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Bhatia R, Chang J, Munoz JL, Walker ND. Forging New Therapeutic Targets: Efforts of Tumor Derived Exosomes to Prepare the Pre-Metastatic Niche for Cancer Cell Dissemination and Dormancy. Biomedicines 2023; 11:1614. [PMID: 37371709 PMCID: PMC10295689 DOI: 10.3390/biomedicines11061614] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [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: 03/31/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/29/2023] Open
Abstract
Tumor-derived exosomes play a multifaceted role in preparing the pre-metastatic niche, promoting cancer dissemination, and regulating cancer cell dormancy. A brief review of three types of cells implicated in metastasis and an overview of other types of extracellular vesicles related to metastasis are described. A central focus of this review is on how exosomes influence cancer progression throughout metastatic disease. Exosomes are crucial mediators of intercellular communication by transferring their cargo to recipient cells, modulating their behavior, and promoting tumor pro-gression. First, their functional role in cancer cell dissemination in the peripheral blood by facilitating the establishment of a pro-angiogenic and pro-inflammatory niche is described during organotro-pism and in lymphatic-mediated metastasis. Second, tumor-derived exosomes can transfer molecular signals that induce cell cycle arrest, dormancy, and survival pathways in disseminated cells, promoting a dormant state are reviewed. Third, several studies highlight exosome involvement in maintaining cellular dormancy in the bone marrow endosteum. Finally, the clinical implications of exosomes as biomarkers or diagnostic tools for cancer progression are also outlined. Understanding the complex interplay between tumor-derived exosomes and the pre-metastatic niche is crucial for developing novel therapeutic strategies to target metastasis and prevent cancer recurrence. To that end, several examples of how exosomes or other nanocarriers are used as a drug delivery system to inhibit cancer metastasis are discussed. Strategies are discussed to alter exosome cargo content for better loading capacity or direct cell targeting by integrins. Further, pre-clinical models or Phase I clinical trials implementing exosomes or other nanocarriers to attack metastatic cancer cells are highlighted.
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Affiliation(s)
- Ranvir Bhatia
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Joanna Chang
- Department of Biological Sciences, University of Maryland, Baltimore, MD 21250, USA
| | - Jessian L Munoz
- Division of Perinatal Surgery, Texas Children's Hospital, Houston, TX 77030, USA
- Division of Maternal Fetal Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nykia D Walker
- Department of Biological Sciences, University of Maryland, Baltimore, MD 21250, USA
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2
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Li G, Chen T, Dahlman J, Eniola‐Adefeso L, Ghiran IC, Kurre P, Lam WA, Lang JK, Marbán E, Martín P, Momma S, Moos M, Nelson DJ, Raffai RL, Ren X, Sluijter JPG, Stott SL, Vunjak‐Novakovic G, Walker ND, Wang Z, Witwer KW, Yang PC, Lundberg MS, Ochocinska MJ, Wong R, Zhou G, Chan SY, Das S, Sundd P. Current challenges and future directions for engineering extracellular vesicles for heart, lung, blood and sleep diseases. J Extracell Vesicles 2023; 12:e12305. [PMID: 36775986 PMCID: PMC9923045 DOI: 10.1002/jev2.12305] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/19/2022] [Accepted: 01/09/2022] [Indexed: 02/14/2023] Open
Abstract
Extracellular vesicles (EVs) carry diverse bioactive components including nucleic acids, proteins, lipids and metabolites that play versatile roles in intercellular and interorgan communication. The capability to modulate their stability, tissue-specific targeting and cargo render EVs as promising nanotherapeutics for treating heart, lung, blood and sleep (HLBS) diseases. However, current limitations in large-scale manufacturing of therapeutic-grade EVs, and knowledge gaps in EV biogenesis and heterogeneity pose significant challenges in their clinical application as diagnostics or therapeutics for HLBS diseases. To address these challenges, a strategic workshop with multidisciplinary experts in EV biology and U.S. Food and Drug Administration (USFDA) officials was convened by the National Heart, Lung and Blood Institute. The presentations and discussions were focused on summarizing the current state of science and technology for engineering therapeutic EVs for HLBS diseases, identifying critical knowledge gaps and regulatory challenges and suggesting potential solutions to promulgate translation of therapeutic EVs to the clinic. Benchmarks to meet the critical quality attributes set by the USFDA for other cell-based therapeutics were discussed. Development of novel strategies and approaches for scaling-up EV production and the quality control/quality analysis (QC/QA) of EV-based therapeutics were recognized as the necessary milestones for future investigations.
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Affiliation(s)
- Guoping Li
- Cardiovascular Research CenterMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Tianji Chen
- Department of Pediatrics, College of MedicineUniversity of Illinois at ChicagoChicagoIllinoisUSA
| | - James Dahlman
- Department of Biomedical EngineeringGeorgia Institute of Technology and Emory University School of MedicineAtlantaGeorgiaUSA
| | - Lola Eniola‐Adefeso
- Department of Biomedical EngineeringUniversity of MichiganAnn ArborMichiganUSA
| | - Ionita C. Ghiran
- Department of Anesthesia and Pain MedicineBeth Israel Deaconess Medical Center, and Harvard Medical SchoolBostonMassachusettsUSA
| | - Peter Kurre
- Children's Hospital of Philadelphia, Comprehensive Bone Marrow Failure Center, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Wilbur A. Lam
- Wallace H. Coulter Department of Biomedical Engineering, Department of PediatricsEmory School of MedicineAflac Cancer and Blood Disorders Center of Children's Healthcare of Atlanta, Emory University and Georgia Institute of TechnologyAtlantaGeorgiaUSA
| | - Jennifer K. Lang
- Department of Medicine, Division of Cardiology, Jacobs School of Medicine and Biomedical SciencesVeterans Affairs Western New York Healthcare SystemBuffaloNew YorkUSA
| | - Eduardo Marbán
- Smidt Heart InstituteCedars‐Sinai Medical CenterLos AngelesCaliforniaUSA
| | - Pilar Martín
- Centro Nacional de Investigaciones Cardiovasculares (CNIC)Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV)MadridSpain
| | - Stefan Momma
- Institute of Neurology (Edinger Institute)University HospitalGoethe UniversityFrankfurt am MainGermany
| | - Malcolm Moos
- Division of Cellular and Gene Therapies, Office of Tissues and Advanced Therapies, Center for Biologics Evaluation and ResearchUnited States Food and Drug AdministrationSilver SpringMarylandUSA
| | - Deborah J. Nelson
- Department of Pharmacological and Physiological SciencesThe University of ChicagoChicagoIllinoisUSA
| | - Robert L. Raffai
- Department of Veterans Affairs, Surgical Service (112G)San Francisco VA Medical CenterSan FranciscoCaliforniaUSA
- Department of Surgery, Division of Vascular and Endovascular SurgeryUniversity of CaliforniaSan FranciscoCaliforniaUSA
| | - Xi Ren
- Department of Biomedical EngineeringCarnegie Mellon UniversityPittsburghPennsylvaniaUSA
| | - Joost P. G. Sluijter
- Department of Experimental Cardiology, Circulatory Health LaboratoryRegenerative Medicine Centre, UMC Utrecht, University UtrechtUtrechtThe Netherlands
| | - Shannon L. Stott
- Massachusetts General Hospital Cancer Center and Harvard Medical SchoolBostonMassachusettsUSA
| | - Gordana Vunjak‐Novakovic
- Department of Biomedical Engineering, Department of MedicineColumbia UniversityNew YorkNew YorkUSA
| | - Nykia D. Walker
- Department of Biological SciencesUniversity of Maryland Baltimore CountyBaltimoreMarylandUSA
| | - Zhenjia Wang
- Department of Pharmaceutical Sciences, College of Pharmacy and Pharmaceutical SciencesWashington State UniversitySpokaneWashingtonUSA
| | - Kenneth W. Witwer
- Department of Molecular and Comparative Pathobiology, Department of Neurology and Neurosurgeryand The Richman Family Precision Medicine Center of Excellence in Alzheimer's DiseaseThe Johns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Phillip C. Yang
- Division of Cardiovascular Medicine, Department of MedicineStanford University School of MedicineStanfordCaliforniaUSA
| | - Martha S. Lundberg
- Division of Cardiovascular Sciences, National Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMarylandUSA
| | - Margaret J. Ochocinska
- Division of Blood Diseases and Resources, National Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMarylandUSA
| | - Renee Wong
- Division of Cardiovascular Sciences, National Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMarylandUSA
| | - Guofei Zhou
- Division of Lung Diseases, National Heart, Lung, and Blood InstituteNational Institutes of HealthBethesdaMarylandUSA
| | - Stephen Y. Chan
- Pittsburgh Heart, Lung and Blood Vascular Medicine InstituteUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
- Division of Cardiology and Department of MedicineUniversity of Pittsburgh School of Medicine and University of Pittsburgh Medical CenterPittsburghPennsylvaniaUSA
| | - Saumya Das
- Cardiovascular Research CenterMassachusetts General Hospital and Harvard Medical SchoolBostonMassachusettsUSA
| | - Prithu Sundd
- Pittsburgh Heart, Lung and Blood Vascular Medicine InstituteUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
- Division of Pulmonary Allergy and Critical Care Medicine and Department of MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
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Morin A, Helling BA, Krishnan S, Risner LE, Walker ND, Schwartz NB. Surveying the experience of postdocs in the United States before and during the COVID-19 pandemic. eLife 2022; 11:75705. [PMID: 35880738 PMCID: PMC9322995 DOI: 10.7554/elife.75705] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 07/11/2022] [Indexed: 01/29/2023] Open
Abstract
In the interest of advocating for the postdoctoral community in the United States (US), we compared the results of surveys of postdocs carried out in 2019 and in late 2020. We found that respondents’ mental health and wellness were significantly impacted by the pandemic irrespective of their gender, race, citizenship, or other identities. Career trajectories and progression were also affected, as respondents reported being less confident about achieving career goals, and having more negative perceptions of the job market compared to before the pandemic. Postdocs working in the US on temporary visas reported experiencing increased stress levels due to changes in immigration policy. Access to institutional Postdoctoral Offices or Associations positively impacted well-being and helped mitigate some of the personal and professional stresses caused by the pandemic.
