1
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Dong Y, Johnson BA, Ruan L, Zeineldin M, Bi T, Liu AZ, Raychaudhuri S, Chiu I, Zhu J, Smith B, Zhao N, Searson P, Watanabe S, Donowitz M, Larman TC, Li R. Disruption of epithelium integrity by inflammation-associated fibroblasts through prostaglandin signaling. Sci Adv 2024; 10:eadj7666. [PMID: 38569041 PMCID: PMC10990275 DOI: 10.1126/sciadv.adj7666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 02/27/2024] [Indexed: 04/05/2024]
Abstract
Inflammation-associated fibroblasts (IAFs) are associated with progression and drug resistance of chronic inflammatory diseases such as inflammatory bowel disease (IBD), but their direct impact on epithelial cells is unknown. Here, we developed an in vitro model whereby human colon fibroblasts are induced by specific cytokines and recapitulate key features of IAFs in vivo. When cocultured with patient-derived colon organoids (colonoids), IAFs induced rapid colonoid expansion and barrier disruption due to swelling and rupture of individual epithelial cells. Colonoids cocultured with IAFs also show increased DNA damage, mitotic errors, and proliferation arrest. These IAF-induced epithelial defects are mediated by a paracrine pathway involving prostaglandin E2 and its receptor EP4, leading to protein kinase A -dependent activation of the cystic fibrosis transmembrane conductance regulator. EP4-specific chemical inhibitors effectively prevented IAF-induced colonoid swelling and restored normal proliferation and genome stability. These findings reveal a mechanism by which IAFs could promote and perpetuate IBD and suggest a therapeutic avenue to mitigate inflammation-associated epithelial injury.
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Affiliation(s)
- Yi Dong
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Blake A. Johnson
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Linhao Ruan
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Maged Zeineldin
- Department of Pathology, Division of GI/Liver Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Tianhao Bi
- Department of Pathology, Division of GI/Liver Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Albert Z. Liu
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Sumana Raychaudhuri
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Ian Chiu
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Jin Zhu
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Barbara Smith
- Microscope Facility, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Nan Zhao
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Peter Searson
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Department of Physiology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Tatianna C. Larman
- Department of Pathology, Division of GI/Liver Pathology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Rong Li
- Department of Cell Biology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
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2
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Dong Y, Johnson BA, Ruan L, Zeineldin M, Liu AZ, Raychaudhuri S, Chiu I, Zhu J, Smith B, Zhao N, Searson P, Watanabe S, Donowitz M, Larman TC, Li R. Disruption of Epithelium Integrity by Inflammation-Associated Fibroblasts through Prostaglandin Signaling: IAFs disrupt colon epithelium via PGE2-EP4. bioRxiv 2023:2023.09.28.560060. [PMID: 37808771 PMCID: PMC10557697 DOI: 10.1101/2023.09.28.560060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Inflammation-associated fibroblasts (IAFs) are associated with the progression and drug resistance of chronic inflammatory diseases such as inflammatory bowel disease (IBD), but their direct impact on epithelial function and architecture is unknown. In this study, we developed an in vitro model whereby human colon fibroblasts are induced to become IAFs by specific cytokines and recapitulate key features of IAFs in vivo. When co-cultured with patient-derived colon organoids (colonoids), IAFs induced rapid colonoid swelling and barrier disruption due to swelling and rupture of individual epithelial cells. Epithelial cells co-cultured with IAFs also exhibit increased DNA damage, mitotic errors, and proliferation arrest. These IAF-induced epithelial defects are mediated through a paracrine pathway involving prostaglandin E2 (PGE2) and the PGE2 receptor EP4, leading to PKA-dependent activation of the CFTR chloride channel. Importantly, EP4-specific chemical inhibitors effectively prevented colonoid swelling and restored normal proliferation and genome stability of IAF-exposed epithelial cells. These findings reveal a mechanism by which IAFs could promote and perpetuate IBD and suggest a potential treatment to mitigate inflammation-associated epithelial injury.
