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Zheng C, Wei Y, Zhang P, Lin K, He D, Teng H, Manyam G, Zhang Z, Liu W, Lee HRL, Tang X, He W, Islam N, Jain A, Chiu Y, Cao S, Diao Y, Meyer-Gauen S, Höök M, Malovannaya A, Li W, Hu M, Wang W, Xu H, Kopetz S, Chen Y. CRISPR-Cas9-based functional interrogation of unconventional translatome reveals human cancer dependency on cryptic non-canonical open reading frames. Nat Struct Mol Biol 2023; 30:1878-1892. [PMID: 37932451 PMCID: PMC10716047 DOI: 10.1038/s41594-023-01117-1] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 09/06/2023] [Indexed: 11/08/2023]
Abstract
Emerging evidence suggests that cryptic translation beyond the annotated translatome produces proteins with developmental or physiological functions. However, functions of cryptic non-canonical open reading frames (ORFs) in cancer remain largely unknown. To fill this gap and systematically identify colorectal cancer (CRC) dependency on non-canonical ORFs, we apply an integrative multiomic strategy, combining ribosome profiling and a CRISPR-Cas9 knockout screen with large-scale analysis of molecular and clinical data. Many such ORFs are upregulated in CRC compared to normal tissues and are associated with clinically relevant molecular subtypes. We confirm the in vivo tumor-promoting function of the microprotein SMIMP, encoded by a primate-specific, long noncoding RNA, the expression of which is associated with poor prognosis in CRC, is low in normal tissues and is specifically elevated in CRC and several other cancer types. Mechanistically, SMIMP interacts with the ATPase-forming domains of SMC1A, the core subunit of the cohesin complex, and facilitates SMC1A binding to cis-regulatory elements to promote epigenetic repression of the tumor-suppressive cell cycle regulators encoded by CDKN1A and CDKN2B. Thus, our study reveals a cryptic microprotein as an important component of cohesin-mediated gene regulation and suggests that the 'dark' proteome, encoded by cryptic non-canonical ORFs, may contain potential therapeutic or diagnostic targets.
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Affiliation(s)
- Caishang Zheng
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yanjun Wei
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Peng Zhang
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Key Laboratory of RNA Biology, Center for Big Data Research in Health, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Kangyu Lin
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Dandan He
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Sema4, Inc., Stamford, CT, USA
| | - Hongqi Teng
- Department of Experimental Radiation Oncology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ganiraju Manyam
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Zhao Zhang
- Department of Biochemistry and Molecular Biology, McGovern Medical School, the University of Texas Health Science Center at Houston, Houston, TX, USA
- MOE Key Laboratory of Metabolism and Molecular Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Wen Liu
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center, Institute of Biosciences of Technology, Houston, TX, USA
| | - Hye Rin Lindsay Lee
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Ximing Tang
- Department of Translational Molecular Pathology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Wei He
- Department of Epigenetics and Molecular Carcinogenesis, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Nelufa Islam
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, TX, USA
| | - Antrix Jain
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, TX, USA
| | - Yulun Chiu
- Department of Melanoma Medical Oncology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Shaolong Cao
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yarui Diao
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA
- Duke Regeneration Center, Duke University Medical Center, Durham, NC, USA
- Department of Orthopedic Surgery, Duke University Medical Center, Durham, NC, USA
| | - Sherita Meyer-Gauen
- Department of Translational Molecular Pathology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center, Institute of Biosciences of Technology, Houston, TX, USA
| | - Anna Malovannaya
- Mass Spectrometry Proteomics Core, Baylor College of Medicine, Houston, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Wenbo Li
- Department of Biochemistry and Molecular Biology, McGovern Medical School, the University of Texas Health Science Center at Houston, Houston, TX, USA
- Graduate School of Biomedical Sciences, University of Texas MD Anderson Cancer Center and UTHealth, Houston, TX, USA
| | - Ming Hu
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Wenyi Wang
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Quantitative Sciences Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Han Xu
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Department of Epigenetics and Molecular Carcinogenesis, the University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Quantitative Sciences Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
- Genetics and Epigenetics Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA
| | - Scott Kopetz
- Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yiwen Chen
- Department of Bioinformatics and Computational Biology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA.
- Quantitative Sciences Program, MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA.
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Bertoglio F, Ko YP, Thomas S, Giordano L, Scommegna FR, Meier D, Polten S, Becker M, Arora S, Hust M, Höök M, Visai L. Antibodies to coagulase of Staphylococcus aureus crossreact to Efb and reveal different binding of shared fibrinogen binding repeats. Front Immunol 2023; 14:1221108. [PMID: 37828992 PMCID: PMC10565355 DOI: 10.3389/fimmu.2023.1221108] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 07/31/2023] [Indexed: 10/14/2023] Open
Abstract
Staphylococcus aureus pathology is caused by a plethora of virulence factors able to combat multiple host defence mechanisms. Fibrinogen (Fg), a critical component in the host coagulation cascade, plays an important role in the pathogenesis of this bacterium, as it is the target of numerous staphylococcal virulence proteins. Amongst its secreted virulence factors, coagulase (Coa) and Extracellular fibrinogen-binding protein (Efb) share common Fg binding motives and have been described to form a Fg shield around staphylococcal cells, thereby allowing efficient bacterial spreading, phagocytosis escape and evasion of host immune system responses. Targeting these proteins with monoclonal antibodies thus represents a new therapeutic option against S. aureus. To this end, here we report the selection and characterization of fully human, sequence-defined, monoclonal antibodies selected against the C-terminal of coagulase. Given the functional homology between Coa and Efb, we also investigated if the generated antibodies bound the two virulence factors. Thirteen unique antibodies were isolated from naïve antibodies gene libraries by antibody phage display. As anticipated, most of the selected antibodies showed cross-recognition of these two proteins and among them, four were able to block the interaction between Coa/Efb and Fg. Furthermore, our monoclonal antibodies could interact with the two main Fg binding repeats present at the C-terminal of Coa and distinguish them, suggesting the presence of two functionally different Fg-binding epitopes.
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Affiliation(s)
- Federico Bertoglio
- Department of Molecular Medicine (DMM), Center for Health Technologies (CHT), Unitá di Ricerca (UdR) Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), University of Pavia, Pavia, Italy
- School of Advanced Studies IUSS Pavia, Pavia, Italy
- Department of Medical Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Ya-Ping Ko
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Sheila Thomas
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Liliana Giordano
- Department of Molecular Medicine (DMM), Center for Health Technologies (CHT), Unitá di Ricerca (UdR) Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), University of Pavia, Pavia, Italy
| | - Francesca Romana Scommegna
- Department of Molecular Medicine (DMM), Center for Health Technologies (CHT), Unitá di Ricerca (UdR) Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), University of Pavia, Pavia, Italy
| | - Doris Meier
- Department of Medical Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Saskia Polten
- Department of Medical Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Marlies Becker
- Department of Medical Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Srishtee Arora
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Michael Hust
- Department of Medical Biotechnology, Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Livia Visai
- Department of Molecular Medicine (DMM), Center for Health Technologies (CHT), Unitá di Ricerca (UdR) Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), University of Pavia, Pavia, Italy
- Medicina Clinica-Specialistica, UOR5 Laboratorio di Nanotecnologie, Istituti Clinici Scientifici (ICS) Maugeri, Istituti di Ricovero e Cura a Carattere Scientifico (IRCCS), Pavia, Italy
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3
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Taylor JC, Gao X, Xu J, Holder M, Petrosino J, Kumar R, Liu W, Höök M, Mackenzie C, Hillhouse A, Brashear W, Nunez MP, Xu Y. A type VII secretion system of Streptococcus gallolyticus subsp. gallolyticus contributes to gut colonization and the development of colon tumors. PLoS Pathog 2021; 17:e1009182. [PMID: 33406160 PMCID: PMC7815207 DOI: 10.1371/journal.ppat.1009182] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/19/2021] [Accepted: 11/23/2020] [Indexed: 02/06/2023] Open
Abstract
Streptococcus gallolyticus subspecies gallolyticus (Sgg) has a strong clinical association with colorectal cancer (CRC) and actively promotes the development of colon tumors. However, the molecular determinants involved in Sgg pathogenicity in the gut are unknown. Bacterial type VII secretion systems (T7SS) mediate pathogen interactions with their host and are important for virulence in pathogenic mycobacteria and Staphylococcus aureus. Through genome analysis, we identified a locus in Sgg strain TX20005 that encodes a putative type VII secretion system (designated as SggT7SST05). We showed that core genes within the SggT7SST05 locus are expressed in vitro and in the colon of mice. Western blot analysis showed that SggEsxA, a protein predicted to be a T7SS secretion substrate, is detected in the bacterial culture supernatant, indicating that this SggT7SST05 is functional. Deletion of SggT7SST05 (TX20005Δesx) resulted in impaired bacterial adherence to HT29 cells and abolished the ability of Sgg to stimulate HT29 cell proliferation. Analysis of bacterial culture supernatants suggest that SggT7SST05-secreted factors are responsible for the pro-proliferative activity of Sgg, whereas Sgg adherence to host cells requires both SggT7SST05-secreted and bacterial surface-associated factors. In a murine gut colonization model, TX20005Δesx showed significantly reduced colonization compared to the parent strain. Furthermore, in a mouse model of CRC, mice exposed to TX20005 had a significantly higher tumor burden compared to saline-treated mice, whereas those exposed to TX20005Δesx did not. Examination of the Sgg load in the colon in the CRC model suggests that SggT7SST05-mediated activities are directly involved in the promotion of colon tumors. Taken together, these results reveal SggT7SST05 as a previously unrecognized pathogenicity determinant for Sgg colonization of the colon and promotion of colon tumors. Colorectal cancer (CRC) is a leading cause of cancer-related death. The development of CRC can be strongly influenced by specific gut microbes. Understanding how gut microbes modulate CRC is critical to developing novel strategies to improve clinical diagnosis and treatment of this disease. S. gallolyticus subsp. gallolyticus (Sgg) has a strong clinical association with CRC and actively promotes the development of colon tumors. However, the specific Sgg molecules that mediate its pro-tumor activity are unknown. Here we report the first characterization of a type VII secretion system (T7SS) in Sgg, designated as SggT7SST05. We further demonstrate that SggT7SST05-mediated activities are important for Sgg to colonize the colon and to promote the development of colon tumors. These findings reveal SggT7SST05 as a novel pathogenicity determinant of Sgg and provide a critical breakthrough in our efforts to understand how Sgg influences the development of CRC. Future investigations of the biological activities of specific effectors of SggT7SST05 will likely lead to the discovery of Sgg molecules that can be used as diagnostic markers and intervention targets aimed at mitigating the harmful effect of Sgg.
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Affiliation(s)
- John Culver Taylor
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Xinsheng Gao
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Juan Xu
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Michael Holder
- Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, Texas, United States of America
| | - Joseph Petrosino
- Center for Metagenomics and Microbiome Research, Baylor College of Medicine, Houston, Texas, United States of America
| | - Ritesh Kumar
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Wen Liu
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Chris Mackenzie
- Department of Microbiology and Molecular Genetics, McGovern Medical School, UT Health, Houston, Texas, United States of America
| | - Andrew Hillhouse
- Texas A&M Institute for Genome Sciences and Society, Texas A&M, Texas, United States of America
| | - Wesley Brashear
- Texas A&M Institute for Genome Sciences and Society, Texas A&M, Texas, United States of America
| | - Maria Patricia Nunez
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
| | - Yi Xu
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center Institute of Biosciences of Technology, Houston, Texas, United States of America
- Department of Microbiology and Molecular Genetics, McGovern Medical School, UT Health, Houston, Texas, United States of America
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Texas, United States of America
- * E-mail:
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4
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Pickering AC, Vitry P, Prystopiuk V, Garcia B, Höök M, Schoenebeck J, Geoghegan JA, Dufrêne YF, Fitzgerald JR. Host-specialized fibrinogen-binding by a bacterial surface protein promotes biofilm formation and innate immune evasion. PLoS Pathog 2019; 15:e1007816. [PMID: 31216354 PMCID: PMC6602291 DOI: 10.1371/journal.ppat.1007816] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [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: 01/24/2019] [Revised: 07/01/2019] [Accepted: 05/06/2019] [Indexed: 11/18/2022] Open
Abstract
Fibrinogen is an essential part of the blood coagulation cascade and a major component of the extracellular matrix in mammals. The interface between fibrinogen and bacterial pathogens is an important determinant of the outcome of infection. Here, we demonstrate that a canine host-restricted skin pathogen, Staphylococcus pseudintermedius, produces a cell wall-associated protein (SpsL) that has evolved the capacity for high strength binding to canine fibrinogen, with reduced binding to fibrinogen of other mammalian species including humans. Binding occurs via the surface-expressed N2N3 subdomains, of the SpsL A-domain, to multiple sites in the fibrinogen α-chain C-domain by a mechanism analogous to the classical dock, lock, and latch binding model. Host-specific binding is dependent on a tandem repeat region of the fibrinogen α-chain, a region highly divergent between mammals. Of note, we discovered that the tandem repeat region is also polymorphic in different canine breeds suggesting a potential influence on canine host susceptibility to S. pseudintermedius infection. Importantly, the strong host-specific fibrinogen-binding interaction of SpsL to canine fibrinogen is essential for bacterial aggregation and biofilm formation, and promotes resistance to neutrophil phagocytosis, suggesting a key role for the interaction during pathogenesis. Taken together, we have dissected a bacterial surface protein-ligand interaction resulting from the co-evolution of host and pathogen that promotes host-specific innate immune evasion and may contribute to its host-restricted ecology. Many bacterial pathogens are specialized for a single host-species and rarely cause infections of other hosts. Our understanding of the bacterial factors underpinning host-specificity are limited. Here we demonstrate that a canine host-restricted bacterial pathogen, Staphylococcus pseudintermedius, produces a surface protein (SpsL) that has the ability to preferentially bind to canine fibrinogen with high strength. This host-specific interaction has evolved via binding to a tandem repeat region of the fibrinogen α-chain which is divergent among mammalian species. Importantly, we found that the strong binding interaction with canine fibrinogen promotes bacterial aggregation and biofilm formation as well as inhibiting neutrophil phagocytosis. Our findings reveal the host-adaptive evolution of a key bacterium-host interaction that promotes evasion of the host immune response.