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Affiliation(s)
- Andréanne Morin
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Britney A Helling
- Department of Human Genetics, University of Chicago, Chicago, United States
| | - Seetha Krishnan
- Department of Neurobiology and Institute for Neuroscience, University of Chicago, Chicago, United States
| | - Laurie E Risner
- Department of Pediatrics, University of Chicago, Chicago, United States
| | - Nykia D Walker
- Ben May Department for Cancer Research, University of Chicago, Chicago, United States
| | - Nancy B Schwartz
- Department of Pediatrics and the Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, United States
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Melgar A, Lage CFA, Nedelkov K, Räisänen SE, Stefenoni H, Fetter ME, Chen X, Oh J, Duval S, Kindermann M, Walker ND, Hristov AN. Enteric methane emission, milk production, and composition of dairy cows fed 3-nitrooxypropanol. J Dairy Sci 2020; 104:357-366. [PMID: 33131815 DOI: 10.3168/jds.2020-18908] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/12/2020] [Indexed: 01/07/2023]
Abstract
This study examined the effect of 3-nitrooxypropanol (3-NOP), an investigational substance, on enteric methane emission, milk production, and composition in Holstein dairy cows. Following a 3-wk covariate period, 48 multi- and primiparous cows averaging (± standard deviation) 118 ± 28 d in milk, 43.4 ± 8 kg/d milk yield, and 594 ± 57 kg of body weight were blocked based on days in milk, milk yield, and enteric methane emission and randomly assigned to 1 of 2 treatment groups: (1) control, no 3-NOP, and (2) 3-NOP applied at 60 mg/kg feed dry matter. Inclusion of 3-NOP was through the total mixed ration and fed for 15 consecutive weeks. Cows were housed in a freestall barn equipped with a Calan Broadbent Feeding System (American Calan Inc., Northwood, NH) for monitoring individual dry matter intake and fed ad libitum once daily. Enteric gaseous emissions (methane, carbon dioxide, and hydrogen) were measured using 3 GreenFeed (C-Lock Inc., Rapid City, SD) units. Dry matter intake, cow body weight, and body weight change were not affected by 3-NOP. Compared with the control group, 3-NOP applied at 60 mg/kg feed dry matter decreased daily methane emission, emission yield, and emission intensity by 26, 27, and 29%, respectively. Enteric emission of carbon dioxide was not affected, and hydrogen emission was increased 6-fold by 3-NOP. Administration of 3-NOP had no effect on milk and energy-corrected milk yields and feed efficiency, increased milk fat and milk urea nitrogen concentrations, and increased milk fat yield but had no other effects on milk components. Concentration of C6:0 and C8:0 and the sum of saturated fatty acids in milk fat were increased by 3-NOP. Total trans fatty acids and the sum of polyunsaturated fatty acids were decreased by 3-NOP. In this experiment, 3-NOP decreased enteric methane daily emission, yield, and intensity without affecting dry matter intake and milk yield, but increased milk fat in high-producing dairy cows.
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Affiliation(s)
- A Melgar
- Department of Animal Science, The Pennsylvania State University, University Park 16802
| | - C F A Lage
- Department of Animal Science, The Pennsylvania State University, University Park 16802; Department of Animal Science, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil 31270-901
| | - K Nedelkov
- Department of Animal Science, The Pennsylvania State University, University Park 16802; Department of Animal Husbandry, Faculty of Veterinary Medicine, Trakia University, Stara Zagora 6000, Bulgaria
| | - S E Räisänen
- Department of Animal Science, The Pennsylvania State University, University Park 16802
| | - H Stefenoni
- Department of Animal Science, The Pennsylvania State University, University Park 16802
| | - M E Fetter
- Department of Animal Science, The Pennsylvania State University, University Park 16802
| | - X Chen
- Department of Animal Science, The Pennsylvania State University, University Park 16802; School of Computing, University of Ulster, Co. Antrim, Northern Ireland, BT37 0QB, United Kingdom
| | - J Oh
- Department of Animal Science, The Pennsylvania State University, University Park 16802
| | - S Duval
- Research Centre for Animal Nutrition and Health, DSM Nutritional Products, Saint Louis Cedex 68305, France
| | - M Kindermann
- Department of Animal Nutrition, DSM Nutritional Products, Wurmisweg 576, 4303 Kaiseraugst, Switzerland
| | - N D Walker
- Department of Animal Nutrition, DSM Nutritional Products, Wurmisweg 576, 4303 Kaiseraugst, Switzerland
| | - A N Hristov
- Department of Animal Science, The Pennsylvania State University, University Park 16802.
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Munoz JL, Walker ND, Mareedu S, Pamarthi SH, Sinha G, Greco SJ, Rameshwar P. Cycling Quiescence in Temozolomide Resistant Glioblastoma Cells Is Partly Explained by microRNA-93 and -193-Mediated Decrease of Cyclin D. Front Pharmacol 2019; 10:134. [PMID: 30853911 PMCID: PMC6395452 DOI: 10.3389/fphar.2019.00134] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 02/05/2019] [Indexed: 12/30/2022] Open
Abstract
Glioblastoma multiforme (GBM) is a fatal malignancy of the central nervous system, commonly associated with chemoresistance. The alkylating agent Temozolomide (TMZ) is the front-line chemotherapeutic agent and has undergone intense studies on resistance. These studies reported on mismatch repair gene upregulation, ABC-targeted drug efflux, and cell cycle alterations. The mechanism by which TMZ induces cell cycle arrest has not been well-established. TMZ-resistant GBM cells have been linked to microRNA (miRNA) and exosomes. A cell cycle miRNA array identified distinct miRNAs only in exosomes from TMZ-resistant GBM cell lines and primary spheres. We narrowed the miRs to miR-93 and -193 and showed in computational analyses that they could target Cyclin D1. Since Cyclin D1 is a major regulator of cell cycle progression, we performed cause-effect studies and showed a blunting effects of miR-93 and -193 in Cyclin D1 expression. These two miRs also decreased cell cycling quiescence and induced resistance to TMZ. Taken together, our data provide a mechanism by which GBM cells can exhibit TMZ-induced resistance through miRNA targeting of Cyclin D1. The data provide a number of therapeutic approaches to reverse chemoresistance at the miRNA, exosomal and cell cycle points.