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Affiliation(s)
- Yi Dong
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Blake A. Johnson
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Linhao Ruan
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Maged Zeineldin
- Department of Pathology, Division of GI/Liver Pathology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Albert Z. Liu
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Sumana Raychaudhuri
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Ian Chiu
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Jin Zhu
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore; Singapore
| | - Barbara Smith
- Microscope Facility, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Nan Zhao
- Institute for Nanobiotechnology, Johns Hopkins University; Baltimore, Maryland, 21218, U.S.A
| | - Peter Searson
- Institute for Nanobiotechnology, Johns Hopkins University; Baltimore, Maryland, 21218, U.S.A
- Department of Materials Science and Engineering, Johns Hopkins University; Baltimore, MD, 21218, U.S.A
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
- Department of Physiology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Tatianna C. Larman
- Department of Pathology, Division of GI/Liver Pathology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
| | - Rong Li
- Department of Cell Biology, Johns Hopkins School of Medicine; Baltimore, MD, 21205, U.S.A
- Mechanobiology Institute and Department of Biological Sciences, National University of Singapore; Singapore
- Department of Biological Sciences, National University of Singapore; Singapore
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3
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Zhao N, Kulkarni S, Zhang S, Linville RM, Chung TD, Guo Z, Jamieson JJ, Norman D, Liang L, Pessell AF, Searson P. Modeling angiogenesis in the human brain in a tissue-engineered post-capillary venule. Angiogenesis 2023; 26:203-216. [PMID: 36795297 PMCID: PMC10789151 DOI: 10.1007/s10456-023-09868-7] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 01/20/2023] [Indexed: 02/17/2023]
Abstract
Angiogenesis plays an essential role in embryonic development, organ remodeling, wound healing, and is also associated with many human diseases. The process of angiogenesis in the brain during development is well characterized in animal models, but little is known about the process in the mature brain. Here, we use a tissue-engineered post-capillary venule (PCV) model incorporating stem cell derived induced brain microvascular endothelial-like cells (iBMECs) and pericyte-like cells (iPCs) to visualize the dynamics of angiogenesis. We compare angiogenesis under two conditions: in response to perfusion of growth factors and in the presence of an external concentration gradient. We show that both iBMECs and iPCs can serve as tip cells leading angiogenic sprouts. More importantly, the growth rate for iPC-led sprouts is about twofold higher than for iBMEC-led sprouts. Under a concentration gradient, angiogenic sprouts show a small directional bias toward the high growth factor concentration. Overall, pericytes exhibited a broad range of behavior, including maintaining quiescence, co-migrating with endothelial cells in sprouts, or leading sprout growth as tip cells.
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Affiliation(s)
- Nan Zhao
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Sarah Kulkarni
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Sophia Zhang
- Department of Biology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Raleigh M Linville
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Tracy D Chung
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Zhaobin Guo
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - John J Jamieson
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Danielle Norman
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Lily Liang
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Alexander F Pessell
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Peter Searson
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA.
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA.
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4
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French MA, Keatley E, Li J, Balasubramanian A, Hansel NN, Wise R, Searson P, Singh A, Raghavan P, Wegener S, Roemmich RT, Celnik P. The feasibility of remotely monitoring physical, cognitive, and psychosocial function in individuals with stroke or chronic obstructive pulmonary disease. Digit Health 2023; 9:20552076231176160. [PMID: 37214659 PMCID: PMC10192672 DOI: 10.1177/20552076231176160] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 04/28/2023] [Indexed: 05/24/2023] Open
Abstract
Objective Clinical implementation of remote monitoring of human function requires an understanding of its feasibility. We evaluated adherence and the resources required to monitor physical, cognitive, and psychosocial function in individuals with either chronic obstructive pulmonary disease or stroke during a three-month period. Methods Seventy-three individuals agreed to wear a Fitbit to monitor physical function and to complete monthly online assessments of cognitive and psychosocial function. During a three-month period, we measured adherence to monitoring (1) physical function using average daily wear time, and (2) cognition and psychosocial function using the percentage of assessments completed. We measured the resources needed to promote adherence as (1) the number of participants requiring at least one reminder to synchronize their Fitbit, and (2) the number of reminders needed for each completed cognitive and psychosocial assessment. Results After accounting for withdrawals, the average daily wear time was 77.5 ± 19.9% of the day and did not differ significantly between months 1, 2, and 3 (p = 0.30). To achieve this level of adherence, 64.9% of participants required at least one reminder to synchronize their device. Participants completed 61.0% of the cognitive and psychosocial assessments; the portion of assessments completed each month didnot significantly differ (p = 0.44). Participants required 1.13 ± 0.57 reminders for each completed assessment. Results did not differ by disease diagnosis. Conclusions Remote monitoring of human function in individuals with either chronic obstructive pulmonary disease or stroke is feasible as demonstrated by high adherence. However, the number of reminders required indicates that careful consideration must be given to the resources available to obtain high adherence.