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Affiliation(s)
- Amy C. Pickering
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, United Kingdom
| | - Pauline Vitry
- Institute of Life Sciences, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Valeriia Prystopiuk
- Institute of Life Sciences, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Brandon Garcia
- Department of Microbiology and Immunology, Brody school of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Texas A&M Health Science Center, Houston, Texas, United States of America
| | - Jeffrey Schoenebeck
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, United Kingdom
| | - Joan A. Geoghegan
- Department of Microbiology, Moyne Institute of Preventive Medicine, School of Genetics and Microbiology, Trinity College Dublin, Dublin, Ireland
| | - Yves F. Dufrêne
- Institute of Life Sciences, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
- Walloon Excellence in Life Sciences and Biotechnology, Wavre, Belgium
| | - J. Ross Fitzgerald
- The Roslin Institute and Edinburgh Infectious Diseases, University of Edinburgh, Easter Bush Campus, Edinburgh, Scotland, United Kingdom
- * E-mail:
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Thomas S, Liu W, Arora S, Ganesh V, Ko YP, Höök M. The Complex Fibrinogen Interactions of the Staphylococcus aureus Coagulases. Front Cell Infect Microbiol 2019; 9:106. [PMID: 31041195 PMCID: PMC6476931 DOI: 10.3389/fcimb.2019.00106] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/27/2019] [Indexed: 11/22/2022] Open
Abstract
The two coagulases, von Willebrand factor binding protein (vWbp) and Coagulase (Coa), are critical virulence factors in several animal models of invasive Staphylococcus aureus (S. aureus) infections. These proteins are part of an intricate system of proteins that S. aureus uses to assemble a fibrinogen (Fg)/fibrin protective shield surrounding itself. This shield allows the microorganism to evade clearance by the host phagocytic cells. The coagulases can non-proteolytically activate the zymogen prothrombin to convert Fg to fibrin and promote the Fg/fibrin shield formation. The coagulases also bind directly to Fg and the interaction between Coa and Fg has been previously characterized in some detail. However, the mechanism(s) by which vWbp interacts with Fg remains unclear. Here, we show that vWbp and Coa have distinct interactions with Fg, despite being structurally similar. Coa binds with a significantly higher affinity to soluble Fg than to Fg coated on a plastic surface, whereas vWbp demonstrates no preference between the two forms of Fg. The two coagulases appear to target different sites on Fg, as they do not compete with each other in binding to Fg. Similar to Coa, both the N- and C-terminal halves of vWbp (vWbp-N, vWbp-C, respectively) harbor Fg-binding activities. The higher affinity Fg-binding activity resides in vWbp-N; whereas, the C-terminal region of Coa encompasses the major Fg-binding activity. Peptides constituting the previously identified Coa/Efb1 Fg-binding motif fail to inhibit vWbp-C from binding to Fg, indicating that vWbp-C lacks a functional homolog to this motif. Interestingly, the N-terminal prothrombin-binding domains of both coagulases recognize the Fg β-chain, but they appear to interact with different sequence motifs in the host protein. Collectively, our data provide insight into the complex interactions between Fg and the S. aureus coagulases.
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Affiliation(s)
- Sheila Thomas
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Wen Liu
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Srishtee Arora
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Vannakambodi Ganesh
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Ya-Ping Ko
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, United States
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Becerra-Bayona SM, Guiza-Arguello VR, Russell B, Höök M, Hahn MS. Influence of collagen-based integrin α 1 and α 2 mediated signaling on human mesenchymal stem cell osteogenesis in three dimensional contexts. J Biomed Mater Res A 2018; 106:2594-2604. [PMID: 29761640 PMCID: PMC7147932 DOI: 10.1002/jbm.a.36451] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 11/14/2017] [Revised: 03/02/2018] [Accepted: 05/03/2018] [Indexed: 01/04/2023]
Abstract
Collagen I interactions with integrins α1 and α2 are known to support human mesenchymal stem cell (hMSC) osteogenesis. Nonetheless, elucidating the relative impact of specific integrin interactions has proven challenging, in part due to the complexity of native collagen. In the present work, we employed two collagen-mimetic proteins-Scl2-2 and Scl2-3- to compare the osteogenic effects of integrin α1 versus α2 signaling. Scl2-2 and Scl2-3 were both derived from Scl2-1, a triple helical protein lacking known cell adhesion, cytokine binding, and matrix metalloproteinase sites. However, Scl2-2 and Scl2-3 were each engineered to display distinct collagen-based cell adhesion motifs: GFPGER (binding integrins α1 and α2 ) or GFPGEN (binding only integrin α1 ), respectively. hMSCs were cultured within poly(ethylene glycol) (PEG) hydrogels containing either Scl2-2 or Scl2-3 for 2 weeks. PEG-Scl2-2 gels were associated with increased hMSC osterix expression, osteopontin production, and calcium deposition relative to PEG-Scl2-3 gels. These data indicate that integrin α2 signaling may have an increased osteogenic effect relative to integrin α1 . Since p38 is activated by integrin α2 but not by integrin α1 , hMSCs were further cultured in PEG-Scl2-2 hydrogels in the presence of a p38 inhibitor. Results suggest that p38 activity may play a key role in collagen-supported hMSC osteogenesis. This knowledge can be used toward the rational design of scaffolds which intrinsically promote hMSC osteogenesis. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2594-2604, 2018.
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Affiliation(s)
- Silvia M Becerra-Bayona
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Viviana R Guiza-Arguello
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
| | - Brooke Russell
- Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas, 77030-3303
| | - Magnus Höök
- Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas, 77030-3303
| | - Mariah S Hahn
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York, 12180
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York, 12180
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Abstract
SummaryPolysaccharide was isolated from human spleen mastocytoma by proteolytic digestion, precipitation with cetylpyridinium chloride, digestion with chondroitinase ABC, and ion-exchange chromatography on DEAE-cellulose. The final product (0.7 mg per g of starting material, MW 8000) behaved like standard heparin on ion-exchange chromatography and on electrophoresis, and contained D-glucuronic acid, L-iduronic acid, D-glucosamine and sulfate in the proportions expected for heparin.Affinity chromatography on antithrombin-Sepharose separated a distinct high-affinity fraction (4–5% of the total material). Structural analysis of this fraction showed that about 10% of the D-glucosamine residues were N-acetylated, the remainder N-sulfated.The anticoagulant activity of the isolated heparin was 71 B.P. units per mg (whole-blood system), or 30 units per mg (antithrombin and chromogenic substrate). 205 and 10–15 units per mg (chromogenic assay) were found for high and low affinity fractions, respectively. These results demonstrate conclusively the occurrence of heparin in a human tissue.
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Affiliation(s)
- L Thunberg
- The Department of Medical and Physiological Chemistry, Swedish University of Agricultural Sciences, The Biomedical Center, Uppsala, Sweden
| | - M Höök
- The Department of Medical and Physiological Chemistry, Swedish University of Agricultural Sciences, The Biomedical Center, Uppsala, Sweden
| | - U Lindahl
- The Department of Medical and Physiological Chemistry, Swedish University of Agricultural Sciences, The Biomedical Center, Uppsala, Sweden
| | - U Abildgaard
- Medical Department A, Aker Hospital, Oslo, Norway
| | - R Langholm
- Department of Pathology, Aker Hospital, Oslo, Norway
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Diaz Quiroz JF, Rodriguez PD, Erndt-Marino JD, Guiza V, Balouch B, Graf T, Reichert WM, Russell B, Höök M, Hahn MS. Collagen-Mimetic Proteins with Tunable Integrin Binding Sites for Vascular Graft Coatings. ACS Biomater Sci Eng 2018; 4:2934-2942. [DOI: 10.1021/acsbiomaterials.8b00070] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Juan Felipe Diaz Quiroz
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Patricia Diaz Rodriguez
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Josh D. Erndt-Marino
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Viviana Guiza
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Bailey Balouch
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Tyler Graf
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - William M. Reichert
- Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Brooke Russell
- Institute of Biosciences and Technology, Texas A&M Health Science Center, College Station, Texas 77843, United States
| | - Magnus Höök
- Institute of Biosciences and Technology, Texas A&M Health Science Center, College Station, Texas 77843, United States
| | - Mariah S. Hahn
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
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9
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Abstract
SummaryFibrinogen (Fg), the major clotting protein in blood plasma, plays key roles in blood coagulation and thrombosis. In addition, this 340 kD glycoprotein is a stress inducible protein; its synthesis is dramatically upregulated during inflammation or under exposure to stress such systemic infections.This regulation of Fg expression indicates that Fg also participates in the host defense system against infections. In fact, a number of reported studies have demonstrated the involvement of both the intrinsic and extrinsic pathways of coagulation; the thrombotic and the fibrinolytic systems in the pathophysiology of infectious diseases. It is, therefore, perhaps not surprising that many pathogenic bacteria can interact with Fg and manipulate its biology.This review focuses on the major Fg-binding proteins (Fgbps) from Gram-positive bacteria with an emphasis on those that are known to have an effect on coagulation and thrombosis
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Casillas-Ituarte NN, Cruz CHB, Lins RD, DiBartola AC, Howard J, Liang X, Höök M, Viana IFT, Sierra-Hernández MR, Lower SK. Amino acid polymorphisms in the fibronectin-binding repeats of fibronectin-binding protein A affect bond strength and fibronectin conformation. J Biol Chem 2017; 292:8797-8810. [PMID: 28400484 DOI: 10.1074/jbc.m117.786012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [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: 03/14/2017] [Revised: 04/08/2017] [Indexed: 11/06/2022] Open
Abstract
The Staphylococcus aureus cell surface contains cell wall-anchored proteins such as fibronectin-binding protein A (FnBPA) that bind to host ligands (e.g. fibronectin; Fn) present in the extracellular matrix of tissue or coatings on cardiac implants. Recent clinical studies have found a correlation between cardiovascular infections caused by S. aureus and nonsynonymous SNPs in FnBPA. Atomic force microscopy (AFM), surface plasmon resonance (SPR), and molecular simulations were used to investigate interactions between Fn and each of eight 20-mer peptide variants containing amino acids Ala, Asn, Gln, His, Ile, and Lys at positions equivalent to 782 and/or 786 in Fn-binding repeat-9 of FnBPA. Experimentally measured bond lifetimes (1/koff) and dissociation constants (Kd = koff/kon), determined by mechanically dissociating the Fn·peptide complex at loading rates relevant to the cardiovascular system, varied from the lowest-affinity H782A/K786A peptide (0.011 s, 747 μm) to the highest-affinity H782Q/K786N peptide (0.192 s, 15.7 μm). These atomic force microscopy results tracked remarkably well to metadynamics simulations in which peptide detachment was defined solely by the free-energy landscape. Simulations and SPR experiments suggested that an Fn conformational change may enhance the stability of the binding complex for peptides with K786I or H782Q/K786I (Kdapp = 0.2-0.5 μm, as determined by SPR) compared with the lowest-affinity double-alanine peptide (Kdapp = 3.8 μm). Together, these findings demonstrate that amino acid substitutions in Fn-binding repeat-9 can significantly affect bond strength and influence the conformation of Fn upon binding. They provide a mechanistic explanation for the observation of nonsynonymous SNPs in fnbA among clinical isolates of S. aureus that cause endovascular infections.
