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Bradshaw TM, Johnson CR, Broberg CA, Anderson DE, Schoenfisch MH. Sterilization Effects on Nitric Oxide-Releasing Glucose Sensors. Sens Actuators B Chem 2024; 405:135311. [PMID: 38464808 PMCID: PMC10922015 DOI: 10.1016/j.snb.2024.135311] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Nitric oxide (NO) release from S-nitrosothiol-modified mesoporous silica nanoparticles imbedded in the diffusion limiting layer of a glucose sensor has been demonstrated as an effective strategy for mitigating the foreign body response common to sensor implantation, resulting in improved analytical performance. With respect to potential clinical translation of this approach, the effects of sterilization on NO-releasing biosensors require careful evaluation, as NO donor chemistry is sensitive to temperature and environment. Herein, we evaluated the influence of multiple sterilization methods on 1) sterilization success; 2) NO payload; and 3) sensor performance to establish the commercialization potential of NO-releasing glucose sensors. Sensors were treated with ethylene oxide gas, the most common sterilization method for intricate medical devices, which led to undesirable (i.e., premature) release of NO. To reduce NO loss, alternative sterilization methods that were studied included exposure to ultraviolet (UV) light and immersion in 70% ethanol (EtOH). Sterilization cycle times required to reach a 10-6 sterility assurance level were determined for both UV light and 70% EtOH against Gram-negative and -positive bacteria. The longest sterilization cycle times (258 s and 628 s for 70% EtOH and UV light, respectively) resulted in a negligible impact on benchtop sensor performance. However, sterilization with 70% ethanol resulted in a reduced NO-release duration. Ultraviolet light exposure for ~10 min proved successful at eliminating bacteria without compromising NO payloads or durations and presents as the most promising method for sterilization of these sensors. In addition, storage of NO-releasing sensor membranes at -20 and -80°C resulted in preservation of NO release for 6 and 12 months, respectively.
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Affiliation(s)
- Taron M. Bradshaw
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, 27599, United States
| | - Courtney R. Johnson
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, 27599, United States
| | - Christopher A. Broberg
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, 27599, United States
| | - Darci E. Anderson
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, 27599, United States
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, 27599, United States
- Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, North Carolina, 27599, United States
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2
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Bleich RM, Li C, Sun S, Ahn JH, Dogan B, Barlogio CJ, Broberg CA, Franks AR, Bulik-Sullivan E, Carroll IM, Simpson KW, Fodor AA, Arthur JC. A consortia of clinical E. coli strains with distinct in vitro adherent/invasive properties establish their own co-colonization niche and shape the intestinal microbiota in inflammation-susceptible mice. Microbiome 2023; 11:277. [PMID: 38124090 PMCID: PMC10731797 DOI: 10.1186/s40168-023-01710-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 10/26/2023] [Indexed: 12/23/2023]
Abstract
BACKGROUND Inflammatory bowel disease (IBD) patients experience recurrent episodes of intestinal inflammation and often follow an unpredictable disease course. Mucosal colonization with adherent-invasive Escherichia coli (AIEC) are believed to perpetuate intestinal inflammation. However, it remains unclear if the 24-year-old AIEC in vitro definition fully predicts mucosal colonization in vivo. To fill this gap, we have developed a novel molecular barcoding approach to distinguish strain variants in the gut and have integrated this approach to explore mucosal colonization of distinct patient-derived E. coli isolates in gnotobiotic mouse models of colitis. RESULTS Germ-free inflammation-susceptible interleukin-10-deficient (Il10-/-) and inflammation-resistant WT mice were colonized with a consortium of AIEC and non-AIEC strains, then given a murine fecal transplant to provide niche competition. E. coli strains isolated from human intestinal tissue were each marked with a unique molecular barcode that permits identification and quantification by barcode-targeted sequencing. 16S rRNA sequencing was used to evaluate the microbiome response to E. coli colonization. Our data reveal that specific AIEC and non-AIEC strains reproducibly colonize the intestinal mucosa of WT and Il10-/- mice. These E. coli expand in Il10-/- mice during inflammation and induce compositional dysbiosis to the microbiome in an inflammation-dependent manner. In turn, specific microbes co-evolve in inflamed mice, potentially diversifying E. coli colonization patterns. We observed no selectivity in E. coli colonization patterns in the fecal contents, indicating minimal selective pressure in this niche from host-microbe and interbacterial interactions. Because select AIEC and non-AIEC strains colonize the mucosa, this suggests the in vitro AIEC definition may not fully predict in vivo colonization potential. Further comparison of seven E. coli genomes pinpointed unique genomic features contained only in highly colonizing strains (two AIEC and two non-AIEC). Those colonization-associated features may convey metabolic advantages (e.g., iron acquisition and carbohydrate consumption) to promote efficient mucosal colonization. CONCLUSIONS Our findings establish the in vivo mucosal colonizer, not necessarily AIEC, as a principal dysbiosis driver through crosstalk with host and associated microbes. Furthermore, we highlight the utility of high-throughput screens to decode the in vivo colonization dynamics of patient-derived bacteria in murine models. Video Abstract.
