1
|
Ribis JW, Shen A. Protocol for quantifying the germination properties of individual bacterial endospores using PySpore. STAR Protoc 2023; 4:102678. [PMID: 37910513 PMCID: PMC10630823 DOI: 10.1016/j.xpro.2023.102678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/11/2023] [Accepted: 10/04/2023] [Indexed: 11/03/2023] Open
Abstract
PySpore is a Python program that tracks the germination of individual bacterial endospores. Here, we present a protocol for segmenting spores and quantifying the germination properties of individual bacterial endospores using PySpore. We describe steps for using GUI-based tools to optimize image processing, annotating data, setting gates, and joining datasets for downstream analyses. We then describe procedures for plotting functionality tools without the user needing to modify the underlying code. For complete details on the use and execution of this protocol, please refer to Ribis et al. (2023).1.
Collapse
Affiliation(s)
- John W Ribis
- Tufts University School of Medicine, Boston, MA 02111, USA; Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA.
| | - Aimee Shen
- Tufts University School of Medicine, Boston, MA 02111, USA.
| |
Collapse
|
2
|
Shrestha S, Taib N, Gribaldo S, Shen A. Diversification of division mechanisms in endospore-forming bacteria revealed by analyses of peptidoglycan synthesis in Clostridioides difficile. Nat Commun 2023; 14:7975. [PMID: 38042849 PMCID: PMC10693644 DOI: 10.1038/s41467-023-43595-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 11/14/2023] [Indexed: 12/04/2023] Open
Abstract
The bacterial enzymes FtsW and FtsI, encoded in the highly conserved dcw gene cluster, are considered to be universally essential for the synthesis of septal peptidoglycan (PG) during cell division. Here, we show that the pathogen Clostridioides difficile lacks a canonical FtsW/FtsI pair, and its dcw-encoded PG synthases have undergone a specialization to fulfill sporulation-specific roles, including synthesizing septal PG during the sporulation-specific mode of cell division. Although these enzymes are directly regulated by canonical divisome components during this process, dcw-encoded PG synthases and their divisome regulators are dispensable for cell division during normal growth. Instead, C. difficile uses a bifunctional class A penicillin-binding protein as the core divisome PG synthase, revealing a previously unreported role for this class of enzymes. Our findings support that the emergence of endosporulation in the Firmicutes phylum facilitated the functional repurposing of cell division factors. Moreover, they indicate that C. difficile, and likely other clostridia, assemble a distinct divisome that therefore may represent a unique target for therapeutic interventions.
Collapse
Affiliation(s)
- Shailab Shrestha
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
- Program in Molecular Microbiology, Tufts University Graduate School of Biomedical Sciences, Boston, MA, USA
| | - Najwa Taib
- Institut Pasteur, Université Paris Cité, Evolutionary Biology of the Microbial Cell Unit, Paris, France
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, F-75015, Paris, France
| | - Simonetta Gribaldo
- Institut Pasteur, Université Paris Cité, Evolutionary Biology of the Microbial Cell Unit, Paris, France
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
| |
Collapse
|
3
|
Zong K, Peng D, Jiang P, Li Y, Cao Z, Wu Z, Mou T, Huang Z, Shen A, Wu Z, Zhou B. Derivation and validation of a novel preoperative risk prediction model for surgical site infection in pancreaticoduodenectomy and comparison of preoperative antibiotics with different risk stratifications in retrospective cohort. J Hosp Infect 2023; 139:228-237. [PMID: 37459915 DOI: 10.1016/j.jhin.2023.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/05/2023] [Accepted: 07/07/2023] [Indexed: 08/14/2023]
Abstract
BACKGROUND Surgical site infections (SSIs) are common postoperative complications of pancreaticoduodenectomy. AIM To develop a model for preoperative identification of the risk of SSI that may improve outcomes and guide preoperative antibiotics. METHODS The prediction model was built by meta-analysis. After literature search and inclusion, data extraction, and quantitative synthesis, the prediction model was established based on the pooled odds ratio of predictors. A single-centre retrospective cohort was the validation cohort. Receiver operating characteristic curves and area under the curve were used to assess the model's ability. We also created a decision curve and a calibration plot to assess the nomogram. The effects of prophylactic antibiotics on SSI were compared between groups by multivariable logistic regression with different risk stratifications. FINDINGS Twenty-eight studies were included in the meta-analysis, 17 studies in the derivation cohort. Age, male gender, body mass index, pancreatic duct diameter, high-risk diagnosis, and preoperative biliary drainage were selected to build the prediction model. The model was validated in an external cohort. The cut-off value was 3.5 and area under the curve (AUC) was 0.76 in open pancreaticoduodenectomy (OPD). In laparoscopic pancreaticoduodenectomy, the cut-off value was 4.5 and AUC was 0.69. Decision curve and calibration plot showed good usability of the model, especially in OPD. Multivariable logistic regression did not indicate differences between broad- and narrow-spectrum antibiotics for SSI in different risk stratifications. CONCLUSION The model can identify patients with a high risk of SSI preoperatively. The choice of prophylactic antibiotics under different risk stratifications should be investigated further.
Collapse
Affiliation(s)
- K Zong
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - D Peng
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - P Jiang
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Y Li
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Z Cao
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Z Wu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - T Mou
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Z Huang
- Department of Hepatobiliary Pancreatic Tumor Center, Chongqing University Cancer Hospital, Chongqing, China
| | - A Shen
- Department of Hepatobiliary Pancreatic Tumor Center, Chongqing University Cancer Hospital, Chongqing, China
| | - Z Wu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| | - B Zhou
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| |
Collapse
|
4
|
Ribis JW, Melo L, Shrestha S, Giacalone D, Rodriguez EE, Shen A, Rohlfing A. Single-spore germination analyses reveal that calcium released during Clostridioides difficile germination functions in a feedforward loop. mSphere 2023; 8:e0000523. [PMID: 37338207 PMCID: PMC10449524 DOI: 10.1128/msphere.00005-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/21/2023] [Indexed: 06/21/2023] Open
Abstract
Clostridioides difficile infections begin when its metabolically dormant spores germinate in response to sensing bile acid germinants alongside amino acid and divalent cation co-germinants in the small intestine. While bile acid germinants are essential for C. difficile spore germination, it is currently unclear whether both co-germinant signals are required. One model proposes that divalent cations, particularly Ca2+, are essential for inducing germination, while another proposes that either co-germinant class can induce germination. The former model is based on the finding that spores defective in releasing large stores of internal Ca2+ in the form of calcium dipicolinic acid (CaDPA) cannot germinate when germination is induced with bile acid germinant and amino acid co-germinant alone. However, since the reduced optical density of CaDPA-less spores makes it difficult to accurately measure their germination, we developed a novel automated, time-lapse microscopy-based germination assay to analyze CaDPA mutant germination at the single-spore level. Using this assay, we found that CaDPA mutant spores germinate in the presence of amino acid co-germinant and bile acid germinant. Higher levels of amino acid co-germinants are nevertheless required to induce CaDPA mutant spores to germinate relative to WT spores because CaDPA released by WT spores during germination can function in a feedforward loop to potentiate the germination of other spores within the population. Collectively, these data indicate that Ca2+ is not essential for inducing C. difficile spore germination because amino acid and Ca2+ co-germinant signals are sensed by parallel signaling pathways. IMPORTANCE Clostridioides difficile spore germination is essential for this major nosocomial pathogen to initiate infection. C. difficile spores germinate in response to sensing bile acid germinant signals alongside co-germinant signals. There are two classes of co-germinant signals: Ca2+ and amino acids. Prior work suggested that Ca2+ is essential for C. difficile spore germination based on bulk population analyses of germinating CaDPA mutant spores. Since these assays rely on optical density to measure spore germination and the optical density of CaDPA mutant spores is reduced relative to WT spores, this bulk assay is limited in its capacity to analyze germination. To overcome this limitation, we developed an automated image analysis pipeline to monitor C. difficile spore germination using time-lapse microscopy. With this analysis pipeline, we demonstrate that, although Ca2+ is dispensable for inducing C. difficile spore germination, CaDPA can function in a feedforward loop to potentiate the germination of neighboring spores.