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Affiliation(s)
- Margaret A French
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
| | - Eva Keatley
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
| | - Junyao Li
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
| | - Aparna Balasubramanian
- Division of Pulmonary and Critical Care
Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Nadia N Hansel
- Division of Pulmonary and Critical Care
Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Robert Wise
- Division of Pulmonary and Critical Care
Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Peter Searson
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
- Department of Materials Science and
Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Anil Singh
- Department of Pulmonary and Critical
Care Medicine, Allegheny Health Network, Pittsburg, PA, USA
| | - Preeti Raghavan
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
| | - Stephen Wegener
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
| | - Ryan T Roemmich
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
- Kennedy Krieger Institute, Center for Movement Studies, Baltimore, MD, USA
| | - Pablo Celnik
- Department of Physical Medicine and
Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, MD,
USA
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5
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Cotton RJ, Segal Rick RL, Seamon BA, Sahu A, McLeod MM, Davis RD, Ramey SL, French MA, Roemmich RT, Daley K, Beier M, Penttinen S, Raghavan P, Searson P, Wegener S, Celnik P. Precision Rehabilitation: Optimizing Function, Adding Value to Health Care. Arch Phys Med Rehabil 2022; 103:1883-1884. [PMID: 35690092 PMCID: PMC9979846 DOI: 10.1016/j.apmr.2022.04.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 04/30/2022] [Indexed: 01/16/2023]
Affiliation(s)
- R James Cotton
- Department of Physical Medicine and Rehabilitation, Northwestern University; Shirley Ryan AbilityLab, Chicago, Illinois
| | - Richard L Segal Rick
- Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina; Department of Rehabilitation Sciences, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina; National Center of Neuromodulation for Rehabilitation, Medical University of South Carolina, Charleston, South Carolina; NIH/NICHD/NCMRR Medical Rehabilitation Research Resource Network National Coordinating Center, Charleston, South Carolina
| | - Bryant A Seamon
- Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina; Department of Rehabilitation Sciences, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina
| | - Amrita Sahu
- Department of Physical Medicine and Rehabilitation, School of Medicine, University of Pittsburgh, Pennsylvania
| | - Michelle M McLeod
- National Center of Neuromodulation for Rehabilitation (NC NM4R), Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina
| | - Randal D Davis
- Department of Health Sciences and Research, College of Health Professions, Medical University of South Carolina, Charleston, South Carolina; National Center of Neuromodulation for Rehabilitation, Medical University of South Carolina, Charleston, South Carolina
| | - Sharon Landesman Ramey
- Fralin Biomedical Research Institute, Virginia Tech, Roanoke, Virginia; VTC School of Medicine, Roanoke, Virginia
| | - Margaret A French
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Ryan T Roemmich
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Kelly Daley
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Meghan Beier
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Sharon Penttinen
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Preeti Raghavan
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Peter Searson
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Stephen Wegener
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
| | - Pablo Celnik
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland
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6
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Zhao N, Guo Z, Kulkarni S, Norman D, Zhang S, Chung TD, Nerenberg RF, Linville R, Searson P. Engineering the human blood-brain barrier at the capillary scale using a double-templating technique. Adv Funct Mater 2022; 32:2110289. [PMID: 36312050 PMCID: PMC9610437 DOI: 10.1002/adfm.202110289] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Indexed: 05/15/2023]
Abstract
In vitro blood-brain barrier (BBB) models have played an important role in studying processes such as immune cell trafficking and drug delivery, as well as contributing to the understanding of mechanisms of disease progression. Many biological and pathological processes in the cerebrovasculature occur in capillaries and hence the lack of robust hierarchical models at the capillary scale is a major roadblock in BBB research. Here we report on a double-templating technique for engineering hierarchical BBB models with physiological barrier function at the capillary scale. We first demonstrate the formation of hierarchical vascular networks using human umbilical vein endothelial cells. We then characterize barrier function in a BBB model using brain microvascular endothelial-like cells (iBMECs) differentiated from induced pluripotent stem cells (iPSCs). Finally, we characterize immune cell adhesion and transmigration in response to perfusion with the inflammatory cytokine tumor necrosis factor-alpha, and show that we can recapitulate capillary-scale effects, such as leukocyte plugging, observed in mouse models. Our double-templated hierarchical model enables the study of a wide range of biological and pathological processes related to the human BBB.