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Affiliation(s)
- Rachel M Bleich
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Biology, Appalachian State University, Boone, NC, USA
| | - Chuang Li
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Shan Sun
- College of Computing and Informatics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Ju-Hyun Ahn
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Belgin Dogan
- Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, USA
| | - Cassandra J Barlogio
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Christopher A Broberg
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Adrienne R Franks
- Center for Gastrointestinal Biology & Disease, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Emily Bulik-Sullivan
- Center for Gastrointestinal Biology & Disease, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ian M Carroll
- Center for Gastrointestinal Biology & Disease, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Kenneth W Simpson
- Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, USA
| | - Anthony A Fodor
- College of Computing and Informatics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Janelle C Arthur
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Center for Gastrointestinal Biology & Disease, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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Nguyen HK, Picciotti SL, Duke MM, Broberg CA, Schoenfisch MH. Nitric Oxide-Induced Morphological Changes to Bacteria. ACS Infect Dis 2023; 9:2316-2324. [PMID: 37831756 PMCID: PMC11041245 DOI: 10.1021/acsinfecdis.3c00415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
Antimicrobial resistance poses a serious threat to global health, necessitating research for alternative approaches to treating infections. Nitric oxide (NO) is an endogenously produced molecule involved in multiple physiological processes, including the response to pathogens. Herein, we employed microscopy- and fluorescence-based techniques to investigate the effects of NO delivered from exogenous NO donors on the bacterial cell envelopes of pathogens, including resistant strains. Our goal was to assess the role of NO donor architecture (small molecules, oligosaccharides, dendrimers) on bacterial wall degradation to representative Gram-negative bacteria (Klebsiella pneumoniae, Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus, Enterococcus faecium) upon treatment. Depending on the NO donor, bactericidal NO doses spanned 1.5-5.5 mM (total NO released). Transmission electron microscopy of bacteria following NO exposure indicated extensive membrane damage to Gram-negative bacteria with warping of the cellular shape and disruption of the cell wall. Among the small-molecule NO donors, those providing a more extended release (t1/2 = 120 min) resulted in greater damage to Gram-negative bacteria. In contrast, rapid NO release (t1/2 = 24 min) altered neither the morphology nor the roughness of these bacteria. For Gram-positive bacteria, NO treatments did not result in any drastic change to cellular shape or membrane integrity, despite permeation of the cell wall as measured by depolarization assays. The use of positively charged quaternary ammonium (QA)-modified NO-releasing dendrimer proved to be the only NO donor system capable of penetrating the thick peptidoglycan layer of Gram-positive bacteria.
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Affiliation(s)
- Huan K. Nguyen
- Department of Chemistry, University of North Carolina at Chapel Hill, NC 27599
| | | | - Magdalena M. Duke
- Department of Chemistry, University of North Carolina at Chapel Hill, NC 27599
| | | | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, NC 27599
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599
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4
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Grayton QE, Nguyen HK, Broberg CA, Ocampo J, Nagy SG, Schoenfisch MH. Biofilm Dispersal, Reduced Viscoelasticity, and Antibiotic Sensitization via Nitric Oxide-Releasing Biopolymers. ACS Infect Dis 2023; 9:1730-1741. [PMID: 37566512 DOI: 10.1021/acsinfecdis.3c00198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/13/2023]
Abstract
Compared to planktonic bacteria, biofilms are notoriously difficult to eradicate due to their inherent protection against the immune response and antimicrobial agents. Inducing biofilm dispersal to improve susceptibility to antibiotics is an attractive therapeutic avenue for eradicating biofilms. Nitric oxide (NO), an endogenous antibacterial agent, has previously been shown to induce biofilm dispersal, but with limited understanding of the effects of NO-release properties. Herein, the antibiofilm effects of five promising NO-releasing biopolymer candidates were studied by assessing dispersal, changes in biofilm viscoelasticity, and increased sensitization to tobramycin after treatment with NO. A threshold level of NO was needed to achieve biofilm dispersal, with longer-releasing systems requiring lower concentrations. The most positively charged NO-release systems (from the presence of primary amines) led to the greatest reduction in viscoelasticity of Pseudomonas aeruginosa biofilms. Co-treatment of tobramycin with the NO-releasing biopolymer greatly decreased the dose of tobramycin required to eradicate tobramycin-susceptible and -resistant biofilms in both cellular and tissue models.