Collapse
Affiliation(s)
- John W. Ribis
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Luana Melo
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Shailab Shrestha
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - David Giacalone
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, USA
| | | | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Amy Rohlfing
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Tufts University, Boston, Massachusetts, USA
| |
Collapse
|
5
|
Shrestha S, Taib N, Gribaldo S, Shen A. Analyses of cell wall synthesis in Clostridioides difficile reveal a diversification in cell division mechanisms in endospore-forming bacteria. bioRxiv 2023:2023.08.06.552200. [PMID: 37609260 PMCID: PMC10441361 DOI: 10.1101/2023.08.06.552200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Current models of bacterial cell division assume that the core synthases of the multiprotein divisome complex, FtsW-FtsI, are the primary drivers of septal peptidoglycan (PG) synthesis. These enzymes are typically encoded in the highly conserved division and cell wall (dcw) cluster and are considered to be universally essential for cell division. Here, we combine bioinformatics analyses with functional characterization in the pathogen Clostridioides difficile to show that dcw-encoded PG synthases have undergone a surprising specialization in the sole endospore-forming phylum, Firmicutes, to fulfill sporulation-specific roles. We describe a novel role for these enzymes in synthesizing septal PG during the sporulation-specific mode of cell division in C. difficile. Although these enzymes are directly regulated by canonical divisome components during this process, dcw-encoded PG synthases and their divisome regulators are unexpectedly dispensable for cell division during normal growth. Instead, C. difficile uses its sole bifunctional class A penicillin-binding protein (aPBP) to drive cell division, revealing a previously unreported role for this class of PG synthases as the core divisome enzyme. Collectively, our findings reveal how the emergence of endosporulation in the Firmicutes phylum was a key driver for the functional repurposing of an otherwise universally conserved cellular process such as cell division. Moreover, they indicate that C. difficile, and likely other clostridia, assemble a divisome that differs markedly from previously studied bacteria, thus representing an attractive, unique target for therapeutic purposes.
Collapse
Affiliation(s)
- Shailab Shrestha
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
- Program in Molecular Microbiology, Tufts University Graduate School of Biomedical Sciences, Boston, MA, USA
| | - Najwa Taib
- Institut Pasteur, Université de Paris, Unit Evolutionary Biology of the Microbial Cell, Paris, France
- Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, F-75015 Paris, France
| | - Simonetta Gribaldo
- Institut Pasteur, Université de Paris, Unit Evolutionary Biology of the Microbial Cell, Paris, France
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA
| |
Collapse
|
6
|
Chiang SS, Graham SM, Schaaf HS, Marais BJ, Sant'Anna CC, Sharma S, Starke JR, Triasih R, Achar J, Amanullah F, Armitage LY, Aurilio RB, Buck WC, Centis R, Chabala C, Cruz AT, Demers AM, du Preez K, Enimil A, Furin J, Garcia-Prats AJ, Gonzalez NE, Hoddinott G, Isaakidis P, Jaganath D, Kabra SK, Kampmann B, Kay A, Kitai I, Lopez-Varela E, Maleche-Obimbo E, Malaspina FM, Velásquez JN, Nuttall JJC, Oliwa JN, Andrade IO, Perez-Velez CM, Rabie H, Seddon JA, Sekadde MP, Shen A, Skrahina A, Soriano-Arandes A, Steenhoff AP, Tebruegge M, Tovar MA, Tsogt B, van der Zalm MM, Welch H, Migliori GB. Clinical standards for drug-susceptible TB in children and adolescents. Int J Tuberc Lung Dis 2023; 27:584-598. [PMID: 37491754 PMCID: PMC10365562 DOI: 10.5588/ijtld.23.0085] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 02/27/2023] [Indexed: 07/27/2023] Open
Abstract
BACKGROUND: These clinical standards aim to provide guidance for diagnosis, treatment, and management of drug-susceptible TB in children and adolescents.METHODS: Fifty-two global experts in paediatric TB participated in a Delphi consensus process. After eight rounds of revisions, 51/52 (98%) participants endorsed the final document.RESULTS: Eight standards were identified: Standard 1, Age and developmental stage are critical considerations in the assessment and management of TB; Standard 2, Children and adolescents with symptoms and signs of TB disease should undergo prompt evaluation, and diagnosis and treatment initiation should not depend on microbiological confirmation; Standard 3, Treatment initiation is particularly urgent in children and adolescents with presumptive TB meningitis and disseminated (miliary) TB; Standard 4, Children and adolescents should be treated with an appropriate weight-based regimen; Standard 5, Treating TB infection (TBI) is important to prevent disease; Standard 6, Children and adolescents should receive home-based/community-based treatment support whenever possible; Standard 7, Children, adolescents, and their families should be provided age-appropriate support to optimise engagement in care and clinical outcomes; and Standard 8, Case reporting and contact tracing should be conducted for each child and adolescent.CONCLUSION: These consensus-based clinical standards, which should be adapted to local contexts, will improve the care of children and adolescents affected by TB.
Collapse
Affiliation(s)
- S S Chiang
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Alpert Medical School of Brown University, Providence, RI, Center for International Health Research, Rhode Island Hospital, Providence, RI, USA
| | - S M Graham
- Department of Paediatrics, University of Melbourne, Melbourne, VIC, Burnet Institute, Melbourne, VIC, Australia
| | - H S Schaaf
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - B J Marais
- Department of Paediatrics and Child Health and the Sydney Infectious Diseases Institute (Sydney ID), Sydney, NSW, Department of Infectious Diseases, The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - C C Sant'Anna
- Department of Paediatrics, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - S Sharma
- Department of Paediatrics, National Institute of Tuberculosis and Respiratory Diseases, New Delhi, India
| | - J R Starke
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, Section of Infectious Diseases, Texas Children's Hospital, Houston, TX, USA
| | - R Triasih
- Department of Paediatrics, Faculty of Medicine, Public Health and Nursing, Universitas Gadjah Mada/Dr Sardjito Hospital, Yogyakarta, Indonesia
| | - J Achar
- Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden
| | - F Amanullah
- Department of Paediatrics, The Indus Hospital and Health Network, Karachi, Department of Paediatrics, The Aga Khan University Hospital, Karachi, Pakistan
| | - L Y Armitage
- Heartland National TB Center, University of Texas Health Science Center at Tyler, San Antonio, TX, USA
| | - R B Aurilio
- Department of Paediatrics, Instituto de Puericultura e Pediatria Martagão Gesteira, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Department of Paediatrics, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - W C Buck
- Department of Pediatrics, University of California Los Angeles David Geffen School of Medicine, Los Angeles, CA, USA
| | - R Centis
- Respiratory Diseases Clinical Epidemiology Unit, Istituti Clinici Scientifici Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico, Tradate, Italy
| | - C Chabala
- School of Medicine, Department of Paediatrics and Child Health, University of Zambia, Lusaka, Children's Hospital, University Teaching Hospitals, Lusaka, Zambia
| | - A T Cruz
- Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - A-M Demers
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa, Division of Microbiology, Department of Laboratory Medicine, CHU Sainte-Justine, Montreal, Canada
| | - K du Preez
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - A Enimil
- Department of Child Health, Kwame Nkrumah University of Science and Technology, Kumasi, Department of Child Health, Komfo Anokye Teaching Hospital, Kumasi, Ghana
| | - J Furin
- Department of Global Health and Social Medicine, Harvard Medical School, Boston, MA, Division of Infectious Diseases, Department of Medicine, Case Western Reserve University, Cleveland, OH
| | - A J Garcia-Prats
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa, Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, USA
| | - N E Gonzalez
- División Neumotisiología, Hospital de Niños Pedro de Elizalde, Buenos Aires, Dirección General de Posgrado, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - G Hoddinott
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - P Isaakidis
- Southern Africa Medical Unit (SAMU), Médecins Sans Frontières, Cape Town, South Africa, Clinical and Molecular Epidemiology Unit, Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
| | - D Jaganath
- Division of Pediatric Infectious Diseases, Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - S K Kabra
- Department of Paediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - B Kampmann
- Charite Centre for Global Health, Charite Universitatsmedizin Berlin, Berlin, Germany, Clinical Research Department, London School of Hygiene & Tropical Medicine, London, UK
| | - A Kay
- Department of Pediatrics, Baylor College of Medicine, Houston, TX
| | - I Kitai
- Department of Paediatrics, Hospital for Sick Children, Toronto, ON, Department of Pediatrics, University of Toronto, Toronto, ON, Canada
| | - E Lopez-Varela
- Hospital Clínic and ISGlobal, Universitat de Barcelona, Barcelona, Spain, Centro de Investigação em Saúde de Manhiça (CISM), Manhiça, Mozambique
| | - E Maleche-Obimbo
- Department of Paediatrics & Child Health, University of Nairobi, Nairobi, Kenya
| | - F Mestanza Malaspina
- Department of Paediatrics, Hospital San Bartólome, Lima, Red Peruana de Tuberculosis Pediátrica, Dirección de Prevención y Control de Tuberculosis, Ministerio de Salud, Lima, Perú
| | - J Niederbacher Velásquez
- Department of Paediatrics, Universidad Industrial de Santander, Bucaramanga, Board of Directors, Asociación Colombiana de Neumología Pediátrica, Bogotá, Colombia
| | - J J C Nuttall
- Paediatric Infectious Diseases Unit, Department of Paediatrics and Child Health, University of Cape Town, Cape Town, South Africa
| | - J N Oliwa
- Faculty of Health Sciences, Department of Paediatrics and Child Health, The University of Nairobi, Nairobi, Health Services Unit, Kenya Medical Research Institute-Wellcome Trust Research Programme, Nairobi, Kenya
| | - I Orozco Andrade
- Center of Diagnosis and Integral Treatment for Tuberculosis, Servicios Médicos de la Frontera, Juárez, Medical Coordination, Juntos Binational Tuberculosis Project, Juárez, México
| | - C M Perez-Velez
- Division of Infectious Diseases, Department of Internal Medicine, University of New Mexico, Albuquerque, NM, USA
| | - H Rabie
- Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - J A Seddon
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa, Department of Infectious Disease, Imperial College London, London, UK
| | - M P Sekadde
- National TB and Leprosy Program, Ministry of Health, Kampala, Uganda
| | - A Shen
- Beijing Paediatric Research Institute, National Centre for Children's Health, Beijing Children's Hospital, Capital Medical University, Beijing, Pediatric Research Institute, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, China
| | - A Skrahina
- Clinical Department, The Republican Scientific and Practical Centre for Pulmonology and TB, Minsk, Belarus
| | - A Soriano-Arandes
- Paediatric Infectious Diseases and Immunodeficiencies Unit, Hospital Universitari Vall d'Hebron, Barcelona, Infection and Immunity in Children, Vall d'Hebron Research Institute, Barcelona, Spain
| | - A P Steenhoff
- Global Health Center and Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA, Department of Paediatric & Adolescent Health, Faculty of Medicine, University of Botswana, Gaborone, Botswana
| | - M Tebruegge
- Department of Infection, Immunity & Inflammation, University College London, Great Ormond Street Institute of Child Health, London, UK, Department of Paediatrics, Klinik Ottakring, Wiener Gesundheitsverbund, Vienna, Austria
| | - M A Tovar
- Socios En Salud Sucursal Perú, Escuela de Medicina, Facultad de Ciencias de la Salud, Universidad Peruana de Ciencias Aplicadas, Lima, Perú
| | - B Tsogt
- Research and Innovation, Mongolian Anti-TB Coalition, Ulaanbaatar, Mongolia
| | - M M van der Zalm
- Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - H Welch
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, Department of Paediatrics, The University of Papua New Guinea School of Medicine and Health Sciences, Port Moresby, Papua New Guinea
| | - G B Migliori
- Respiratory Diseases Clinical Epidemiology Unit, Istituti Clinici Scientifici Maugeri, Istituto di Ricovero e Cura a Carattere Scientifico, Tradate, Italy
| |
Collapse
|
7
|
Darwin KH, Aldridge B, Seeliger J, Shen A, Stanley S. Confusion. EMBO Rep 2023; 24:e57041. [PMID: 36876580 PMCID: PMC10074050 DOI: 10.15252/embr.202357041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 03/07/2023] Open
Abstract
Can we do better when it comes to the "other-race effect"?