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Affiliation(s)
- Nan Zhao
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Zhaobin Guo
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Sarah Kulkarni
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Danielle Norman
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Sophia Zhang
- Department of Biology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Tracy D. Chung
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Renée F. Nerenberg
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Raleigh Linville
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Peter Searson
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
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7
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French MA, Roemmich RT, Daley K, Beier M, Penttinen S, Raghavan P, Searson P, Wegener S, Celnik P. Response to Letter to the Editor Regarding "Precision rehabilitation: optimizing function, adding value to health care". Arch Phys Med Rehabil 2022; 103:1884-1885. [PMID: 35691361 DOI: 10.1016/j.apmr.2022.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 05/18/2022] [Indexed: 11/02/2022]
Affiliation(s)
| | - Margaret A French
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ryan T Roemmich
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland, United States of America
| | - Kelly Daley
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Meghan Beier
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Sharon Penttinen
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Preeti Raghavan
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Peter Searson
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America.; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Stephen Wegener
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Pablo Celnik
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America..
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8
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French MA, Roemmich RT, Daley K, Beier M, Penttinen S, Raghavan P, Searson P, Wegener S, Celnik P. Precision rehabilitation: optimizing function, adding value to health care. Arch Phys Med Rehabil 2022; 103:1233-1239. [PMID: 35181267 DOI: 10.1016/j.apmr.2022.01.154] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 01/07/2022] [Accepted: 01/31/2022] [Indexed: 12/12/2022]
Abstract
Precision medicine efforts are underway in many medical disciplines; however, the power of precision rehabilitation has not yet been explored. Precision medicine aims to deliver the right intervention, at the right time, in the right setting, for the right person, ultimately, bolstering the value of the care that we provide. To date precision medicine efforts have rarely focused on function at the level of a person, but precision rehabilitation is poised to change this and bring the focus on function to the broader precision medicine enterprise. To do this, subgroups of individuals must be identified based on their level of function via precise measurement of their abilities in the physical, cognitive, and psychosocial domains. Adoption of electronic health records, advances in data storage and analytics, and improved measurement technology make this shift possible. Here we detail critical components of the precision rehabilitation framework, including 1) the synergistic use of various study designs, 2) the need for standardized functional measurements, 3) the importance of precise and longitudinal measures of function, 4) the utility of comprehensive databases, 5) the importance of predictive analyses, and 6) the need for system and team science. Precision rehabilitation has the potential to revolutionize clinical care, optimize function for all individuals, and magnify the value of rehabilitation in healthcare; however, to reap the benefits of precision rehabilitation, the rehabilitation community must actively pursue this shift.
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Affiliation(s)
- Margaret A French
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ryan T Roemmich
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland, United States of America
| | - Kelly Daley
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Meghan Beier
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Sharon Penttinen
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Kennedy Krieger Institute, Center for Movement Studies, Baltimore, Maryland, United States of America; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Preeti Raghavan
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Peter Searson
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America; Institute of Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Stephen Wegener
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Pablo Celnik
- Department of Physical Medicine and Rehabilitation, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
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9
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Huang YJ, Schiapparelli P, Kozielski K, Green J, Lavell E, Guerrero-Cazares H, Quinones-Hinojosa A, Searson P. Electrophoresis of cell membrane heparan sulfate regulates galvanotaxis in glial cells. J Cell Sci 2017; 130:2459-2467. [PMID: 28596239 DOI: 10.1242/jcs.203752] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [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: 03/15/2017] [Accepted: 06/02/2017] [Indexed: 12/12/2022] Open
Abstract
Endogenous electric fields modulate many physiological processes by promoting directional migration, a process known as galvanotaxis. Despite the importance of galvanotaxis in development and disease, the mechanism by which cells sense and migrate directionally in an electric field remains unknown. Here, we show that electrophoresis of cell surface heparan sulfate (HS) critically regulates this process. HS was found to be localized at the anode-facing side in fetal neural progenitor cells (fNPCs), fNPC-derived astrocytes and brain tumor-initiating cells (BTICs), regardless of their direction of galvanotaxis. Enzymatic removal of HS and other sulfated glycosaminoglycans significantly abolished or reversed the cathodic response seen in fNPCs and BTICs. Furthermore, Slit2, a chemorepulsive ligand, was identified to be colocalized with HS in forming a ligand gradient across cellular membranes. Using both imaging and genetic modification, we propose a novel mechanism for galvanotaxis in which electrophoretic localization of HS establishes cell polarity by functioning as a co-receptor and provides repulsive guidance through Slit-Robo signaling.
