibition of actin-dependent processes decreases bacterial invasion, suggesting that pathogens can utilize macropinocytotic pathways for invasion. The purpose of this project is to study the factors that lead to dysfunction of the BBB. We demonstrate that infection with GBS increases rates of endocytosis in BECs. We identified a potential pathway, PLC-PKC-Nox2, in BECs that contributes to macropinocytosis regulation. Here we demonstrate that downstream inhibition of PLC, PKC, or Nox2 significantly blocks GBS invasion of BECs. Additionally, we show that pharmacological activation of PKC can turn on macropinocytosis and increase bacterial invasion of nonpathogenic yet genetically similar Lactococcus lactis. Our results suggest that GBS activates BEC signaling pathways that increase rates of macropinocytosis and subsequently the invasion of GBS.
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14
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Zhao Y, Lian B, Liu X, Wang Q, Zhang D, Sheng Q, Cao L. Case report: Cryptogenic giant brain abscess caused by Providencia rettgeri mimicking stroke and tumor in a patient with impaired immunity. Front Neurol 2022; 13:1007435. [PMID: 36212658 PMCID: PMC9538924 DOI: 10.3389/fneur.2022.1007435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 09/01/2022] [Indexed: 02/05/2023] Open
Abstract
The highly lethal cryptogenic brain abscess can be easily misdiagnosed. However, cryptogenic brain abscess caused by Providencia rettgeri is rarely reported. We present the case of a cryptogenic Providencia rettgeri brain abscess and analyze the clinical manifestations, imaging findings, treatment, and outcome to improve the level of awareness, aid in accurate diagnosis, and highlight effective clinical management. A 39-year-old man was admitted to the hospital after experiencing acute speech and consciousness disorder for 1 day. The patient had a medical history of nephrotic syndrome and membranous nephropathy requiring immunosuppressant therapy. Magnetic resonance imaging revealed giant, space-occupying lesions involving the brain stem, basal ganglia, and temporal-parietal lobes without typical ring enhancement, mimicking a tumor. Initial antibiotic treatment was ineffective. Afterward, pathogen detection in cerebrospinal fluid using metagenomic next-generation sequencing revealed Providencia rettgeri. Intravenous maximum-dose ampicillin was administered for 5 weeks, and the patient's symptoms resolved. Cryptogenic Providencia rettgeri brain abscess typically occurs in patients with impaired immunity. Our patient exhibited a sudden onset with non-typical neuroimaging findings, requiring differentiation of the lesion from stroke and brain tumor. Metagenomic next-generation sequencing was important in identifying the pathogen. Rapid diagnosis and appropriate use of antibiotics were key to obtaining a favorable outcome.
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Affiliation(s)
- Yu Zhao
- Department of Neurology, Shenzhen Third People's Hospital, Shenzhen, China
- Department of Neurology, The Second Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Baorong Lian
- Shantou University Medical College, Shantou University, Shantou, China
| | - Xudong Liu
- Department of Neurology, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Qizheng Wang
- Department of Neurology, Shenzhen Third People's Hospital, Shenzhen, China
- Department of Neurology, The Second Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Daxue Zhang
- School of Nursing, Anhui Medical University, Hefei, China
| | - Qi Sheng
- Department of Neurology, Shenzhen Third People's Hospital, Shenzhen, China
- Department of Neurology, The Second Affiliated Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Liming Cao
- Department of Neurology, The First Affiliated Hospital of Shenzhen University, Shenzhen, China
- *Correspondence: Liming Cao
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15
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Awwad E, Srour M, Hasan S, Khatib S. Molecular determination, serotyping, antibiotic profile and virulence factors of group B Streptococcus isolated from invasive patients at Arabcare Hospital Laboratory, Palestine. Am J Infect Control 2021; 50:934-940. [PMID: 34963647 DOI: 10.1016/j.ajic.2021.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 11/17/2022]
Abstract
BACKGROUND Streptococcus agalactiae (group B Streptococcus) is beta-hemolytic, catalase negative, gram-positive cocci, recognized as main bacterial pathogen causing infections in newborns, infants, adults, and elderly people around the world. The aim of this study is to investigate group B Streptococcus samples recovered from invasive patients and determine serotype, virulent genes, and antibiotic-resistant profile of Streptococcus agalactiae in Palestine. METHODS A total of 95 group B Streptococcus strains were isolated from neonates, infants, pregnant and non-pregnant women and males at Arabcare Hospital Laboratory, Palestine, between the period of June 2018 and September 2020. Species identification was carried out through cultivation and conventional biochemical tests. A conventional Polymerase Chain Reaction (cPCR) was used to determine the 5 serotypes and virulent genes of the Streptococcus agalactiae strains. The antibiotic resistance test of group B Streptococcus was evaluated using Kirby-Bauer disk susceptibility. Sequencing and BLAST analysis were used to determine the relationship of the isolates in this study to worldwide isolates. RESULTS Serotype III (35%) was the major group B Streptococcus strains serotype causing invasive infections in neonates, infants, pregnant and nonpregnant women, and males, followed by serotypes V (19%), Ia, and II (15%), Ib (6%), respectively. All our isolates encoding for surface protein virulent factors, including a highly virulent gene (HvgA) were mostly found in strains isolated from pregnant women (12%). These group B Streptococcus strains exhibited a high rate of resistance to clindamycin (26%). The overall percentage of levofloxacin resistance was 11%, while vancomycin and ampicillin showed higher resistance, at 14.7 and 16% respectively. In addition, the phylogenetic relationship dendrogram illustrates that Streptococcus agalactiae isolated from an invasive patient (newborn) in Palestine was similar to strains found in China and Japan. CONCLUSIONS The outcomes of this study demonstrate that resistant group B Streptococcus strains are common in Palestine, therefore, evidence-based infection prevention and antibiotic stewardship efforts are necessary.
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Affiliation(s)
| | - Mahmoud Srour
- Biology and Biochemistry Department, Faculty of Science, Birzeit University, Palestine
| | - Shadi Hasan
- Biology and Biochemistry Department, Faculty of Science, Birzeit University, Palestine
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16
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Functional Insights into the High-Molecular-Mass Penicillin-Binding Proteins of Streptococcus agalactiae Revealed by Gene Deletion and Transposon Mutagenesis Analysis. J Bacteriol 2021; 203:e0023421. [PMID: 34124943 DOI: 10.1128/jb.00234-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
High-molecular-mass penicillin-binding proteins (PBPs) are enzymes that catalyze the biosynthesis of bacterial cell wall peptidoglycan. The Gram-positive bacterial pathogen Streptococcus agalactiae (group B streptococcus [GBS]) produces five high-molecular-mass PBPs, namely, PBP1A, PBP1B, PBP2A, PBP2B, and PBP2X. Among these, only PBP2X is essential for cell viability, whereas the other four PBPs are individually dispensable. The biological function of the four nonessential PBPs is poorly characterized in GBS. We deleted the pbp1a, pbp1b, pbp2a, and pbp2b genes individually from a genetically well-characterized serotype V GBS strain and studied the phenotypes of the four isogenic mutant strains. Compared to the wild-type parental strain, (i) none of the pbp isogenic mutant strains had a significant growth defect in Todd-Hewitt broth supplemented with 0.2% yeast extract (THY) rich medium, (ii) isogenic mutant Δpbp1a and Δpbp1b strains had significantly increased susceptibility to penicillin and ampicillin, and (iii) isogenic mutant Δpbp1a and Δpbp2b strains had significantly longer chain lengths. Using saturated transposon mutagenesis and transposon insertion site sequencing, we determined the genes essential for the viability of the wild-type GBS strain and each of the four isogenic pbp deletion mutant strains in THY rich medium. The pbp1a gene is essential for cell viability in the pbp2b deletion background. Reciprocally, pbp2b is essential in the pbp1a deletion background. Moreover, the gene encoding RodA, a peptidoglycan polymerase that works in conjunction with PBP2B, is also essential in the pbp1a deletion background. Together, our results suggest functional overlap between PBP1A and the PBP2B-RodA complex in GBS cell wall peptidoglycan biosynthesis. IMPORTANCE High-molecular-mass penicillin-binding proteins (HMM PBPs) are enzymes required for bacterial cell wall biosynthesis. Bacterial pathogen group B streptococcus (GBS) produces five distinct HMM PBPs. The biological functions of these proteins are not well characterized in GBS. In this study, we performed a comprehensive deletion analysis of genes encoding HMM PBPs in GBS. We found that deleting certain PBP-encoding genes altered bacterial susceptibility to beta-lactam antibiotics, cell morphology, and the essentiality of other enzymes involved in cell wall peptidoglycan synthesis. The results of our study shed new light on the biological functions of PBPs in GBS.
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17
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Zhao Z, Shang X, Chen Y, Zheng Y, Huang W, Jiang H, Lv Q, Kong D, Jiang Y, Liu P. Bacteria elevate extracellular adenosine to exploit host signaling for blood-brain barrier disruption. Virulence 2021; 11:980-994. [PMID: 32772676 PMCID: PMC7549952 DOI: 10.1080/21505594.2020.1797352] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Bacterial meningitis remains a substantial cause of mortality worldwide and survivors may have severe lifelong disability. Although we know that meningeal bacterial pathogens must cross blood-central nervous system (CNS) barriers, the mechanisms which facilitate the virulence of these pathogens are poorly understood. Here, we show that adenosine from a surface enzyme (Ssads) of Streptococcus suis facilitates this pathogen’s entry into mouse brains. Monolayer translocation assays (from the human cerebrovascular endothelium) and experiments using diverse inhibitors and agonists together demonstrate that activation of the A1 adenosine receptor signaling cascade in hosts, as well as attendant cytoskeleton remodeling, promote S. suis penetration across blood-CNS barriers. Importantly, our additional findings showing that Ssads orthologs from other bacterial species also promote their translocation across barriers suggest that exploitation of A1 AR signaling may be a general mechanism of bacterial virulence.