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Affiliation(s)
| | - Carlos H B Cruz
- the Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, PE, 50.740-465, Brazil, and
| | - Roberto D Lins
- the Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, PE, 50.740-465, Brazil, and
| | | | | | - Xiaowen Liang
- the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030
| | - Magnus Höök
- the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030
| | - Isabelle F T Viana
- the Aggeu Magalhães Institute, Oswaldo Cruz Foundation, Recife, PE, 50.740-465, Brazil, and
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11
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Munoz-Pinto DJ, Erndt-Marino JD, Becerra-Bayona SM, Guiza-Arguello VR, Samavedi S, Malmut S, Reichert WM, Russell B, Höök M, Hahn MS. Evaluation of late outgrowth endothelial progenitor cell and umbilical vein endothelial cell responses to thromboresistant collagen-mimetic hydrogels. J Biomed Mater Res A 2017; 105:1712-1724. [PMID: 28218444 DOI: 10.1002/jbm.a.36045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [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: 12/15/2016] [Revised: 02/01/2017] [Accepted: 02/16/2017] [Indexed: 01/01/2023]
Abstract
Bioactive coatings which support the adhesion of late-outgrowth peripheral blood endothelial progenitor cells (EOCs) are actively being investigated as a means to promote rapid endothelialization of "off-the-shelf," small-caliber arterial graft prostheses following implantation. In the present work, we evaluated the behavior of EOCs on thromboresistant graft coatings based on the collagen-mimetic protein Scl2-2 and poly(ethylene glycol) (PEG) diacrylate. Specifically, the attachment, proliferation, migration, and phenotype of EOCs on PEG-Scl2-2 hydrogels were evaluated as a function of Scl2-2 concentration (4, 8, and 12 mg/mL) relative to human umbilical vein endothelial cells (HUVECs). Results demonstrate the ability of each PEG-Scl2-2 hydrogel formulation to support EOC and HUVEC adhesion, proliferation, and spreading. However, only the 8 and 12 mg/mL PEG-Scl2-2 hydrogels were able to support stable EOC and HUVEC confluence. These PEG-Scl2-2 formulations were, therefore, selected for evaluation of their impact on EOC and HUVEC phenotype relative to PEG-collagen hydrogels. Cumulatively, both gene and protein level data indicated that 8 mg/mL PEG-Scl2-2 hydrogels supported similar or improved levels of EOC maturation relative to PEG-collagen controls based on evaluation of CD34, VEGFR2, PECAM-1, and VE-Cadherin. The 8 mg/mL PEG-Scl2-2 hydrogels also appeared to support similar or improved levels of EOC homeostatic marker expression relative to PEG-collagen hydrogels based on von Willebrand factor, collagen IV, NOS3, thrombomodulin, and E-selectin assessment. Combined, the present results indicate that PEG-Scl2-2 hydrogels warrant further investigation as "off-the-shelf" graft coatings. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1712-1724, 2017.
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Affiliation(s)
- Dany J Munoz-Pinto
- Department of Engineering Science, Trinity University, San Antonio, Texas
| | - Josh D Erndt-Marino
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | | | | | - Satyavrata Samavedi
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - Sarah Malmut
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
| | - William M Reichert
- Department of Biomedical Engineering, Duke University, Durham, North Carolina
| | - Brooke Russell
- Center for Infectious and Inflammatory Diseases, TAM Health Science Center, Houston, Texas
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, TAM Health Science Center, Houston, Texas
| | - Mariah S Hahn
- Department of Biomedical Engineering, Rensselaer Polytechnic Institute, Troy, New York
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12
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Liang X, Garcia BL, Visai L, Prabhakaran S, Meenan NAG, Potts JR, Humphries MJ, Höök M. Allosteric Regulation of Fibronectin/α5β1 Interaction by Fibronectin-Binding MSCRAMMs. PLoS One 2016; 11:e0159118. [PMID: 27434228 PMCID: PMC4951027 DOI: 10.1371/journal.pone.0159118] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [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: 05/07/2016] [Accepted: 06/27/2016] [Indexed: 12/03/2022] Open
Abstract
Adherence of microbes to host tissues is a hallmark of infectious disease and is often mediated by a class of adhesins termed MSCRAMMs (Microbial Surface Components Recognizing Adhesive Matrix Molecules). Numerous pathogens express MSCRAMMs that specifically bind the heterodimeric human glycoprotein fibronectin (Fn). In addition to roles in adhesion, Fn-binding MSCRAMMs exploit physiological Fn functions. For example, several pathogens can invade host cells by a mechanism whereby MSCRAMM-bound Fn bridges interaction with α5β1 integrin. Here, we investigate two Fn-binding MSCRAMMs, FnBPA (Staphylococcus aureus) and BBK32 (Borrelia burgdorferi) to probe structure-activity relationships of MSCRAMM-induced Fn/α5β1integrin activation. Circular dichroism, fluorescence resonance energy transfer, and dynamic light scattering techniques uncover a conformational rearrangement of Fn involving domains distant from the MSCRAMM binding site. Surface plasmon resonance experiments demonstrate a significant enhancement of Fn/α5β1 integrin affinity in the presence of FnBPA or BBK32. Detailed kinetic analysis of these interactions reveal that this change in affinity can be attributed solely to an increase in the initial Fn/α5β1 on-rate and that this rate-enhancement is dependent on high-affinity Fn-binding by MSCRAMMs. These data implicate MSCRAMM-induced perturbation of specific intramolecular contacts within the Fn heterodimer resulting in activation by exposing previously cryptic α5β1 interaction motifs. By correlating structural changes in Fn to a direct measurement of increased Fn/α5β1 affinity, this work significantly advances our understanding of the structural basis for the modulation of integrin function by Fn-binding MSCRAMMs.
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Affiliation(s)
- Xiaowen Liang
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, 77030, United States of America
| | - Brandon L. Garcia
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, 77030, United States of America
| | - Livia Visai
- Dep. of Molecular Medicine, UdR INSTM, Center for Tissue Engineering (C.I.T.), University of Pavia, 27100, Pavia, Italy
- Dep. of Occupational Medicine, Ergonomy and Disability, Salvatore Maugeri Foundation, IRCCS, Nanotechnology Laboratory, 27100, Pavia, Italy
| | - Sabitha Prabhakaran
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, 77030, United States of America
| | | | - Jennifer R. Potts
- Department of Biology, University of York, York, YO10 5DD, United Kingdom
| | - Martin J. Humphries
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, United Kingdom
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX, 77030, United States of America
- * E-mail:
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13
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Browning MB, Guiza V, Russell B, Rivera J, Cereceres S, Höök M, Hahn MS, Cosgriff-Hernandez EM. Endothelial cell response to chemical, biological, and physical cues in bioactive hydrogels. Tissue Eng Part A 2015; 20:3130-41. [PMID: 24935249 DOI: 10.1089/ten.tea.2013.0602] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The highly tunable biological, chemical, and physical properties of bioactive hydrogels enable their use in an array of tissue engineering and drug delivery applications. Systematic modulation of these properties can be used to elucidate key cell-material interactions to improve therapeutic effects. For example, the rate and extent of endothelialization are critical to the long-term success of many blood-contacting devices. To this end, we have developed a bioactive hydrogel that could be used as coating on cardiovascular devices to enhance endothelial cell (EC) adhesion and migration. The current work investigates the relative impact of hydrogel variables on key endothelialization processes. The bioactive hydrogel is based on poly(ethylene glycol) (PEG) and a streptococcal collagen-like (Scl2-2) protein that has been modified with integrin α1β1 and α2β1 binding sites. The use of PEG hydrogels allows for incorporation of specific bioactive cues and independent manipulation of scaffold properties. The selective integrin binding of Scl2-2 was compared to more traditional collagen-modified PEG hydrogels to determine the effect of integrin binding on cell behavior. Protein functionalization density, protein concentration, and substrate modulus were independently tuned with both Scl2-2 and collagen to determine the effect of each variable on EC adhesion, spreading, and migration. The findings here demonstrate that increasing substrate modulus, decreasing functionalization density, and increasing protein concentration can be utilized to increase EC adhesion and migration. Additionally, PEG-Scl2-2 hydrogels had higher migration speeds and proliferation over 1 week compared with PEG-collagen gels, demonstrating that selective integrin binding can be used to enhance cell-material interactions. Overall, these studies contribute to the understanding of the effects of matrix cues on EC interactions and demonstrate the strong potential of PEG-Scl2-2 hydrogels to promote endothelialization of blood-contacting devices.
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Affiliation(s)
- Mary Beth Browning
- 1 Department of Biomedical Engineering, Texas A&M University , College Station, Texas
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14
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Cereceres S, Touchet T, Browning MB, Smith C, Rivera J, Höök M, Whitfield-Cargile C, Russell B, Cosgriff-Hernandez E. Chronic Wound Dressings Based on Collagen-Mimetic Proteins. Adv Wound Care (New Rochelle) 2015; 4:444-456. [PMID: 26244101 DOI: 10.1089/wound.2014.0614] [Citation(s) in RCA: 31] [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] [Received: 11/10/2014] [Accepted: 03/27/2015] [Indexed: 12/26/2022] Open
Abstract
Objective: Chronic wounds are projected to reach epidemic proportions due to the aging population and the increasing incidence of diabetes. There is a strong clinical need for an improved wound dressing that can balance wound moisture, promote cell migration and proliferation, and degrade at an appropriate rate to minimize the need for dressing changes. Approach: To this end, we have developed a bioactive, hydrogel microsphere wound dressing that incorporates a collagen-mimetic protein, Scl2GFPGER, to promote active wound healing. A redesigned Scl2GFPGER, engineered collagen (eColGFPGER), was created to reduce steric hindrance of integrin-binding motifs and increase overall stability of the triple helical backbone, thereby resulting in increased cell adhesion to substrates. Results: This study demonstrates the successful modification of the Scl2GFPGER protein to eColGFPGER, which displayed enhanced stability and integrin interactions. Fabrication of hydrogel microspheres provided a matrix with adaptive moisture technology, and degradation rates have potential for use in human wounds. Innovation: This collagen-mimetic wound dressing was designed to permit controlled modulation of cellular interactions and degradation rate without impact on other physical properties. Its fabrication into uniform hydrogel microspheres provides a bioactive dressing that can readily conform to irregular wounds. Conclusion: Overall, this new eColGFPGER shows strong promise in the generation of bioactive hydrogels for wound healing as well as a variety of tissue scaffolds.
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Affiliation(s)
- Stacy Cereceres
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - Tyler Touchet
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - Mary Beth Browning
- Institute for Bioscience and Technology, Texas A&M Health Science Center, Houston, Texas
| | - Clayton Smith
- Department of Biomedical Engineering, Texas A&M University, College Station, Texas
| | - Jose Rivera
- Institute for Bioscience and Technology, Texas A&M Health Science Center, Houston, Texas
| | - Magnus Höök
- Institute for Bioscience and Technology, Texas A&M Health Science Center, Houston, Texas
| | | | - Brooke Russell
- Institute for Bioscience and Technology, Texas A&M Health Science Center, Houston, Texas
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15
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Zhi H, Weening EH, Barbu EM, Hyde JA, Höök M, Skare JT. The BBA33 lipoprotein binds collagen and impacts Borrelia burgdorferi pathogenesis. Mol Microbiol 2015; 96:68-83. [PMID: 25560615 DOI: 10.1111/mmi.12921] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2015] [Indexed: 12/14/2022]
Abstract
Borrelia burgdorferi, the etiologic agent of Lyme disease, adapts to the mammalian hosts by differentially expressing several genes in the BosR and Rrp2-RpoN-RpoS dependent pathways, resulting in a distinct protein profile relative to that seen for survival in the Ixodes spp. tick. Previous studies indicate that a putative lipoprotein, BBA33, is produced in an RpoS-dependent manner under conditions that mimic the mammalian component of the borrelial lifecycle. However, the significance and function for BBA33 is not known. Given its linkage to the BosR/Rrp2-RpoN-RpoS regulatory cascade, we hypothesized that BBA33 facilitates B. burgdorferi infection in the mammalian host. The deletion of bba33 eliminated B. burgdorferi infectivity in C3H mice, which was rescued by genetic complementation with intact bba33. With regard to function, a combinatorial peptide approach, coupled with subsequent in vitro binding assays, indicated that BBA33 binds to collagen type VI and, to a lesser extent, collagen type IV. Whole cell binding assays demonstrated BBA33-dependent binding to human collagen type VI. Taken together, these results suggest that BBA33 interacts with collagenous structures and may function as an adhesin in a process that is required to prevent bacterial clearance.