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Affiliation(s)
- Yu-Ja Huang
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Paula Schiapparelli
- Department of Neurosurgery and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Kristen Kozielski
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Jordan Green
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Emily Lavell
- Department of Neurosurgery and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Hugo Guerrero-Cazares
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Neurosurgery and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Alfredo Quinones-Hinojosa
- Department of Neurosurgery and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21231, USA
| | - Peter Searson
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA .,Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
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10
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Kraya R, Komin A, Searson P. On Chip Bioelectric Impedance Spectroscopy Reveals the Effect of P-Glycoprotein Efflux Pumps on the Paracellular Impedance of Tight Junctions at the Blood-Brain Barrier. IEEE Trans Nanobioscience 2016; 15:697-703. [PMID: 28029615 PMCID: PMC9923887 DOI: 10.1109/tnb.2016.2604322] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [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: 11/09/2022]
Abstract
Bioelectric impedance spectroscopy was used to elucidate the influence of P-gp efflux pumps on the kinetics of tight junction down-regulation in confluent monolayers of Madine Darby Canine Kidney Epithelial Cells (MDCK) following administration of phenylarsine oxide (PAO), a molecule that inhibits protein tyrosine phosphatases (PTP) and induces matrix metalloproteinase activity. Matrix metalloproteinases (MMPs) and phosphatase inhibitors induce modification of occludin tight junction proteins critical for the proper function of the blood-brain barrier. The addition of PAO to MDCKII cell lines resulted in a dramatic decrease in monolayer resistance. In contrast, MDCKII-MDR1 cells transfected with the MDR1 gene treated with PAO showed an initial decrease in monolayer resistance followed by a partial recovery and subsequent decrease. This resistance decay reversal was suppressed with the addition of the P-glycoprotein (P-gp) pump inhibitor elacridar, and is attributed to PAO efflux. These results illustrate impedance spectroscopy can be used to characterize the competing kinetics of efflux and down-regulation of tight junctions. In addition, the resistance decay reversal effect can be used to evaluate P-gp pump inhibitor efficacy.
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Affiliation(s)
- Ramsey Kraya
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218 USA and completed this work while with the Institute for Nanobiotechnology, Johns Hopkins University ()
| | - Alexander Komin
- Institute for Nanobiotechnology and Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218
| | - Peter Searson
- Institute for Nanobiotechnology and Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218. ()
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11
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Huang YJ, Hoffmann G, Wheeler B, Schiapparelli P, Quinones-Hinojosa A, Searson P. Cellular microenvironment modulates the galvanotaxis of brain tumor initiating cells. Sci Rep 2016; 6:21583. [PMID: 26898606 PMCID: PMC4761929 DOI: 10.1038/srep21583] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 01/27/2016] [Indexed: 12/19/2022] Open
Abstract
Galvanotaxis is a complex process that represents the collective outcome of various contributing mechanisms, including asymmetric ion influxes, preferential activation of voltage-gated channels, and electrophoretic redistribution of membrane components. While a large number of studies have focused on various up- and downstream signaling pathways, little is known about how the surrounding microenvironment may interact and contribute to the directional response. Using a customized galvanotaxis chip capable of carrying out experiments in both two- and three-dimensional microenvironments, we show that cell-extracellular matrix (ECM) interactions modulate the galvanotaxis of brain tumor initiating cells (BTICs). Five different BTICs across three different glioblastoma subtypes were examined and shown to all migrate toward the anode in the presence of a direct-current electric field (dcEF) when cultured on a poly-L-ornithine/laminin coated surface, while the fetal-derived neural progenitor cells (fNPCs) migrated toward the cathode. Interestingly, when embedded in a 3D ECM composed of hyaluronic acid and collagen, BTICs exhibited opposite directional response and migrated toward the cathode. Pharmacological inhibition against a panel of key molecules involved in galvanotaxis further revealed the mechanistic differences between 2- and 3D galvanotaxis in BTICs. Both myosin II and phosphoinositide 3-kinase (PI3K) were found to hold strikingly different roles in different microenvironments.