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Affiliation(s)
- Zunquan Zhao
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
| | - Xueyi Shang
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China.,Department of Critical Care Medicine, The Fifth Medical Center of Chinese PLA General Hospital , Beijing, China
| | - Ying Chen
- School of Food and Chemical Engineering, Beijing Technology and Business University , Beijing, China
| | - Yuling Zheng
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
| | - Wenhua Huang
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
| | - Hua Jiang
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
| | - Qingyu Lv
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
| | - Decong Kong
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
| | - Yongqiang Jiang
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
| | - Peng Liu
- State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology , Beijing, China
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18
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Yue C, Hu C, Xiang P, Zhang S, Xiao H, Zhou W, Jin H, Shi D, Li J, Xu L, Chen Y, Zeng Y. Autophagy is a defense mechanism controlling Streptococcus suis serotype 2 infection in murine microglia cells. Vet Microbiol 2021; 258:109103. [PMID: 33991788 DOI: 10.1016/j.vetmic.2021.109103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 05/05/2021] [Indexed: 01/03/2023]
Abstract
Streptococcus suis (S. suis) is an important swine and human pathogen, causing severe meningitis with high morbidity and mortality worldwide. Microglial activation and inflammation are responsible for bacterial meningitis. S. suis has been identified to activate microglia, but the role of autophagy following S. suis infection in microglial cells remains elusive. In this study, using western blot, immunofluorescent staining and transmission electron microscopy (TEM), we demonstrated that S. suis serotype 2 (SS2) triggered autophagosome and enhanced autophagic flux in BV2 microglial cells. Autophagy activators, rapamycin, could further promote autophagy in S. suis-infected BV2 cells. Conversely, autophagy inhibitors including siRNA targeting ATG5, Beclin-1, ATG9a and ATG12 attenuated the autophagic process. Consistent with the in vitro results, autophagy was activated following S. suis infection in brain tissue including frontal cortex and hippocampus in a mouse model of meningitis. Further experiment showed that autophagy serves as a cellular defense mechanism to limit invaded bacteria and microglia inflammation in S. suis-infected BV2 cells. This is the first study reporting that the interaction between autophagy and microglia cells in response to S. suis infection. The possible mechanism involved could additionally suggest potential therapeutic approaches for bacterial meningitis.
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Affiliation(s)
- Chaoxiong Yue
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Chenlu Hu
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Peng Xiang
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Siming Zhang
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Hongde Xiao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Wei Zhou
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Hui Jin
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Deshi Shi
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China
| | - Jinquan Li
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Lang Xu
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China
| | - Yushan Chen
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China.
| | - Yan Zeng
- Brain Science and Advanced Technology Institute, Wuhan University of Science and Technology, Wuhan, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, China.
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19
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Reinscheid F. A new proposal for the causative agent of the sporadic form of Alzheimer's disease. Med Hypotheses 2020; 146:110453. [PMID: 33373829 DOI: 10.1016/j.mehy.2020.110453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
Group B streptococcus (Streptococcus agalactiae) is proposed as causative agent for the development of the sporadic form of Alzheimer's disease. Using a fibrinogen binding protein, aggregates are formed including A-beta. After triggering Alzheimer's disease by the bacterium, the next down-stream events mainly follow the well known so called A-beta hypothesis. The combination of the two hypotheses is able to explain a number of epidemiological and biochemial aspects of Alzheimer's disease.
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Affiliation(s)
- Frauke Reinscheid
- Institution: GoePharmResearch, Pfaffenstück 16, 37077 Göttingen, Germany.
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20
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Yang Z, Lin P, Chen B, Zhang X, Xiao W, Wu S, Huang C, Feng D, Zhang W, Zhang J. Autophagy alleviates hypoxia-induced blood-brain barrier injury via regulation of CLDN5 (claudin 5). Autophagy 2020; 17:3048-3067. [PMID: 33280500 DOI: 10.1080/15548627.2020.1851897] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Blood-brain barrier (BBB) disruption is a key event in triggering secondary damage to the central nervous system (CNS) under stroke, and is frequently associated with abnormal macroautophagy/autophagy in brain microvascular endothelial cells (BMECs). However, the underlying mechanism of autophagy in maintaining BBB integrity remains unclear. Here we report that in BMECs of patients suffering stroke, CLDN5 (claudin 5) abnormally aggregates in the cytosol accompanied by autophagy activation. In vivo zebrafish and in vitro cell studies reveal that BBB breakdown is partially caused by CAV1 (caveolin 1)-mediated redistribution of membranous CLDN5 into the cytosol under hypoxia. Meanwhile, autophagy is activated and contributes mainly to the degradation of CAV1 and aggregated CLDN5 in the cytosol of BMECs, therefore alleviating BBB breakdown. Blockage of autophagy by genetic methods or chemicals aggravates cytosolic aggregation of CLDN5, resulting in severer BBB impairment. These data demonstrate that autophagy functions in the protection of BBB integrity by regulating CLDN5 redistribution and provide a potential therapeutic strategy for BBB disorder-related cerebrovascular disease.Abbreviations: BBB: blood-brain barrier; BECN1: beclin 1; BMEC: brain microvascular endothelial cell; CAV1: caveolin 1; CCA: common carotid artery; CLDN5: claudin 5; CNS: central nervous system; CQ: chloroquine; HIF1A: hypoxia inducible factor 1 subunit alpha; MCAO: middle cerebral artery occlusion-reperfusion; OCLN: occludin; ROS: reactive oxygen species; STED: stimulated emission depletion; TEER: trans-endothelial electrical resistance; TEM: transmission electron microscopy; TJ: tight junction; TJP1: tight junction protein 1; UPS: ubiquitin-proteasome system.
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Affiliation(s)
- Zhenguo Yang
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease of Guangdong Medical University, Zhanjiang, China
| | - Panpan Lin
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease of Guangdong Medical University, Zhanjiang, China
| | - Bing Chen
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease of Guangdong Medical University, Zhanjiang, China
| | - Xiaoqi Zhang
- Nanshan School, Guangzhou Medical University, Guangzhou, China
| | - Wei Xiao
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease of Guangdong Medical University, Zhanjiang, China
| | - Shuilong Wu
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease of Guangdong Medical University, Zhanjiang, China
| | - Chunnian Huang
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease of Guangdong Medical University, Zhanjiang, China
| | - Du Feng
- School of Basic Medical Sciences, Guangzhou Medical University, Guangzhou, China
| | - Wenqing Zhang
- Laboratory of Developmental Biology and Regenerative Medicine, School of Medicine, South China University of Technology, Guangzhou, China
| | - Jingjing Zhang
- Affiliated Hospital of Guangdong Medical University & Key Laboratory of Zebrafish Model for Development and Disease of Guangdong Medical University, Zhanjiang, China
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21
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Genetic Basis Underlying the Hyperhemolytic Phenotype of Streptococcus agalactiae Strain CNCTC10/84. J Bacteriol 2020; 202:JB.00504-20. [PMID: 32958630 DOI: 10.1128/jb.00504-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 09/11/2020] [Indexed: 01/30/2023] Open
Abstract
Streptococcus agalactiae (group B streptococcus [GBS]) is a major cause of infections in newborns, pregnant women, and immunocompromised patients. GBS strain CNCTC10/84 is a clinical isolate that has high virulence in animal models of infection and has been used extensively to study GBS pathogenesis. Two unusual features of this strain are hyperhemolytic activity and hypo-CAMP factor activity. These two phenotypes are typical of GBS strains that are functionally deficient in the CovR-CovS two-component regulatory system. A previous whole-genome sequencing study found that strain CNCTC10/84 has intact covR and covS regulatory genes. We investigated CovR-CovS regulation in CNCTC10/84 and discovered that a single-nucleotide insertion in a homopolymeric tract in the covR promoter region underlies the strong hemolytic activity and weak CAMP activity of this strain. Using isogenic mutant strains, we demonstrate that this single-nucleotide insertion confers significantly decreased expression of covR and covS and altered expression of CovR-CovS-regulated genes, including that of genes encoding β-hemolysin and CAMP factor. This single-nucleotide insertion also confers significantly increased GBS survival in human whole blood ex vivo IMPORTANCE Group B streptococcus (GBS) is the leading cause of neonatal sepsis, pneumonia, and meningitis. GBS strain CNCTC10/84 is a highly virulent blood isolate that has been used extensively to study GBS pathogenesis for over 20 years. Strain CNCTC10/84 has an unusually strong hemolytic activity, but the genetic basis is unknown. In this study, we discovered that a single-nucleotide insertion in an intergenic homopolymeric tract is responsible for the elevated hemolytic activity of CNCTC10/84.
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22
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Genome-Wide Assessment of Streptococcus agalactiae Genes Required for Survival in Human Whole Blood and Plasma. Infect Immun 2020; 88:IAI.00357-20. [PMID: 32747604 DOI: 10.1128/iai.00357-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 07/26/2020] [Indexed: 12/17/2022] Open
Abstract
Streptococcus agalactiae (group B streptococcus, or GBS) is a common cause of bacteremia and sepsis in newborns, pregnant women, and immunocompromised patients. The molecular mechanisms used by GBS to survive and proliferate in blood are not well understood. Here, using a highly virulent GBS strain and transposon-directed insertion site sequencing (TraDIS), we performed genome-wide screens to discover novel GBS genes required for bacterial survival in human whole blood and plasma. The screen identified 85 and 41 genes that are required for GBS growth in whole blood and plasma, respectively. A common set of 29 genes was required in both whole blood and plasma. Targeted gene deletion confirmed that (i) genes encoding methionine transporter (metP) and manganese transporter (mtsA) are crucial for GBS survival in whole blood and plasma, (ii) gene W903_1820, encoding a small multidrug export family protein, contributes significantly to GBS survival in whole blood, (iii) the shikimate pathway gene aroA is essential for GBS growth in whole blood and plasma, and (iv) deletion of srr1, encoding a fibrinogen-binding adhesin, increases GBS survival in whole blood. Our findings provide new insight into the GBS-host interactions in human blood.