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Affiliation(s)
- Hui Zhi
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Bryan, TX, 77807, USA
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16
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Barbu EM, Mackenzie C, Foster TJ, Höök M. SdrC induces staphylococcal biofilm formation through a homophilic interaction. Mol Microbiol 2014; 94:172-85. [PMID: 25115812 DOI: 10.1111/mmi.12750] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2014] [Indexed: 02/03/2023]
Abstract
The molecular pathogenesis of many Staphylococcus aureus infections involves growth of bacteria as biofilm. In addition to polysaccharide intercellular adhesin (PIA) and extracellular DNA, surface proteins appear to mediate the transition of bacteria from planktonic growth to sessile lifestyle as well as biofilm growth, and can enable these processes even in the absence of PIA expression. However, the molecular mechanisms by which surface proteins contribute to biofilm formation are incompletely understood. Here we demonstrate that self-association of the serine-aspartate repeat protein SdrC promotes both bacterial adherence to surfaces and biofilm formation. However, this homophilic interaction is not required for the attachment of bacteria to abiotic surfaces. We identified the subdomain that mediates SdrC dimerization and subsequent cell-cell interactions. In addition, we determined that two adjacently located amino acid sequences within this subdomain are required for the SdrC homophilic interaction. Comparative amino acid sequence analysis indicated that these binding sites are conserved. In summary, our study identifies SdrC as a novel molecular determinant in staphylococcal biofilm formation and describes the mechanism responsible for intercellular interactions. Furthermore, these findings contribute to a growing body of evidence suggesting that homophilic interactions between surface proteins present on neighbouring bacteria induce biofilm growth.
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Affiliation(s)
- E Magda Barbu
- Center for Infectious & Inflammatory Diseases, Institute and Bioscience and Technology, Texas A&M Health Science Center, Houston, TX, USA; Department of Infectious Diseases, The University of Texas M.D. Anderson Cancer Center, Houston, TX, USA
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17
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Bronk JK, Russell BH, Rivera JJ, Pasqualini R, Arap W, Höök M, Barbu EM. A multifunctional streptococcal collagen-mimetic protein coating prevents bacterial adhesion and promotes osteoid formation on titanium. Acta Biomater 2014; 10:3354-62. [PMID: 24732634 DOI: 10.1016/j.actbio.2014.04.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 03/28/2014] [Accepted: 04/04/2014] [Indexed: 02/01/2023]
Abstract
The major barriers to the clinical success of orthopedic and dental implants are poor integration of fixtures with bone tissue and biomaterial-associated infections. Although multifunctional device coatings have long been considered a promising strategy, their development is hindered by difficulties in integrating biocompatibility, anti-infective activity and antithrombotic properties within a single grafting agent. In this study, we used cell adhesion assays and confocal microscopy of primary murine osteoblasts and human osteoblast cell lines MG-63 and Saos-2 to demonstrate that a streptococcal collagen-like protein engineered to display the α1 and α2 integrin recognition sequences enhances osteoblast adhesion and spreading on titanium fixtures. By measuring calcium deposition and alkaline phosphatase activity, we also showed that selective activation of α2β1 integrin induces osteoblast differentiation, osteoid formation and mineralization. Moreover, cell adhesion assays and scanning electron microscopy of clinical isolates Staphylococcus aureus Philips and Staphylococcus epidermidis 9491 indicated that streptococcal collagen-mimetic proteins inhibit bacterial colonization and biofilm formation irrespective of their interaction with integrins. Given that streptococcal collagenous substrates neither interact with platelets nor trigger a strong immune response, this novel bioactive coating appears to have desirable multifaceted properties with promising translational applications.
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18
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Foster TJ, Geoghegan JA, Ganesh VK, Höök M. Adhesion, invasion and evasion: the many functions of the surface proteins of Staphylococcus aureus. Nat Rev Microbiol 2014; 12:49-62. [PMID: 24336184 DOI: 10.1038/nrmicro3161] [Citation(s) in RCA: 922] [Impact Index Per Article: 92.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Staphylococcus aureus is an important opportunistic pathogen and persistently colonizes about 20% of the human population. Its surface is 'decorated' with proteins that are covalently anchored to the cell wall peptidoglycan. Structural and functional analysis has identified four distinct classes of surface proteins, of which microbial surface component recognizing adhesive matrix molecules (MSCRAMMs) are the largest class. These surface proteins have numerous functions, including adhesion to and invasion of host cells and tissues, evasion of immune responses and biofilm formation. Thus, cell wall-anchored proteins are essential virulence factors for the survival of S. aureus in the commensal state and during invasive infections, and targeting them with vaccines could combat S. aureus infections.
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Affiliation(s)
- Timothy J Foster
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Joan A Geoghegan
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
| | - Vannakambadi K Ganesh
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA
| | - Magnus Höök
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA
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19
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Ko YP, Kuipers A, Freitag CM, Jongerius I, Medina E, van Rooijen WJ, Spaan AN, van Kessel KPM, Höök M, Rooijakkers SHM. Phagocytosis escape by a Staphylococcus aureus protein that connects complement and coagulation proteins at the bacterial surface. PLoS Pathog 2013; 9:e1003816. [PMID: 24348255 PMCID: PMC3861539 DOI: 10.1371/journal.ppat.1003816] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [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: 03/01/2013] [Accepted: 10/21/2013] [Indexed: 01/01/2023] Open
Abstract
Upon contact with human plasma, bacteria are rapidly recognized by the complement system that labels their surface for uptake and clearance by phagocytic cells. Staphylococcus aureus secretes the 16 kD Extracellular fibrinogen binding protein (Efb) that binds two different plasma proteins using separate domains: the Efb N-terminus binds to fibrinogen, while the C-terminus binds complement C3. In this study, we show that Efb blocks phagocytosis of S. aureus by human neutrophils. In vitro, we demonstrate that Efb blocks phagocytosis in plasma and in human whole blood. Using a mouse peritonitis model we show that Efb effectively blocks phagocytosis in vivo, either as a purified protein or when produced endogenously by S. aureus. Mutational analysis revealed that Efb requires both its fibrinogen and complement binding residues for phagocytic escape. Using confocal and transmission electron microscopy we show that Efb attracts fibrinogen to the surface of complement-labeled S. aureus generating a ‘capsule’-like shield. This thick layer of fibrinogen shields both surface-bound C3b and antibodies from recognition by phagocytic receptors. This information is critical for future vaccination attempts, since opsonizing antibodies may not function in the presence of Efb. Altogether we discover that Efb from S. aureus uniquely escapes phagocytosis by forming a bridge between a complement and coagulation protein. Staphylococcus aureus is a leading cause of severe bacterial infections in both hospital and community settings. Due to its increasing resistance to antibiotics, development of additional therapeutic strategies like vaccination is required to control this pathogen. Vaccination attempts against S. aureus have not been successful so far and an important reason may be the pathogen's elaborate repertoire of molecules that dampen the immune response. These evasion molecules not only suppress natural immunity but also hamper the current attempts to create effective vaccines. In this paper, we describe a novel mechanism by which S. aureus can prevent uptake by phagocytic immune cells. We discover that the secreted S. aureus protein Extracellular fibrinogen binding protein (Efb) generates a ‘capsule’-like shield around the bacterial surface through a dual interaction with the plasma proteins complement C3b and fibrinogen. The Efb-dependent fibrinogen shield masks important opsonic molecules like C3b and antibodies from binding to phagocyte receptors. This information is critical for future vaccination attempts, since opsonizing antibodies may not function in the presence of this anti-phagocytic shield.
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Affiliation(s)
- Ya-Ping Ko
- Center for Infectious and Inflammatory Disease, Institute of Bioscience and Technology, Texas A&M University Health Science Center, Houston, Texas, United States of America
| | - Annemarie Kuipers
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Claudia M. Freitag
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
- Utrecht University, Faculty of Veterinary Medicine, Department of Infectious Diseases and Immunology, Utrecht, The Netherlands
| | - Ilse Jongerius
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Eva Medina
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - András N. Spaan
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kok P. M. van Kessel
- Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Magnus Höök
- Center for Infectious and Inflammatory Disease, Institute of Bioscience and Technology, Texas A&M University Health Science Center, Houston, Texas, United States of America
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Abstract
The highly tunable properties of poly(ethylene glycol) (PEG)-based hydrogel systems permit their use in a wide array of regenerative medicine and drug delivery applications. One of the most valuable properties of PEG hydrogels is their intrinsic resistance to protein adsorption and cell adhesion, as it allows for a controlled introduction of desired bioactive factors including proteins, peptides, and drugs. Acrylate-PEG-N-hydroxysuccinimide (Acr-PEG-NHS) is widely utilized as a PEG linker to functionalize bioactive factors with photo-cross-linkable groups. This enables their facile incorporation into PEG hydrogel networks or the use of PEGylation strategies for drug delivery. However, PEG linkers can sterically block integrin binding sites on functionalized proteins and reduce cell-material interactions. In this study we demonstrate that reducing the density of PEG linkers on protein backbones during functionalization results in significantly improved cell adhesion and spreading to bioactive hydrogels. However, this reduction in functionalization density also increases protein loss from the matrix over time due to ester hydrolysis of the Acr-PEG-NHS linkers. To address this, a novel PEG linker, acrylamide-PEG-isocyanate (Aam-PEG-I), with enhanced hydrolytic stability was synthesized. It was found that decreasing functionalization density with Aam-PEG-I resulted in comparable increases in cell adhesion and spreading to Acr-PEG-NHS systems while maintaining protein and bioactivity levels within the hydrogel network over a significantly longer time frame. Thus, Aam-PEG-I provides a new option for protein functionalization for use in a wide range of applications that improves initial and sustained cell-material interactions to enhance control of bioactivity.
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Affiliation(s)
- Mary Beth Browning
- Department of Biomedical Engineering, Texas A&M University, 5045 Emerging Technologies Building, College Station, TX 77843-3120
| | - Brooke Russell
- Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Boulevard, Houston, Texas 77303-3303
| | - Jose Rivera
- Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Boulevard, Houston, Texas 77303-3303
| | - Magnus Höök
- Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Boulevard, Houston, Texas 77303-3303
| | - Elizabeth M. Cosgriff-Hernandez
- Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Boulevard, Houston, Texas 77303-3303
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21
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Kang M, Ko YP, Liang X, Ross CL, Liu Q, Murray BE, Höök M. Collagen-binding microbial surface components recognizing adhesive matrix molecule (MSCRAMM) of Gram-positive bacteria inhibit complement activation via the classical pathway. J Biol Chem 2013; 288:20520-31. [PMID: 23720782 DOI: 10.1074/jbc.m113.454462] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Members of a family of collagen-binding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) from Gram-positive bacteria are established virulence factors in several infectious diseases models. Here, we report that these adhesins also can bind C1q and act as inhibitors of the classical complement pathway. Molecular analyses of Cna from Staphylococcus aureus suggested that this prototype MSCRAMM bound to the collagenous domain of C1q and interfered with the interactions of C1r with C1q. As a result, C1r2C1s2 was displaced from C1q, and the C1 complex was deactivated. This novel function of the Cna-like MSCRAMMs represents a potential immune evasion strategy that could be used by numerous Gram-positive pathogens.