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Affiliation(s)
- Jessian L Munoz
- Rutgers New Jersey Medical School, Rutgers University, Newark, NJ, United States.,Rutgers School of Graduate Studies at New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Nykia D Walker
- Rutgers School of Graduate Studies at New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Satvik Mareedu
- Rutgers New Jersey Medical School, Rutgers University, Newark, NJ, United States.,Rutgers School of Graduate Studies at New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Sri Harika Pamarthi
- Rutgers New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Garima Sinha
- Rutgers New Jersey Medical School, Rutgers University, Newark, NJ, United States.,Rutgers School of Graduate Studies at New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Steven J Greco
- Rutgers New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Pranela Rameshwar
- Rutgers New Jersey Medical School, Rutgers University, Newark, NJ, United States.,Rutgers School of Graduate Studies at New Jersey Medical School, Rutgers University, Newark, NJ, United States
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6
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Walker ND, Mourad Y, Liu K, Buxhoeveden M, Schoenberg C, Eloy JD, Wilson DJ, Brown LG, Botea A, Chaudhry F, Greco SJ, Ponzio NM, Pyrsopoulos N, Koneru B, Gubenko Y, Rameshwar P. Steroid-Mediated Decrease in Blood Mesenchymal Stem Cells in Liver Transplant could Impact Long-Term Recovery. Stem Cell Rev Rep 2018; 13:644-658. [PMID: 28733800 DOI: 10.1007/s12015-017-9751-3] [Citation(s) in RCA: 3] [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: 12/15/2022]
Abstract
Orthotopic liver transplant (OLT) remains the standard of care for end stage liver disease. To circumvent allo-rejection, OLT subjects receive gluococorticoids (GC). We investigated the effects of GC on endogenous mesenchymal stem (stromal) cells (MSCs) in OLT. This question is relevant because MSCs have regenerative potential and immune suppressor function. Phenotypic analyses of blood samples from 12 OLT recipients, at pre-anhepatic, anhepatic and post-transplant (2 h, Days 1 and 5) indicated a significant decrease in MSCs after GC injection. The MSCs showed better recovery in the blood from subjects who started with relatively low MSCs as compared to those with high levels at the prehepatic phase. This drop in MSCs appeared to be linked to GC since similar change was not observed in liver resection subjects. In order to understand the effects of GC on decrease MSC migration, in vitro studies were performed in transwell cultures. Untreated MSCs could not migrate towards the GC-exposed liver tissue, despite CXCR4 expression and the production of inflammatory cytokines from the liver cells. GC-treated MSCs were inefficient with respect to migration towards CXCL12, and this correlated with retracted cytoskeleton and motility. These dysfunctions were partly explained by decreases in the CXCL12/receptor axis. GC-associated decrease in MSCs in OLT recipients recovered post-transplant, despite poor migratory ability towards GC-exposed liver. In total, the study indicated that GC usage in transplant needs to be examined to determine if this could be reduced or avoided with adjuvant cell therapy.
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Affiliation(s)
- Nykia D Walker
- Department of Medicine, Division of Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA.,Rutgers Graduate School of Biomedical Sciences, Newark, NJ, USA
| | - Yasmine Mourad
- Rutgers Graduate School of Biomedical Sciences, Newark, NJ, USA
| | - Katherine Liu
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Michael Buxhoeveden
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Catherine Schoenberg
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Jean D Eloy
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Dorian J Wilson
- Department of Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Lloyd G Brown
- Department of Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Andrei Botea
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Faraz Chaudhry
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Steven J Greco
- Department of Medicine, Division of Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Nicholas M Ponzio
- Department of Pathology and Laboratory Medicine, Rutgers, New Jersey Medical School, Newark, NJ, USA
| | - Nikolaos Pyrsopoulos
- Department of Medicine, Division of Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Baburao Koneru
- Department of Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Yuriy Gubenko
- Department of Anesthesiology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA.
| | - Pranela Rameshwar
- Department of Medicine, Division of Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA. .,Rutgers Graduate School of Biomedical Sciences, Newark, NJ, USA.
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7
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Basch CH, Yin J, Walker ND, de Leon AJ, Fung ICH. TMJ online: Investigating temporomandibular disorders as "TMJ" on YouTube. J Oral Rehabil 2017; 45:34-40. [PMID: 28965355 DOI: 10.1111/joor.12580] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2017] [Indexed: 11/26/2022]
Abstract
As the understanding of temporomandibular disorders' (TMDs) aetiologies and treatments develops from non-evidence-based to evidence-based approaches, the availability of sound information will likewise grow and need to be disseminated. The purpose of this study is to describe the content most commonly viewed in YouTube videos related to TMDs or "TMJ" and see whether videos from different sources have different content. Video information was gathered by searching YouTube for the term "TMJ," and data were recorded related to descriptive information as well as content. Statistical analyses included Kruskal-Wallis H Test, Spearman's Rho and univariate logistic regression. The sources of upload were Consumer (n = 62), Professional (n = 29) and News (n = 9). There were almost no statistically significant differences in content distribution among video sources. Videos garnered a total of 4 749 360 views, with an overall median of 7014.5 views. About two-thirds of the videos (68/100) explained what "TMJ" is, with a surprising third of Professional videos (9/29) not covering the subject. Roughly half of the videos mentioned at least one reason "TMJ" occurs (55/100), and seven in ten mentioned some kind of treatment (70/100). Video names mentioned a cure or treatment in 64 cases, while the other 36 referred to TMJ anatomy or "TMJ" aetiology. Future research should focus on ways to popularise professional videos with reliable information for those who are searching on YouTube for advice related to "TMJ."
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Affiliation(s)
- C H Basch
- Department of Public Health, William Paterson University, Wayne, NJ, USA
| | - J Yin
- Department of Biostatistics, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA, USA
| | - N D Walker
- Department of Biostatistics, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA, USA
| | - A J de Leon
- Department of Public Health, William Paterson University, Wayne, NJ, USA
| | - I C-H Fung
- Department of Epidemiology & Environmental Health Sciences, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA, USA
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He ZX, Walker ND, McAllister TA, Yang WZ. Effect of wheat dried distillers grains with solubles and fibrolytic enzymes on ruminal fermentation, digestibility, growth performance, and feeding behavior of beef cattle. J Anim Sci 2016; 93:1218-28. [PMID: 26020898 DOI: 10.2527/jas.2014-8412] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Two experiments were conducted to evaluate the effect of wheat dried distillers grains with solubles (DDGS) and fibrolytic enzymes (FE) on ruminal fermentation, in situ ruminal and in vivo total tract digestibility, growth performance, and feeding behavior of growing beef cattle. In Exp. 1, 6 ruminally cannulated Angus heifers (average BW of 794 ± 44.2 kg) were used in a 6 × 6 Latin square design with 2 × 3 factorial arrangement of treatments. Treatments were a control diet consisting of 50% barley silage, 10% grass hay, and 40% barley grain-based concentrate (CON) and the CON with 15% DDGS substituted for barley grain (WDG) combined with either 0, 1, or 2 mL FE/kg diet DM, respectively. Inclusion of DDGS increased total tract digestibility of CP ( < 0.01), NDF ( = 0.04), and ADF ( = 0.03). Increasing FE linearly ( = 0.03) increased CP digestibility without affecting the digestibility of other nutrients. There were no effects of DDGS inclusion or FE on ruminal pH or VFA concentration except that propionate was greater ( = 0.04) with the WDG. In situ ruminal DM and NDF disappearance of barley silage was greater ( < 0.04) in heifers fed the WDG than in heifers fed the CON after 24 h of incubation. Increasing FE linearly ( = 0.03) increased in situ NDF disappearance of barley silage after 24 h of incubation. In Exp. 2, 120 weaned steers (initial BW of 289 ± 11.0 kg) were fed diets similar to those in Exp. 1. The steers fed the WDG had greater ( < 0.01) final BW, ADG, DMI, and G:F compared with steers fed the CON. Increasing FE did not alter ADG or G:F but tended ( < 0.07) to linearly decrease DMI. There were interactions ( < 0.02) between DDGS and FE on eating rate and the time spent at the feed bunk. Supplementing FE decreased ( < 0.01) time at the bunk and increased ( < 0.01) eating rate for steers fed the WDG but not for steers fed the CON. Eating rate ( < 0.01) and meal frequency ( = 0.02) were greater but eating duration was shorter ( < 0.01) for steers fed the WDG than for those fed the CON. These results indicate that inclusion of wheat DDGS in a growing diet increased total tract digestibility of NDF and CP and improved the feed efficiency of steers. Moreover, supplementation of FE in barley silage-based growing diets may also have the potential to increase profits, with the evidence of the trend for a decline on DMI without decreasing ADG when adding FE.