Collapse
Affiliation(s)
| | | | | | - Aimee Shen
- Tufts University Medical SchoolBostonMAUSA
| | | |
Collapse
|
8
|
Shen A, Patel J, Kittleson M, Chang D, Esmailian G, Singer-Englar T, De Leon F, Hamilton M, Geft D, Czer L, Megna D, Kobashigawa J. Transthyretin Amyloid May Have a Protective Effect for Rejection after Heart Transplantation. J Heart Lung Transplant 2023. [DOI: 10.1016/j.healun.2023.02.544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023] Open
|
9
|
Dumitrescu DG, Gordon EM, Kovalyova Y, Seminara AB, Duncan-Lowey B, Forster ER, Zhou W, Booth CJ, Shen A, Kranzusch PJ, Hatzios SK. A microbial transporter of the dietary antioxidant ergothioneine. Cell 2022; 185:4526-4540.e18. [PMID: 36347253 PMCID: PMC9691600 DOI: 10.1016/j.cell.2022.10.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/16/2022] [Accepted: 10/07/2022] [Indexed: 11/09/2022]
Abstract
Low-molecular-weight (LMW) thiols are small-molecule antioxidants required for the maintenance of intracellular redox homeostasis. However, many host-associated microbes, including the gastric pathogen Helicobacter pylori, unexpectedly lack LMW-thiol biosynthetic pathways. Using reactivity-guided metabolomics, we identified the unusual LMW thiol ergothioneine (EGT) in H. pylori. Dietary EGT accumulates to millimolar levels in human tissues and has been broadly implicated in mitigating disease risk. Although certain microorganisms synthesize EGT, we discovered that H. pylori acquires this LMW thiol from the host environment using a highly selective ATP-binding cassette transporter-EgtUV. EgtUV confers a competitive colonization advantage in vivo and is widely conserved in gastrointestinal microbes. Furthermore, we found that human fecal bacteria metabolize EGT, which may contribute to production of the disease-associated metabolite trimethylamine N-oxide. Collectively, our findings illustrate a previously unappreciated mechanism of microbial redox regulation in the gut and suggest that inter-kingdom competition for dietary EGT may broadly impact human health.
Collapse
Affiliation(s)
- Daniel G Dumitrescu
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Chemistry, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Elizabeth M Gordon
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Yekaterina Kovalyova
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Chemistry, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
| | - Anna B Seminara
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA; Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Brianna Duncan-Lowey
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Emily R Forster
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA; Graduate Program in Molecular Microbiology, Graduate School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Wen Zhou
- Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Carmen J Booth
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Philip J Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Stavroula K Hatzios
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA; Department of Chemistry, Yale University, New Haven, CT 06520, USA; Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA.
| |
Collapse
|
10
|
Forster ER, Yang X, Tai AK, Hang HC, Shen A. Identification of a Bile Acid-Binding Transcription Factor in Clostridioides difficile Using Chemical Proteomics. ACS Chem Biol 2022; 17:3086-3099. [PMID: 36279369 PMCID: PMC10518218 DOI: 10.1021/acschembio.2c00463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Clostridioides difficile is a Gram-positive anaerobic bacterium that is the leading cause of hospital-acquired gastroenteritis in the US. In the gut milieu, C. difficile encounters microbiota-derived, growth-inhibiting bile acids that are thought to be a significant mechanism of colonization resistance. While the levels of certain bile acids in the gut correlate with susceptibility to C. difficile infection, their molecular targets in C. difficile remain unknown. In this study, we sought to use chemical proteomics to identify bile acid-interacting proteins in C. difficile. Using photoaffinity bile acid probes and chemical proteomics, we identified a previously uncharacterized MerR family protein, CD3583 (now BapR), as a putative bile acid-sensing transcription regulator. Our data indicate that BapR specifically binds to and is stabilized by lithocholic acid (LCA) in C. difficile. Although loss of BapR did not affect C. difficile's sensitivity to LCA, ΔbapR cells elongated more in the presence of LCA compared to wild-type cells. Transcriptomics revealed that BapR regulates several gene clusters, with the expression of the mdeA-cd3573 locus being specifically de-repressed in the presence of LCA in a BapR-dependent manner. Electrophoretic mobility shift assays revealed that BapR directly binds to the mdeA promoter region. Because mdeA is involved in amino acid-related sulfur metabolism and the mdeA-cd3573 locus encodes putative transporters, we propose that BapR senses a gastrointestinal tract-specific small molecule, LCA, as an environmental cue for metabolic adaptation.
Collapse
Affiliation(s)
- Emily R Forster
- Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts 02111, United States
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
| | - Xinglin Yang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
| | - Albert K Tai
- Department of Immunology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
- Data Intensive Studies Center, Tufts University, Medford, Massachusetts 02155, United States
| | - Howard C Hang
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California 92037, United States
- Department of Chemistry, Scripps Research, La Jolla, California 92037, United States
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
| |
Collapse
|
11
|
Wang F, Xu Y, Xiang Y, Wu P, Shen A, Wang P. The feasibility of amide proton transfer imaging at 3 T for bladder cancer: a preliminary study. Clin Radiol 2022; 77:776-783. [PMID: 35985845 DOI: 10.1016/j.crad.2022.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 11/03/2022]
Abstract
AIM To investigate the optimal amide proton transfer (APT) imaging parameters for bladder cancer (BCa), the influence of different protein concentrations and pH values on APT imaging, and to establish the reliability of APT imaging in healthy volunteers and patients with BCa. MATERIALS AND METHODS The optimal APT imaging parameters for BCa were experimentally optimised using cross-linked bovine serum albumin (BSA) phantoms. BSA phantoms were scanned with different values for the saturation power, saturation duration and number of excitations. Meanwhile, BSA phantoms containing different protein concentrations and solutions of different pH levels were scanned. The interobserver agreement of the asymmetric magnetisation transfer ratio (MTRasym) was assessed in 11 healthy volunteers and 18 patients with BCa. RESULTS The optimal scanning scheme consisted of 1 excitation, a saturation power of 2 μT, and a saturation time of 2 s. The APT signal intensity increased as the protein concentration increased and as the pH decreased. The MTRasym showed good concordance for all subjects. The MTRasym of BCa tissue was significantly higher (1.81 ± 0.71) than that of bladder wall in healthy volunteers (0.34 ± 0.12) and normal bladder wall in patients with BCa (0.31 ± 0.11; p<0.001). There was no significant difference between the bladder wall of healthy volunteers and the normal bladder wall of patients with BCa. CONCLUSION APT imaging showed potential value for application in BCa.