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Affiliation(s)
- Mingsong Kang
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA
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22
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Bix G, Fu J, Gonzalez EM, Macro L, Barker A, Campbell S, Zutter MM, Santoro SA, Kim JK, Höök M, Reed CC, Iozzo RV. Endorepellin causes endothelial cell disassembly of actin cytoskeleton and focal adhesions through α2β1 integrin. J Cell Biol 2013. [PMCID: PMC3653354 DOI: 10.1083/jcb.20040115004252013c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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23
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Cohen ALV, Roh JH, Nallapareddy SR, Höök M, Murray BE. Expression of the collagen adhesin ace by Enterococcus faecalis strain OG1RF is not repressed by Ers but requires the Ers box. FEMS Microbiol Lett 2013; 344:18-24. [PMID: 23551253 DOI: 10.1111/1574-6968.12146] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/26/2013] [Accepted: 03/29/2013] [Indexed: 11/30/2022] Open
Abstract
Expression of adhesin to collagen of Enterococcus faecalis (ace), a known virulence factor, is increased by environmental signals such as the presence of serum, high temperature, and bile salts. Currently, the enterococcal regulator of survival (Ers) of E. faecalis strain JH2-2 is the only reported repressor of ace. Here, we show that for strain OG1RF, Ers is not involved in the regulation of ace. Our data showed similar levels of ace expression by OG1RF and its Δers derivative in the presence of bile salts, serum, and high temperature. Using ace promoter-lacZ fusions and site-directed mutagenesis, we confirmed these results and further showed that, while the previously designated Ers box is important for increased expression from the ace promoter of OG1RF, the region responsible for the increase is bigger than the Ers box. In summary, these results indicate that, in strain OG1RF, Ers is not a repressor of ace expression. Although JH2-2 and OG1RF differ by six nucleotides in the region upstream of ace as well as in production of Fsr and gelatinase, the reason(s) for the difference in ace expression between JH2-2 and OG1RF and for increased ace expression in bile, serum and at 46 °C remain(s) to be determined.
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Affiliation(s)
- Ana Luisa V Cohen
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School, Houston, TX 77030, USA
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24
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Browning M, Dempsey D, Guiza V, Becerra S, Rivera J, Russell B, Höök M, Clubb F, Miller M, Fossum T, Dong J, Bergeron A, Hahn M, Cosgriff-Hernandez E. Corrigendum to “Multilayer vascular grafts based on collagen-mimetic proteins” [Acta Biomaterialia 8 (2012) 1010–1021]. Acta Biomater 2012. [DOI: 10.1016/j.actbio.2012.09.002] [Citation(s) in RCA: 2] [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: 11/28/2022]
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25
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Ya-Ping K, Mingsong K, Liang X, Ross CL, Liu Q, Murray BE, Höök M. Collagen-binding MSCRAMMS of Gram-positive bacteria inhibit complement activation via the classical pathway. Immunobiology 2012. [DOI: 10.1016/j.imbio.2012.08.065] [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]
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26
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Abstract
Type II collagen is a major component of cartilage where it is present at a high concentration, which is essential for the functional maintenance of the tissue. Therefore, any fundamental understanding of the physiology of cartilage tissue must include an understanding of the mechanism that allows the high level of expression of type II collagen gene, Col2a1, by chondrocytes. To this end, we developed a new reporter assay system based on the co-transfection of candidate enhancer elements and reporter construct into Swarm rat chondrosarcoma chondrocytes that allowed their stable expression. Using this system, we screened more than 70 kb of the Col2a1 gene and found an enhancer domain that is responsible for the regulation of its expression level. The domain is localized in intron 7, and consists of an 800-bp region that contains within it a previously unidentified domain, ∼140 bp in size.
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Affiliation(s)
- Tamayuki Shinomura
- Tissue Regeneration, Department of Hard Tissue Engineering, Tokyo Medical and Dental University, Tokyo 113-8549, Japan.
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27
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Ross CL, Liang X, Liu Q, Murray BE, Höök M, Ganesh VK. Targeted protein engineering provides insights into binding mechanism and affinities of bacterial collagen adhesins. J Biol Chem 2012; 287:34856-65. [PMID: 22865854 DOI: 10.1074/jbc.m112.371054] [Citation(s) in RCA: 15] [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: 11/06/2022] Open
Abstract
The collagen-binding bacterial proteins, Ace and Cna, are well characterized on the biochemical and structural level. Despite overall structural similarity, recombinant forms of the Ace and Cna ligand-binding domains exhibit significantly different affinities and binding kinetics for collagen type I (CI) in vitro. In this study, we sought to understand, in submolecular detail, the bases for these differences. Using a structure-based approach, we engineered Cna and Ace variants by altering specific structural elements within the ligand-binding domains. Surface plasmon resonance-based binding analysis demonstrated that mutations that are predicted to alter the orientation of the Ace and Cna N(1) and N(2) subdomains significantly affect the interaction between the MSCRAMM (microbial surface components recognizing adhesive matrix molecule) and CI in vitro, including affinity, association/dissociation rates and binding ratio. Moreover, we utilized this information to engineer an Ace variant with an 11,000-fold higher CI affinity than the parent protein. Finally, we noted that several engineered proteins that exhibited a weak interaction with CI recognized more sites on CI, suggesting an inverse correlation between affinity and specificity.
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Affiliation(s)
- Caná L Ross
- Center for Inflammatory and Infectious Disease, Institute for Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA
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28
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Browning M, Dempsey D, Guiza V, Becerra S, Rivera J, Russell B, Höök M, Clubb F, Miller M, Fossum T, Dong J, Bergeron A, Hahn M, Cosgriff-Hernandez E. Multilayer vascular grafts based on collagen-mimetic proteins. Acta Biomater 2012; 8:1010-21. [PMID: 22142564 DOI: 10.1016/j.actbio.2011.11.015] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/14/2011] [Accepted: 11/11/2011] [Indexed: 12/20/2022]
Abstract
A major roadblock in the development of an off-the-shelf, small-caliber vascular graft is achieving rapid endothelialization of the conduit while minimizing the risk of thrombosis, intimal hyperplasia, and mechanical failure. To address this need, a collagen-mimetic protein derived from group A Streptococcus, Scl2.28 (Scl2), was conjugated into a poly(ethylene glycol) (PEG) hydrogel to generate bioactive hydrogels that bind to endothelial cells (ECs) and resist platelet adhesion. The PEG-Scl2 hydrogel was then reinforced with an electrospun polyurethane mesh to achieve suitable biomechanical properties. In the current study, initial evaluation of this multilayer design as a potential off-the-shelf graft was conducted. First, electrospinning parameters were varied to achieve composite burst pressure, compliance, and suture retention strength that matched reported values of saphenous vein autografts. Composite stability following drying, sterilization, and physiological conditioning under pulsatile flow was then demonstrated. Scl2 bioactivity was also maintained after drying and sterilization as indicated by EC adhesion and spreading. Evaluation of platelet adhesion, aggregation, and activation indicated that PEG-Scl2 hydrogels had minimal platelet interactions and thus appear to provide a thromboresistant blood contacting layer. Finally, evaluation of EC migration speed demonstrated that PEG-Scl2 hydrogels promoted higher migration speeds than PEG-collagen analogs and that migration speed was readily tuned by altering protein concentration. Collectively, these results indicate that this multilayer design warrants further investigation and may have the potential to improve on current synthetic options.
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29
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Hyde JA, Weening EH, Chang M, Trzeciakowski JP, Höök M, Cirillo JD, Skare JT. Bioluminescent imaging of Borrelia burgdorferi in vivo demonstrates that the fibronectin-binding protein BBK32 is required for optimal infectivity. Mol Microbiol 2011; 82:99-113. [PMID: 21854463 DOI: 10.1111/j.1365-2958.2011.07801.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The aetiological agent of Lyme disease, Borrelia burgdorferi, is transmitted via infected Ixodes spp. ticks. Infection, if untreated, results in dissemination to multiple tissues and significant morbidity. Recent developments in bioluminescence technology allow in vivo imaging and quantification of pathogenic organisms during infection. Herein, luciferase-expressing B. burgdorferi and strains lacking the decorin adhesins DbpA and DbpB, as well as the fibronectin adhesin BBK32, were quantified by bioluminescent imaging to further evaluate their pathogenic potential in infected mice. Quantification of bacterial load was verified by quantitative PCR (qPCR) and cultivation. B. burgdorferi lacking DbpA and DbpB were only seen at the 1 h time point post infection, consistent with its low infectivity phenotype. The bbk32 mutant exhibited a significant decrease in its infectious load at day 7 relative to its parent. This effect was most pronounced at lower inocula and imaging correlated well with qPCR data. These data suggest that BBK32-mediated binding plays an important role in B. burgdorferi colonization. As such, in vivo imaging of bioluminescent Borrelia provides a sensitive means to detect, quantify and temporally characterize borrelial dissemination in a non-invasive, physiologically relevant environment and, more importantly, demonstrated a quantifiable infectivity defect for the bbk32 mutant.
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Affiliation(s)
- Jenny A Hyde
- Department of Microbial and Molecular Pathogenesis, Texas A&M Health Science Center, Bryan, TX 77807, USA
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30
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Ganesh VK, Barbu EM, Deivanayagam CCS, Le B, Anderson AS, Matsuka YV, Lin SL, Foster TJ, Narayana SVL, Höök M. Structural and biochemical characterization of Staphylococcus aureus clumping factor B/ligand interactions. J Biol Chem 2011; 286:25963-72. [PMID: 21543319 DOI: 10.1074/jbc.m110.217414] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Clumping factor B (ClfB) from Staphylococcus aureus is a bifunctional protein that binds to human cytokeratin 10 (K10) and fibrinogen (Fg). ClfB has been implicated in S. aureus colonization of nasal epithelium and is therefore a key virulence factor. People colonized with S. aureus are at an increased risk for invasive staphylococcal disease. In this study, we have determined the crystal structures of the ligand-binding region of ClfB in an apo-form and in complex with human K10 and Fg α-chain-derived peptides, respectively. We have determined the structures of MSCRAMM binding to two ligands with different sequences in the same site showing the versatile nature of the ligand recognition mode of microbial surface components recognizing adhesive matrix molecules. Both ligands bind ClfB by parallel β-sheet complementation as observed for the clumping factor A·γ-chain peptide complex. The β-sheet complementation is shorter in the ClfB·Fg α-chain peptide complex. The structures show that several residues in ClfB are important for binding to both ligands, whereas others only make contact with one of the ligands. A common motif GSSGXG found in both ligands is part of the ClfB-binding site. This motif is found in many human proteins thus raising the possibility that ClfB recognizes additional ligands.
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Affiliation(s)
- Vannakambadi K Ganesh
- Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas 77030, USA.
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31
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Marjenberg ZR, Ellis IR, Hagan RM, Prabhakaran S, Höök M, Talay SR, Potts JR, Staunton D, Schwarz-Linek U. Cooperative binding and activation of fibronectin by a bacterial surface protein. J Biol Chem 2011; 286:1884-94. [PMID: 21059652 PMCID: PMC3023484 DOI: 10.1074/jbc.m110.183053] [Citation(s) in RCA: 26] [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: 09/08/2010] [Revised: 11/03/2010] [Indexed: 11/06/2022] Open
Abstract
Integrin-dependent cell invasion of some pathogenic bacteria is mediated by surface proteins targeting the extracellular matrix protein fibronectin (FN). Although the structural basis for bacterial FN recognition is well understood, it has been unclear why proteins such as streptococcal SfbI contain several FN-binding sites. We used microcalorimetry to reveal cooperative binding of FN fragments to arrays of binding sites in SfbI. In combination with thermodynamic analyses, functional cell-based assays show that SfbI induces conformational changes in the N-terminal 100-kDa region of FN (FN100kDa), most likely by competition with intramolecular interactions defining an inactive state of FN100kDa. This study provides insights into how long range conformational changes resulting in FN activation may be triggered by bacterial pathogens.
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Affiliation(s)
- Zoe R. Marjenberg
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews KY16 9ST, Scotland, United Kingdom
| | - Ian R. Ellis
- the Unit of Cell and Molecular Biology, Dental School, University of Dundee, Dundee DD1 4HR, Scotland, United Kingdom
| | - Robert M. Hagan
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews KY16 9ST, Scotland, United Kingdom
| | - Sabitha Prabhakaran
- the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | - Magnus Höök
- the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | - Susanne R. Talay
- the Department of Microbial Pathogenesis, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Jennifer R. Potts
- the Department of Biology and Department of Chemistry, University of York, York YO10 5YW, United Kingdom, and
| | - David Staunton
- the Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Ulrich Schwarz-Linek
- From the Biomedical Sciences Research Complex, University of St. Andrews, St. Andrews KY16 9ST, Scotland, United Kingdom
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32
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Abstract
In addition to its pivotal role in hemostasis, fibrinogen (Fg) and provisional fibrin matrices play important roles in inflammation and regulate innate immune responses by interacting with leukocytes. Efb (the extracellular fibrinogen-binding protein) is a secreted Staphylococcus aureus protein that engages host Fg and complement C3. However, the molecular details underlying the Efb-Fg interaction and the biological relevance of this interaction have not been determined. In the present study, we characterize the interaction of Efb with Fg. We demonstrate that the Fg binding activity is located within the intrinsically disordered N-terminal half of Efb (Efb-N) and that the D fragment of Fg is the region that mediates Efb-N binding. More detailed studies of the Efb-N-Fg interactions using ELISA and surface plasmon resonance analyses revealed that Efb-N exhibits a much higher affinity for Fg than typically observed with Fg-binding MSCRAMMs (microbial surface components recognizing adhesive matrix molecules), and data obtained from ELISA analyses using truncated Efb-N constructs demonstrate that Efb-N contains two binding sites located within residues 30-67 and 68-98, respectively. Efb-N inhibits neutrophil adhesion to immobilized Fg by binding to Fg and blocking the interaction of the protein with the leukocyte integrin receptor, α(M)β(2). A motif in the Fg γ chain previously shown to be central to the α(M)β(2) interaction was shown to be functionally distinguishable from the Efb-N binding site, suggesting that the Fg-Efb interaction indirectly impedes Fg engagement by α(M)β(2). Taken together, these studies provide insights into how Efb interacts with Fg and suggest that Efb may support bacterial virulence at least in part by impeding Fg-driven leukocyte adhesion events.