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5
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Bleich RM, Li C, Sun S, Barlogio CJ, Broberg CA, Franks AR, Bulik-Sullivan E, Dogan B, Simpson KW, Carroll IM, Fodor AA, Arthur JC. A consortia of clinical E. coli strains with distinct in-vitro adherent/invasive properties establish their own co-colonization niche and shape the intestinal microbiota in inflammation-susceptible mice. Res Sq 2023:rs.3.rs-2899665. [PMID: 37214858 PMCID: PMC10197778 DOI: 10.21203/rs.3.rs-2899665/v1] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Background Inflammatory bowel disease (IBD) patients experience recurrent episodes of intestinal inflammation and often follow an unpredictable disease course. Mucosal colonization with adherent-invasive Escherichia coli (AIEC) are believed to perpetuate intestinal inflammation. However, it remains unclear if the 24-year-old AIEC in-vitro definition fully predicts mucosal colonization in-vivo. To fill this gap, we have developed a novel molecular barcoding approach to distinguish strain variants in the gut and have integrated this approach to explore mucosal colonization of distinct patient-derived E. coli isolates in gnotobiotic mouse models of colitis. Results Germ-free inflammation-susceptible interleukin-10-deficient (Il10-/-) and inflammation-resistant WT mice were colonized with a consortia of AIEC and non-AIEC strains, then given a murine fecal transplant to provide niche competition. E. coli strains isolated from human intestinal tissue were each marked with a unique molecular barcode that permits identification and quantification by barcode-targeted sequencing. 16S rRNA sequencing was used to evaluate the microbiome response to E. coli colonization. Our data reveal that specific AIEC and non-AIEC strains reproducibly colonize the intestinal mucosa of WT and Il10-/- mice. These E. coli expand in Il10-/- mice during inflammation and induce compositional dysbiosis to the microbiome in an inflammation-dependent manner. In turn, specific microbes co-evolve in inflamed mice, potentially diversifying E. coli colonization patterns. We observed no selectivity in E. coli colonization patterns in the fecal contents, indicating minimal selective pressure in this niche from host-microbe and interbacterial interactions. Because select AIEC and non-AIEC strains colonize the mucosa, this suggests the in vitro AIEC definition may not fully predict in vivo colonization potential. Further comparison of seven E. coli genomes pinpointed unique genomic features contained only in highly colonizing strains (two AIEC and two non-AIEC). Those colonization-associated features may convey metabolic advantages (e.g., iron acquisition and carbohydrate consumption) to promote efficient mucosal colonization. Conclusions Our findings establish the in-vivo mucosal colonizer, not necessarily AIEC, as a principal dysbiosis driver through crosstalk with host and associated microbes. Furthermore, we highlight the utility of high-throughput screens to decode the in-vivo colonization dynamics of patient-derived bacteria in murine models.