Collapse
Affiliation(s)
- F Wang
- Department of Radiology, Tongji Hospital, School of Medicine, Tongji University, Shanghai, 200065, China
| | - Y Xu
- Department of Radiology, Tongji Hospital, School of Medicine, Tongji University, Shanghai, 200065, China
| | - Y Xiang
- Department of Radiology, Tongji Hospital, School of Medicine, Tongji University, Shanghai, 200065, China
| | - P Wu
- Philips Healthcare, Shanghai, 200072, China
| | - A Shen
- Department of Radiology, Tongji Hospital, School of Medicine, Tongji University, Shanghai, 200065, China
| | - P Wang
- Department of Radiology, Tongji Hospital, School of Medicine, Tongji University, Shanghai, 200065, China.
| |
Collapse
|
12
|
Shen A, Vecerek N, Worswick S, Hogeling M. 184 Is prurigo pigmentosa simply a “keto” rash? J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
13
|
Ma BQ, Meng HJ, Dong XF, Gao XL, Wu YN, Zhang W, Li SP, Shen A. [Predictive value of prognostic inflammatory and tumor score in intrahepatic cholangiocarcinoma]. Zhonghua Gan Zang Bing Za Zhi 2022; 30:777-783. [PMID: 36038350 DOI: 10.3760/cma.j.cn501113-20211108-00539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Objective: To compare and analyze the predictive value of different inflammatory factors and tumor markers in intrahepatic cholangiocarcinoma and to develop a new and effective preoperative prognostic scoring system. Methods: 102 and 72 cases with intrahepatic cholangiocarcinoma who underwent radical surgery in Tianjin Medical University Cancer Institute and Hospital and the Affiliated Hospital of Weifang Medical University were selected as the experimental group and the validation group, respectively. Clinicopathological and follow-up data were collected. Cox proportional-hazards model was used to analyze the predictive value of different prognostic markers. The relationship between prognostic markers and clinicopathological data was analyzed by rank sum test, χ2 or Fisher's exact test. Results: Among the direct inflammatory factors, tumor markers and combined inflammatory factors, prognostic inflammatory index (PII), carbohydrate antigen (CA) 19-9 and systemic inflammation score (SIS) were the most significant predictive factors for postoperative survival outcomes in patients with intrahepatic cholangiocarcinoma. The prognostic inflammatory and tumor score (PITS) was proposed as a new prognostic scoring system for intrahepatic cholangiocarcinoma. PII and CA19-9 were included into the scoring criteria for prognostic stratification of patients. PITS was an independent predictor of tumor-free survival and overall survival in patients with intrahepatic cholangiocarcinoma. Patients with high-grade PITS had later tumor grade and higher frequency of vascular invasion. Conclusion: PITS is highly effective prognostic scoring system for patients with intrahepatic cholangiocarcinoma. In addition, PITS is recommended for preoperative prognostic stratification in patients with intrahepatic cholangiocarcinoma.
Collapse
Affiliation(s)
- B Q Ma
- Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - H J Meng
- Department of Dermatology, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - X F Dong
- Department of Hepatobiliary, Pancreas and Spleen Surgery, the People's Hospital of Guangxi Zhuang Autonomous Region (Guangxi Academy of Medical Sciences), Nanning 530021, China
| | - X L Gao
- Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - Y N Wu
- Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - W Zhang
- Department of Hepatobiliary Surgery, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China
| | - S P Li
- Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| | - A Shen
- Department of Hepatopancreatobiliary Surgery, Affiliated Hospital of Weifang Medical University, Weifang 261031, China
| |
Collapse
|
14
|
Hoorens I, Waalboer-Spuij R, Van Coile L, Debaveye M, Shen A, Verhaeghe E, Brochez L. Health state utility instruments in patients with keratinocyte cancer and actinic keratosis: a cross-sectional study. J Eur Acad Dermatol Venereol 2022; 36:e906-e907. [PMID: 35734826 DOI: 10.1111/jdv.18349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- I Hoorens
- Department of Dermatology, Ghent University Hospital, Ghent, Belgium.,CRIG, Cancer Research Institute Ghent, Ghent, Belgium
| | - R Waalboer-Spuij
- Department of Dermatology, Erasmus University Medical Centre, Rotterdam, The Netherlands
| | - L Van Coile
- Department of Dermatology, Ghent University Hospital, Ghent, Belgium.,CRIG, Cancer Research Institute Ghent, Ghent, Belgium
| | - M Debaveye
- Department of Dermatology, Ghent University Hospital, Ghent, Belgium
| | - A Shen
- Department of Dermatology, Ghent University Hospital, Ghent, Belgium
| | - E Verhaeghe
- Department of Dermatology, Ghent University Hospital, Ghent, Belgium.,CRIG, Cancer Research Institute Ghent, Ghent, Belgium
| | - L Brochez
- Department of Dermatology, Ghent University Hospital, Ghent, Belgium.,CRIG, Cancer Research Institute Ghent, Ghent, Belgium
| |
Collapse
|
15
|
Shen A, Tamayo R. Editorial overview: Gene regulation mechanisms governing Clostridioides difficile physiology and virulence. Curr Opin Microbiol 2022; 67:102139. [PMID: 35231749 DOI: 10.1016/j.mib.2022.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
| | - Rita Tamayo
- Department of Microbiology and Immunology, University of North Carolina Chapel Hill School of Medicine, Chapel Hill, NC, USA.
| |
Collapse
|
16
|
Alves Feliciano C, Eckenroth BE, Diaz OR, Doublié S, Shen A. A lipoprotein allosterically activates the CwlD amidase during Clostridioides difficile spore formation. PLoS Genet 2021; 17:e1009791. [PMID: 34570752 PMCID: PMC8496864 DOI: 10.1371/journal.pgen.1009791] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/07/2021] [Accepted: 08/23/2021] [Indexed: 11/19/2022] Open
Abstract
Spore-forming pathogens like Clostridioides difficile depend on germination to initiate infection. During gemination, spores must degrade their cortex layer, which is a thick, protective layer of modified peptidoglycan. Cortex degradation depends on the presence of the spore-specific peptidoglycan modification, muramic-∂-lactam (MAL), which is specifically recognized by cortex lytic enzymes. In C. difficile, MAL production depends on the CwlD amidase and its binding partner, the GerS lipoprotein. To gain insight into how GerS regulates CwlD activity, we solved the crystal structure of the CwlD:GerS complex. In this structure, a GerS homodimer is bound to two CwlD monomers such that the CwlD active sites are exposed. Although CwlD structurally resembles amidase_3 family members, we found that CwlD does not bind Zn2+ stably on its own, unlike previously characterized amidase_3 enzymes. Instead, GerS binding to CwlD promotes CwlD binding to Zn2+, which is required for its catalytic mechanism. Thus, in determining the first structure of an amidase bound to its regulator, we reveal stabilization of Zn2+ co-factor binding as a novel mechanism for regulating bacterial amidase activity. Our results further suggest that allosteric regulation by binding partners may be a more widespread mode for regulating bacterial amidase activity than previously thought. Spore germination is essential for many spore-forming pathogens to initiate infection. In order for spores to germinate, they must degrade a thick, protective layer of cell wall known as the cortex. The enzymes that digest this layer selectively recognize the spore-specific cell wall modification, muramic-∂-lactam (MAL). MAL is made in part through the activity of the CwlD amidase, which is found in all spore-forming bacteria. While Bacillus subtilis CwlD appears to have amidase activity on its own, Clostridioides difficile CwlD activity depends on its binding partner, the GerS lipoprotein. To understand why C. difficile CwlD requires GerS, we determined the X-ray crystal structure of the CwlD:GerS complex and discovered that GerS binds to a site distant from CwlD’s active site. We also found that GerS stabilizes CwlD binding to its co-factor, Zn2+, indicating that GerS allosterically activates CwlD amidase. Notably, regulation at the level of Zn2+ binding has not previously been described for bacterial amidases, and GerS is the first protein to be shown to allosterically activate an amidase. Since binding partners of bacterial amidases were only first discovered 15 years ago, our results suggest that diverse mechanisms remain to be discovered for these critical enzymes.
Collapse
Affiliation(s)
- Carolina Alves Feliciano
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Brian E. Eckenroth
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Oscar R. Diaz
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
17
|
Abstract
Spore formation and germination are essential for the bacterial pathogen Clostridioides difficile to transmit infection. Despite the importance of these developmental processes to the infection cycle of C. difficile, the molecular mechanisms underlying how this obligate anaerobe forms infectious spores and how these spores germinate to initiate infection were largely unknown until recently. Work in the last decade has revealed that C. difficile uses a distinct mechanism for sensing and transducing germinant signals relative to previously characterized spore formers. The C. difficile spore assembly pathway also exhibits notable differences relative to Bacillus spp., where spore formation has been more extensively studied. For both these processes, factors that are conserved only in C. difficile or the related Peptostreptococcaceae family are employed, and even highly conserved spore proteins can have differential functions or requirements in C. difficile compared to other spore formers. This review summarizes our current understanding of the mechanisms controlling C. difficile spore formation and germination and describes strategies for inhibiting these processes to prevent C. difficile infection and disease recurrence.