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Affiliation(s)
- Ya-Ping Ko
- Center for Infectious and Inflammatory Disease, Institute of Bioscience and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA
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33
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Xue Q, Gu C, Rivera J, Höök M, Chen X, Pozzi A, Xu Y. Entry of Bacillus anthracis spores into epithelial cells is mediated by the spore surface protein BclA, integrin α2β1 and complement component C1q. Cell Microbiol 2010; 13:620-34. [PMID: 21134100 DOI: 10.1111/j.1462-5822.2010.01558.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inhalational anthrax is initiated by pulmonary exposure to Bacillus anthracis spores. Spore entry into lung epithelial cells is observed both in vitro and in vivo and evidence suggests it is important for bacterial dissemination and virulence. However the specific host receptor and spore factor that mediate the entry process were unknown. Here, we report that integrin α2β1 is a major receptor for spore entry. This is supported by results from blocking antibodies, siRNA knock-down, colocalization, and comparison of spore entry into cells that do or do not express α2. BclA, a major spore surface protein, is found to be essential for entry and α2β1-mediated entry is dependent on BclA. However, BclA does not appear to bind directly to α2. Furthermore, spore entry into α2-expressing cells is dramatically reduced in the absence of serum, suggesting that additional factors are involved. Finally, complement component C1q, also an α2β1 ligand, appears to act as a bridging molecule or a cofactor for BclA/α2β1-mediated spore entry and BclA binds to C1q in a dose-dependent and saturable manner. These findings suggest a novel mechanism for pathogen entry into host cells as well as a new function for C1q-integrin interactions. The implications of these findings are discussed.
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Affiliation(s)
- Qiong Xue
- Center for Inflammatory and Infectious Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
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34
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Staquicini FI, Ozawa MG, Moya CA, Driessen WHP, Barbu EM, Nishimori H, Soghomonyan S, Flores LG, Liang X, Paolillo V, Alauddin MM, Basilion JP, Furnari FB, Bogler O, Lang FF, Aldape KD, Fuller GN, Höök M, Gelovani JG, Sidman RL, Cavenee WK, Pasqualini R, Arap W. Systemic combinatorial peptide selection yields a non-canonical iron-mimicry mechanism for targeting tumors in a mouse model of human glioblastoma. J Clin Invest 2010; 121:161-73. [PMID: 21183793 DOI: 10.1172/jci44798] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 10/27/2010] [Indexed: 01/09/2023] Open
Abstract
The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles targeted with certain ligand motifs selected in vivo from a combinatorial peptide library can cross the BBB under normal and pathological conditions. Specifically, we demonstrated that phage clones displaying an iron-mimic peptide were able to target a protein complex of transferrin and transferrin receptor (TfR) through a non-canonical allosteric binding mechanism and that this functional protein complex mediated transport of the corresponding viral particles into the normal mouse brain. We also showed that, in an orthotopic mouse model of human glioblastoma, a combination of TfR overexpression plus extended vascular permeability and ligand retention resulted in remarkable brain tumor targeting of chimeric adeno-associated virus/phage particles displaying the iron-mimic peptide and carrying a gene of interest. As a proof of concept, we delivered the HSV thymidine kinase gene for molecular-genetic imaging and targeted therapy of intracranial xenografted tumors. Finally, we established that these experimental findings might be clinically relevant by determining through human tissue microarrays that many primary astrocytic tumors strongly express TfR. Together, our combinatorial selection system and results may provide a translational avenue for the targeted detection and treatment of brain tumors.
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Affiliation(s)
- Fernanda I Staquicini
- David H. Koch Center, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
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35
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Seo N, Russell BH, Rivera JJ, Liang X, Xu X, Afshar-Kharghan V, Höök M. An engineered alpha1 integrin-binding collagenous sequence. J Biol Chem 2010; 285:31046-54. [PMID: 20675378 PMCID: PMC2945595 DOI: 10.1074/jbc.m110.151357] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [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: 06/04/2010] [Indexed: 01/15/2023] Open
Abstract
Collagen is an extracellular matrix structural component that can regulate cellular processes through its interaction with the integrins, α1β1, α2β1, α10β1, and α11β1. Collagen-like proteins have been identified in a number of bacterial species. Here, we used Scl2 from Streptococcus pyogenes serotype M28 strain MGAS6274 as a backbone for the introduction of discrete integrin-binding sequences. The introduced sequences GLPGER, GFPGER, or GFPGEN did not affect triple helix stability of the Scl (Streptococcal collagen-like) protein. Using ELISA and surface plasmon resonance, we determined that Scl2(GLPGER) and Scl2(GFPGER) bound to recombinant human α1 and α2 I-domains in a metal ion-dependent manner and without a requirement for hydroxyproline. We predicted a novel and selective integrin-binding sequence, GFPGEN, through the use of computer modeling and demonstrated that Scl2(GFPGEN) shows specificity toward the α1 I-domain and does not bind the α2 I-domain. Using C2C12 cells, we determined that intact integrins interact with the modified Scl2 proteins with the same selectivity as recombinant I-domains. These modified Scl2 proteins also acted as cell attachment substrates for fibroblast, endothelial, and smooth muscle cells. However, the modified Scl2 proteins were unable to aggregate platelets. These results indicate that Scl2 is a suitable backbone for the introduction of mammalian integrin-binding sequences, and these sequences may be manipulated to individually target α1β1 and α2β1.
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Affiliation(s)
- Neungseon Seo
- From the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030 and
| | - Brooke H. Russell
- From the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030 and
| | - Jose J. Rivera
- From the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030 and
| | - Xiaowen Liang
- From the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030 and
| | - Xuejun Xu
- From the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030 and
| | | | - Magnus Höök
- From the Center for Infectious and Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030 and
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36
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Cosgriff-Hernandez E, Hahn MS, Russell B, Wilems T, Munoz-Pinto D, Browning MB, Rivera J, Höök M. Bioactive hydrogels based on Designer Collagens. Acta Biomater 2010; 6:3969-77. [PMID: 20466083 DOI: 10.1016/j.actbio.2010.05.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 05/03/2010] [Accepted: 05/06/2010] [Indexed: 01/01/2023]
Abstract
Designer Collagens are based on streptococcal collagen-like (Scl) proteins that form a triple helix similar to mammalian collagens but that are non-platelet aggregating. In contrast to the numerous cell-binding sites on collagen, Scl2 from Streptococcus pyogenes serotype M28 does not contain any known cell-binding sites and thus provides a blank slate in terms of cellular interactions. In the current study, Scl2 protein was modified to include receptor binding motifs that interact with alpha1 and/or alpha2 integrin subunits. The modfied Scl2 proteins have been demonstrated to mediate differential endothelial cell (EC) and smooth muscle cell (SMC) adhesion via these integrins and to retain the non-platelet aggregating properties of the "parent" Scl2. Thromboresistant scaffolds which selectively bind ECs vs. SMCs would be desirable for vascular repair or replacement. Despite the potential of these Scl proteins in vascular applications, the utility of this recombinant protein family is currently limited to coatings due to the inability of Scl proteins to assemble into stable three-dimensional networks. To address this limitation, the Scl2 proteins were functionalized with photocrosslinking sites to enable incorporation into a hydrogel matrix. Characterization studies confirmed that the functionalization of the Scl2 proteins did not disrupt triple helix conformation, integrin binding or cell adhesion. Bioactive hydrogels were fabricated by combining the functionalized Scl2 proteins with poly(ethylene glycol) diacrylate (PEGDA) and photocrosslinking. EC and SMC adhesion studies confirmed cell-specific adhesion due to selective integrin binding to the two receptor binding motifs investigated. These results serve to highlight the potential of this novel biomaterial platform in the development of improved tissue engineered vascular grafts.
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Affiliation(s)
- E Cosgriff-Hernandez
- Department of Biomedical Engineering, Texas A&M University, College Station, 77843-3120, USA.
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Barbu EM, Ganesh VK, Gurusiddappa S, Mackenzie RC, Foster TJ, Sudhof TC, Höök M. beta-Neurexin is a ligand for the Staphylococcus aureus MSCRAMM SdrC. PLoS Pathog 2010; 6:e1000726. [PMID: 20090838 PMCID: PMC2800189 DOI: 10.1371/journal.ppat.1000726] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 12/15/2009] [Indexed: 11/18/2022] Open
Abstract
Gram-positive bacteria contain a family of surface proteins that are covalently anchored to the cell wall of the organism. These cell-wall anchored (CWA) proteins appear to play key roles in the interactions between pathogenic organisms and the host. A subfamily of the CWA has a common structural organization with multiple domains adopting characteristic IgG-like folds. The identified microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) belong to this subfamily, as does SdrC from S. aureus. However, an interactive host ligand for the putative MSCRAMM SdrC was not previously identified. We have screened a phage display peptide library and identified a peptide sequence found in beta-neurexin that binds SdrC. A synthetic peptide corresponding to the identified sequence as well as a recombinant form of the beta-neurexin 1 exodomain binds SdrC with high affinity and specificity. Furthermore, expression of SdrC on bacteria greatly enhances microbial adherence to cultured mammalian cells expressing beta-neurexin on their surface. Taken together, our experimental results demonstrate that beta-neurexin is a ligand for SdrC. This interaction involves a specific sequence located in the N-terminal region of the mammalian protein and the N(2)N(3) domain of the MSCRAMM. The fact that these two proteins interact when expressed on the appropriate cells demonstrates the functionality of the interaction. Possible implications of this interaction are discussed.
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Affiliation(s)
- E Magda Barbu
- Center for Infectious & Inflammatory Diseases, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas, United States of America
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Nuka S, Zhou W, Henry SP, Gendron CM, Schultz JB, Shinomura T, Johnson J, Wang Y, Keene DR, Ramírez-Solis R, Behringer RR, Young MF, Höök M. Phenotypic characterization of epiphycan-deficient and epiphycan/biglycan double-deficient mice. Osteoarthritis Cartilage 2010; 18:88-96. [PMID: 19932218 PMCID: PMC3013283 DOI: 10.1016/j.joca.2009.11.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2008] [Accepted: 05/15/2008] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To characterize the in vivo role epiphycan (Epn) has in cartilage development and/or maintenance. METHODS Epn-deficient mice were generated by disrupting the Epn gene in mouse embryonic stem cells. Epn/biglycan (Bgn) double-deficient mice were produced by crossing Epn-deficient mice with Bgn-deficient mice. Whole knee joint histological sections were stained using van Gieson or Fast green/Safranin-O to analyze collagen or proteoglycan content, respectively. Microarray analysis was performed to detect gene expression changes within knee joints. RESULTS Epn-deficient and Epn/Bgn double-deficient mice appeared normal at birth. No significant difference in body weight or femur length was detected in any animal at 1 month of age. However, 9-month Epn/Bgn double-deficient mice were significantly lighter and had shorter femurs than wild type mice, regardless of gender. Male Epn-deficient mice also had significantly shorter femurs than wild type mice at 9 months. Most of the deficient animals developed osteoarthritis (OA) with age; the onset of OA was observed earliest in Epn/Bgn double-deficient mice. Message RNA isolated from Epn/Bgn double-deficient knee joints displayed increased matrix protein expression compared with wild type mice, including other small leucine-rich proteoglycan (SLRP) members such as asporin, fibromodulin and lumican. CONCLUSION Similar to other previously studied SLRPs, EPN plays an important role in maintaining joint integrity. However, the severity of the OA phenotype in the Epn/Bgn double-deficient mouse suggests a synergy between these two proteins. These data are the first to show a genetic interaction involving class I and class III SLRPs in vivo.