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Walker ND, Elias M, Greco S, Rameshwar P. Abstract A42: The role of M1 and M2 macrophage in the cycling phase of breast cancer. Cancer Res 2016. [DOI: 10.1158/1538-7445.tummet15-a42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Breast cancer malignancy is the second leading cause of death among women. The majority of deaths associated with cancer, from solid tumors are the result of metastasis and not from the primary tumor site Clinical evidence indicates that breast cancer (BC) cells (BCC) can exist in dormancy within the bone marrow (BM), for >10 years. Methods by which BCCs adapt dormancy as well as reversed dormancy into metastatic cells are highly significant for the development of new and safe therapies. This research focuses on the BM because it is the preferred organ for dormant BCCs. Furthermore, in several cases, the BM has been identified as a source of BCCs during clinical resurgence. A subset of BCCs with tumor initiating property (cancer stem cells, CSCs) has been identified as those responsible for dormancy and chemoresistance. We will take advantage of our working hierarchy of BCCs to determine how M2 macrophage (MΦ) facilitates dormancy or clinical resurgence into metastatic cells. The mechanisms by which dormancy occurs followed by later resurgence into metastatic role for the BM microenvironment to facilitate CSC dormancy. CSCs can form gap junctional intercellular communication (GJIC) with stroma, by release of miRNA, which induces cycling quiescence. MΦ are classified into two subsets, either M1 or M2 type. M1 are mostly pro-inflammatory (classically activated to kill microorganisms and tumor cells), while M2 are non-inflammatory (alternatively activated to promote tissue repair). M2 MΦ is one cell type that comprises the stromal compartment inside the BM hematopoietic microenvironment. We studied how activated MSCs can influence M1 or M2 polarization. Our supporting studies indicate that M2 MΦ can arrest BCCs in G1/G0, while M1 MΦ can induce cell cycle progression. Activated MSCs transitioned M2 into M1 phenotype whereas inactivated MSCs maintains M2 MΦ phenotype. Here we present how the transitional changes in M2 to M1 MΦ affect the behavior of the CSCs within the BM stromal compartment.
Citation Format: Nykia D. Walker, Michael Elias, Steve Greco, Pranela Rameshwar. The role of M1 and M2 macrophage in the cycling phase of breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Metastasis; 2015 Nov 30-Dec 3; Austin, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(7 Suppl):Abstract nr A42.
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Nahas GR, Sinha GA, Sherman LS, Walker ND, Rameshwar P. Abstract P1-06-07: Msi1 in maintaining breast cancer stem cell involves the AKT/PI3K pathway. Cancer Res 2016. [DOI: 10.1158/1538-7445.sabcs15-p1-06-07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Musashi1 (Msi1) was originally described in neural stem cells in a role influencing neural differentiation in the Numb/Notch pathway. Due to its role in neural stem cells, there has been much interest in the role of Msi1 in the breast cancer (BC) stem cell population. In this vein, with we have demonstrated a possible feedback loop between the stem cell marker OCT4 and Msi1, in addition to other stem cell-associated genes. Flow cytometry analyses demonstrated that the subset of BC cells (BCCs) that we previously identified as those with high Oct4 was also enriched for Msi1. Msi1 knockdown BCCs showed decreased doubling time and with limited ability to be passaged, indicating the loss of the self-renewal subset needed for cell passaging. These in vitro findings were consistent with the inability of the Msi1 knockdown BCCs to undergo serial passages in vivo. We therefore examined the Msi1 knockdown BCCs for intracellular proteins that could explain the reduced cell growth and the reduced initiating cells. We selected the AKT/PI3K pathway due to its recent connection to the maintenance of BC stem cells. Msi1 knockdown repressed several molecules within the AKT/PI3K pathway: PTEN, AKT, and PI3K. There were no significant differences found however, in the apoptotic factors, BCL-2 and Caspase-3. Upon further investigation, we observed increases in molecules that are linked to decreased cell proliferation and senescence, p16, p53 and p21. Since Msi1 is an RNA binding protein, it is possible that its loss could leave RNAs for binding to miRNAs and this might be partly responsible for the decrease in key intracellular molecules needed for the survival and proliferation of the Msi1 knockdown BCCs. Further studies are needed to investigate how miRNAs and Msi1 interact to maintain the survival of BCCs. Finally, Msi1 KD positively affects the expression of the immune checkpoint inhibitor PD-1L, suggesting increased PD-1L expression in cells that are not of the CSC phenotype. The studies may identify Msi1 or its associated molecules as a potential therapeutic intervention for BC.
Citation Format: Nahas GR, Sinha GA, Sherman LS, Walker ND, Rameshwar P. Msi1 in maintaining breast cancer stem cell involves the AKT/PI3K pathway. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-06-07.
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Affiliation(s)
- GR Nahas
- Rutgers University-Graduate School of Biomedical Sciences, Newark, NJ
| | - GA Sinha
- Rutgers University-Graduate School of Biomedical Sciences, Newark, NJ
| | - LS Sherman
- Rutgers University-Graduate School of Biomedical Sciences, Newark, NJ
| | - ND Walker
- Rutgers University-Graduate School of Biomedical Sciences, Newark, NJ
| | - P Rameshwar
- Rutgers University-Graduate School of Biomedical Sciences, Newark, NJ
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Walker ND, Patel J, Munoz JL, Hu M, Guiro K, Sinha G, Rameshwar P. The bone marrow niche in support of breast cancer dormancy. Cancer Lett 2015; 380:263-71. [PMID: 26546045 DOI: 10.1016/j.canlet.2015.10.033] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 10/13/2015] [Accepted: 10/27/2015] [Indexed: 12/15/2022]
Abstract
Despite the success in detecting breast cancer (BC) early and, with aggressive therapeutic intervention, BC remains a clinical problem. The bone marrow (BM) is a favorable metastatic site for breast cancer cells (BCCs). In BM, the survival of BCCs is partly achieved by the supporting microenvironment, including the presence of immune suppressive cells such as mesenchymal stem cells (MSCs). The heterogeneity of BCCs brings up the question of how each subset interacts with the BM microenvironment. The cancer stem cells (CSCs) survive in the BM as cycling quiescence cells and, forming gap junctional intercellular communication (GJIC) with the hematopoietic supporting stromal cells and MSCs. This type of communication has been identified close to the endosteum. Additionally, dormancy can occur by soluble mediators such as cytokines and also by the exchange of exosomes. These latter mechanisms are reviewed in the context of metastasis of BC to the BM for transition as dormant cells. The article also discusses how immune cells such as macrophages and regulatory T-cells facilitate BC dormancy. The challenges of studying BC dormancy in 2-dimensional (2-D) system are also incorporated by proposing 3-D system by engineering methods to recapitulate the BM microenvironment.
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Affiliation(s)
- Nykia D Walker
- Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA; Graduate School of Biomedical Sciences at New Jersey Medical School, Newark, NJ, USA
| | - Jimmy Patel
- Graduate School of Biomedical Sciences at New Jersey Medical School, Newark, NJ, USA
| | - Jessian L Munoz
- Ob/Gyn and Women's Health Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Madeleine Hu
- Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA; Graduate School of Biomedical Sciences at New Jersey Medical School, Newark, NJ, USA
| | - Khadidiatou Guiro
- Graduate School of Biomedical Sciences at New Jersey Medical School, Newark, NJ, USA
| | - Garima Sinha
- Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA; Graduate School of Biomedical Sciences at New Jersey Medical School, Newark, NJ, USA
| | - Pranela Rameshwar
- Department of Medicine, Rutgers New Jersey Medical School, Newark, NJ, USA; Graduate School of Biomedical Sciences at New Jersey Medical School, Newark, NJ, USA.
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Nahas GR, Walker ND, Bryan M, Rameshwar P. A Perspective of Immunotherapy for Breast Cancer: Lessons Learned and Forward Directions for All Cancers. Breast Cancer (Auckl) 2015; 9:35-43. [PMID: 26568682 PMCID: PMC4631157 DOI: 10.4137/bcbcr.s29425] [Citation(s) in RCA: 3] [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] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 07/09/2015] [Accepted: 07/12/2015] [Indexed: 12/14/2022]
Abstract
Immunotherapy for cancer has been a focus 50 years ago. At the time, this treatment was developed prior to cloning of the cytokines, no knowledge of regulatory T-cells, and very little information that mesenchymal stem cells (MSCs) (originally colony forming unit-fibroblasts [CFU-F]) could be licensed by the inflammatory microenvironment to suppress an immune response. Given the information available at that time, mononuclear cells from the peripheral blood were activated ex vivo and then replaced in the patients with tumor. The intent was to harness these activated immune cells to target the cancer cells. These studies did not lead to long-term responses because the activated cells when reinfused into the patients were an advantage to the resident MSCs, which can home the tumor and then become suppressive in the presence of the immune cells. The immune suppression caused by MSCs would also expand regulatory T-cells, resulting instead in tumor protection. As time progressed, these different fields converged into a new approach to use immunotherapy for cancer. This article discusses these approaches and also reviews chimeric antigen receptor in the context of future treatments for solid tumors, including breast cancer.