Collapse
Affiliation(s)
- Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA;
| |
Collapse
|
18
|
Ding X, Jing N, Shen A, Guo F, Song Y, Pan M, Ma X, Zhao L, Zhang H, Wu L, Qin G, Zhao Y. MiR-21-5p in macrophage-derived extracellular vesicles affects podocyte pyroptosis in diabetic nephropathy by regulating A20. J Endocrinol Invest 2021; 44:1175-1184. [PMID: 32930981 DOI: 10.1007/s40618-020-01401-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 08/19/2020] [Indexed: 01/01/2023]
Abstract
OBJECTIVES Podocyte pyroptosis, characterized by inflammasome activation, plays an important role in inflammation-mediated diabetic nephropathy (DN). Our study aimed to investigate whether miR-21-5p in macrophage-derived extracellular vesicles (EVs) could affect podocyte injury in DN. METHODS EVs were extracted after the treatment of RAW 264.7 (mouse macrophage line) with high glucose (HG). The podocyte pyroptosis was determined using the flow cytometry and the western blot. After the knockdown of miR-21-5p in HG-induced RAW264.7 cells, we injected the extracted EVs into DN model mice. RESULTS The level of miR-21-5p was higher in HG-stimulated macrophage-derived EVs than in normal glucose-cultured macrophage-derived EVs. The co-culture of EVs and podocytes promoted reactive oxygen species (ROS) production and activation of inflammatory in MPC5 cells (mouse podocyte line). However, restraint of miR-21-5p in EVs reduced ROS production and inhibit inflammasome activation in MPC5 cells, thereby reducing podocytes injury. Meanwhile, we found that miR-21-5p inhibited the A20 expression through binding with its 3'-untranslated regions in MPC5 cells. Further studies showed that A20 was also involved in the regulation of miR-21-5p of RAW 264.7-derived EVs on MPC5 injury. At the same time, it was also proved in the DN model mice that miR-21-5p in macrophage-derived EVs could regulate podocyte injury. CONCLUSION MiR-21-5p in macrophage-derived EVs can regulate pyroptosis-mediated podocyte injury by A20 in DN.
Collapse
Affiliation(s)
- X Ding
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - N Jing
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - A Shen
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - F Guo
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - Y Song
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - M Pan
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - X Ma
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - L Zhao
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - H Zhang
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - L Wu
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - G Qin
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China
| | - Y Zhao
- Department of Endocrinology and Metabolism, The First Affiliated Hospital of Zhengzhou University, No. 1 Jianshe East Road, Zhengzhou City, 450052, Henan, People's Republic of China.
| |
Collapse
|
19
|
Wang M, Liu F, Li Q, Yin Q, Shen A. Quality assessment of guidelines for the management of Mycobacterium tuberculosis infection in children. Int J Tuberc Lung Dis 2021; 24:287-294. [PMID: 32228758 DOI: 10.5588/ijtld.19.0224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE: The quality of paediatric clinical practice guidelines (CPGs) for the management of Mycobacterium tuberculosis infection is unclear. We aimed to comprehensively assess the quality of these CPGs and identify areas requiring improvement.DESIGN: CPGs were systematically searched and identified before being appraised by independent reviewers using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) and Reporting Items for Practice Guidelines in HealThcare (RIGHT) tools. Inter-rater reliability was assessed using intra-class correlation coefficient (ICC).RESULTS: Twenty-five CPGs were evaluated. All CPG agreements among four reviewers were good (ICC 0.753-0.939). The mean CPG score was 50.5% (23.5-78.4%), and seven CPGs were recommended for use. The mean scores of three domains were low: 38% for stakeholder involvement (5.6-93.1%), 38.4% for rigour of development (1-97.4%) and 36.3% for applicability (12.5-64.6%). The mean reporting rate of Reporting Items for Practice Guidelines in HealThcare fields was 41.8%, and the evidence field had the highest reporting rate (63.1%), while the review and quality assurance field had the lowest rate (15.4%) for CPGs that include methods.CONCLUSION: The methodological and reporting quality of the CPGs was variable and poor, respectively. More effort is needed in stakeholder involvement, rigour of development, applicability domains and reporting to produce higher-quality CPGs.
Collapse
Affiliation(s)
- M Wang
- Beijing Key Laboratory of Paediatric Respiratory Diseases, Beijing Paediatric Research Institute, Beijing, National Clinical Research Centre for Respiratory Diseases, National Key Discipline of Paediatrics, Capital Medical University, Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, Beijing
| | - F Liu
- National Clinical Research Centre for Respiratory Diseases, National Key Discipline of Paediatrics, Capital Medical University, Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, Beijing, Department of Interventional Pulmonology, Beijing Children's Hospital, Beijing
| | - Q Li
- National Clinical Research Centre for Respiratory Diseases, National Key Discipline of Paediatrics, Capital Medical University, Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, Beijing, Department of Infectious Diseases, Beijing Children's Hospital, Beijing
| | - Q Yin
- National Clinical Research Centre for Respiratory Diseases, National Key Discipline of Paediatrics, Capital Medical University, Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, Beijing, Department of Respiratory Diseases, Beijing Children's Hospital, Beijing, China
| | - A Shen
- Beijing Key Laboratory of Paediatric Respiratory Diseases, Beijing Paediatric Research Institute, Beijing, National Clinical Research Centre for Respiratory Diseases, National Key Discipline of Paediatrics, Capital Medical University, Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing Children's Hospital, Capital Medical University, National Centre for Children's Health, Beijing
| |
Collapse
|
20
|
Wu X, Wang Y, Yin Q, Jiao W, Sun L, Qi H, Li J, Quan S, Xu B, Shen A. A diagnostic test that uses isothermal amplification and lateral flow detection sdaA can detect tuberculosis in 60 min. J Appl Microbiol 2020; 130:2102-2110. [PMID: 33070404 DOI: 10.1111/jam.14902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/29/2020] [Accepted: 10/13/2020] [Indexed: 11/28/2022]
Abstract
AIMS Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), is now the leading cause of death from infectious disease, thus rapid diagnostic and screening techniques for TB are urgently needed. METHODS AND RESULTS Here, a detection of MTB using multiple cross displacement amplification coupling with nanoparticles-based lateral flow device (MCDA-LFD) was developed and validated, targeting the specific sdaA gene. The whole detection procedure, including rapid genomic DNA extraction (15 min), amplification (30 min) and result reporting (2 min), was completed within 50 min. No cross-reaction with non-mycobacteria and non-tuberculous mycobacteria (NTM) strains was observed. The sensitivity of sdaA-MCDA-LFD, Xpert MTB/RIF assay and culture results was 81·6, 48·3 and 37·9%, respectively, in TB patients. Among positive culture samples, the sensitivity of sdaA-MCDA-LFD and Xpert MTB/RIF assay was 93·9% (31/33) and 81·8% (27/33), respectively. Among culture-negative samples, the sensitivity of sdaA-MCDA-LFD and Xpert MTB/RIF assay was 74·1% (40/54) and 27·8% (15/54), respectively. The specificity of sdaA-MCDA-LFD and Xpert MTB/RIF was 95·4% (62/65) and 100% (65/65) in clinical samples from non-TB patients. CONCLUSION The sdaA-MCDA-LFD assay was a rapid, simple, specific and sensitive TB diagnostic test. SIGNIFICANCE AND IMPACT OF THE STUDY The sdaA-MCDA-LFD assay holds promise for application as a useful point-of-care test to detect MTB, and will play an important role in controlling and preventing TB.
Collapse
Affiliation(s)
- X Wu
- Department of Respiratory Diseases, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Y Wang
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Q Yin
- Department of Respiratory Diseases, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - W Jiao
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - L Sun
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - H Qi
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - J Li
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - S Quan
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - B Xu
- Department of Respiratory Diseases, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - A Shen
- Beijing Key Laboratory of Pediatric Respiratory Infection Diseases, Key Laboratory of Major Diseases in Children, Ministry of Education, National Clinical Research Center for Respiratory Diseases, National Key Discipline of Pediatrics (Capital Medical University), Beijing Pediatric Research Institute, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| |
Collapse
|
21
|
Chiu S, Nayak R, Duan L, Shen A, Lee M. Triggers of stress cardiomyopathy and their association with clinical outcomes. Eur Heart J 2020. [DOI: 10.1093/ehjci/ehaa946.1811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Stress cardiomyopathy can be a result of physical stress, emotional stress, or both. Whether the type of trigger affects clinical outcomes is not well studied.
Purpose
The objectives of this study were to identify the prevalence of emotional and physical stressors and to assess differences in patient characteristics and mortality based on the type of trigger.
Methods
We conducted a retrospective review of 523 consecutive patients who presented to our institution from 2006 to 2016. All patients presented with acute coronary syndrome. Triggers for stress cardiomyopathy were abstracted from reviewing patients' medical records. Patients were categorized into those with 1) physical trigger, 2) emotional trigger, 3) both physical and emotional trigger, or 4) no known trigger. Baseline characteristics and clinical outcomes were reported.