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Affiliation(s)
- Satoshi Nuka
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Wei Zhou
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Stephen P. Henry
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Christi M. Gendron
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Jason B. Schultz
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Tamayuki Shinomura
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Jan Johnson
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Ying Wang
- Department of Molecular Genetics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030
| | | | - Ramiro Ramírez-Solis
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030
| | - Richard R. Behringer
- Department of Molecular Genetics, The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030
| | - Marian F. Young
- Craniofacial and Skeletal Diseases Branch, NIDCR, National Institutes of Health, Bethesda, MD 20892
| | - Magnus Höök
- Texas A&M University System Health Science Center, Albert B Alkek Institute of Biosciences and Technology, Center for Extracellular Matrix Biology, 2121 W. Holcombe Boulevard, Houston, TX 77030,To whom correspondence and reprint requests should be addressed: Dr. Magnus Höök, Telephone: (713)677-7552, Fax: (713)677-7576,
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Geoghegan JA, Ganesh VK, Smeds E, Liang X, Höök M, Foster TJ. Molecular characterization of the interaction of staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMM) ClfA and Fbl with fibrinogen. J Biol Chem 2009; 285:6208-16. [PMID: 20007717 DOI: 10.1074/jbc.m109.062208] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ligand-binding domain of Fbl (the fibrinogen binding protein from Staphylococcus lugdunensis) shares 60% sequence identity with ClfA (clumping factor A) of Staphylococcus aureus. Recombinant Fbl corresponding to the minimum fibrinogen-binding region (subdomains N2N3) was compared with ClfA for binding to fibrinogen. Fbl and ClfA had very similar affinities for fibrinogen by surface plasmon resonance. The binding site for Fbl in fibrinogen was localized to the extreme C terminus of the fibrinogen gamma-chain at the same site recognized by ClfA. Isothermal titration calorimetry showed that Fbl and ClfA had very similar affinities for a peptide mimicking the C-terminal segment of the fibrinogen gamma-chain. The peptide also inhibited binding of Fbl and ClfA to fibrinogen. A series of substituted gamma-chain variant peptides behaved very similarly when used to inhibit ClfA and Fbl binding to immobilized fibrinogen. Both ClfA and Fbl bound to bovine fibrinogen with a lower affinity compared with human fibrinogen and did not bind detectably to ovine fibrinogen. The structure of the N2N3 subdomains of Fbl in complex with the fibrinogen gamma-chain peptide was modeled based on the crystal structure of the N2N3 subdomains of the ClfA-gamma-chain peptide complex. Residues in the putative binding trench likely to be involved in fibrinogen binding were identified. Fbl variant proteins with alanine substitutions in key residues had reduced affinities for fibrinogen. Thus Fbl and ClfA bind the same site in fibrinogen by similar mechanisms.
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Affiliation(s)
- Joan A Geoghegan
- Microbiology Department, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
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Luo J, Zhou W, Zhou X, Li D, Weng J, Yi Z, Cho SG, Li C, Yi T, Wu X, Li XY, de Crombrugghe B, Höök M, Liu M. Regulation of bone formation and remodeling by G-protein-coupled receptor 48. Development 2009; 136:2747-56. [PMID: 19605502 DOI: 10.1242/dev.033571] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
G-protein-coupled receptor (GPCR) 48 (Gpr48; Lgr4), a newly discovered member of the glycoprotein hormone receptor subfamily of GPCRs, is an orphan GPCR of unknown function. Using a knockout mouse model, we have characterized the essential roles of Gpr48 in bone formation and remodeling. Deletion of Gpr48 in mice results in a dramatic delay in osteoblast differentiation and mineralization, but not in chondrocyte proliferation and maturation, during embryonic bone formation. Postnatal bone remodeling is also significantly affected in Gpr48(-/-) mice, including the kinetic indices of bone formation rate, bone mineral density and osteoid formation, whereas the activity and number of osteoclasts are increased as assessed by tartrate-resistant acid phosphatase staining. Examination of the molecular mechanism of Gpr48 action in bone formation revealed that Gpr48 can activate the cAMP-PKA-CREB signaling pathway to regulate the expression level of Atf4 in osteoblasts. Furthermore, we show that Gpr48 significantly downregulates the expression levels of Atf4 target genes/proteins, such as osteocalcin (Ocn; Bglap2), bone sialoprotein (Bsp; Ibsp) and collagen. Together, our data demonstrate that Gpr48 regulates bone formation and remodeling through the cAMP-PKA-Atf4 signaling pathway.
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Affiliation(s)
- Jian Luo
- The Institute of Biomedical Sciences and School of Life Sciences, East China Normal University, Shanghai, China
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Sillanpää J, Nallapareddy SR, Houston J, Ganesh VK, Bourgogne A, Singh KV, Murray BE, Höök M. A family of fibrinogen-binding MSCRAMMs from Enterococcus faecalis. Microbiology (Reading) 2009; 155:2390-2400. [PMID: 19389755 DOI: 10.1099/mic.0.027821-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We report that three (EF0089, EF2505 and EF1896, renamed here Fss1, Fss2 and Fss3, respectively, for Enterococcus faecalis surface protein) of the recently predicted MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) in E. faecalis strain V583 bind fibrinogen (Fg). Despite an absence of extensive primary sequence homology, the three proteins appear to be related structurally. Within the N-terminal regions of the three enterococcal proteins, we identified pairs of putative IgG-like modules with a high degree of predicted structural similarity to the Fg-binding N2 and N3 domains of the staphylococcal MSCRAMMs ClfA and SdrG. A second N2N3-like segment was predicted in Fss1. Far-UV circular dichroism spectroscopy revealed that all four predicted N2N3-like regions are composed mainly of beta-sheets with only a minor proportion of alpha-helices, which is characteristic of Ig-like folded domains. Three of the four identified enterococcal N2N3-like regions showed potent dose-dependent binding to Fg. However, the specificity of the Fg-binding MSCRAMMs differs, as indicated by far-Western blots, which showed that recombinant segments of the MSCRAMMs bound different Fg polypeptide chains. Enterococci grown in serum-supplemented broth adhere to Fg-coated surfaces, and inactivation in strain OG1RF of the gene encoding Fss2 resulted in reduced adherence, whilst complementation of the mutant restored full Fg adherence. Thus, E. faecalis contains a family of MSCRAMMs that structurally and functionally resemble the Fg-binding MSCRAMMs of staphylococci.
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Affiliation(s)
- Jouko Sillanpää
- Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Medical School, Houston, TX, USA.,Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School, Houston, TX, USA.,Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Sreedhar R Nallapareddy
- Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Medical School, Houston, TX, USA.,Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School, Houston, TX, USA
| | - Janeu Houston
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Vannakambadi K Ganesh
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
| | - Agathe Bourgogne
- Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Medical School, Houston, TX, USA.,Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School, Houston, TX, USA
| | - Kavindra V Singh
- Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Medical School, Houston, TX, USA.,Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School, Houston, TX, USA
| | - Barbara E Murray
- Department of Microbiology and Molecular Genetics, University of Texas Medical School, Houston, TX, USA.,Center for the Study of Emerging and Re-emerging Pathogens, University of Texas Medical School, Houston, TX, USA.,Division of Infectious Diseases, Department of Internal Medicine, University of Texas Medical School, Houston, TX, USA
| | - Magnus Höök
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, TX, USA
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Evans SE, Scott BL, Clement CG, Larson DT, Kontoyiannis D, Lewis RE, Lasala PR, Pawlik J, Peterson JW, Chopra AK, Klimpel G, Bowden G, Höök M, Xu Y, Tuvim MJ, Dickey BF. Stimulated innate resistance of lung epithelium protects mice broadly against bacteria and fungi. Am J Respir Cell Mol Biol 2009; 42:40-50. [PMID: 19329554 DOI: 10.1165/rcmb.2008-0260oc] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Pneumonia is a serious problem worldwide. We recently demonstrated that innate defense mechanisms of the lung are highly inducible against pneumococcal pneumonia. To determine the breadth of protection conferred by stimulation of lung mucosal innate immunity, and to identify cells and signaling pathways activated by this treatment, mice were treated with an aerosolized bacterial lysate, then challenged with lethal doses of bacterial and fungal pathogens. Mice were highly protected against a broad array of Gram-positive, Gram-negative, and class A bioterror bacterial pathogens, and the fungal pathogen, Aspergillus fumigatus. Protection was associated with rapid pathogen killing within the lungs, and this effect was recapitulated in vitro using a respiratory epithelial cell line. Gene expression analysis of lung tissue showed marked activation of NF-kappaB, type I and II IFN, and antifungal Card9-Bcl10-Malt1 pathways. Cytokines were the most strongly induced genes, but the inflammatory cytokines TNF and IL-6 were not required for protection. Lung-expressed antimicrobial peptides were also highly up-regulated. Taken together, stimulated innate resistance appears to occur through the activation of multiple host defense signaling pathways in lung epithelial cells, inducing rapid pathogen killing, and conferring broad protection against virulent bacterial and fungal pathogens. Augmentation of innate antimicrobial defenses of the lungs might have therapeutic value for protection of patients with neutropenia or impaired adaptive immunity against opportunistic pneumonia, and for defense of immunocompetent subjects against a bioterror threat or epidemic respiratory infection.
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Affiliation(s)
- Scott E Evans
- Department of Pulmonary Medicine, M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030-4009, USA.
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Ganesh VK, Rivera JJ, Smeds E, Ko YP, Bowden MG, Wann ER, Gurusiddappa S, Fitzgerald JR, Höök M. A structural model of the Staphylococcus aureus ClfA-fibrinogen interaction opens new avenues for the design of anti-staphylococcal therapeutics. PLoS Pathog 2008; 4:e1000226. [PMID: 19043557 PMCID: PMC2582960 DOI: 10.1371/journal.ppat.1000226] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [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: 08/12/2008] [Accepted: 11/03/2008] [Indexed: 12/15/2022] Open
Abstract
The fibrinogen (Fg) binding MSCRAMM Clumping factor A (ClfA) from Staphylococcus aureus interacts with the C-terminal region of the fibrinogen (Fg) γ-chain. ClfA is the major virulence factor responsible for the observed clumping of S. aureus in blood plasma and has been implicated as a virulence factor in a mouse model of septic arthritis and in rabbit and rat models of infective endocarditis. We report here a high-resolution crystal structure of the ClfA ligand binding segment in complex with a synthetic peptide mimicking the binding site in Fg. The residues in Fg required for binding to ClfA are identified from this structure and from complementing biochemical studies. Furthermore, the platelet integrin αIIbβ3 and ClfA bind to the same segment in the Fg γ-chain but the two cellular binding proteins recognize different residues in the common targeted Fg segment. Based on these differences, we have identified peptides that selectively antagonize the ClfA-Fg interaction. The ClfA-Fg binding mechanism is a variant of the “Dock, Lock and Latch” mechanism previously described for the Staphylococcus epidermidis SdrG–Fg interaction. The structural insights gained from analyzing the ClfANFg peptide complex and identifications of peptides that selectively recognize ClfA but not αIIbβ3 may allow the design of novel anti-staphylococcal agents. Our results also suggest that different MSCRAMMs with similar structural organization may have originated from a common ancestor but have evolved to accommodate specific ligand structures. Staphylococcus aureus (S. aureus) is a common pathogen that can cause a range of diseases from mild skin infections to life-threatening sepsis in humans. Some surface proteins on S. aureus play important roles in the S. aureus disease process. One of these bacterial surface proteins is clumping factor A (ClfA) that binds to the C-terminal region of one of the three chains of fibrinogen (Fg), a blood protein that plays a key role in coagulation. We carried out biochemical and structural studies to understand the binding mechanism of ClfA to Fg and to define the residues in Fg that interact with ClfA. Interestingly, the platelet integrin, which is important for platelet aggregation and thrombi formation, also binds to the same region of Fg as ClfA. Despite the fact that the two proteins bind at the same region, the mode of recognition is significantly different. Exploiting this difference in recognition, we have demonstrated that agents could be designed that inhibit the ClfA–Fg interaction but do not interfere with the interaction of Fg with the platelet integrin. This opens the field for the design of a novel class of anti-staph therapeutics.