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Affiliation(s)
- Yu-Ja Huang
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland, United States of America.,Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Gwendolyn Hoffmann
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland, United States of America.,Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Benjamin Wheeler
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland, United States of America.,Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Paula Schiapparelli
- Department of Neurosurgery and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Alfredo Quinones-Hinojosa
- Department of Neurosurgery and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Peter Searson
- Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, Maryland, United States of America.,Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
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12
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Wiedman G, Fuselier T, He J, Searson P, Hristova K, Wimley WC. A Novel Functional Class of Pore-Forming Peptides. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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13
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Wiedman G, Herman K, Searson P, Wimley WC, Hristova K. The electrical response of bilayers to the bee venom toxin melittin: evidence for transient bilayer permeabilization. Biochim Biophys Acta 2013; 1828:1357-64. [PMID: 23384418 DOI: 10.1016/j.bbamem.2013.01.021] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/09/2013] [Accepted: 01/28/2013] [Indexed: 10/27/2022]
Abstract
Melittin is a 26-residue bee venom peptide that folds into amphipathic α-helix and causes membrane permeabilization via a mechanism that is still disputed. While an equilibrium transmembrane pore model has been a central part of the mechanistic dialogue for decades, there is growing evidence that a transmembrane pore is not required for melittin's activity. In part, the controversy is due to limited experimental tools to probe the bilayer's response to melittin. Electrochemical impedance spectroscopy (EIS) is a technique that can reveal details of molecular mechanism of peptide activity, as it yields direct, real-time measurements of membrane resistance and capacitance of supported bilayers. In this work, EIS was used in conjunction with vesicle leakage studies to characterize the response of bilayers of different lipid compositions to melittin. Experiments were carried out at low peptide to lipid ratios between 1:5000 and 1:100. The results directly demonstrate that the response of the bilayer to melittin at these concentrations cannot be explained by an equilibrium transmembrane pore model.
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Affiliation(s)
- Gregory Wiedman
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
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14
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Wiedman G, Herman K, Searson P, Wimley WC, Hristova K. Electrical Response of Bilayers to the Bee Venom Toxin Melittin. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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15
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Wiedman G, Wimley W, Searson P, Hristova K. Effect of Melittin and Gain-of-Function Melittin Analogs, Discovered by High-Throughput Screening, on Bilayer Properties: An Electrical Impedance Spectroscopy Study. Biophys J 2012. [DOI: 10.1016/j.bpj.2011.11.517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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16
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Li E, Merzlyakov M, Lin J, Searson P, Hristova K. Utility of surface-supported bilayers in studies of transmembrane helix dimerization. J Struct Biol 2009; 168:53-60. [DOI: 10.1016/j.jsb.2009.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Revised: 01/06/2009] [Accepted: 03/10/2009] [Indexed: 01/09/2023]
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17
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Guo L, Zhang S, Searson P. Growth kinetics of disk-shaped copper islands in electrochemical deposition. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 79:051601. [PMID: 19518461 DOI: 10.1103/physreve.79.051601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Indexed: 05/27/2023]
Abstract
The ability to independently dictate the shape and crystal orientation of islands in electrocrystallization remains a significant challenge. The main reason for this is that the complex interplay between the substrate, nucleation, and surface chemistry is not fully understood. Here we report on the kinetics of island growth for copper on ruthenium oxide. The small nucleation overpotential leads to enhanced lateral growth and the formation of hexagonal disk-shaped islands. The amorphous substrate allows the nuclei to achieve the thermodynamically favorable orientation, i.e., a 111 surface normal. Island growth follows power law kinetics in both lateral and vertical directions. At shorter times, the two growth exponents are equal to 1/2 whereas at longer times lateral growth slows down while vertical growth speeds up. We propose a growth mechanism, wherein the lateral growth of disk-shaped islands is initiated by attachment of Cu adatoms on the ruthenium oxide surface onto the island periphery while vertical growth is initiated by two-dimensional nucleation on the top terrace and followed by lateral step propagation. These results indicate three criteria for enhanced lateral growth in electrodeposition: (i) a substrate that leads to a small nucleation overpotential, (ii) fast adatom surface diffusion on substrate to promote lateral growth, and (iii) preferential anion adsorption to stabilize the basal plane.