Results
Among 523 patients with stress cardiomyopathy, 151 (28.9%) had a physical trigger, 189 (36.1%) had an emotional trigger, 30 (5.7%) had both physical and emotional triggers, and 153 (29.3%) had no known triggers identified. Men comprised the higher proportion of patients with physical triggers. Comorbidities including diabetes, pulmonary disease, chronic kidney disease and hypothyroidism were more prevalent among patients with physical triggers. Compared to patients with no obvious triggers, patients with a physical trigger had a much higher mortality rate (hazard ratio 2.0, 95% CI 1.2–3.3, p=0.007), whereas patients with an emotional trigger had significantly lower mortality (hazard ratio 0.40, 95% CI 0.21–0.89, p=0.007).
Conclusion
Different triggers for stress cardiomyopathy is associated with different baseline characteristics and clinical outcomes. Overall survival is worst in the group with an identified physical trigger.
Figure 1
Funding Acknowledgement
Type of funding source: None
Collapse
Affiliation(s)
- S Chiu
- Kaiser Permanente Los Angeles Medical Center, Department of Internal Medicine, Los Angeles, United States of America
| | - R Nayak
- Kaiser Permanente Los Angeles Medical Center, Department of Internal Medicine, Los Angeles, United States of America
| | - L Duan
- Kaiser Permanente Southern California, Department of Research and Evaluation, Pasadena, United States of America
| | - A Shen
- Kaiser Permanente Los Angeles Medical Center, Division of Cardiology, Los Angeles, United States of America
| | - M Lee
- Kaiser Permanente Los Angeles Medical Center, Division of Cardiology, Los Angeles, United States of America
| |
Collapse
|
22
|
Lanfredini M, Bestion D, D'Auria F, Aksan N, Fillion P, Gaillard P, Heo J, Karppinen I, Kim K, Kurki J, Liu L, Shen A, Vacher JL, Wang D. Critical flow prediction by system codes – Recent analyses made within the FONESYS network. Nuclear Engineering and Design 2020. [DOI: 10.1016/j.nucengdes.2020.110731] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
23
|
Su D, Ning L, Zhou R, Shen A. PBI3 The Economic Evaluation Of Clopidogrel In Antiplatelet Therapy Guided By CYP2C19 Gene Polymorphism In The Treatment Of Patients With Coronary Heart Disease. Value Health Reg Issues 2020. [DOI: 10.1016/j.vhri.2020.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
24
|
Yang X, Forster ER, Darabedian N, Kim AT, Pratt MR, Shen A, Hang HC. Translation of Microbiota Short-Chain Fatty Acid Mechanisms Affords Anti-infective Acyl-Salicylic Acid Derivatives. ACS Chem Biol 2020; 15:1141-1147. [PMID: 32091869 DOI: 10.1021/acschembio.9b01009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The discovery of specific microbiota metabolite mechanisms has begun to motivate new therapeutic approaches. Inspired by our mechanistic studies of microbiota-derived short chain fatty acid (SCFA) acylation of bacterial virulence factors, here we explored covalent protein acylation therapeutics as potential anti-infectives. For these studies, we focused on acetyl-salicylic acid, aspirin, and discovered that SCFA analogues such as butyryl-salicylic acid showed significantly improved anti-infective activity against Salmonella Typhimurium. Structure-activity studies showed that the ester functionality of butyryl-salicylic acid was crucial and associated with the acylation of key bacterial virulence factors and metabolic enzymes, which are important for Salmonella infection of host cells and bacterial growth. Beyond the Gram-negative bacterial pathogens, butyryl-salicylic acid also showed better antibacterial activity compared to aspirin against Clostridioides difficile, a clinically challenging Gram-positive bacterial pathogen. Notably, coadministration of butyryl-salicylic acid, but not aspirin, effectively attenuated Salmonella pathogenesis in vivo. This study highlights how the analysis of microbiota metabolite mechanisms may inspire the repurposing and development of new anti-infective agents.
Collapse
Affiliation(s)
- Xinglin Yang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| | - Emily R. Forster
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
- Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts 02111, United States
| | - Narek Darabedian
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Alexander T. Kim
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| | - Matthew R. Pratt
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, United States
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, United States
| | - Howard C. Hang
- Laboratory of Chemical Biology and Microbial Pathogenesis, The Rockefeller University, New York, New York 10065, United States
| |
Collapse
|
25
|
Youn J, Seguchi O, Cole R, Geft D, Nishihara K, Shen A, Sharoff R, Ramzy D, Kobashigawa J, Moriguchi J. Desensitization in Mechanical Circulatory Support Patients Awaiting Heart Transplantation: What is the Post-Transplant Outcome? J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
26
|
Gomez S, Huang H, Duan J, Combrié S, Shen A, Baili G, de Rossi A, Grillot F. High coherence collapse of a hybrid III–V/Si semiconductor laser with a large quality factor. J Phys Photonics 2020. [DOI: 10.1088/2515-7647/ab6a74] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
The high-speed dynamics of a hybrid distributed feedback semiconductor laser heterogeneously integrated onto silicon is experimentally investigated in the presence of external optical feedback. The laser fabrication relies on a proper modal engineering in which light is generated in the III–V material and stored in the low-loss silicon region in order to substantially enhance the quality factor of the cavity resonator. In this work, the hybrid laser is found to be insensitive to parasitic reflections leading to a 10 Gbps floor-free transmission with a power penalty no greater than 1.5 dB at room temperature. As a conclusion, owing to the large quality factor, a high coherence collapse level is unveiled in such laser indicating its vast potential to serve as an alternative solution for the development of isolator-free applications in future photonics integrated circuits. A qualitative interpretation is also provided by linking the standard feedback equations to the quality factor of the resonator.
Collapse
|
27
|
Kittleson M, Patel J, Kransdorf E, Shen A, Nishihara K, Rajkumar S, Velleca A, Geft D, Czer L, Moriguchi J, Kobashigawa J. Desensitization Therapy for Mechanical Circulatory Support Patients with Existing Driveline Infection: Is It Safe with Current Desensitization Therapies? J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
28
|
Patel J, Kittleson M, Chang D, Nishihara K, Shen A, Harris G, Velleca A, Azarbal B, Czer L, Ramzy D, Kobashigawa J. Pre-Transplant Collagen Vascular Disease as a Risk Factor for Increase in Cardiac Allograft Vasculopathy after Heart Transplantation. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
29
|
Patel J, Kittleson M, Kransdorf E, Chang D, Czer L, Shen A, Nishihara K, Sharoff R, Hamilton M, Esmailian F, Kobashigawa J. The Natural History of Pre-Existing Donor Specific Antibody and Amnestic Responses after Heart Transplantation. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.1174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
30
|
Seguchi O, Youn J, Geft D, Cole R, Shen A, Nishihara K, Mersola S, Runyan C, Hajj J, Ramzy D, Kobashigawa J, Moriguchi J. The Burden of Total Artificial Heart Patients and Complications after Heart Transplantation. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
31
|
Patel J, Kittleson M, Kransdorf E, Shen A, Nishihara K, Jamero G, Azarbal B, Hage A, Czer L, Megna D, Kobashigawa J. Does the Development of Donor Specific Antibody after Heart Transplantation Depend on the Presence or Absence of Corticosteroids as Maintenance Therapy? J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
32
|
Patel J, Kittleson M, Chang D, Nishihara K, Shen A, Sharoff R, Velleca A, Coleman B, Hage A, Czer L, Ramzy D, Kobashigawa J. 5-Year Outcome of Patients Weaned off Corticosteroids after Heart Transplantation: Is There a Downside? J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
33
|
Patel J, Kittleson M, Chang D, Nishihara K, Shen A, Megerdichian T, Zabner R, Lor K, Czer L, Esmailian F, Trento A, Kobashigawa J. The Forgotten Hepatitis B Donor in Heart Transplantation. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
34
|
Patel J, Kittleson M, Chang D, Nishihara K, Shen A, Mersola S, Velleca A, Hage A, Czer L, Emerson D, Kobashigawa J. Does the Dose of Mycophenolate Mofetil Impact Outcome after Heart Transplantation? J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
35
|
Kobashigawa J, Kittleson M, Chang D, Kransdorf E, Shen A, Nishihara K, Jamero G, Coleman B, Czer L, Ramzy D, Esmailian F, Patel J. Post-Heart Transplant Outcomes of Sensitized Patients Who Have Undergone Desensitization Therapy. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
36
|
Kittleson M, Patel J, Chang D, Nishihara K, Shen A, Velleca A, Hamilton M, Zakowski P, Czer L, Esmailian F, Kobashigawa J. Effect of the Shingles Vaccine in Altering Clinical Shingles after Heart Transplantation. J Heart Lung Transplant 2020. [DOI: 10.1016/j.healun.2020.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
37
|
Abstract
The Gram-positive, spore-forming bacterium, Clostridioides difficile is the leading cause of healthcare-associated infections in the United States, although it also causes a significant number of community-acquired infections. C. difficile infections, which range in severity from mild diarrhea to toxic megacolon, cost more to treat than matched infections, with an annual treatment cost of approximately $6 billion for almost half-a-million infections. These high-treatment costs are due to the high rates of C. difficile disease recurrence (>20%) and necessity for special disinfection measures. These complications arise in part because C. difficile makes metabolically dormant spores, which are the major infectious particle of this obligate anaerobe. These seemingly inanimate life forms are inert to antibiotics, resistant to commonly used disinfectants, readily disseminated, and capable of surviving in the environment for a long period of time. However, upon sensing specific bile salts in the vertebrate gut, C. difficile spores transform back into the vegetative cells that are responsible for causing disease. This review discusses how spores are ideal vectors for disease transmission and how antibiotics modulate this process. We also describe the resistance properties of spores and how they create challenges eradicating spores, as well as promote their spread. Lastly, environmental reservoirs of C. difficile spores and strategies for destroying them particularly in health care environments will be discussed.