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Affiliation(s)
| | - Nykia D Walker
- Rutgers New Jersey Medical School, Newark, NJ, USA. ; Rutgers Graduate School of Biomedical Sciences, Newark, NJ, USA
| | | | - Pranela Rameshwar
- Rutgers New Jersey Medical School, Newark, NJ, USA. ; Rutgers Graduate School of Biomedical Sciences, Newark, NJ, USA
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Munoz JL, Walker ND, Scotto KW, Rameshwar P. Temozolomide competes for P-glycoprotein and contributes to chemoresistance in glioblastoma cells. Cancer Lett 2015. [PMID: 26208431 DOI: 10.1016/j.canlet.2015.07.013] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Chemotherapeutic resistance can occur by P-glycoprotein (P-gp), a 12-transmembrane ATP-dependent drug efflux pump. Glioblastoma (GBM) has poor survival rate and uniformly acquired chemoresistance to its frontline agent, Temozolomide (TMZ). Despite much effort, overcoming TMZ resistance remains a challenge. We reported on autonomous induction of TMZ resistance by increased transcription MDR1, the gene for P-gp. This study investigated how P-gp and TMZ interact to gain resistance. Using an experimental model of Adriamycin-resistant DC3F cells (DC3F/Adx), we showed that increased P-gp caused TMZ resistance. Increasing concentrations of TMZ competed with Calcein for P-gp, resulting in reduced efflux in the DC3F/Adx cells. Three different inhibitors of P-gp reversed the resistance to TMZ in two different GBM cell lines, by increasing active Caspase 3. Molecular modeling predicted the binding sites to be the intracellular region of P-gp and also identified specific amino acids and kinetics of energy for the efflux of TMZ. Taken together, we confirmed P-gp targeting of TMZ, a crucial regulator of TMZ resistance in GBM. This study provides insights on the effectiveness by which TMZ competes with other P-gp substrates, thereby opening the door for combined targeted therapies.
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Abstract
Chemotherapy with Temozolomide (TMZ), radiation and surgery are the primary methods to treat Glioblastoma Multiforme (GBM), the most common adult intracranial tumor with dismal outcome. GBM resistance to therapy is the main reason of poor patient outcomes. Thus, methods to overcome the resistance are an area of extensive research. This highlight focuses on three recently published articles on the mechanism of resistance and possible therapeutic intervention, including RNA treatment with stem cells. We showed a crucial role of the developmental Sonic Hedgehog (SHH) pathway in the acquisition and maintenance of TMZ resistance. SHH signaling caused TMZ resistance in GBM cells through an increase in the multiple drug resistance gene (MDR1). The SHH receptor, Patched-1 (PTCH1), negatively regulate SHH signaling. In GBM, miR-9 suppressed PTCH1 levels, resulting in the activation of SHH pathway. Thus, SHH signaling is independent of the ligand in resistant GBM cells. MiR-9 was also increased in chemoresistance CD133+ GBM cells. A potential method to reverse resistance was tested by delivering the anti-miR in bone marrow-derived Mesenchymal Stem Cells (MSCs). The anti-miR-9 was transferred into the resistant GBM cells through exosomes and gap junctional intercellular communication. We also review on-going clinical trials with inhibitor of SHH signaling, and also discuss drug delivery by cell therapy for GBM. While GBM treatment has proven to be a challenge, there are a number of novel approaches we are currently developing to manage this malignancy.
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Affiliation(s)
- Jessian L Munoz
- Department of Medicine-Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Vivian Rodriguez-Cruz
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences-SUNY University of Buffalo, Buffalo, NY, USA
| | - Nykia D Walker
- Department of Medicine-Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, USA; Rutgers Graduate School of Biomedical Sciences, Newark, NJ, USA
| | - Steven J Greco
- Department of Medicine-Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - Pranela Rameshwar
- Department of Medicine-Hematology/Oncology, Rutgers New Jersey Medical School, Newark, NJ, USA; Rutgers Graduate School of Biomedical Sciences, Newark, NJ, USA
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He ZX, He ML, Walker ND, McAllister TA, Yang WZ. Using a fibrolytic enzyme in barley-based diets containing wheat dried distillers grains with solubles: ruminal fermentation, digestibility, and growth performance of feedlot steers. J Anim Sci 2014; 92:3978-87. [PMID: 24987082 DOI: 10.2527/jas.2014-7707] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [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: 11/13/2022] Open
Abstract
Two experiments were conducted to evaluate the effects of adding an exogenous fibrolytic enzyme (FE) on ruminal pH and fermentation, digestibility, and growth performance of feedlot beef cattle fed a finishing diet containing wheat dried distillers grains with solubles (DDGS). In Exp. 1, 4 ruminally cannulated Angus heifers (average BW of 807 ± 93.9 kg) were used in a replicated 4 × 4 Latin square design. Treatments were 1) control (CON; 10% barley silage and 90% barley grain-based concentrate), 2) CON diet substituting 30% wheat DDGS for barley grain (WDG), 3) WDG diet supplemented with low FE (WDGL), and 4) WDG diet supplemented with high FE (WDGH). Heifers fed WDG had less (P = 0.01) total tract DM digestibility than heifers fed CON. Increasing FE linearly (P < 0.05) increased starch digestibility without affecting digestibility of other nutrients. Addition of FE also reduced (P = 0.03) ruminal ammonia-N (NH3-N) concentration but did not affect VFA concentration. Moreover, application of FE to wheat DDGS linearly increased in situ ruminal DM (P < 0.01) and NDF (P = 0.02) disappearance after 48 h of incubation. In Exp. 2, 160 yearling steers (initial BW = 495 ± 37.9 kg) were fed the same diets as in Exp. 1. No differences in DMI, final BW, ADG, dietary NEg, or carcass characteristics were observed among diets. However, the steers fed WDG had less (P < 0.05) G:F and greater number of (P < 0.01) abscessed livers than steers fed CON. Increasing FE application in wheat DDGS diets did not affect DMI, final BW, or ADG but tended (P < 0.09) to linearly improve feed efficiency and decreased (P = 0.03) the incidence of abscessed livers. These results demonstrated adverse effects of including wheat DDGS in finishing diets on feed digestion, feed efficiency, and animal health. Application of FE in wheat DDGS-based diets potentially improved starch digestion, protein metabolism in the rumen, feed efficiency, and animal health.
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Affiliation(s)
- Z X He
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta T1J 4B1, Canada Key Laboratory for Agro-Ecological Processes in Subtropical Region, Hunan Research Center of Livestock & Poultry Sciences, South-Central Experimental Station of Animal Nutrition and Feed Science in Ministry of Agriculture, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, Hunan 410125, China
| | - M L He
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta T1J 4B1, Canada
| | - N D Walker
- AB Vista Feed Ingredients, Marlborough, Wiltshire SN8 4AN, UK
| | - T A McAllister
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta T1J 4B1, Canada
| | - W Z Yang
- Lethbridge Research Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta T1J 4B1, Canada
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Vyas D, Uwizeye A, Mohammed R, Yang WZ, Walker ND, Beauchemin KA. The effects of active dried and killed dried yeast on subacute ruminal acidosis, ruminal fermentation, and nutrient digestibility in beef heifers. J Anim Sci 2014; 92:724-32. [PMID: 24398831 DOI: 10.2527/jas.2013-7072] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [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 study addressed the importance of yeast (Saccharomyces cerevisiae) viability for reducing the incidence of subacute ruminal acidosis (SARA) and improving total tract nutrient digestibility in beef heifers. Six ruminally cannulated beef heifers (680 ± 50 kg BW) were used in a replicated 3 × 3 Latin square design and were fed a diet consisting of 40% barley silage, 10% chopped grass hay, and 50% barley grain-based concentrate (DM basis). Treatments were 1) no yeast (Control), 2) active dried yeast (ADY; 4 g providing 10(10) cfu/g; AB Vista, Marlborough, UK), and 3) killed dried yeast (KDY; 4 g autoclaved ADY). The treatments were directly dosed via the ruminal cannula daily at the time of feeding. The periods consisted of 2 wk of adaptation (d 1 to 14) and 7 d of measurements (d 15 to 21). Ruminal pH was continuously measured (d 15 to 21) using an indwelling system. Ruminal contents were sampled on d 15 and 17 at 0, 3, 6, 9, and 12 h after feeding. Total tract nutrient digestibility was measured using an external marker (YbCl3) from d 15 to 19. No treatment difference was observed for DMI (P = 0.86). Yeast supplementation (ADY and KDY) tended to increase total tract digestibility of starch (P = 0.07) whereas no effects were observed on digestibility of other nutrients. Both ADY and KDY elevated minimum (P < 0.01) and mean ruminal pH (P = 0.02) whereas no effects were observed on maximum pH (P = 0.12). Irrespective of its viability, yeast supplementation was effective in reducing time that ruminal pH was below 5.8 (P < 0.01) and 5.6 (P < 0.01). No treatment differences were observed for the ruminal VFA profile and lactate concentration. No treatment differences were observed on the relative population size of Streptococcus bovis, Fibrobacter succinogenes, and Megasphaera elsdenii (P > 0.10); however, the proportion of Ruminococcus flavefaciens in solid fraction of digesta was greater with KDY (P = 0.05). The study demonstrates the positive effects of yeast, irrespective of its viability, in reducing the severity of SARA. However, further studies are required to evaluate the importance of yeast viability for other dietary conditions, particularly when the risk of acidosis is high.