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Affiliation(s)
- Lian Guo
- Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
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18
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Celedon A, Nodelman IM, Wildt B, Dewan R, Searson P, Wirtz D, Bowman GD, Sun SX. Magnetic tweezers measurement of single molecule torque. Nano Lett 2009; 9:1720-5. [PMID: 19301859 PMCID: PMC4823137 DOI: 10.1021/nl900631w] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Torsional stress in linear biopolymers such as DNA and chromatin has important consequences for nanoscale biological processes. We have developed a new method to directly measure torque on single molecules. Using a cylindrical magnet, we manipulate a novel probe consisting of a nanorod with a 0.1 microm ferromagnetic segment coupled to a magnetic bead. We achieve controlled introduction of turns into the molecule and precise measurement of torque and molecule extension as a function of the number of turns at low pulling force. We show torque measurement of single DNA molecules and demonstrate for the first time measurements of single chromatin fibers.
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Affiliation(s)
- Alfredo Celedon
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore Maryland 21218
- Howard Hughes Medical Institute Graduate Training Program and Institute for NanoBioTechnology, Johns Hopkins University, Baltimore Maryland 21218
- Departamento de Ingeniería Mecánica y Metalúrgica, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Ilana M. Nodelman
- Department of Biophysics, Johns Hopkins University, Baltimore Maryland 21218
| | - Bridget Wildt
- Department of Material Science and Engineering, Johns Hopkins University, Baltimore Maryland 21218
| | - Rohit Dewan
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore Maryland 21218
| | - Peter Searson
- Department of Material Science and Engineering, Johns Hopkins University, Baltimore Maryland 21218
| | - Denis Wirtz
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore Maryland 21218
- Howard Hughes Medical Institute Graduate Training Program and Institute for NanoBioTechnology, Johns Hopkins University, Baltimore Maryland 21218
| | - Gregory D. Bowman
- Department of Biophysics, Johns Hopkins University, Baltimore Maryland 21218
- Howard Hughes Medical Institute Graduate Training Program and Institute for NanoBioTechnology, Johns Hopkins University, Baltimore Maryland 21218
| | - Sean X. Sun
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore Maryland 21218
- Howard Hughes Medical Institute Graduate Training Program and Institute for NanoBioTechnology, Johns Hopkins University, Baltimore Maryland 21218
- Whitaker Biomedical Engineering Institute, Johns Hopkins University, Baltimore Maryland 21218
- Corresponding author,
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19
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Celedon A, Sun S, Bowman G, Wirtz D, Searson P. Magnetic Tweezers Measurement of Single Molecule Torque. Biophys J 2009. [DOI: 10.1016/j.bpj.2008.12.3651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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20
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Azila AA, Barbari T, Searson P. Poly(vinyl alcohol) : a potential matrix for glucose oxidase immobilization? Med J Malaysia 2004; 59 Suppl B:51-2. [PMID: 15468814] [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: 04/30/2023]
Abstract
Considerable effort has been focused on the method of immobilizing glucose oxidase (GOD) for amperometric glucose biosensors since the technique employed may influence the available activity of the enzyme and thus affect the performance of the sensor. Narrow measuring range and low current response are still considered problems in this area. In this work, poly(vinyl alcohol)(PVA) was investigated as a potential matrix for GOD immobilization. GOD was entrapped in cross-linked PVA. The use of a PVA-GOD membrane as the enzymatic component of a glucose biosensor was found to be promising in both the magnitude of its signal and its relative stability over time. The optimum PVA-GOD membrane (cross-linking density of 0.06) was obtained through careful selection of the cross-linking density of the PVA matrix.
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Affiliation(s)
- A A Azila
- Department of Bioprocess Engineering, Universiti Teknologi Malaysia, Malaysia
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