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23
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Wu C, Yang M, Liu R, Hu H, Ji L, Zhang X, Huang S, Wang L. Nicotine Reduces Human Brain Microvascular Endothelial Cell Response to Escherichia coli K1 Infection by Inhibiting Autophagy. Front Cell Infect Microbiol 2020; 10:484. [PMID: 33042863 PMCID: PMC7522313 DOI: 10.3389/fcimb.2020.00484] [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: 01/07/2020] [Accepted: 08/04/2020] [Indexed: 01/22/2023] Open
Abstract
Studies have shown that exposure to environmental tobacco smoke can increase the risk of bacterial meningitis, and nicotine is the core component of environmental tobacco smoke. Autophagy is an important way for host cells to eliminate invasive pathogens and resist infection. Escherichia coli K1 strain (E. coli K1) is the most common Gram-negative bacterial pathogen that causes neonatal meningitis. The mechanism of nicotine promoting E. coli K1 to invade human brain microvascular endothelial cells (HBMECs), the main component of the blood–brain barrier, is not clear yet. Our study found that the increase of HBMEC autophagy level during E. coli K1 infection could decrease the survival of intracellular bacteria, while nicotine exposure could inhibit the HBMEC autophagic response of E. coli K1 infection by activating the NF-kappa B and PI3K/Akt/mTOR pathway. We concluded that nicotine could inhibit HBMEC autophagy upon E. coli K1 infection and decrease the scavenging effect on E. coli K1, thus promoting the occurrence and development of neonatal meningitis.
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Affiliation(s)
- Chao Wu
- Department of Histology and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Mengzhen Yang
- Department of Histology and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Rui Liu
- Department of Histology and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Department of Human Anatomy, School of Basic Medical Sciences, Hubei University of Medicine, Shiyan, China
| | - Hanyang Hu
- Department of Histology and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Lulu Ji
- Department of Histology and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Xiaoli Zhang
- Department of Ultrasound Imaging, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Shenghe Huang
- Kunming Key Laboratory of Children Infection and Immunity, Yunnan Institute of Pediatrics, Kunming Children's Hospital, Kunming, China.,Department of Pediatrics, Children's Hospital Los Angeles, University of Southern California, Los Angeles, CA, United States
| | - Lin Wang
- Department of Histology and Embryology, School of Basic Medical Sciences, Wuhan University, Wuhan, China.,Hubei Provincial Key Laboratory of Developmentally Originated Disease, Wuhan, China
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24
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Abstract
Group B Streptococcus (GBS) remains the leading cause of neonatal meningitis, a disease associated with high rates of adverse neurological sequelae. The in vivo relationship between GBS and brain tissues remains poorly characterized, partly because past studies had focused on microbial rather than host processes. Additionally, the field has not capitalized on systems-level technologies to probe the host-pathogen relationship. Here, we use multiplexed quantitative proteomics to investigate the effect of GBS infection in the murine brain at various levels of tissue complexity, beginning with the whole organ and moving to brain vascular substructures. Infected whole brains showed classical signatures associated with the acute-phase response. In isolated brain microvessels, classical blood-brain barrier proteins were unaltered, but interferon signaling and leukocyte recruitment proteins were upregulated. The choroid plexus showed increases in peripheral immune cell proteins. Proteins that increased in abundance in the vasculature during GBS invasion were associated with major histocompatibility complex (MHC) class I antigen processing and endoplasmic reticulum dysfunction, a finding which correlated with altered host protein glycosylation profiles. Globally, there was low concordance between the infection proteome of whole brains and isolated vascular tissues. This report underscores the utility of unbiased, systems-scale analyses of functional tissue substructures for understanding disease.IMPORTANCE Group B Streptococcus (GBS) meningitis remains a major cause of poor health outcomes very early in life. Both the host-pathogen relationship leading to disease and the massive host response to infection contributing to these poor outcomes are orchestrated at the tissue and cell type levels. GBS meningitis is thought to result when bacteria present in the blood circumvent the selectively permeable vascular barriers that feed the brain. Additionally, tissue damage subsequent to bacterial invasion is mediated by inflammation and by immune cells from the periphery crossing the blood-brain barrier. Indeed, the vasculature plays a central role in disease processes occurring during GBS infection of the brain. Here, we employed quantitative proteomic analysis of brain vascular substructures during invasive GBS disease. We used the generated data to map molecular alterations associated with tissue perturbation, finding widespread intracellular dysfunction and punctuating the importance of investigations relegated to tissue type over the whole organ.
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25
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Wang G, Fu Y, Ma K, Liu J, Liu X. NOD2 regulates microglial inflammation through the TAK1-NF-κB pathway and autophagy activation in murine pneumococcal meningitis. Brain Res Bull 2020; 158:20-30. [PMID: 32109527 DOI: 10.1016/j.brainresbull.2020.02.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 01/16/2020] [Accepted: 02/11/2020] [Indexed: 10/24/2022]
Abstract
Streptococcus pneumoniae is responsible for pneumococcal meningitis, with significant mortality and morbidity worldwide. Microglial inflammation plays a vital role in meningitis. The peptidoglycan sensor NOD2 (nucleotide-binding oligomerization domain 2) has been identified to promote microglia activation, but the role in autophagy following pneumococcal meningitis remains unclear. In the present study, we investigated the role of NOD2 in microglial inflammation and autophagy, as well as related signaling pathways, during S. pneumonia infection. NOD2 expression was knocked down by the injection of lentivirus-mediated short-hairpin RNA (shRNA). Our results revealed that NOD2 promotes microglial inflammation by increasing inflammatory mediators. We also showed that the TAK1-NF-κB pathway is involved in this process. In addition, NOD2 increased the expression of autophagy-related proteins and induced autophagosome formation. Rapamycin and 3-MA were utilized to assess the role of autophagy in microglial inflammation induced by S. pneumonia. We demonstrated that autophagy serves as a cellular defense mechanism to reduce inflammatory mediators. Similar to the in vitro results, NOD2 induced inflammation and autophagy in the brain in a mouse meningitis model. Moreover, NOD2 silencing significantly reduced brain edema and improved the neurological function of pneumococcal meningitis mice. Taken together, these data demonstrate that NOD2 promotes microglial inflammation and autophagy in murine pneumococcal meningitis, and the TAK1-NF-κB pathway is involved in microglial activation.
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Affiliation(s)
- Guan Wang
- Department of Pediatrics, Qilu Hospital, Shandong University, 107#, Wen Hua Xi Road, Jinan, Shandong, 250012, PR China
| | - Yanan Fu
- Qilu Hospital, Shandong University, 107#, Wen Hua Xi Road, Jinan, Shandong, 250012, PR China
| | - Kun Ma
- Department of Pediatrics, Shandong Provincial Qianfoshan Hospital, The Frist Hospital Affiliated with Shandong First Medical University, 16766#, Jing Shi Road, Jinan, Shandong, 250014, PR China
| | - Junli Liu
- Department of Pediatrics, Taian Central Hospital, 29#, Long Tan Road, Taian, Shandong, 271000, PR China
| | - Xinjie Liu
- Department of Pediatrics, Qilu Hospital, Shandong University, 107#, Wen Hua Xi Road, Jinan, Shandong, 250012, PR China.
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26
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Shing SR, Ramos AR, Patras KA, Riestra AM, McCabe S, Nizet V, Coady A. The Fungal Pathogen Candida albicans Promotes Bladder Colonization of Group B Streptococcus. Front Cell Infect Microbiol 2020; 9:437. [PMID: 31998657 PMCID: PMC6966239 DOI: 10.3389/fcimb.2019.00437] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 12/05/2019] [Indexed: 12/16/2022] Open
Abstract
Group B Streptococcus (GBS) is a common cause of bacterial urinary tract infections (UTI) in susceptible populations, including pregnant women and the elderly. However, the factors that govern GBS persistence and disease severity in this niche are not fully understood. Here, we report that the presence of the fungus Candida albicans, a common urogenital colonizer, can promote GBS UTI. Co-inoculation of GBS with C. albicans increased bacterial adherence to bladder epithelium and promoted GBS colonization in vivo in a C. albicans adhesin-dependent manner. This study demonstrates that fungal colonization of the urogenital tract may be an important determinant of bacterial pathogenesis during UTI.