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Affiliation(s)
| | - Chuang Li
- University of North Carolina at Chapel Hill
| | - Shan Sun
- University of North Carolina at Charlotte
| | | | | | | | | | - Belgin Dogan
- Cornell University College of Veterinary Medicine
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6
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Maloney SE, Broberg CA, Grayton QE, Picciotti SL, Hall HR, Wallet SM, Maile R, Schoenfisch MH. Role of Nitric Oxide-Releasing Glycosaminoglycans in Wound Healing. ACS Biomater Sci Eng 2022; 8:2537-2552. [PMID: 35580341 DOI: 10.1021/acsbiomaterials.2c00392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Two glycosaminoglycan (GAG) biopolymers, hyaluronic acid (HA) and chondroitin sulfate (CS), were chemically modified via carbodiimide chemistry to facilitate the loading and release of nitric oxide (NO) to develop a multi-action wound healing agent. The resulting NO-releasing GAGs released 0.2-0.9 μmol NO mg-1 GAG into simulated wound fluid with NO-release half-lives ranging from 20 to 110 min. GAGs containing alkylamines with terminal primary amines and displaying intermediate NO-release kinetics exhibited potent, broad spectrum bactericidal action against three strains each of Pseudomonas aeruginosa and Staphylococcus aureus ranging in antibiotic resistance profile. NO loading of the GAGs was also found to decrease murine TLR4 activation, suggesting that the therapeutic exhibits anti-inflammatory mechanisms. In vitro adhesion and proliferation assays utilizing human dermal fibroblasts and human epidermal keratinocytes displayed differences as a function of the GAG backbone, alkylamine identity, and NO-release properties. In combination with antibacterial properties, the adhesion and proliferation profiles of the GAG derivatives enabled the selection of the most promising wound healing candidates for subsequent in vivo studies. A P. aeruginosa-infected murine wound model revealed the benefits of CS over HA as a pro-wound healing NO donor scaffold, with benefits of accelerated wound closure and decreased bacterial burden attributable to both active NO release and the biopolymer backbone.
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Affiliation(s)
- Sara E Maloney
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Christopher A Broberg
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Quincy E Grayton
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Samantha L Picciotti
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Hannah R Hall
- Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Shannon M Wallet
- Division of Oral, Craniofacial, and Health Sciences, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.,Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Robert Maile
- Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.,Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.,North Carolina Jaycee Burn Center Research Laboratory, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mark H Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.,Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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7
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Lopez LR, Barlogio CJ, Broberg CA, Wang J, Arthur JC. A nadA Mutation Confers Nicotinic Acid Auxotrophy in Pro-carcinogenic Intestinal Escherichia coli NC101. Front Microbiol 2021; 12:670005. [PMID: 34149655 PMCID: PMC8207962 DOI: 10.3389/fmicb.2021.670005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/12/2021] [Indexed: 12/12/2022] Open
Abstract
Inflammatory bowel diseases (IBDs) and inflammation-associated colorectal cancer (CRC) are linked to blooms of adherent-invasive Escherichia coli (AIEC) in the intestinal microbiota. AIEC are functionally defined by their ability to adhere/invade epithelial cells and survive/replicate within macrophages. Changes in micronutrient availability can alter AIEC physiology and interactions with host cells. Thus, culturing AIEC for mechanistic investigations often involves precise nutrient formulation. We observed that the pro-inflammatory and pro-carcinogenic AIEC strain NC101 failed to grow in minimal media (MM). We hypothesized that NC101 was unable to synthesize a vital micronutrient normally found in the host gut. Through nutrient supplementation studies, we identified that NC101 is a nicotinic acid (NA) auxotroph. NA auxotrophy was not observed in the other non-toxigenic E. coli or AIEC strains we tested. Sequencing revealed NC101 has a missense mutation in nadA, a gene encoding quinolinate synthase A that is important for de novo nicotinamide adenine dinucleotide (NAD) biosynthesis. Correcting the identified nadA point mutation restored NC101 prototrophy without impacting AIEC function, including motility and AIEC-defining survival in macrophages. Our findings, along with the generation of a prototrophic NC101 strain, will greatly enhance the ability to perform in vitro functional studies that are needed for mechanistic investigations on the role of intestinal E. coli in digestive disease.