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Affiliation(s)
- Vannakambadi K. Ganesh
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
| | - Jose J. Rivera
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
| | - Emanuel Smeds
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
| | - Ya-Ping Ko
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
| | - M. Gabriela Bowden
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
| | - Elisabeth R. Wann
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
| | - Shivasankarappa Gurusiddappa
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
| | - J. Ross Fitzgerald
- Centre for Infectious Diseases, School of Biomedical Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Magnus Höök
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A & M University Health Science Center, Houston, Texas, United States of America
- * E-mail:
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Shinomura T, Nakamura S, Ito K, Shirasawa SI, Höök M, Kimura JH. Adsorption of follicular dendritic cell-secreted protein (FDC-SP) onto mineral deposits. Application of a new stable gene expression system. J Biol Chem 2008; 283:33658-64. [PMID: 18806264 DOI: 10.1074/jbc.m800719200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Follicular dendritic cell-secreted protein (FDC-SP) is a small secretory protein having structural similarities to statherin, a protein in saliva thought to play a role in calcium retention in saliva. In contrast, FDC-SP is thought to play a role in the immune system associated with germinal centers. We report here the very specific expression of FDC-SP in junctional epithelium at the gingival crevice. This region is very important for the host defense against pathogens and for periodontal protection. To be able to better understand the function of FDC-SP, we developed a novel gene expression system that exploited gene trapping and site-specific gene integration to introduce the protein into a mammalian cell culture system. Using this system we were able to express FDC-SP as a fusion protein with green fluorescent protein in an osteogenic progenitor cell line with long term stability, which we then used to find that the fusion protein specifically adsorbs onto mineral deposits and the surface of hydroxyapatite particles exogenously added to the culture. This adsorption was highly dependent on the structural integrity of FDC-SP. These results suggest that FDC-SP may play an important role, adsorbing onto the surface of cementum and alveolar bone adjacent to periodontal ligament and onto tooth surface at the gingival crevice.
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Affiliation(s)
- Tamayuki Shinomura
- Department of Hard Tissue Engineering, Tokyo Medical and Dental University, Tokyo 113-8549, Japan.
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Bingham RJ, Rudiño-Piñera E, Meenan NAG, Schwarz-Linek U, Turkenburg JP, Höök M, Garman EF, Potts JR. Crystal structures of fibronectin-binding sites from Staphylococcus aureus FnBPA in complex with fibronectin domains. Proc Natl Acad Sci U S A 2008; 105:12254-8. [PMID: 18713862 PMCID: PMC2518095 DOI: 10.1073/pnas.0803556105] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.7] [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: 04/11/2008] [Indexed: 01/22/2023] Open
Abstract
Staphylococcus aureus can adhere to and invade endothelial cells by binding to the human protein fibronectin (Fn). FnBPA and FnBPB, cell wall-attached proteins from S. aureus, have multiple, intrinsically disordered, high-affinity binding repeats (FnBRs) for Fn. Here, 30 years after the first report of S. aureus/Fn interactions, we present four crystal structures that together comprise the structures of two complete FnBRs, each in complex with four of the N-terminal modules of Fn. Each approximately 40-residue FnBR forms antiparallel strands along the triple-stranded beta-sheets of four sequential F1 modules ((2-5)F1) with each FnBR/(2-5)F1 interface burying a total surface area of approximately 4,300 A(2). The structures reveal the roles of residues conserved between S. aureus and Streptococcus pyogenes FnBRs and show that there are few linker residues between FnBRs. The ability to form large intermolecular interfaces with relatively few residues has been proposed to be a feature of disordered proteins, and S. aureus/Fn interactions provide an unusual illustration of this efficiency.
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Affiliation(s)
- Richard J. Bingham
- *Department of Biology, University of York, PO Box 373, York YO10 5YW, United Kingdom
| | - Enrique Rudiño-Piñera
- Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, P. O. Box 510-3 Cuernavaca, MOR 62271, Mexico
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Nicola A. G. Meenan
- *Department of Biology, University of York, PO Box 373, York YO10 5YW, United Kingdom
| | - Ulrich Schwarz-Linek
- Centre for Biomolecular Sciences, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, United Kingdom
| | - Johan P. Turkenburg
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom; and
| | - Magnus Höök
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, TX 77030-3303
| | - Elspeth F. Garman
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Jennifer R. Potts
- *Department of Biology, University of York, PO Box 373, York YO10 5YW, United Kingdom
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom; and
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Abstract
Previous studies have shown that sulphated proteoglycans are integral components of basement membranes. We have used mouse parietal yolk sac cells as a model system for our studies. These cells produce several basement membrane components, including a heparan sulphate proteoglycan and a chondroitin sulphate proteoglycan. The structure of the heparan sulphate proteoglycan has been described previously. The chondroitin sulphate proteoglycan has an Mr of 200 000-300 000 and contains 10-20 chondroitin sulphate chains (Mr = 14 000-16 000), attached to a core protein that on polyacrylamide gel electrophoresis appears as a doublet (with Mr = 34 000 and 27 000). Further structural analysis suggests that the majority of the polysaccharide chains are clustered around one segment of the core protein. The polysaccharide chains carry sulphate residues predominantly attached to C-4 of the galactosamine unit. More than 60% of the uronic acid residues are of the glucuronic configuration, the rest being iduronic acid. The parietal yolk sac cells secrete about equal amounts of the two proteoglycans into the culture medium, whereas heparan sulphate proteoglycan is the predominant proteoglycan found in the extracellular matrix of these cells. This proteoglycan appears to be anchored in the matrix by interactions involving the core protein rather than the polysaccharide chains.
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Ferdous Z, Lazaro LD, Iozzo RV, Höök M, Grande-Allen KJ. Influence of cyclic strain and decorin deficiency on 3D cellularized collagen matrices. Biomaterials 2008; 29:2740-8. [PMID: 18394699 DOI: 10.1016/j.biomaterials.2008.03.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [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] [Received: 01/22/2008] [Accepted: 03/18/2008] [Indexed: 11/15/2022]
Abstract
Cyclic strain evokes the expression of the small leucine-rich proteoglycans decorin and biglycan in 2D cultures and native tissues. However, strain-dependent expression of these proteoglycans has not been demonstrated in engineered tissues. We hypothesized that the absence of decorin may compromise the effect of cyclic strain on the development of engineered tissues. Thus, we investigated the contribution of decorin to tissue organization in cyclically strained collagen gels relative to statically cultured controls. Decorin null (Dcn(-/-)) and wild-type murine embryonic fibroblasts were seeded within collagen gels and mechanically conditioned using a Flexcell Tissue Train culture system. After 8 days, the cyclically strained samples demonstrated greater collagen fibril density, proteoglycan content, and material strength for both cell types. On the other hand, increases in cell density, collagen fibril diameter, and biglycan expression were observed only in the cyclically strained gels seeded with Dcn(-/-) cells. Although cyclic strain caused an elevation in proteoglycan expression regardless of cell type, the type of proteoglycan differed between groups: the Dcn(-/-) cell-seeded gels produced an excess of biglycan not found in the wild-type controls. These results suggest that decorin-mediated tissue organization is strongly dependent upon tissue type and mechanical environment.
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Affiliation(s)
- Zannatul Ferdous
- Department of Bioengineering, Rice University, P.O. Box 1892, MS 142, Houston, TX 77251-1892, USA
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Bowden MG, Heuck AP, Ponnuraj K, Kolosova E, Choe D, Gurusiddappa S, Narayana SVL, Johnson AE, Höök M. Evidence for the "dock, lock, and latch" ligand binding mechanism of the staphylococcal microbial surface component recognizing adhesive matrix molecules (MSCRAMM) SdrG. J Biol Chem 2007; 283:638-647. [PMID: 17991749 DOI: 10.1074/jbc.m706252200] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Staphylococcus epidermidis is an opportunistic pathogen and a major cause of foreign body infections. The S. epidermidis fibrinogen (Fg)-binding adhesin SdrG is necessary and sufficient for the attachment of this pathogen to Fg-coated materials. Based largely on structural analyses of the ligand binding domain of SdrG as an apo-protein and in complex with a Fg-like peptide, we proposed that SdrG follows a "dock, lock, and latch" mechanism to bind to Fg. This binding mechanism involves the docking of the ligand in a pocket formed between two SdrG subdomains followed by the movement of a C-terminal extension of one subdomain to cover the ligand and to insert and complement a beta-sheet in a neighboring subdomain. These proposed events result in a greatly stabilized closed conformation of the MSCRAMM-ligand complex. In this report, we describe a biochemical analysis of the proposed conformational changes that SdrG undergoes upon binding to its ligand. We have introduced disulfide bonds into SdrG to stabilize the open and closed forms of the apo-form of the MSCRAMM. We show that the stabilized closed form does not bind to the ligand and that binding can be restored in the presence of reducing agents such as dithiothreitol. We have also used Förster resonance energy transfer to dynamically show the conformational changes of SdrG upon binding to its ligand. Finally, we have used isothermic calorimetry to determine that hydrophobic interactions between the ligand and the protein are responsible for re-directing the C-terminal extension of the second subdomain required for triggering the beta-strand complementation event.
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Affiliation(s)
- M Gabriela Bowden
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030.
| | - Alejandro P Heuck
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003; Department of Molecular and Cellular Medicine, School of Medicine, Texas A&M University System Health Science Center, College Station, Texas 77843
| | - Karthe Ponnuraj
- Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama 35294; Center of Advanced Study in Crystallography and Biophysics, University of Madras, Chennai 600025, India
| | - Elena Kolosova
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030
| | - Damon Choe
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030
| | - Sivashankarappa Gurusiddappa
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030
| | - Sthanam V L Narayana
- Center for Biophysical Sciences and Engineering, University of Alabama, Birmingham, Alabama 35294
| | - Arthur E Johnson
- Department of Molecular and Cellular Medicine, School of Medicine, Texas A&M University System Health Science Center, College Station, Texas 77843
| | - Magnus Höök
- Center for Extracellular Matrix Biology, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, Houston, Texas 77030
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Ferdous Z, Wei VM, Iozzo R, Höök M, Grande-Allen KJ. Decorin-transforming growth factor- interaction regulates matrix organization and mechanical characteristics of three-dimensional collagen matrices. J Biol Chem 2007; 282:35887-98. [PMID: 17942398 DOI: 10.1074/jbc.m705180200] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The small leucine-rich proteoglycan decorin has been demonstrated to be a key regulator of collagen fibrillogenesis; decorin deficiencies lead to irregularly shaped collagen fibrils and weakened material behavior in postnatal murine connective tissues. In an in vitro investigation of the contributions of decorin to tissue organization and material behavior, model tissues were engineered by seeding embryonic fibroblasts, harvested from 12.5-13.5 days gestational aged decorin null (Dcn(-/-)) or wild-type mice, within type I collagen gels. The resulting three-dimensional collagen matrices were cultured for 4 weeks under static tension. The collagen matrices seeded with Dcn(-/-) cells exhibited greater contraction, cell density, ultimate tensile strength, and elastic modulus than those seeded with wild-type cells. Ultrastructurally, the matrices seeded with Dcn(-/-) cells contained a greater density of collagen. The decorin-null tissues contained more biglycan than control tissues, suggesting that this related proteoglycan compensated for the absence of decorin. The effect of transforming growth factor-beta (TGF-beta), which is normally sequestered by decorin, was also investigated in this study. The addition of TGF-beta1 to the matrices seeded with wild-type cells improved their contraction and mechanical strength, whereas blocking TGF-beta1 in the Dcn(-/-) cell-seeded matrices significantly reduced the collagen gel contraction. These results indicate that the inhibitory interaction between decorin and TGF-beta1 significantly influenced the matrix organization and material behavior of these in vitro model tissues.
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Affiliation(s)
- Zannatul Ferdous
- Department of Bioengineering, Rice University, Houston, Texas 77005, USA
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50
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Abstract
Proteoglycans (primarily heparan sulphate proteoglycans) are found at the surface of most adherent eukaryotic cells. Earlier studies suggest that these molecules can be associated with the cell surface principally by two different mechanisms. Proteoglycans may occur as membrane-intercalated glycoproteins, where the core protein of the proteoglycan is anchored in the lipid interior of the plasma membrane, or they may be bound via the polysaccharide components of the molecule to specific anchoring proteins present at the cell surface. A number of functions have been proposed for cell surface-associated proteoglycans, including: regulation of cell-substrate adhesion; regulation of cell proliferation; participation in the binding and uptake of extracellular components; and participation in the regulation of extracellular matrix formation. Evidence is discussed suggesting that the cell-associated heparan sulphate helps to connect the intracellular cytoskeleton to the extracellular matrix in focal adhesions. This evidence includes: the co-localization of actin and heparan sulphate proteoglycan during the process of cell spreading, and in isolated focal adhesions; biochemical analyses of a hydrophobic heparan sulphate proteoglycan from isolated focal adhesions; and the formation of focal adhesions on substrates made from isolated fibronectin fragments requires the presence of a heparan sulphate-binding site.
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