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Affiliation(s)
- Samuel R Shing
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Anissa R Ramos
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Kathryn A Patras
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Angelica M Riestra
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Sinead McCabe
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
| | - Victor Nizet
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States.,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, United States
| | - Alison Coady
- Collaborative to Halt Antibiotic-Resistant Microbes, Department of Pediatrics, University of California, San Diego, La Jolla, CA, United States
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27
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Le Guennec L, Coureuil M, Nassif X, Bourdoulous S. Strategies used by bacterial pathogens to cross the blood-brain barrier. Cell Microbiol 2019; 22:e13132. [PMID: 31658405 DOI: 10.1111/cmi.13132] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 10/11/2019] [Accepted: 10/13/2019] [Indexed: 12/15/2022]
Abstract
The skull, spine, meninges, and cellular barriers at the blood-brain and the blood-cerebrospinal fluid interfaces well protect the brain and meningeal spaces against microbial invasion. However, once in the bloodstream, a range of pathogenic bacteria is able to reach the brain and cause meningitis. Despite advances in antibacterial therapy, bacterial meningitis remains one of the most important infectious diseases worldwide. The most common causative bacteria in children and adults are Streptococcus pneumoniae and Neisseria meningitidis associated with high morbidity and mortality, while among neonates, most cases of bacterial meningitis are due to group B Streptococcus and Escherichia coli. Here we summarise our current knowledge on the strategies used by these bacterial pathogens to survive in the bloodstream, to colonise the brain vasculature and to cross the blood-brain barrier.
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Affiliation(s)
- Loic Le Guennec
- Inserm (Institut National de la Sante et de la Recherche Medicale), U1016, Institut Cochin, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Mathieu Coureuil
- Inserm (Institut National de la Sante et de la Recherche Medicale), unité U1151, Institut-Necker-Enfants-Malades, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR 8253, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, Paris, France
| | - Xavier Nassif
- Inserm (Institut National de la Sante et de la Recherche Medicale), unité U1151, Institut-Necker-Enfants-Malades, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR 8253, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, Paris, France.,Assistance Publique - Hôpitaux de Paris, Hôpital Necker Enfants Malades, Paris, France
| | - Sandrine Bourdoulous
- Inserm (Institut National de la Sante et de la Recherche Medicale), U1016, Institut Cochin, Paris, France.,CNRS (Centre National de la recherche Scientifique), UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
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28
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Kim BJ, McDonagh MA, Deng L, Gastfriend BD, Schubert-Unkmeir A, Doran KS, Shusta EV. Streptococcus agalactiae disrupts P-glycoprotein function in brain endothelial cells. Fluids Barriers CNS 2019; 16:26. [PMID: 31434575 PMCID: PMC6704684 DOI: 10.1186/s12987-019-0146-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/30/2019] [Indexed: 01/16/2023] Open
Abstract
Bacterial meningitis is a serious life threatening infection of the CNS. To cause meningitis, blood-borne bacteria need to interact with and penetrate brain endothelial cells (BECs) that comprise the blood-brain barrier. BECs help maintain brain homeostasis and they possess an array of efflux transporters, such as P-glycoprotein (P-gp), that function to efflux potentially harmful compounds from the CNS back into the circulation. Oftentimes, efflux also serves to limit the brain uptake of therapeutic drugs, representing a major hurdle for CNS drug delivery. During meningitis, BEC barrier integrity is compromised; however, little is known about efflux transport perturbations during infection. Thus, understanding the impact of bacterial infection on P-gp function would be important for potential routes of therapeutic intervention. To this end, the meningeal bacterial pathogen, Streptococcus agalactiae, was found to inhibit P-gp activity in human induced pluripotent stem cell-derived BECs, and live bacteria were required for the observed inhibition. This observation was correlated to decreased P-gp expression both in vitro and during infection in vivo using a mouse model of bacterial meningitis. Given the impact of bacterial interactions on P-gp function, it will be important to incorporate these findings into analyses of drug delivery paradigms for bacterial infections of the CNS.
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Affiliation(s)
- Brandon J. Kim
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
- Department of Hygiene and Microbiology, University of Würzburg, Joseph Schneider Strasse 2/E1, 97080 Würzburg, Germany
| | - Maura A. McDonagh
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
| | - Liwen Deng
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO USA
| | - Benjamin D. Gastfriend
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
| | - Alexandra Schubert-Unkmeir
- Department of Hygiene and Microbiology, University of Würzburg, Joseph Schneider Strasse 2/E1, 97080 Würzburg, Germany
| | - Kelly S. Doran
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO USA
| | - Eric V. Shusta
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI USA
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29
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The Group B Streptococcal surface antigen I/II protein, BspC, interacts with host vimentin to promote adherence to brain endothelium and inflammation during the pathogenesis of meningitis. PLoS Pathog 2019; 15:e1007848. [PMID: 31181121 PMCID: PMC6586375 DOI: 10.1371/journal.ppat.1007848] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/20/2019] [Accepted: 05/16/2019] [Indexed: 12/29/2022] Open
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) normally colonizes healthy adults but can cause invasive disease, such as meningitis, in the newborn. To gain access to the central nervous system, GBS must interact with and penetrate brain or meningeal blood vessels; however, the exact mechanisms are still being elucidated. Here, we investigate the contribution of BspC, an antigen I/II family adhesin, to the pathogenesis of GBS meningitis. Disruption of the bspC gene reduced GBS adherence to human cerebral microvascular endothelial cells (hCMEC), while heterologous expression of BspC in non-adherent Lactococcus lactis conferred bacterial attachment. In a murine model of hematogenous meningitis, mice infected with ΔbspC mutants exhibited lower mortality as well as decreased brain bacterial counts and inflammatory infiltrate compared to mice infected with WT GBS strains. Further, BspC was both necessary and sufficient to induce neutrophil chemokine expression. We determined that BspC interacts with the host cytoskeleton component vimentin and confirmed this interaction using a bacterial two-hybrid assay, microscale thermophoresis, immunofluorescent staining, and imaging flow cytometry. Vimentin null mice were protected from WT GBS infection and also exhibited less inflammatory cytokine production in brain tissue. These results suggest that BspC and the vimentin interaction is critical for the pathogenesis of GBS meningitis. Group B Streptococcus (GBS) typically colonizes healthy adults but can cause severe disease in immune-compromised individuals, including newborns. Despite wide-spread intrapartum antibiotic prophylaxis given to pregnant women, GBS remains a leading cause of neonatal meningitis. To cause meningitis, GBS must interact with and penetrate the blood-brain barrier (BBB), which separates bacteria and immune cells in the blood from the brain. In order to develop targeted therapies to treat GBS meningitis, it is important to understand the mechanisms of BBB crossing. Here, we describe the role of the GBS surface factor, BspC, in promoting meningitis and discover the host ligand for BspC, vimentin, which is an intermediate filament protein that is constitutively expressed by endothelial cells. We determined that BspC interacts with the C-terminal domain of cell-surface vimentin to promote bacterial attachment to brain endothelial cells and that purified BspC protein can induce immune signaling pathways. In a mouse model of hematogenous meningitis, we observed that a GBS mutant lacking BspC was less virulent compared to WT GBS and resulted in less inflammatory disease. We also observed that mice lacking vimentin were protected from GBS infection. These results reveal the importance of the BspC-vimentin interaction in the progression of GBS meningitis disease.
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30
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Tsai MH, Hsu JF, Lai MY, Lin LC, Chu SM, Huang HR, Chiang MC, Fu RH, Lu JJ. Molecular Characteristics and Antimicrobial Resistance of Group B Streptococcus Strains Causing Invasive Disease in Neonates and Adults. Front Microbiol 2019; 10:264. [PMID: 30833941 PMCID: PMC6387999 DOI: 10.3389/fmicb.2019.00264] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 02/01/2019] [Indexed: 11/17/2022] Open
Abstract
We aimed to analyze the molecular characteristics, clonality and antimicrobial resistance profiles of group B streptococcus (GBS) isolates collected in Taiwan from invasive diseases and carriage. Multilocus sequence typing (MLST) was used to assess the genetic diversity of 225 GBS strains from neonates and adults with invasive GBS diseases. 100 GBS strains collected from colonized pregnant women during the same period were compared, and all strains were characterized for one of nine capsule genotypes. We also determined the susceptibilities of all GBS isolates to various antimicrobial agents. The most frequently identified serotypes that caused invasive disease in neonates were III (60.6%) and Ia (17.3%), whereas type VI (32.7%), Ib (19.4%), and V (19.4%) were the most common to cause invasive disease in adults. Serotype VI was the leading type that colonized pregnant women (35.0%). Twenty-six sequence types (STs) were identified, and 90.5% of GBS strains were represented by 6 STs. ST-17 and ST-1 were more prevalent in invasive diseases in neonates and adults, respectively. The majority of serotype III and VI isolates belonged to clonal complex (CC)-17 and CC-1, respectively. ST-17 strains were more likely to cause meningitis and late-onset disease than other strains. In addition, ST-12 and ST-17 GBS strains showed the highest rate of resistance to erythromycin and clindamycin (range: 75.8–100%). In conclusion, CC-17/type III and CC-1/type VI are the most important invasive pathogens in infants and non-pregnant adults in Taiwan, respectively. GBS genotypes vary between different age groups and geographical areas and should be considered during GBS vaccine development.