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Affiliation(s)
- D Vyas
- Agriculture and Agri-Food Canada, Lethbridge Research Center, Lethbridge, AB T1J 4B1, Canada
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Wang W, Walker ND, Zhu LJ, Wu W, Ge L, Gutstein DE, Yates NA, Hendrickson RC, Ogletree ML, Cleary M, Opiteck GJ, Chen Z. Quantification of circulating D-dimer by peptide immunoaffinity enrichment and tandem mass spectrometry. Anal Chem 2012; 84:6891-8. [PMID: 22788854 DOI: 10.1021/ac301494d] [Citation(s) in RCA: 17] [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: 11/28/2022]
Abstract
D-dimer is a product of the coagulation cascade and is associated with venous thromboembolism, disseminated intravascular coagulation, and additional clinical conditions. Despite its importance, D-dimer measurement has limited clinical utility due in part to the lack of reliable assays. The difficulty in developing an immunoassay that is specific for D-dimer arises from the inherent heterogeneity in its structure. In this report, we describe a highly specific method for the quantification of D-dimer level in human plasma. In our method, the reciprocally cross-linked peptide resulting from factor XIIIa-catalyzed dimerization of fibrin γ chains was selected to represent the D-dimer antigen. Using an antipeptide antibody, we enriched the cross-linked peptide from trypsin-digested plasma prior to quantitative analysis with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The assay has a quantitative range of 500 pmol/L to 100 nmol/L in human plasma. In further characterization of the assay, we found that it exhibited good correlation with fibrinolytic activity in human donors and with thrombin generation and clot strength in an in vitro thromboelastography assay. These observations thus establish the biological relevance of the assay and suggest it may be a valuable biomarker in characterization and treatment of blood coagulation disorders.
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Affiliation(s)
- Weixun Wang
- Department of Molecular Biomarkers, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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Conway JP, Johns DG, Wang SP, Walker ND, McAvoy TA, Zhou H, Zhao X, Previs SF, Roddy TP, Hubbard BK, Yates NA, Hendrickson RC. Measuring H218O Tracer Incorporation on a QQQ-MS Platform Provides a Rapid, Transferable Screening Tool for Relative Protein Synthesis. J Proteome Res 2012; 11:1591-7. [DOI: 10.1021/pr2007494] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- James P. Conway
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Douglas G. Johns
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Sheng-Ping Wang
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Nykia D. Walker
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Thomas A. McAvoy
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Haihong Zhou
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Xuemei Zhao
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Stephen F. Previs
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Thomas P. Roddy
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Brian K. Hubbard
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Nathan A. Yates
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
| | - Ronald C. Hendrickson
- Merck Research Laboratories, 126 East Lincoln Avenue, Rahway, New Jersey
07065, United States
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Chung YH, Walker ND, McGinn SM, Beauchemin KA. Differing effects of 2 active dried yeast (Saccharomyces cerevisiae) strains on ruminal acidosis and methane production in nonlactating dairy cows. J Dairy Sci 2011; 94:2431-9. [PMID: 21524535 DOI: 10.3168/jds.2010-3277] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 12/16/2010] [Indexed: 11/19/2022]
Abstract
Fifteen ruminally cannulated, nonlactating Holstein cows were used to measure the effects of 2 strains of Saccharomyces cerevisiae, fed as active dried yeasts, on ruminal pH and fermentation and enteric methane (CH(4)) emissions. Nonlactating cows were blocked by total duration (h) that their ruminal pH was below 5.8 during a 6-d pre-experimental period. Within each block, cows were randomly assigned to control (no yeast), yeast strain 1 (Levucell SC), or yeast strain 2 (a novel strain selected for enhanced in vitro fiber degradation), with both strains (Lallemand Animal Nutrition, Montréal, QC, Canada) providing 1 × 10(10) cfu/head per day. Cows were fed once daily a total mixed ration consisting of a 50:50 forage to concentrate ratio (dry matter basis). The yeast strains were dosed via the rumen cannula daily at the time of feeding. During the 35-d experiment, ruminal pH was measured continuously for 7 d (d 22 to 28) by using an indwelling system, and CH(4) gas was measured for 4 d (d 32 to 35) using the sulfur hexafluoride tracer gas technique (with halters and yokes). Rumen contents were sampled on 2 d (d 22 and 26) at 0, 3, and 6h after feeding. Dry matter intake, body weight, and apparent total-tract digestibility of nutrients were not affected by yeast feeding. Strain 2 decreased the average daily minimum (5.35 vs. 5.65 or 5.66), mean (5.98 vs. 6.24 or 6.34), and maximum ruminal pH (6.71 vs. 6.86 or 6.86), and prolonged the time that ruminal pH was below 5.8 (7.5 vs. 3.3 or 1.0 h/d) compared with the control or strain 1, respectively. The molar percentage of acetate was lower and that of propionate was greater in the ruminal fluid of cows receiving strain 2 compared with cows receiving no yeast or strain 1. Enteric CH(4) production adjusted for intake of dry matter or gross energy, however, did not differ between either yeast strain compared with the control but it tended to be reduced by 10% when strain 2 was compared with strain 1. The study shows that different strains of S. cerevisiae fed as active dried yeasts vary in their ability to modify the rumen fermentative pattern in nonlactating dairy cows. Because strain 2 tended (when compared with strain 1) to lower CH(4) emissions but increase the risk of acidosis, it may be prudent to further evaluate this strain in cattle fed high-forage diets, for which the risk of acidosis is low but CH(4) emissions are high.
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Affiliation(s)
- Y-H Chung
- Agriculture and Agri-Food Canada, Research Center, Lethbridge, AB, T1J 4B1, Canada
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White JR, Fulweiler RW, Li CY, Bargu S, Walker ND, Twilley RR, Green SE. Mississippi River flood of 2008: observations of a large freshwater diversion on physical, chemical, and biological characteristics of a shallow estuarine lake. Environ Sci Technol 2009; 43:5599-5604. [PMID: 19731650 DOI: 10.1021/es900318t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
High nitrogen (N) loading to coastal aquatic systems can be expressed as increased algal production and subsequent low dissolved oxygen. In April, 2008, predictions for extreme flood stage for the Lower Mississippi River triggered the opening of the Bonnet Carré Spillway, a major release valve for the river. The spillway diverted approximately 8 km3 of water over one month of operation into Lake Pontchartrain with a concomitant 10000 t of NO3-N. Satellite imagery, physical, water quality, and chlorophyll a (chl a) measurements show that the Mississippi River plume mixed with < 40% of the lake during this time, and much of the nutrient load was transported to the coastal ocean. Nitrate, dissolved reactive phosphorus (P), and dissolved silica (Si) concentrations were 4.8, 5.0, and 3.2 times higher, respectively, within the river plume when compared with those of the lake water. Despite the high nutrient concentrations within the river plume, phytoplankton biomass, evidenced by chl a concentrations, was low. Much of the nutrient load appeared to bypass the lake and was transported to the coastal ocean during the opening of the diversion. The potential removal of a total of 7.6% of the N load from the Mississippi River during the one month of flood level flow may have been a contributing factor in the lower than predicted hypoxia zone off the Louisiana coast during the summer of 2008.