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Affiliation(s)
- Lacey R Lopez
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Cassandra J Barlogio
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Christopher A Broberg
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jeremy Wang
- Department of Genetics, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Janelle C Arthur
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Center for Gastrointestinal Biology and Disease, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States.,Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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8
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Kirkpatrick CL, Broberg CA, McCool EN, Lee WJ, Chao A, McConnell EW, Pritchard DA, Hebert M, Fleeman R, Adams J, Jamil A, Madera L, Strömstedt AA, Göransson U, Liu Y, Hoskin DW, Shaw LN, Hicks LM. The "PepSAVI-MS" Pipeline for Natural Product Bioactive Peptide Discovery. Anal Chem 2017; 89:1194-1201. [PMID: 27991763 PMCID: PMC8609470 DOI: 10.1021/acs.analchem.6b03625] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The recent increase in extensively drug-resistant bacterial pathogens and the associated increase of morbidity and mortality demonstrate the immediate need for new antibiotic backbones with novel mechanisms of action. Here, we report the development of the PepSAVI-MS pipeline for bioactive peptide discovery. This highly versatile platform employs mass spectrometry and statistics to identify bioactive peptide targets from complex biological samples. We validate the use of this platform through the successful identification of known bioactive peptides from a botanical species, Viola odorata. Using this pipeline, we have widened the known antimicrobial spectrum for V. odorata cyclotides, including antibacterial activity of cycloviolacin O2 against A. baumannii. We further demonstrate the broad applicability of the platform through the identification of novel anticancer activities for cycloviolacins by their cytotoxicity against ovarian, breast, and prostate cancer cell lines.
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Affiliation(s)
| | | | - Elijah N. McCool
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Woo Jean Lee
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Alex Chao
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Evan W. McConnell
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - David A. Pritchard
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Michael Hebert
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Renee Fleeman
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL
| | - Jessie Adams
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL
| | - Amer Jamil
- Department of Biochemistry, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Laurence Madera
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia
| | - Adam A. Strömstedt
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Ulf Göransson
- Division of Pharmacognosy, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Yufeng Liu
- Department of Statistics and Operations Research, Department of Genetics, Department of Biostatistics, and Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - David W. Hoskin
- Department of Pathology, Dalhousie University, Halifax, Nova Scotia
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL
| | - Leslie M. Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC
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Abstract
Klebsiella pneumoniae is the causative agent of a variety of diseases, including pneumonia, urinary tract infections, septicemia, and the recently recognized pyogenic liver abscesses (PLA). Renewed efforts to identify and understand the bacterial determinants required to cause disease have come about because of the worldwide increase in the isolation of strains resistant to a broad spectrum of antibiotics. The recent increased isolation of carbapenem-resistant strains further reduces the available treatment options. The rapid geographic spread of the resistant isolates and the spread to other pathogens are of particular concern. For many years, the best characterized virulence determinants were capsule, lipopolysaccharide, siderophores, and types 1 and 3 fimbriae. Recent efforts to expand this list include in vivo screens and whole-genome sequencing. However, we still know little about how this bacterium is able to cause disease. Some recent clonal analyses of K. pneumoniae strains indicate that there are distinct clonal groups, some of which may be associated with specific disease syndromes. However, what makes one clonal group more virulent and what changes the disease pattern are not yet clear and remain important questions for the future.
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Affiliation(s)
- Christopher A. Broberg
- Department of Microbiology and Immunology, The University of North Carolina, Chapel Hill125 Mason Farm Road, 6101 Marsico Hall, Chapel Hill, NC 27599-7290USA
| | - Michelle Palacios
- Department of Microbiology and Immunology, The University of North Carolina, Chapel Hill125 Mason Farm Road, 6101 Marsico Hall, Chapel Hill, NC 27599-7290USA
| | - Virginia L. Miller
- Department of Microbiology and Immunology, The University of North Carolina, Chapel Hill125 Mason Farm Road, 6101 Marsico Hall, Chapel Hill, NC 27599-7290USA
- Department of Genetics, The University of North Carolina, Chapel Hill120 Mason Farm Road, 5000D Genetic Medicine Building, CB#7264, Chapel Hill, NC 27599USA
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Zhang L, Krachler AM, Broberg CA, Li Y, Mirzaei H, Gilpin CJ, Orth K. Type III effector VopC mediates invasion for Vibrio species. Cell Rep 2012; 1:453-60. [PMID: 22787576 DOI: 10.1016/j.celrep.2012.04.004] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 03/26/2012] [Accepted: 04/17/2012] [Indexed: 11/30/2022] Open
Abstract
Vibrio spp. are associated with infections caused by contaminated food and water. A type III secretion system (T3SS2) is a shared feature of all clinical isolates of V. parahaemolyticus and some V. cholerae strains. Despite its being responsible for enterotoxicity, no molecular mechanism has been determined for the T3SS2-dependent pathogenicity. Here, we show that although Vibrio spp. are typically thought of as extracellular pathogens, the T3SS2 of Vibrio mediates host cell invasion, vacuole formation, and replication of intracellular bacteria. The catalytically active effector VopC is critical for Vibrio T3SS2-mediated invasion. There are other marine bacteria encoding VopC homologs associated with a T3SS; therefore, we predict that these bacteria are also likely to use T3SS-mediated invasion as part of their pathogenesis mechanisms. These findings suggest a new molecular paradigm for Vibrio pathogenicity and modify our view of the roles of T3SS effectors that are translocated during infection.