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Affiliation(s)
- Ming-Horng Tsai
- Division of Neonatology and Pediatric Hematology/Oncology, Department of Pediatrics, Chang Gung Memorial Hospital, Yunlin, Taiwan.,College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Jen-Fu Hsu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Mei-Yin Lai
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Lee-Chung Lin
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Shih-Ming Chu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Hsuan-Rong Huang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ming-Chou Chiang
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ren-Huei Fu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Jang-Jih Lu
- College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
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31
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Dong Y, Wang J, Du KX, Jia TM, Zhu CL, Zhang Y, Xu FL. MicroRNA-135a participates in the development of astrocytes derived from bacterial meningitis by downregulating HIF-1α. Am J Physiol Cell Physiol 2019; 316:C711-C721. [PMID: 30726113 DOI: 10.1152/ajpcell.00440.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Accumulating evidence has highlighted the potential of microRNAs (miRs) as biomarkers in various human diseases. However, the roles of miRs in bacterial meningitis (BM), a severe infectious condition, still remain unclear. Thus, the present study aimed to investigate the effects of miR-135a on proliferation and apoptosis of astrocytes in BM. Neonatal rats were injected with Streptococcus pneumoniae to establish the BM model. The expression of miR-135a and hypoxia-inducible factor 1α (HIF-1α) in the BM rat models were characterized, followed by determination of their interaction. Using gain- and loss-of-function approaches, the effects of miR-135a on proliferation, apoptosis, and expression of glial fibrillary acidic protein (GFAP), in addition to apoptosis-related factors in astrocytes were examined accordingly. The regulatory effect of HIF-1α was also determined along with the overexpression or knockdown of HIF-1α. The results obtained indicated that miR-135a was poorly expressed, whereas HIF-1α was highly expressed in the BM rat models. In addition, restored expression levels of miR-135a were determined to promote proliferation while inhibiting the apoptosis of astrocytes, along with downregulated Bax and Bad, as well as upregulated Bcl-2, Bcl-XL, and GFAP. As a target gene of miR-135a, HIF-1α expression was determined to be diminished by miR-135a. The upregulation of HIF-1α reversed the miR-135a-induced proliferation of astrocytes. Taken together, the key findings of the current study present evidence suggesting that miR-135a can downregulate HIF-1α and play a contributory role in the development of astrocytes derived from BM, providing a novel theoretical perspective for BM treatment approaches.
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Affiliation(s)
- Yan Dong
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University , Zhengzhou , China.,Henan Provincial Key Laboratory of Child Brain Injury , Zhengzhou , China
| | - Jun Wang
- Department of Children Rehabilitation, Third Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Kai-Xian Du
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Tian-Ming Jia
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University , Zhengzhou , China
| | - Chang-Lian Zhu
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University , Zhengzhou , China.,Henan Provincial Key Laboratory of Child Brain Injury , Zhengzhou , China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
| | - Yan Zhang
- Clinical Laboratory, Henan Red Cross Blood Center , Zhengzhou , China
| | - Fa-Lin Xu
- Department of Pediatrics, Third Affiliated Hospital of Zhengzhou University , Zhengzhou , China
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Meng L, Zhao X, Zhang H. HIPK1 Interference Attenuates Inflammation and Oxidative Stress of Acute Lung Injury via Autophagy. Med Sci Monit 2019; 25:827-835. [PMID: 30734722 PMCID: PMC6362758 DOI: 10.12659/msm.912507] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
<strong>BACKGROUND</strong> Acute respiratory distress syndrome (ARDS), which is characterized by severe hypoxemia (PaO2/FIO2 ≤300 mmHg), is usually companied by uncontrolled inflammation, oxidative injury, and the damage to the alveolar-capillary barrier. Severe ARDS is usually companied with acute lung injury that worsen the patients' condition. HIPK1 is a modulator of homeodomain-containing transcription factors and regulates multiple cellular biological process associated with inflammation and anti-stress responses. <strong>MATERIAL AND METHODS</strong> We used an LPS-induced mouse acute lung injury (ALI) model to investigate the possible role of HIPK1 in ALI pathophysiology. <strong>RESULTS</strong> We found the HIPK1 was elevated in ALI model mice while interference of HIPK1 by siRNA attenuated the inflammation and oxidative stress indicators (H2O2, O-2, and NO). Further research found HIPK1 interference enhanced the autophagy. <strong>CONCLUSIONS</strong> Decreased HIPK1 in ALI showed protective effects in attenuating inflammation and oxidative stress and enhancing autophagy, indicating HIPK1 as a possible target in ALI management.
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Affiliation(s)
- Lan Meng
- Department of Anesthesiology, Qingdao Municipal Hospital of Shandong Province, Qingdao, Shandong, China (mainland)
| | - Xin Zhao
- Department of Obstetrics, Qingdao Municipal Hospital of Shandong Province, Qingdao, Shandong, China (mainland)
| | - Hongxia Zhang
- Department of Obstetrics, Qingdao Municipal Hospital of Shandong Province, Qingdao, Shandong, China (mainland)
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Xu M, Hu L, Huang H, Wang L, Tan J, Zhang Y, Chen C, Zhang X, Huang L. Etiology and Clinical Features of Full-Term Neonatal Bacterial Meningitis: A Multicenter Retrospective Cohort Study. Front Pediatr 2019; 7:31. [PMID: 30815433 PMCID: PMC6381005 DOI: 10.3389/fped.2019.00031] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 01/24/2019] [Indexed: 01/30/2023] Open
Abstract
Objective: Neonatal bacterial meningitis is a severe infectious disease with a high risk of neurodevelopmental sequelae. The causative pathogens may be related to specific clinical features of the disease. Therefore, this study aimed at determining the pathogen-specific and clinical features of bacterial meningitis in full-term neonates. Methods: We enrolled neonates from the Shanghai Neonate Meningitis Cohort (2005-2017), which is a multicenter retrospective cohort that recruits almost all full-term neonates in Shanghai who underwent lumbar puncture. Patient history and clinical examination results were extracted from the computer-documented information systems of four hospitals. The trends of pathogen distribution were analyzed and differences in the clinical manifestations, treatment, and clinical outcomes at discharge were compared according to the causative pathogen. Logistic regression was used to evaluate the pathogen-specific risk of neurological complications. Results: In total, 518 cases of neonatal meningitis, including 189 proven cases, were included. Group B Streptococcus (GBS) and Escherichia coli (E. coli) were the leading pathogens in proven cases of early-onset and late-onset neonatal meningitis, respectively. The proportion of early-onset and late-onset GBS and late-onset E. coli meningitis cases increased gradually. GBS meningitis had the highest risk of neurological complications, whereas the overall incidence of hydrocephalus and brain abscess in E. coli was higher than that in GBS. Conclusions: Rates of neonatal GBS and E. coli meningitis were high in 2005-2017 in Shanghai, and the risk of neurological complications was also high. Therefore, active prevention, rational use of antibiotics, and continuous monitoring of GBS and E. coli in neonates should be initiated in Shanghai.
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Affiliation(s)
- Min Xu
- Department of Neonatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Lan Hu
- Department of Neonatology, Children Hospital of Fudan University, Shanghai, China
| | - Heyu Huang
- Department of Pediatric Infectious Diseases, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Liping Wang
- Department of Neonatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jintong Tan
- Department of Neonatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Yongjun Zhang
- Department of Neonatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Chao Chen
- Department of Neonatology, Children Hospital of Fudan University, Shanghai, China
| | - Xi Zhang
- Clinical Research Unit, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Lisu Huang
- Department of Pediatric Infectious Diseases, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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In vitro and ex vivo systems at the forefront of infection modeling and drug discovery. Biomaterials 2018; 198:228-249. [PMID: 30384974 PMCID: PMC7172914 DOI: 10.1016/j.biomaterials.2018.10.030] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 10/05/2018] [Accepted: 10/23/2018] [Indexed: 12/11/2022]
Abstract
Bacterial infections and antibiotic resistant bacteria have become a growing problem over the past decade. As a result, the Centers for Disease Control predict more deaths resulting from microorganisms than all cancers combined by 2050. Currently, many traditional models used to study bacterial infections fail to precisely replicate the in vivo bacterial environment. These models often fail to incorporate fluid flow, bio-mechanical cues, intercellular interactions, host-bacteria interactions, and even the simple inclusion of relevant physiological proteins in culture media. As a result of these inadequate models, there is often a poor correlation between in vitro and in vivo assays, limiting therapeutic potential. Thus, the urgency to establish in vitro and ex vivo systems to investigate the mechanisms underlying bacterial infections and to discover new-age therapeutics against bacterial infections is dire. In this review, we present an update of current in vitro and ex vivo models that are comprehensively changing the landscape of traditional microbiology assays. Further, we provide a comparative analysis of previous research on various established organ-disease models. Lastly, we provide insight on future techniques that may more accurately test new formulations to meet the growing demand of antibiotic resistant bacterial infections.
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Stable Expression of Modified Green Fluorescent Protein in Group B Streptococci To Enable Visualization in Experimental Systems. Appl Environ Microbiol 2018; 84:AEM.01262-18. [PMID: 30006391 DOI: 10.1128/aem.01262-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 07/04/2018] [Indexed: 12/17/2022] Open
Abstract
Group B streptococcus (GBS) is a Gram-positive bacterium associated with various diseases in humans and animals. Many studies have examined GBS physiology, virulence, and microbe-host interactions using diverse imaging approaches, including fluorescence microscopy. Strategies to label and visualize GBS using fluorescence biomarkers have been limited to antibody-based methods or nonspecific stains that bind DNA or protein; an effective plasmid-based system to label GBS with a fluorescence biomarker would represent a useful visualization tool. In this study, we developed and validated a green fluorescent protein (GFP)-variant-expressing plasmid, pGU2664, which can be applied as a marker to visualize GBS in experimental studies. The synthetic constitutively active CP25 promoter drives strong and stable expression of the GFPmut3 biomarker in GBS strains carrying pGU2664. GBS maintains GFPmut3 activity at different phases of growth. The application of fluorescence polarization enables easy discrimination of GBS GFPmut3 activity from the autofluorescence of culture media commonly used to grow GBS. Differential interference contrast microscopy, in combination with epifluorescence microscopy to detect GFPmut3 in GBS, enabled visualization of bacterial attachment to live human epithelial cells in real time. Plasmid pGU2664 was also used to visualize phenotypic differences in the adherence of wild-type GBS and an isogenic gene-deficient mutant strain lacking CovR (the control of virulence regulator) in adhesion assays. The system for GFPmut3 expression in GBS described in this study provides a new tool for the visualization of this organism in diverse research applications. We discuss the advantages and consider the limitations of this fluorescent biomarker system developed for GBS.IMPORTANCE Group B streptococcus (GBS) is a bacterium associated with various diseases in humans and animals. This study describes the development of a strategy to label and visualize GBS using a fluorescence biomarker, termed GFPmut3. We show that this biomarker can be successfully applied to track the growth of bacteria in liquid medium, and it enables the detailed visualization of GBS in the context of live human cells in real-time microscopic analysis. The system for GFPmut3 expression in GBS described in this study provides a new tool for the visualization of this organism in diverse research applications.