Collapse
Affiliation(s)
- Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts
| |
Collapse
|
38
|
Abstract
As obligate anaerobes, clostridial pathogens depend on their metabolically dormant, oxygen-tolerant spore form to transmit disease. However, the molecular mechanisms by which those spores germinate to initiate infection and then form new spores to transmit infection remain poorly understood. While sporulation and germination have been well characterized in Bacillus subtilis and Bacillus anthracis, striking differences in the regulation of these processes have been observed between the bacilli and the clostridia, with even some conserved proteins exhibiting differences in their requirements and functions. Here, we review our current understanding of how clostridial pathogens, specifically Clostridium perfringens, Clostridium botulinum, and Clostridioides difficile, induce sporulation in response to environmental cues, assemble resistant spores, and germinate metabolically dormant spores in response to environmental cues. We also discuss the direct relationship between toxin production and spore formation in these pathogens.
Collapse
Affiliation(s)
- Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University Medical School, Boston, MA
| | - Adrianne N Edwards
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA
| | - Mahfuzur R Sarker
- Department of Microbiology, College of Science, Oregon State University, Corvallis, OR
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR
| | - Daniel Paredes-Sabja
- Department of Gut Microbiota and Clostridia Research Group, Departamento de Ciencias Biolo gicas, Facultad de Ciencias Biologicas, Universidad Andres Bello, Santiago, Chile
| |
Collapse
|
39
|
Zhang Y, Zhang M, Wang CY, Shen A. Ketamine alleviates LPS induced lung injury by inhibiting HMGB1-RAGE level. Eur Rev Med Pharmacol Sci 2019; 22:1830-1836. [PMID: 29630133 DOI: 10.26355/eurrev_201803_14603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Inflammatory cytokines secretion is an important reason to promote lung tissue inflammation in acute lung injury (ALI). High mobility group box 1 (HMGB-1) and its receptor for advanced glycation end products (RAGEs) play a role in ALI. Ketamine can significantly alleviate ALI, whereas its specific mechanism has not been fully elucidated. MATERIALS AND METHODS A total of 60 male Wistar rats were equally randomly divided into three groups, including ALI group which was established by 10 mg/kg LPS femoral vein injection, ketamine group which was constructed by 50 mg/kg ketamine femoral vein injection based on ALI model, and control group. Blood gas analysis was applied to detect arterial blood oxygen partial pressure (PaO2) and pH. Lung tissue wet/dry weight ratio (W/D), myeloperoxidase (MPO) and superoxide dismutase (SOD) activity were detected. Real-time PCR and ELISA were used to test HMGB-1 expression in lung tissue and serum. RAGE and NF-κB changes were determined by Real-time PCR and Western blot. RESULTS Compared with control, ALI group presented decreased PaO2 and PH, elevated W/D, enhanced MPO activity, declined SOD activity, upregulated HMGB-1 mRNA, increased HMGB-1 secretion, and increased RAGE and NF-κB mRNA and protein (p < 0.05). Ketamine treatment significantly elevated PaO2 and PH, reduced W/D, declined MPO activity, enhanced SOD activity, inhibited HMGB-1 mRNA and secretion, and downregulated RAGE and NF-κB mRNA and protein (p < 0.05). CONCLUSIONS Ketamine can alleviate LPS induced lung injury through inhibiting HMGB1-RAGE level. It could be treated as a new choice for ALI treatment.
Collapse
Affiliation(s)
- Y Zhang
- Department of ICU, Affiliated Hospital of Weifang Medical College, Weifang, China.
| | | | | | | |
Collapse
|
40
|
Wasiak J, Tyack Z, Tacey M, Young A, Shen A, Jnr CMF. Poor Methodological Quality but Higher Reporting Standards Seen in Systematic Reviews in Radiation Dermatitis. Int J Radiat Oncol Biol Phys 2019. [DOI: 10.1016/j.ijrobp.2019.06.1422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
41
|
Sekulovic O, Bourgeois J, Shen A, Camilli A. Expanding the repertoire of conservative site-specific recombination in Clostridioides difficile. Anaerobe 2019; 60:102073. [PMID: 31323290 DOI: 10.1016/j.anaerobe.2019.102073] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/13/2019] [Accepted: 07/15/2019] [Indexed: 01/20/2023]
Abstract
Recent genomic analysis of an epidemic ribotype 027 (RT027) Clostridioides difficile strain revealed the presence of several chromosomal site-specific invertible sites hypothesized to control the expression of adjacent genes in a bimodal on-off mode. This process, named phase variation, is thought to enhance phenotypic variability under homogeneous conditions ultimately increasing population fitness in unpredictable environmental fluctuations. The full extent of phase variation mediated by DNA-inversions in C. difficile is currently unknown. Here, we sought to expand our previous analysis by screening for site-specific inversions in isolates that belong to the rapidly emerging ribotypes RT017 and RT078. We report the finding of one novel inversion site for which we demonstrate the inversion potential and quantify inversion proportions during exponential and stationary growth in both historic and modern isolates of the same ribotype. We then employ a computational approach to assess the prevalence of all sites identified so far in a large collection of sequenced C. difficile isolates. We show that phase-variable loci are widespread with some sites being present in virtually all analyzed strains. Furthermore, in our small subset of RT017 and RT078 strains, we detect no evidence of gain or loss of invertible sites in historic versus modern isolates demonstrating the relative stability of those genomic elements. Overall, our results support the idea that C. difficile has adopted phase variation mediated by DNA inversions as its major generator of diversity which could be beneficial during the pathogenesis process.
Collapse
Affiliation(s)
- Ognjen Sekulovic
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
| | - Jacob Bourgeois
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
| | - Andrew Camilli
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.
| |
Collapse
|
42
|
Rohlfing AE, Eckenroth BE, Forster ER, Kevorkian Y, Donnelly ML, Benito de la Puebla H, Doublié S, Shen A. The CspC pseudoprotease regulates germination of Clostridioides difficile spores in response to multiple environmental signals. PLoS Genet 2019; 15:e1008224. [PMID: 31276487 PMCID: PMC6636752 DOI: 10.1371/journal.pgen.1008224] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 07/17/2019] [Accepted: 05/31/2019] [Indexed: 12/18/2022] Open
Abstract
The gastrointestinal pathogen, Clostridioides difficile, initiates infection when its metabolically dormant spore form germinates in the mammalian gut. While most spore-forming bacteria use transmembrane germinant receptors to sense nutrient germinants, C. difficile is thought to use the soluble pseudoprotease, CspC, to detect bile acid germinants. To gain insight into CspC's unique mechanism of action, we solved its crystal structure. Guided by this structure, we identified CspC mutations that confer either hypo- or hyper-sensitivity to bile acid germinant. Surprisingly, hyper-sensitive CspC variants exhibited bile acid-independent germination as well as increased sensitivity to amino acid and/or calcium co-germinants. Since mutations in specific residues altered CspC's responsiveness to these different signals, CspC plays a critical role in regulating C. difficile spore germination in response to multiple environmental signals. Taken together, these studies implicate CspC as being intimately involved in the detection of distinct classes of co-germinants in addition to bile acids and thus raises the possibility that CspC functions as a signaling node rather than a ligand-binding receptor.
Collapse
Affiliation(s)
- Amy E. Rohlfing
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Brian E. Eckenroth
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Emily R. Forster
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Yuzo Kevorkian
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
- Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - M. Lauren Donnelly
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
- Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Hector Benito de la Puebla
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Sylvie Doublié
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, United States of America
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
43
|
Ribis JW, Fimlaid KA, Shen A. Differential requirements for conserved peptidoglycan remodeling enzymes during Clostridioides difficile spore formation. Mol Microbiol 2019; 110:370-389. [PMID: 30066347 DOI: 10.1111/mmi.14090] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2018] [Indexed: 12/24/2022]
Abstract
Spore formation is essential for the bacterial pathogen and obligate anaerobe, Clostridioides (Clostridium) difficile, to transmit disease. Completion of this process depends on the mother cell engulfing the developing forespore, but little is known about how engulfment occurs in C. difficile. In Bacillus subtilis, engulfment is mediated by a peptidoglycan degradation complex consisting of SpoIID, SpoIIP and SpoIIM, which are all individually required for spore formation. Using genetic analyses, we determined the functions of these engulfment-related proteins along with the putative endopeptidase, SpoIIQ, during C. difficile sporulation. While SpoIID, SpoIIP and SpoIIQ were critical for engulfment, loss of SpoIIM minimally impacted C. difficile spore formation. Interestingly, a small percentage of ∆spoIID and ∆spoIIQ cells generated heat-resistant spores through the actions of SpoIIQ and SpoIID, respectively. Loss of SpoIID and SpoIIQ also led to unique morphological phenotypes: asymmetric engulfment and forespore distortions, respectively. Catalytic mutant complementation analyses revealed that these phenotypes depend on the enzymatic activities of SpoIIP and SpoIID, respectively. Lastly, engulfment mutants mislocalized polymerized coat even though the basement layer coat proteins, SpoIVA and SipL, remained associated with the forespore. Collectively, these findings advance our understanding of several stages during infectious C. difficile spore assembly.