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Affiliation(s)
- Lingling Zhang
- Department of Molecular Biology, UT Southwestern Medical Center, Dallas, TX 75390, USA
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11
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Broberg CA, Calder TJ, Orth K. Vibrio parahaemolyticus cell biology and pathogenicity determinants. Microbes Infect 2011; 13:992-1001. [PMID: 21782964 DOI: 10.1016/j.micinf.2011.06.013] [Citation(s) in RCA: 247] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Revised: 06/15/2011] [Accepted: 06/17/2011] [Indexed: 10/18/2022]
Abstract
Vibrio parahaemolyticus is a significant cause of gastroenteritis worldwide. Characterization of this pathogen has revealed a unique repertoire of virulence factors that allow for colonization of the human host and disease. The following describes the known pathogenicity determinants while establishing the need for continued research.
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Affiliation(s)
- Christopher A Broberg
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd, Dallas TX 75390-9148, USA
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12
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Abstract
The post-translational modification AMPylation is emerging as a significant regulatory mechanism in both prokaryotic and eukaryotic biology. This process involves the covalent addition of an adenosine monophosphate to a protein resulting in a modified protein with altered activity. Proteins capable of catalyzing AMPylation, termed AMPylators, are comparable to kinases in that they both hydrolyze ATP and reversibly transfer a part of this primary metabolite to a hydroxyl side chain of the protein substrate. To date, only four AMPylators have been characterized, though many more potential candidates have been identified through amino acid sequence analysis and preliminary in vitro studies. This modification was first discovered over 40 years ago by Earl Stadtman and colleagues through the modification of glutamine synthetase by adenylyl transferase; however research into this mechanism has only just been reenergized by the studies on bacterial effectors. New AMPylators were revealed due to the discovery that a bacterial effector having a conserved Fic domain transfers an AMP group to protein substrates. Current research focuses on identifying and characterizing various types of AMPylators homologous to Fic domains and adenylyl transferase domains and their respective substrates. While all AMPylators characterized thus far are bacterial proteins, the conservation of the Fic domain in eukaryotic organisms suggests that AMPylation is omnipresent in various forms of life and has significant impact on a wide range of regulatory processes.
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Affiliation(s)
- Andrew R Woolery
- Department of Molecular Biology, University of Texas Southwestern Medical Center Dallas, TX, USA
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Broberg CA, Clark DD. Shotgun proteomics of Xanthobacter autotrophicus Py2 reveals proteins specific to growth on propylene. Arch Microbiol 2010; 192:945-57. [DOI: 10.1007/s00203-010-0623-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Accepted: 08/13/2010] [Indexed: 11/28/2022]
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Broberg CA, Zhang L, Gonzalez H, Laskowski-Arce MA, Orth K. A Vibrio effector protein is an inositol phosphatase and disrupts host cell membrane integrity. Science 2010; 329:1660-2. [PMID: 20724587 DOI: 10.1126/science.1192850] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The marine bacterium Vibrio parahaemolyticus causes gastroenteritis in humans and encodes the type III effector protein VPA0450, which contributes to host cell death caused by autophagy, cell rounding, and cell lysis. We found that VPA0450 is an inositol polyphosphate 5-phosphatase that hydrolyzed the D5 phosphate from the plasma membrane phospholipid phosphatidylinositol 4,5-bisphosphate. VPA0450 disrupted cytoskeletal binding sites on the inner surface of membranes of human cells and caused plasma membrane blebbing, which compromised membrane integrity and probably contributed to cell death by facilitating lysis. Thus, bacterial pathogens can disrupt adaptor protein-binding sites required for proper membrane and cytoskeleton dynamics by altering the homeostasis of membrane-bound inositol-signaling molecules.
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Affiliation(s)
- Christopher A Broberg
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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