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36
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Jiang Z, Bo L, Meng Y, Wang C, Chen T, Wang C, Yu X, Deng X. Overexpression of homeodomain-interacting protein kinase 2 (HIPK2) attenuates sepsis-mediated liver injury by restoring autophagy. Cell Death Dis 2018; 9:847. [PMID: 30154452 PMCID: PMC6113252 DOI: 10.1038/s41419-018-0838-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 06/22/2018] [Accepted: 06/25/2018] [Indexed: 12/12/2022]
Abstract
Sepsis is the leading cause of death in intensive care units worldwide. Autophagy has recently been shown to protect against sepsis-induced liver injury. Here, we investigated the roles of homeodomain-interacting protein kinase 2 (HIPK2) in the molecular mechanism of sepsis-induced liver injury. HIPK2 expression was reduced in sepsis-induced liver injury, and HIPK2 overexpression increased the survival rate and improved caecal ligation and puncture (CLP)-induced liver injury by reducing serum and liver aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) levels in mice with sepsis. HIPK2 overexpression significantly decreased CLP-induced release of inflammatory cytokines into the serum and attenuated oxidative stress-associated indicators in mice with CLP-induced liver injury, whereas HIPK2 knockdown produced the opposite results, suggesting that HIPK2 is a negative regulator of sepsis. Furthermore, HIPK2 overexpression inhibited lipopolysaccharide (LPS)-induced apoptosis of primary hepatocytes, increased the autophagic flux, and restored both autophagosome and autolysosome formation in the livers of CLP-induced mice by suppressing calpain signalling. Importantly, HIPK2 overexpression reduced the elevated cytosolic Ca2+ concentration in LPS-treated primary hepatocytes by interacting with calpain 1 and calmodulin. Finally, several anti-inflammatory drugs, including resveratrol, aspirin, vitamin E and ursolic acid, significantly increased the levels of the HIPK2 mRNA and protein by modulating promoter activity and the 3′-UTR stability of the HIPK2 gene. In conclusion, HIPK2 overexpression may improve sepsis-induced liver injury by restoring autophagy and thus might be a promising target for the clinical treatment of sepsis.
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Affiliation(s)
- Zhengyu Jiang
- Faculty of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
| | - Lulong Bo
- Faculty of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
| | - Yan Meng
- Faculty of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
| | - Chen Wang
- Department of Cell Biology, School of Basic Medicine, Second Military Medical University, Shanghai, 200433, China
| | - Tianxing Chen
- School of Life Science, Nanjing University, 210023, Nanjing, Jiangsu Province, China.,State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, 210023, Nanjing, Jiangsu Province, China
| | - Changli Wang
- Faculty of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China
| | - Xiya Yu
- Faculty of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China.
| | - Xiaoming Deng
- Faculty of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai, 200433, China.
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37
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Kim KA, Shin D, Kim JH, Shin YJ, Rajanikant GK, Majid A, Baek SH, Bae ON. Role of Autophagy in Endothelial Damage and Blood-Brain Barrier Disruption in Ischemic Stroke. Stroke 2018; 49:1571-1579. [PMID: 29724893 DOI: 10.1161/strokeaha.117.017287] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Kyeong-A Kim
- From the College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Republic of Korea (K.-A.K., D.S., J.-H.K., Y.-J.S., O.-N.B.)
| | - Donggeun Shin
- From the College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Republic of Korea (K.-A.K., D.S., J.-H.K., Y.-J.S., O.-N.B.)
| | - Jeong-Hyeon Kim
- From the College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Republic of Korea (K.-A.K., D.S., J.-H.K., Y.-J.S., O.-N.B.)
| | - Young-Jun Shin
- From the College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Republic of Korea (K.-A.K., D.S., J.-H.K., Y.-J.S., O.-N.B.)
| | - G K Rajanikant
- School of Biotechnology, National Institute of Technology Calicut, Kerala, India (G.K.R.)
| | - Arshad Majid
- Sheffield Institute for Translational Neuroscience, University of Sheffield, England (A.M.)
| | - Seung-Hoon Baek
- College of Pharmacy and Research Institute of Pharmaceutical Science and Technology, Ajou University, Suwon, Republic of Korea (S.-H.B.)
| | - Ok-Nam Bae
- From the College of Pharmacy Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, Republic of Korea (K.-A.K., D.S., J.-H.K., Y.-J.S., O.-N.B.)
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38
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Siqueira MDS, Ribeiro RDM, Travassos LH. Autophagy and Its Interaction With Intracellular Bacterial Pathogens. Front Immunol 2018; 9:935. [PMID: 29875765 PMCID: PMC5974045 DOI: 10.3389/fimmu.2018.00935] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Accepted: 04/16/2018] [Indexed: 12/20/2022] Open
Abstract
Cellular responses to stress can be defined by the overwhelming number of changes that cells go through upon contact with and stressful conditions such as infection and modifications in nutritional status. One of the main cellular responses to stress is autophagy. Much progress has been made in the understanding of the mechanisms involved in the induction of autophagy during infection by intracellular bacteria. This review aims to discuss recent findings on the role of autophagy as a cellular response to intracellular bacterial pathogens such as, Streptococcus pyogenes, Mycobacterium tuberculosis, Shigella flexneri, Salmonella typhimurium, Listeria monocytogenes, and Legionella pneumophila, how the autophagic machinery senses these bacteria directly or indirectly (through the detection of bacteria-induced nutritional stress), and how some of these bacterial pathogens manage to escape from autophagy.
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Affiliation(s)
- Mariana da Silva Siqueira
- Laboratory of Immunoreceptors and Signaling, Immunobiology Program, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Renato de Moraes Ribeiro
- Laboratory of Immunoreceptors and Signaling, Immunobiology Program, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Leonardo H Travassos
- Laboratory of Immunoreceptors and Signaling, Immunobiology Program, Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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39
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Radomski N, Rebbig A, Leonhardt RM, Knittler MR. Xenophagic pathways and their bacterial subversion in cellular self-defense - παντα ρει - everything is in flux. Int J Med Microbiol 2017; 308:185-196. [PMID: 29126745 DOI: 10.1016/j.ijmm.2017.10.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 10/24/2017] [Accepted: 10/29/2017] [Indexed: 01/09/2023] Open
Abstract
Autophagy is an evolutionarily ancient and highly conserved eukaryotic mechanism that targets cytoplasmic material for degradation. Autophagic flux involves the formation of autophagosomes and their degradation by lysosomes. The process plays a crucial role in maintaining cellular homeostasis and responds to various environmental conditions. While autophagy had previously been thought to be a non-selective process, it is now clear that it can also selectively target cellular organelles, such as mitochondria (referred to as mitophagy) and/or invading pathogens (referred to as xenophagy). Selective autophagy is characterized by specific substrate recognition and requires distinct cellular adaptor proteins. Here we review xenophagic mechanisms involved in the recognition and autolysosomal or autophagolysosomal degradation of different intracellular bacteria. In this context, we also discuss a recently discovered cellular self-defense pathway, termed mito-xenophagy, which occurs during bacterial infection of dendritic cells and depends on a TNF-α-mediated metabolic switch from oxidative phosphorylation to glycolysis.
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Affiliation(s)
- Nadine Radomski
- Institute of Immunology, Friedrich-Loeffler-Institut, Institute of Immunology, Federal Research Institute of Animal Health, D-17493 Greifswald, Isle of Riems, Germany
| | - Annica Rebbig
- Institute of Immunology, Friedrich-Loeffler-Institut, Institute of Immunology, Federal Research Institute of Animal Health, D-17493 Greifswald, Isle of Riems, Germany
| | - Ralf M Leonhardt
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Michael R Knittler
- Institute of Immunology, Friedrich-Loeffler-Institut, Institute of Immunology, Federal Research Institute of Animal Health, D-17493 Greifswald, Isle of Riems, Germany.
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40
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Modeling Group B Streptococcus and Blood-Brain Barrier Interaction by Using Induced Pluripotent Stem Cell-Derived Brain Endothelial Cells. mSphere 2017; 2:mSphere00398-17. [PMID: 29104935 PMCID: PMC5663983 DOI: 10.1128/msphere.00398-17] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Accepted: 10/05/2017] [Indexed: 11/20/2022] Open
Abstract
Bacterial meningitis is a serious infection of the central nervous system (CNS) that occurs after bacteria interact with and penetrate the blood-brain barrier (BBB). The BBB is comprised of highly specialized brain microvascular endothelial cells (BMECs) that function to separate the circulation from the CNS and act as a formidable barrier for toxins and pathogens. Certain bacteria, such as Streptococcus agalactiae (group B Streptococcus [GBS]), possess the ability to interact with and penetrate the BBB to cause meningitis. Modeling bacterial interaction with the BBB in vitro has been limited to primary and immortalized BMEC culture. While useful, these cells often do not retain BBB-like properties, and human primary cells have limited availability. Recently, a human induced pluripotent stem cell (iPSC)-derived BMEC model has been established that is readily renewable and retains key BBB phenotypes. Here, we sought to evaluate whether the iPSC-derived BMECs were appropriate for modeling bacterial interaction with the BBB. Using GBS as a model meningeal pathogen, we demonstrate that wild-type GBS adhered to, invaded, and activated the iPSC-derived BMECs, while GBS mutants known to have diminished BBB interaction were attenuated in the iPSC-derived model. Furthermore, bacterial infection resulted in the disruption of tight junction components ZO-1, occludin, and claudin-5. Thus, we show for the first time that the iPSC-derived BBB model can be utilized to study BBB interaction with a bacterial CNS pathogen. IMPORTANCE Here for the first time, human iPSC-derived BMECs were used to model bacterial interaction with the BBB. Unlike models previously used to study these interactions, iPSC-derived BMECs possess robust BBB properties, such as the expression of complex tight junctions that are key components for the investigation of bacterial effects on the BBB. Here, we demonstrated that GBS interacts with the iPSC-derived BMECs and specifically disrupts these tight junctions. Thus, using this BBB model may allow researchers to uncover novel mechanisms of BBB disruption during meningitis that are inaccessible to immortalized or primary cell models that lack substantial tight junctions.