Collapse
Affiliation(s)
- John W Ribis
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.,Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - Kelly A Fimlaid
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA, USA.,Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, VT, USA
| |
Collapse
|
44
|
Touchette MH, Benito de la Puebla H, Ravichandran P, Shen A. SpoIVA-SipL Complex Formation Is Essential for Clostridioides difficile Spore Assembly. J Bacteriol 2019; 201:e00042-19. [PMID: 30692174 PMCID: PMC6436350 DOI: 10.1128/jb.00042-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 01/23/2019] [Indexed: 01/05/2023] Open
Abstract
Spores are the major infectious particle of the Gram-positive nosocomial pathogen Clostridioides difficile (formerly Clostridium difficile), but the molecular details of how this organism forms these metabolically dormant cells remain poorly characterized. The composition of the spore coat in C. difficile differs markedly from that defined in the well-studied organism Bacillus subtilis, with only 25% of the ∼70 spore coat proteins being conserved between the two organisms and with only 2 of 9 coat assembly (morphogenetic) proteins defined in B. subtilis having homologs in C. difficile We previously identified SipL as a clostridium-specific coat protein essential for functional spore formation. Heterologous expression analyses in Escherichia coli revealed that SipL directly interacts with C. difficile SpoIVA, a coat-morphogenetic protein conserved in all spore-forming organisms, through SipL's C-terminal LysM domain. In this study, we show that SpoIVA-SipL binding is essential for C. difficile spore formation and identify specific residues within the LysM domain that stabilize this interaction. Fluorescence microscopy analyses indicate that binding of SipL's LysM domain to SpoIVA is required for SipL to localize to the forespore while SpoIVA requires SipL to promote encasement of SpoIVA around the forespore. Since we also show that clostridial LysM domains are functionally interchangeable at least in C. difficile, the basic mechanism for SipL-dependent assembly of clostridial spore coats may be conserved.IMPORTANCE The metabolically dormant spore form of the major nosocomial pathogen Clostridioides difficile is its major infectious particle. However, the mechanisms controlling the formation of this resistant cell type are not well understood, particularly with respect to its outermost layer, the spore coat. We previously identified two spore-morphogenetic proteins in C. difficile: SpoIVA, which is conserved in all spore-forming organisms, and SipL, which is conserved only in the clostridia. Both SpoIVA and SipL are essential for heat-resistant spore formation and directly interact through SipL's C-terminal LysM domain. In this study, we demonstrate that the LysM domain is critical for SipL and SpoIVA function, likely by helping recruit SipL to the forespore during spore morphogenesis. We further identified residues within the LysM domain that are important for binding SpoIVA and, thus, functional spore formation. These findings provide important insight into the molecular mechanisms controlling the assembly of infectious C. difficile spores.
Collapse
Affiliation(s)
- Megan H Touchette
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Hector Benito de la Puebla
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Priyanka Ravichandran
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Department of Microbiology and Molecular Genetics, University of Vermont, Burlington, Vermont, USA
| |
Collapse
|
45
|
Patel J, Kittleson M, Levine R, Sana S, Shen A, Geft D, Azarbal B, Kransdorf E, Kobashigawa J. Heart Transplantation for Cardiac Amyloidosis - Worthwhile? J Heart Lung Transplant 2019. [DOI: 10.1016/j.healun.2019.01.523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
46
|
Kransdorf E, Patel J, Kittleson M, Chang D, Dimbil S, Levine R, Shen A, Jain A, Olymbios M, Czer L, Zhang X, Kobashigawa J. What Antigens to Avoid in Heart Transplant to Optimize Outcome via the Virtual Crossmatch. J Heart Lung Transplant 2019. [DOI: 10.1016/j.healun.2019.01.656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
47
|
Fagan R, McBride SM, Shen A. Editorial. Anaerobe 2018; 53:1. [DOI: 10.1016/j.anaerobe.2018.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
48
|
Diaz OR, Sayer CV, Popham DL, Shen A. Clostridium difficile Lipoprotein GerS Is Required for Cortex Modification and Thus Spore Germination. mSphere 2018; 3:e00205-18. [PMID: 29950380 PMCID: PMC6021603 DOI: 10.1128/msphere.00205-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 04/22/2018] [Indexed: 02/04/2023] Open
Abstract
Clostridium difficile, also known as Clostridioides difficile, is a Gram-positive, spore-forming bacterium that is a leading cause of antibiotic-associated diarrhea. C. difficile infections begin when its metabolically dormant spores germinate to form toxin-producing vegetative cells. Successful spore germination depends on the degradation of the cortex, a thick layer of modified peptidoglycan that maintains dormancy. Cortex degradation is mediated by the SleC cortex lytic enzyme, which is thought to recognize the cortex-specific modification muramic-δ-lactam. C. difficile cortex degradation also depends on the Peptostreptococcaceae-specific lipoprotein GerS for unknown reasons. In this study, we tested whether GerS regulates production of muramic-δ-lactam and thus controls the ability of SleC to recognize its cortex substrate. By comparing the muropeptide profiles of ΔgerS spores to those of spores lacking either CwlD or PdaA, both of which mediate cortex modification in Bacillus subtilis, we determined that C. difficile GerS, CwlD, and PdaA are all required to generate muramic-δ-lactam. Both GerS and CwlD were needed to cleave the peptide side chains from N-acetylmuramic acid, suggesting that these two factors act in concert. Consistent with this hypothesis, biochemical analyses revealed that GerS and CwlD directly interact and that CwlD modulates GerS incorporation into mature spores. Since ΔgerS, ΔcwlD, and ΔpdaA spores exhibited equivalent germination defects, our results indicate that C. difficile spore germination depends on cortex-specific modifications, reveal GerS as a novel regulator of these processes, and highlight additional differences in the regulation of spore germination in C. difficile relative to B. subtilis and other spore-forming organisms.IMPORTANCE The Gram-positive, spore-forming bacterium Clostridium difficile is a leading cause of antibiotic-associated diarrhea. Because C. difficile is an obligate anaerobe, its aerotolerant spores are essential for transmitting disease, and their germination into toxin-producing cells is necessary for causing disease. Spore germination requires the removal of the cortex, a thick layer of modified peptidoglycan that maintains spore dormancy. Cortex degradation is mediated by the SleC hydrolase, which is thought to recognize cortex-specific modifications. Cortex degradation also requires the GerS lipoprotein for unknown reasons. In our study, we tested whether GerS is required to generate cortex-specific modifications by comparing the cortex composition of ΔgerS spores to the cortex composition of spores lacking two putative cortex-modifying enzymes, CwlD and PdaA. These analyses revealed that GerS, CwlD, and PdaA are all required to generate cortex-specific modifications. Since loss of these modifications in ΔgerS, ΔcwlD, and ΔpdaA mutants resulted in spore germination and heat resistance defects, the SleC cortex lytic enzyme depends on cortex-specific modifications to efficiently degrade this protective layer. Our results further indicate that GerS and CwlD are mutually required for removing peptide chains from spore peptidoglycan and revealed a novel interaction between these proteins. Thus, our findings provide new mechanistic insight into C. difficile spore germination.
Collapse
Affiliation(s)
- Oscar R Diaz
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- NIH Postbaccalaureate Research Education Program (PREP), Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Cameron V Sayer
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - David L Popham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Aimee Shen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| |
Collapse
|
49
|
Khadka D, Oh G, Kim H, Shen A, Lee S, Sharma S, Yang S, So H. PO-251 Modulation of NAD+levels by NQO1 enzymatic action alleviates adriamycin-induced cardiac dysfunction in mice. ESMO Open 2018. [DOI: 10.1136/esmoopen-2018-eacr25.284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
|
50
|
Fernando D, Shen A, Weinzimer L, McInnes E, Chiofalo J. 1.2-O1An analysis of asylum-seeking torture survivors' utilization of mental health services at a human rights center in the US. Eur J Public Health 2018. [DOI: 10.1093/eurpub/cky047.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- D Fernando
- Libertas Center for Human Rights, Elmhurst Hospital/Icahn School of Medicine at Mount Sinai, United States
| | - A Shen
- Icahn School of Medicine at Mount Sinai, New York, United States
| | - L Weinzimer
- Partnerships for Trauma Recovery, Berkeley, United States
| | - E McInnes
- Libertas Center for Human Rights, Elmhurst Hospital/Icahn School of Medicine at Mount Sinai, United States
| | - J Chiofalo
- Libertas Center for Human Rights, Elmhurst Hospital/Icahn School of Medicine at Mount Sinai, United States
| |
Collapse
|