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Affiliation(s)
- J R White
- Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
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Wallace RJ, McKain N, Broderick GA, Rode LM, Walker ND, Newbold CJ, Kopecny J. Peptidases of the rumen bacterium, Prevotella ruminicola. Anaerobe 2007; 3:35-42. [PMID: 16887560 DOI: 10.1006/anae.1996.0065] [Citation(s) in RCA: 57] [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: 06/14/1996] [Accepted: 11/20/1996] [Indexed: 11/22/2022]
Abstract
Prevotella (formerly Bacteroides) ruminicola is a numerous rumen bacterium which plays a significant role in the metabolism of proteins and peptides in the rumen. Measurement of the hydrolysis of synthetic aminopeptidase substrates by sonicated extracts and whole cells of different species of rumen bacteria indicated that P. ruminicola had the greatest range and specific activity of dipeptidyl peptidases among the species tested. Streptococcus bovis hydrolysed some dipeptidyl peptidase substrates to a lesser extent, and several species broke down Ala2-p-nitroanilide, including Ruminobacter amylophilus, Ruminococcus spp. and Veillonella parvula. Dipeptidyl peptidases, which cleave dipeptides from the amino-terminus of longer peptides, were much more active than aminopeptidases removing single amino acids in P. ruminicola. Ion-exchange chromatography of sonicated extracts of P. ruminicola M384 revealed at least four distinct activities: one hydrolysed Ala2-p-nitroanilide, ValAla-p-nitroanilide, Ala4and Ala5; another was an O2-sensitive activity hydrolysing GlyArg-4-methoxynapthylamide, ArgArg-4-methoxynaphthylamide, Gly5 and ValGlySerGlu, similar to dipeptidyl peptidase type I DPP-1); a third hydrolysed GlyPro-p-nitroanilide and GlyPro-4-methoxynapthylamide and was similar to dipeptidyl peptidase type IV XDPP-4); a fourth broke down LysAla-4-methoxynaphthylamide. All of the enzymes, and particularly those active against Ala2-p-nitroanilide and GlyPro-p-nitroanilide, were inhibited by serine protease inhibitors, and all except DPP-4 were inhibited by EDTA. Both DPP-1 and the enzyme hydrolysing LysAla-4-methoxynaphthylamide were inhibited strongly by iodoacetate. DPP-4 was inhibited completely by diprotin A. Competitive inhibition experiments suggested that DPP-1 was less important than the other enzymes in the breakdown of peptide mixtures.
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Affiliation(s)
- R J Wallace
- Rowett Research Institute, Bucksburn, Aberdeen, UK.
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Wallace RJ, McKain N, McEwan NR, Miyagawa E, Chaudhary LC, King TP, Walker ND, Apajalahti JHA, Newbold CJ. Eubacterium pyruvativorans sp. nov., a novel non-saccharolytic anaerobe from the rumen that ferments pyruvate and amino acids, forms caproate and utilizes acetate and propionate. Int J Syst Evol Microbiol 2003; 53:965-970. [PMID: 12892112 DOI: 10.1099/ijs.0.02110-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two similar gram-positive rods were isolated from 10(-6) dilutions of ruminal fluid from a sheep receiving a mixed grass hay/concentrate diet, using a medium containing pancreatic casein hydrolysate as sole source of carbon and energy. The isolates did not ferment sugars, but grew on pyruvate or trypticase, forming caproate as the main fermentation product and valerate to a lesser extent. Acetate and propionate were utilized. One of these strains, I-6T, was selected for further study. Strain I-6T was a non-motile coccal rod, 1.2 x 0.4 microm, with a gram-positive cell wall ultrastructure and a G + C content of 56.8 mol%. No spores were visible, and strain I-6T did not survive heating at 80 degrees C for 10 min. Its rate of NH3 production was 375 nmol (mg protein)(-1) min(-1), placing it in the 'ammonia-hyperproducing' (or HAP) group of ruminal bacteria. 16S rDNA sequence analysis (1296 bases) indicated that it represents a novel species within the 'low-G + C' gram-positive group, for which the name Eubacterium pyruvativorans sp. nov. is proposed. Among cultivated bacteria, strain I-6T was most closely related (89% identity) to other asaccharolytic Eubacterium isolates from the mouth and the rumen. It was 98% identical to uncultured bacterial sequences amplified by others from ruminal digesta.
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Affiliation(s)
- R J Wallace
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
| | - N McKain
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
| | - N R McEwan
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
| | - E Miyagawa
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
| | - L C Chaudhary
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
| | - T P King
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
| | - N D Walker
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
| | | | - C J Newbold
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK
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Eschenlauer SCP, McKain N, Walker ND, McEwan NR, Newbold CJ, Wallace RJ. Ammonia production by ruminal microorganisms and enumeration, isolation, and characterization of bacteria capable of growth on peptides and amino acids from the sheep rumen. Appl Environ Microbiol 2002; 68:4925-31. [PMID: 12324340 PMCID: PMC126416 DOI: 10.1128/aem.68.10.4925-4931.2002] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Excessive NH(3) production in the rumen is a major nutritional inefficiency in ruminant animals. Experiments were undertaken to compare the rates of NH(3) production from different substrates in ruminal fluid in vitro and to assess the role of asaccharolytic bacteria in NH(3) production. Ruminal fluid was taken from four rumen-fistulated sheep receiving a mixed hay-concentrate diet. The calculated rate of NH(3) production from Trypticase varied from 1.8 to 19.7 nmol mg of protein(-1) min(-1) depending on the substrate, its concentration, and the method used. Monensin (5 micro M) inhibited NH(3) production from proteins, peptides, and amino acids by an average of 28% with substrate at 2 mg/ml, compared to 48% with substrate at 20 mg/ml (P = 0.011). Of the total bacterial population, 1.4% grew on Trypticase alone, of which 93% was eliminated by 5 micro M monensin. Many fewer bacteria (0.002% of the total) grew on amino acids alone. Nineteen isolates capable of growth on Trypticase were obtained from four sheep. 16S ribosomal DNA and traditional identification methods indicated the bacteria fell into six groups. All were sensitive to monensin, and all except one group (group III, similar to Atopobium minutum), produced NH(3) at >250 nmol min(-1) mg of protein(-1), depending on the medium, as determined by a batch culture method. All isolates had exopeptidase activity, but only group III had an apparent dipeptidyl peptidase I activity. Groups I, II, and IV were most closely related to asaccharolytic ruminal and oral Clostridium and Eubacterium spp. Group V comprised one isolate, similar to Desulfomonas piger (formerly Desulfovibrio pigra). Group VI was 95% similar to Acidaminococcus fermentans. Growth of the Atopobium- and Desulfomonas-like isolates was enhanced by sugars, while growth of groups I, II, and V was significantly depressed by sugars. This study therefore demonstrates that different methodologies and different substrate concentrations provide an explanation for different apparent rates of ruminal NH(3) production reported in different studies and identifies a diverse range of hyper-ammonia-producing bacteria in the rumen of sheep.
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Affiliation(s)
- S C P Eschenlauer
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, United Kingdom
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Walker ND, McEwan NR, Wallace RJ. Overlapping sequences with high homology to functional proteins coexist on complementary strands of DNA in the rumen bacterium Prevotella albensis. Biochem Biophys Res Commun 1999; 263:58-62. [PMID: 10486253 DOI: 10.1006/bbrc.1999.1316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The potential for two complementary fragments of DNA from a clone from the ruminal bacterium Prevotella albensis to encode sequences with homology to at least part of functional proteins is described. One strand contains a sequence with high homology to dnaK, a member of the hsp70 family, and the other strand contains a sequence with some homology to glutamate dehydrogenase genes. Overlapping of these two genes on opposite strands has been reported in eukaryotic species, and is now reported for the first time in a bacterial species. Further investigation of previously described dnaK genes demonstrates that it is more widespread than might be anticipated, with all thirty other dnaK genes investigated also retaining long sequences encoding at least part of a sequence with high homology to a glutamate dehydrogenase gene.
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Affiliation(s)
- N D Walker
- Rowett Research Institute, Greenburn Road, Aberdeen, Bucksburn, AB21 9SB, Scotland
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Atasoglu C, Valdés C, Walker ND, Newbold CJ, Wallace RJ. De novo synthesis of amino acids by the ruminal bacteria Prevotella bryantii B14, Selenomonas ruminantium HD4, and Streptococcus bovis ES1. Appl Environ Microbiol 1998; 64:2836-43. [PMID: 9687438 PMCID: PMC106780 DOI: 10.1128/aem.64.8.2836-2843.1998] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The influence of peptides and amino acids on ammonia assimilation and de novo synthesis of amino acids by three predominant noncellulolytic species of ruminal bacteria, Prevotella bryantii B14, Selenomonas ruminantium HD4, and Streptococcus bovis ES1, was determined by growing these bacteria in media containing 15NH4Cl and various additions of pancreatic hydrolysates of casein (peptides) or amino acids. The proportion of cell N and amino acids formed de novo decreased as the concentration of peptides increased. At high concentrations of peptides (10 and 30 g/liter), the incorporation of ammonia accounted for less than 0.16 of bacterial amino acid N and less than 0.30 of total N. At 1 g/liter, which is more similar to peptide concentrations found in the rumen, 0.68, 0.87, and 0.46 of bacterial amino acid N and 0.83, 0.89, and 0.64 of total N were derived from ammonia by P. bryantii, S. ruminantium, and S. bovis, respectively. Concentration-dependent responses were also obtained with amino acids. No individual amino acid was exhausted in any incubation medium. For cultures of P. bryantii, peptides were incorporated and stimulated growth more effectively than amino acids, while cultures of the other species showed no preference for peptides or amino acids. Apparent growth yields increased by between 8 and 57%, depending on the species, when 1 g of peptides or amino acids per liter was added to the medium. Proline synthesis was greatly decreased when peptides or amino acids were added to the medium, while glutamate and aspartate were enriched to a greater extent than other amino acids under all conditions. Thus, the proportion of bacterial protein formed de novo in noncellulolytic ruminal bacteria varies according to species and the form and identity of the amino acid and in a concentration-dependent manner.