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41
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Sachdev U, Lotze MT. Perpetual change: autophagy, the endothelium, and response to vascular injury. J Leukoc Biol 2017; 102:221-235. [PMID: 28626046 PMCID: PMC6608075 DOI: 10.1189/jlb.3ru1116-484rr] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 05/05/2017] [Accepted: 05/08/2017] [Indexed: 12/15/2022] Open
Abstract
Current studies of vascular health, aging, and autophagy emphasize how the endothelium adapts to stress and contributes to disease. The endothelium is far from an inert barrier to blood-borne cells, pathogens, and chemical signals; rather, it actively translates circulating mediators into tissue responses, changing rapidly in response to physiologic stressors. Macroautophagy-the cellular ingestion of effete organelles and protein aggregates to provide anabolic substrates to fuel bioenergetics in times of stress-plays an important role in endothelial cell homeostasis, vascular remodeling, and disease. These roles include regulating vascular tone, sustaining or limiting cell survival, and contributing to the development of atherosclerosis secondary to infection, inflammation, and angiogenesis. Autophagy modulates these critical functions of the endothelium in a dynamic and perpetual response to tissue and intravascular cues.
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Affiliation(s)
- Ulka Sachdev
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Michael T Lotze
- Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
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42
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Li H, Wu J, Shen H, Yao X, Liu C, Pianta S, Han J, Borlongan CV, Chen G. Autophagy in hemorrhagic stroke: Mechanisms and clinical implications. Prog Neurobiol 2017; 163-164:79-97. [PMID: 28414101 DOI: 10.1016/j.pneurobio.2017.04.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 02/13/2017] [Accepted: 04/08/2017] [Indexed: 02/07/2023]
Abstract
Accumulating evidence advances the critical role of autophagy in brain pathology after stroke. Investigations employing autophagy induction or inhibition using pharmacological tools or autophagy-related gene knockout mice have recently revealed the biological significance of intact and functional autophagy in stroke. Most of the reported cases attest to a pro-survival role for autophagy in stroke, by facilitating removal of damaged proteins and organelles, which can be recycled for energy generation and cellular defenses. However, these observations are difficult to reconcile with equally compelling evidence demonstrating stroke-induced upregulation of brain cell death index that parallels enhanced autophagy. This begs the question of whether drug-induced autophagy during stroke culminates in improved or worsened pathological outcomes. A corollary fascinating hypothesis, but presents as a tricky conundrum, involves the effects of autophagy on cell death and inflammation, which are two main culprits in the disease progression of stroke-induced brain injury. Evidence has extended the roles of autophagy in inflammation via cytokine regulation in an unconventional secretion manner or by targeting inflammasomes for degradation. Moreover, in the recently concluded Vancouver Autophagy Symposium (VAS) held in 2014, the potential of selective autophagy for clinical treatment has been recognized. The role of autophagy in ischemic stroke has been reviewed previously in detail. Here, we evaluate the strength of laboratory and clinical evidence by providing a comprehensive summary of the literature on autophagy, and thereafter we offer our perspectives on exploiting autophagy as a drug target for cerebral ischemia, especially in hemorrhagic stroke.
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Affiliation(s)
- Haiying Li
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Jiang Wu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Haitao Shen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Xiyang Yao
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - Chenglin Liu
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China
| | - S Pianta
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery & Brain Repair, University of South Florida Morsani College of Medicine,12901 Bruce B Downs Blvd Tampa, FL 33612 USA
| | - J Han
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery & Brain Repair, University of South Florida Morsani College of Medicine,12901 Bruce B Downs Blvd Tampa, FL 33612 USA
| | - C V Borlongan
- Center of Excellence for Aging and Brain Repair, Department of Neurosurgery & Brain Repair, University of South Florida Morsani College of Medicine,12901 Bruce B Downs Blvd Tampa, FL 33612 USA
| | - Gang Chen
- Department of Neurosurgery & Brain and Nerve Research Laboratory, The First Affiliated Hospital of Soochow University,188 Shizi Street, Suzhou 215006, China.
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A journey into the brain: insight into how bacterial pathogens cross blood-brain barriers. Nat Rev Microbiol 2017; 15:149-159. [PMID: 28090076 DOI: 10.1038/nrmicro.2016.178] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The blood-brain barrier, which is one of the tightest barriers in the body, protects the brain from insults, such as infections. Indeed, only a few of the numerous blood-borne bacteria can cross the blood-brain barrier to cause meningitis. In this Review, we focus on invasive extracellular pathogens, such as Neisseria meningitidis, Streptococcus pneumoniae, group B Streptococcus and Escherichia coli, to review the obstacles that bacteria have to overcome in order to invade the meninges from the bloodstream, and the specific skills they have developed to bypass the blood-brain barrier. The medical importance of understanding how these barriers can be circumvented is underlined by the fact that we need to improve drug delivery into the brain.
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Lubkin A, Torres VJ. Bacteria and endothelial cells: a toxic relationship. Curr Opin Microbiol 2016; 35:58-63. [PMID: 28013162 DOI: 10.1016/j.mib.2016.11.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 11/26/2016] [Accepted: 11/30/2016] [Indexed: 12/24/2022]
Abstract
Pathogenic bacteria use the bloodstream as a highway for getting around the body, and thus have to find ways to enter and exit through the endothelium. Many bacteria approach this problem by producing toxins that can breach the endothelial barrier through diverse creative mechanisms, including directly killing endothelial cells (ECs), weakening the cytoskeleton within ECs, and breaking the junctions between ECs. Toxins can also modulate the immune response by influencing endothelial biology, and can modulate endothelial function by influencing the response of leukocytes. Understanding these interactions, in both the in vitro and in vivo contexts, is of critical importance for designing new therapies for sepsis and other severe bacterial diseases.
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Affiliation(s)
- Ashira Lubkin
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, United States
| | - Victor J Torres
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, United States.
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Kimmey JM, Stallings CL. Bacterial Pathogens versus Autophagy: Implications for Therapeutic Interventions. Trends Mol Med 2016; 22:1060-1076. [PMID: 27866924 DOI: 10.1016/j.molmed.2016.10.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Revised: 10/18/2016] [Accepted: 10/18/2016] [Indexed: 12/19/2022]
Abstract
Research in recent years has focused significantly on the role of selective macroautophagy in targeting intracellular pathogens for lysosomal degradation, a process termed xenophagy. In this review we evaluate the proposed roles for xenophagy in controlling bacterial infection, highlighting the concept that successful pathogens have evolved ways to subvert or exploit this defense, minimizing the actual effectiveness of xenophagy in innate immunity. Instead, studies in animal models have revealed that autophagy-associated proteins often function outside of xenophagy to influence bacterial pathogenesis. In light of current efforts to manipulate autophagy and the development of host-directed therapies to fight bacterial infections, we also discuss the implications stemming from the complicated relationship that exists between autophagy and bacterial pathogens.
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Affiliation(s)
- Jacqueline M Kimmey
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Christina L Stallings
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO, USA.
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Kim JY, Paton JC, Briles DE, Rhee DK, Pyo S. Streptococcus pneumoniae induces pyroptosis through the regulation of autophagy in murine microglia. Oncotarget 2016; 6:44161-78. [PMID: 26683708 PMCID: PMC4792549 DOI: 10.18632/oncotarget.6592] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 11/26/2015] [Indexed: 01/14/2023] Open
Abstract
Streptococcus pneumoniae is responsible for significant mortality and morbidity worldwide and causes invasive pneumococcal diseases including pneumococcal meningitis. Pyroptosis is caspase-1-dependent inflammatory cell death and is known to be induced by various microbial infections. In the present study, we investigated the molecular mechanisms that regulate pyroptosis induced by S. pneumoniae in microglia. Our results revealed that S. pneumoniae induced pyroptosis through caspase-1 activation and IL-1β production. We also found that the activation of caspase-1 and the maturation of IL-1β and IL-18 in the S. pneumoniae-triggered pyroptotic cell death process were mediated by NLRP3 inflammasome. In addition, pneumococcal infection increased the expression of autophagy-related genes and induced autophagosome formation. We also showed that the inhibition of autophagy promoted pneumococcus-induced pyroptosis. Furthermore, ROS was generated by pneumococcal infection and inhibited caspase-1 activation within 4 h of infection. However, in the late phase of infection, IL-1β secretion and caspase-1-dependent cell death were induced by ROS. These results suggest that autophagy induction transiently delay pyroptosis induced by S. pneumoniae in microglia. Our study also revealed that the activation of caspase-1 and the production of IL-1β were induced by pneumolysin and that pneumolysin triggered pyroptosis in microglial cells. Similar to the in vitro results, S. pneumoniae induced caspase-1 activation and caspase-1-dependent cytokine maturation in the mouse meningitis model. Thus, the present data demonstrate that S. pneumoniae induces pyroptosis in murine microglia and that NLRP3 inflammasome is critical for caspase-1 activation during the process. Furthermore, the induction of autophagy could transiently protect microglia from pyroptosis.
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Affiliation(s)
- Ji-Yun Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, Kyunggi-do, Republic of Korea
| | - James C Paton
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA, Australia
| | - David E Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Genetics, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Dong-Kwon Rhee
- School of Pharmacy, Sungkyunkwan University, Suwon, Kyunggi-do, Republic of Korea
| | - Suhkneung Pyo
- School of Pharmacy, Sungkyunkwan University, Suwon, Kyunggi-do, Republic of Korea
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Mu R, Cutting AS, Del Rosario Y, Villarino N, Stewart L, Weston TA, Patras KA, Doran KS. Identification of CiaR Regulated Genes That Promote Group B Streptococcal Virulence and Interaction with Brain Endothelial Cells. PLoS One 2016; 11:e0153891. [PMID: 27100296 PMCID: PMC4839699 DOI: 10.1371/journal.pone.0153891] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/05/2016] [Indexed: 11/18/2022] Open
Abstract
Group B Streptococcus (GBS) is a major causative agent of neonatal meningitis due to its ability to efficiently cross the blood-brain barrier (BBB) and enter the central nervous system (CNS). It has been demonstrated that GBS can invade human brain microvascular endothelial cells (hBMEC), a primary component of the BBB; however, the mechanism of intracellular survival and trafficking is unclear. We previously identified a two component regulatory system, CiaR/H, which promotes GBS intracellular survival in hBMEC. Here we show that a GBS strain deficient in the response regulator, CiaR, localized more frequently with Rab5, Rab7 and LAMP1 positive vesicles. Further, lysosomes isolated from hBMEC contained fewer viable bacteria following initial infection with the ΔciaR mutant compared to the WT strain. To characterize the contribution of CiaR-regulated genes, we constructed isogenic mutant strains lacking the two most down-regulated genes in the CiaR-deficient mutant, SAN_2180 and SAN_0039. These genes contributed to bacterial uptake and intracellular survival. Furthermore, competition experiments in mice showed that WT GBS had a significant survival advantage over the Δ2180 and Δ0039 mutants in the bloodstream and brain.
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Affiliation(s)
- Rong Mu
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Andrew S. Cutting
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Yvette Del Rosario
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Nicholas Villarino
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Lara Stewart
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Thomas A. Weston
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Kathryn A. Patras
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
| | - Kelly S. Doran
- Department of Biology and Center for Microbial Sciences, San Diego State University, San Diego, California, 92182, United States of America
- Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, California, 92093, United States of America
- * E-mail:
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Scholl J, Nasioudis D, Boester A, Speleotes M, Grunebaum A, Witkin SS. Group B streptococcus alters properties of vaginal epithelial cells in pregnant women. Am J Obstet Gynecol 2016; 214:383.e1-5. [PMID: 26928153 DOI: 10.1016/j.ajog.2015.12.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 12/18/2015] [Accepted: 12/29/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Group B streptococcus (GBS) infection in pregnancy is a major cause of maternal and neonatal morbidity. An understanding of the mechanisms responsible for GBS persistence in the genital tract, as well as recognition of host defenses employed to combat its presence, are crucial to our efforts to reduce maternal GBS colonization and prevent the acquisition of neonatal infections. However, alterations in vaginal immunity in response to GBS colonization in pregnant women remain incompletely defined. Whether GBS modulates autophagy, a major host defense mechanism and contributor to the control of intracellular microbial infections, also remains unclear. OBJECTIVE We sought to identify differences in the extent of autophagy as well as in the concentration of biomarkers previously shown to be involved in vaginal innate immunity between GBS-positive and GBS-negative pregnant women. STUDY DESIGN We performed a prospective cohort study of healthy pregnant women, who had vaginal secretions obtained at 35-37 weeks of gestation, just prior to the standard GBS rectovaginal sample collection. The contents of the swabs were released into tubes containing 1 mL of sterile phosphate-buffered saline. Samples were centrifuged, and supernatant and cell pellet fractions were collected and stored separately at -80°C until used for analysis. Epithelial cells were then lysed, and the extent of autophagy was determined by measuring the residual level of p62 remaining in the cytoplasm. p62 is a protein that is consumed during autophagy, and so its concentration detectable in the cytoplasm is inversely related to the extent of autophagy induction. The intracellular level of the inducible 70-kDa heat shock protein (hsp70), an inhibitor of autophagy, was also measured. The cell-free fraction was assayed for D- and L-lactic acid, neutrophil gelatinase-associated lipocalin, extracellular matrix metalloproteinase inducer (EMMPRIN), matrix metalloproteinase (MMP)-8, alpha amylase, hyaluronan, and total protein. Laboratory personnel were blinded to all clinical data. RESULTS There were 145 women included in the study, of which 45 (31%) were culture-positive for GBS. Vaginal cells from GBS-positive women had elevated intracellular levels of p62 (2.1 vs 0.7 pg/mL, P < .01) and hsp70 (16.9 vs 9.6 ng/mL, P = .03) as compared to GBS-negative women. The p62 and hsp70 levels were highly correlated in both groups of subjects (P < .01). In vaginal fluid, concentrations of neutrophil gelatinase-associated lipocalin (1.1 vs 0.7 ng/μg total protein, P = .01), MMP-8 (21.9 vs 11.1 pg/μg total protein, P = .01), and extracellular MMP inducer (8.8 vs 7.2 pg/μg total protein, P = .03) were highest in GBS-positive women. There were no differences in the concentrations of D- and L-lactic acid, alpha amylase, or hyaluronan between the 2 groups of women. CONCLUSION The inhibition of autophagy in vaginal epithelial cells by GBS-induced hsp70 production is associated with its persistence. Concurrently, alterations in components known to influence vaginal bacterial colonization or facilitate microbial passage to the upper genital tract also occur in relation to GBS carriage.
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Cho HI, Kim SJ, Choi JW, Lee SM. Genipin alleviates sepsis-induced liver injury by restoring autophagy. Br J Pharmacol 2016; 173:980-91. [PMID: 26660048 DOI: 10.1111/bph.13397] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 11/18/2015] [Accepted: 11/30/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Autophagy is an essential cytoprotective system that is rapidly activated in response to various stimuli including inflammation and microbial infection. Genipin, an aglycon of geniposide found in gardenia fruit, is well known to have anti-inflammatory, antibacterial and antioxidative properties. This study examined the protective mechanisms of genipin against sepsis, with particular focus on the autophagic signalling pathway. EXPERIMENTAL APPROACH Mice were subjected to sepsis by caecal ligation and puncture (CLP). Genipin (1, 2.5 and 5 mg·kg(-1) ) or vehicle (saline) was injected i.v. immediately (0 h) after CLP, and chloroquine (60 mg·kg(-1) ), an autophagy inhibitor, was injected i.p. 1 h before CLP. Blood and liver tissues were isolated 6 h after CLP. KEY RESULTS Genipin improved survival rate and decreased serum levels of aminotransferases and pro-inflammatory cytokines after CLP; effects abolished by chloroquine. The liver expression of autophagy-related protein (Atg)12-Atg5 conjugate increased after CLP, and this increase was enhanced by genipin. CLP decreased Atg3 protein liver expression, and genipin attenuated this decrease. CLP impaired autophagic flux, as indicated by increased liver expression of microtubule-associated protein-1 light chain 3-II and sequestosome-1/p62 protein; this impaired autophagic flux was restored by genipin, and chloroquine abolished this effect. Genipin also attenuated the decreased expression of lysosome-associated membrane protein-2 and Rab7 protein and increased expression of calpain 1 protein induced by CLP in the liver. CONCLUSIONS AND IMPLICATIONS Our findings suggest that genipin protects against septic injury by restoring impaired autophagic flux. Therefore, genipin might be a potential therapeutic agent for the treatment of sepsis.
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Affiliation(s)
- Hong-Ik Cho
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - So-Jin Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - Joo-Wan Choi
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - Sun-Mee Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
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Doran KS, Fulde M, Gratz N, Kim BJ, Nau R, Prasadarao N, Schubert-Unkmeir A, Tuomanen EI, Valentin-Weigand P. Host-pathogen interactions in bacterial meningitis. Acta Neuropathol 2016; 131:185-209. [PMID: 26744349 PMCID: PMC4713723 DOI: 10.1007/s00401-015-1531-z] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 12/26/2022]
Abstract
Bacterial meningitis is a devastating disease occurring worldwide with up to half of the survivors left with permanent neurological sequelae. Due to intrinsic properties of the meningeal pathogens and the host responses they induce, infection can cause relatively specific lesions and clinical syndromes that result from interference with the function of the affected nervous system tissue. Pathogenesis is based on complex host–pathogen interactions, some of which are specific for certain bacteria, whereas others are shared among different pathogens. In this review, we summarize the recent progress made in understanding the molecular and cellular events involved in these interactions. We focus on selected major pathogens, Streptococcus pneumonia, S. agalactiae (Group B Streptococcus), Neisseria meningitidis, and Escherichia coli K1, and also include a neglected zoonotic pathogen, Streptococcus suis. These neuroinvasive pathogens represent common themes of host–pathogen interactions, such as colonization and invasion of mucosal barriers, survival in the blood stream, entry into the central nervous system by translocation of the blood–brain and blood–cerebrospinal fluid barrier, and induction of meningeal inflammation, affecting pia mater, the arachnoid and subarachnoid spaces.
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