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Affiliation(s)
- C Atasoglu
- Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, United Kingdom
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Abstract
The final step in the conversion of protein to amino acids by the common Gram-negative rumen bacterium, Prevotella (formerly Bacteroides) ruminicola , is the cleavage of di- and tripeptides. Dipeptidase and tripeptidase activities were predominantly cytoplasmic, and toluene treatment increased the rate of Ala2 and Ala3 hydrolysis by whole cells, suggesting that transport limited the rate of hydrolysis of extracellular di- and tripeptides. The hydrolysis of Ala2 and Ala3 by whole cells was not affected by protonophores, ionophores or dicyclohexylcarbodiimide, but Ala2 hydrolysis by EDTA-treated cells was inhibited by the Ca2+/H+ ionophore, tetronasin. Ala3 hydrolysis was not affected by protonophores or ionophores in EDTA-treated cells. The dipeptidase of strain M384 was inhibited > 99% by 1,10-phenanthroline and 39% by EDTA but not other protease inhibitors, consistent with the enzyme being a metalloprotease. Tripeptidase was insensitive to protease inhibitors, except for a 33% inhibition by EDTA. Cleavage of tripeptides occurred at the bond adjacent to the N-terminal amino acid. Distinct di-, tri- and oligopeptidase peaks were obtained by anion-exchange liquid chromatography of disrupted cells. Banding patterns on native PAGE using activity staining also indicated that P. ruminicola M384 had separate single dipeptidase and tripeptidase enzymes which hydrolysed a range of peptides. The dipeptidase of strain M384 was different from other strains of P. ruminicola: strains GA33 and B(1)4 had activities which ran at the same R(f); strain GA33 had another band of lower activity; strain 23 had two bands different from those of the other strains. The tripeptidases ran at the same R(f) for the different strains. Dipeptidase activity of all strains was inhibited by 1,10-phenanthroline on gels. Gel permeation chromatography indicated that the M(r) of the dipeptidases from strains M384 and B(1)4 were 115,000 and 114,500 respectively, and 112,500 and 121,500 for the corresponding tripeptidases. Thus the metabolism of small peptides by P. ruminicola involves separate permeases and intracellular peptidases for di- and tripeptides.
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Affiliation(s)
- R J Wallace
- Rowett Research Institute, Bucksburn, Aberdeen AB2 9SB, UK
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Wallace RJ, Eschenlauer S, Newbold CJ, McKain N, Walker ND. Rumen bacteria capable of growth on peptides and amino acids as sole source of energy : numbers and their role in ammonia production. ACTA ACUST UNITED AC 1995. [DOI: 10.1051/animres:199505115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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Abstract
Treatment of Trypticase peptides with acetic anhydride, succinic anhydride, or maleic anhydride inhibited their breakdown to ammonia by rumen microorganisms by an average of 89% after 12 h of incubation in vitro. All three treatments gave similar protection. Acetylation also protected dipeptides containing lysine and methionine from degradation. However, more effective protection was obtained by linking lysine and methionine as N-epsilon-methionyl lysine.
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Affiliation(s)
- R J Wallace
- Rowett Research Institute, Bucksburn, Aberdeen, United Kingdom
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Newbold CJ, Wallace RJ, Walker ND. The effect of tetronasin and monensin on fermentation, microbial numbers and the development of ionophore-resistant bacteria in the rumen. J Appl Bacteriol 1993; 75:129-34. [PMID: 8407673 DOI: 10.1111/j.1365-2672.1993.tb02757.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The Gram-negative rumen bacteria Fibrobacter succinogenes S85, Prevotella ruminicola M384 and Veillonella parvula L59 were grown in media containing successively increasing concentrations of the ionophores, monensin and tetronasin. All three species became more resistant to the ionophore with which they were grown. Increased resistance to one ionophore caused increased resistance to the other, and cross-resistance to another ionophore--lasalocid--and an antibiotic--avoparcin. Recovery of tetronasin-resistant bacteria from the rumen of monensin-fed sheep increased and vice versa, indicating that similar cross-resistance occurred in vivo.
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Affiliation(s)
- C J Newbold
- Rowett Research Institute, Bucksburn, Aberdeen, UK
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Abstract
Bacteria that use sorbitol, xylitol, maltitol and dulcitol (galactitol) were isolated from the sheep rumen following enrichments in which bacteria were grown in rumen fluid medium where the sugar alcohol was the only added energy source. Only isolates obtained with sorbitol and maltitol grew sufficiently rapidly to be considered for enrichment by the sugar alcohol in vivo. Isolate SS2, a strain of Selenomonas ruminantium var. lactilytica which grew on sorbitol at 0.87 h-1, was selected for further study and a rifampicin-resistant mutant, SS2/R5, was isolated to facilitate tracking in the mixed population. Despite an initial transient increase in numbers, a significant population of S. ruminantium SS2/R5 failed to establish in sheep which were dosed twice daily with 10 g of sorbitol. Continuous infusion of sorbitol increased numbers only slightly compared with twice-daily dosing. In vitro experiments indicated that strain SS2/R5 grew less well in the presence of other rumen organisms, particularly ciliate protozoa, than in pure culture. Furthermore, the concentration of sorbitol in vivo was lower than predicted from in vitro experiments, indicating that sorbitol was absorbed rapidly from the rumen. Similar observations were made with xylitol, dulcitol and maltitol. Proposed enrichment strategies that use sugar alcohols or other materials to support the growth of introduced bacteria will thus have to take account of the combined problems of microbe-microbe interactions and the loss of the compounds by absorption from the rumen.
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Affiliation(s)
- R J Wallace
- Rowett Research Institute, Bucksburn, Aberdeen, UK
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Wells JE, Walker ND. Mortality in a follow up study of 616 alcoholics admitted to an inpatient alcoholism clinic 1972-76. N Z Med J 1990; 103:1-3. [PMID: 2304671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Six hundred and sixteen alcoholics were admitted to an inpatient alcoholism clinic (Mahu clinic, Sunnyside Hospital, Christchurch) between 1972 and 1976. The national register of deaths was searched for deaths of these patients up until 30 September 1983. Eighty-three deaths were recorded which, when compared with the general population, matched for age and sex, yielded a standardised mortality ratio of 1.6, that is 60% higher than expected. However because the patients were nearly all under 65 years of age the absolute death rate was not high--98% survived one year and 86% survived ten years. Similarly the excess death rate was quite low at 6 extra deaths per 1000 alcoholic years.
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Affiliation(s)
- J E Wells
- Department of Community Health and General Practice, Christchurch School of Medicine
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Edwards DB, Edginton AB, Walker ND. Anthrax outbreak. Vet Rec 1989; 125:161. [PMID: 2800274 DOI: 10.1136/vr.125.7.161-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Edwards DB, Edginton AB, Lyon DG, Walker ND, Ashworth RP. Prostaglandin and clostridial vaccination. Vet Rec 1989; 124:471. [PMID: 2728308 DOI: 10.1136/vr.124.17.471-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Walker ND. Long term outcome for alcoholic patients treated in a hospital based unit. N Z Med J 1987; 100:554-7. [PMID: 3451139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This study describes the long term outcome for patients admitted for treatment of alcoholism at Mahu clinic, Sunnyside Hospital, Christchurch. Details of 1000 consecutive admissions were recorded from March 1972 to October 1976. This included 616 patients with the data base taken from the first admission as some were readmitted. After known deaths were excluded in October 1983, 100 patients were randomly selected for followup until October 1984. Followup time varied from 8-12.5 years. Forty percent were found to be recovered. Implications for improved salvage rates are discussed.
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Affiliation(s)
- N D Walker
- Mahu Clinic, Sunnyside Hospital, Christchurch
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Walker ND, Lightfoot CG. An analysis of 1000 admissions to an alcohol treatment unit. N Z Med J 1980; 92:323-5. [PMID: 6934433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The following report contains a summary of the analysis of 1000 consecutive inpatient admissions to Mahu Clinic, an alcohol treatment unit. The results obtained show an average of four and half months abstinence after discharge from the clinic with a 48.8 percent long term recovery rate. This reflects the acceptance of recovery following relapse in alcoholism.
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