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Rosenbalm TN, Levi NH, Morykwas MJ, Wagner WD. Electrical stimulation via repeated biphasic conducting materials for peripheral nerve regeneration. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2023; 34:61. [PMID: 37964030 PMCID: PMC10645611 DOI: 10.1007/s10856-023-06763-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 10/26/2023] [Indexed: 11/16/2023]
Abstract
Improved materials for peripheral nerve repair are needed for the advancement of new surgical techniques in fields spanning from oncology to trauma. In this study, we developed bioresorbable materials capable of producing repeated electric field gradients spaced 600 μm apart to assess the impact on neuronal cell growth, and migration. Electrically conductive, biphasic composites comprised of poly (glycerol) sebacate acrylate (PGSA) alone, and doped with poly (pyrrole) (PPy), were prepared to create alternating segments with high and low electrically conductivity. Conductivity measurements demonstrated that 0.05% PPy added to PSA achieved an optimal value of 1.25 × 10-4 S/cm, for subsequent electrical stimulation. Tensile testing and degradation of PPy doped and undoped PGSA determined that 35-40% acrylation of PGSA matched nerve mechanical properties. Both fibroblast and neuronal cells thrived when cultured upon the composite. Biphasic PGSA/PPy sheets seeded with neuronal cells stimulated for with 3 V, 20 Hz demonstrated a 5x cell increase with 1 day of stimulation and up to a 10x cell increase with 3 days stimulation compared to non-stimulated composites. Tubular conduits composed of repeated high and low conductivity materials suitable for implantation in the rat sciatic nerve model for nerve repair were evaluated in vivo and were superior to silicone conduits. These results suggest that biphasic conducting conduits capable of maintaining mechanical properties without inducing compression injuries while generating repeated electric fields are a promising tool for acceleration of peripheral nerve repair to previously untreatable patients.
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Affiliation(s)
- Tabitha N Rosenbalm
- School of Biomedical Engineering and Sciences, Wake Forest University-Virginia Polytechnic Institute and State University, Winston-Salem, NC, 27106, USA
- Department of Plastic and Reconstructive Surgery, Wake Forest Baptist Health, Winston-Salem, NC, 27157, USA
| | - Nicole H Levi
- School of Biomedical Engineering and Sciences, Wake Forest University-Virginia Polytechnic Institute and State University, Winston-Salem, NC, 27106, USA.
- Department of Plastic and Reconstructive Surgery, Wake Forest Baptist Health, Winston-Salem, NC, 27157, USA.
| | - Michael J Morykwas
- School of Biomedical Engineering and Sciences, Wake Forest University-Virginia Polytechnic Institute and State University, Winston-Salem, NC, 27106, USA
- Department of Plastic and Reconstructive Surgery, Wake Forest Baptist Health, Winston-Salem, NC, 27157, USA
| | - William D Wagner
- School of Biomedical Engineering and Sciences, Wake Forest University-Virginia Polytechnic Institute and State University, Winston-Salem, NC, 27106, USA
- Department of Plastic and Reconstructive Surgery, Wake Forest Baptist Health, Winston-Salem, NC, 27157, USA
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Unnithan AR, Sasikala ARK. Biomedical Applications of Electrospun Piezoelectric Nanofibrous Scaffolds. ADVANCES IN POLYMER SCIENCE 2023. [DOI: 10.1007/12_2023_144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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3
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Sanie-Jahromi F, Azizi A, Shariat S, Johari M. Effect of Electrical Stimulation on Ocular Cells: A Means for Improving Ocular Tissue Engineering and Treatments of Eye Diseases. BIOMED RESEARCH INTERNATIONAL 2021; 2021:6548554. [PMID: 34840978 PMCID: PMC8612806 DOI: 10.1155/2021/6548554] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/25/2021] [Accepted: 11/08/2021] [Indexed: 01/09/2023]
Abstract
Tissue engineering is biomedical engineering that uses suitable biochemical and physicochemical factors to assemble functional constructs that restore or improve damaged tissues. Recently, cell therapies as a subset of tissue engineering have been very promising in the treatment of ocular diseases. One of the most important biophysical factors to make this happen is noninvasive electrical stimulation (ES) to target ocular cells that may preserve vision in multiple retinal and optic nerve diseases. The science of cellular and biophysical interactions is very exciting in regenerative medicine now. Although the exact effect of ES on cells is unknown, multiple mechanisms are considered to underlie the effects of ES, including increased production of neurotrophic agents, improved cell migration, and inhibition of proinflammatory cytokines and cellular apoptosis. In this review, we highlighted the effects of ES on ocular cells, especially on the corneal, retinal, and optic nerve cells. Initially, we summarized the current literature on the in vitro and in vivo effects of ES on ocular cells and then we provided the clinical studies describing the effect of ES on ocular complications. For each area, we used some of the most impactful articles to show the important concepts and results that advanced the state of these interactions. We conclude with reflections on emerging new areas and perspectives for future development in this field.
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Affiliation(s)
- Fatemeh Sanie-Jahromi
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ali Azizi
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sahar Shariat
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammadkarim Johari
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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4
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Guan L, Fan P, Liu X, Liu R, Liu Y, Bai H. Migration of Human Renal Tubular Epithelial Cells in Response to Physiological Electric Signals. Front Cell Dev Biol 2021; 9:724012. [PMID: 34595174 PMCID: PMC8476913 DOI: 10.3389/fcell.2021.724012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/27/2021] [Indexed: 02/05/2023] Open
Abstract
Restoration of proximal tubular cell integrity and function after ischemic injury involves cell migration and proliferation. Endogenous fields are present during embryonic development and wound healing. Electric field (EF)-induced effects on cell migration have been observed in many cell types. This study investigated the effect of physiological direct current EF (dc EF) on the motility of renal epithelial cells. Human renal tubular epithelial (HK-2) and human-derived renal epithelial (HEK-293) cells were exposed to dc EF at physiological magnitude. Cell images were recorded and analyzed using an image analyzer. Cell lysates were used to detect protein expression by western blot. Scratch wounds were created in monolayers of HK-2 cells, and wound areas of cells were measured in response to EF exposure. Cells migrated significantly faster in the presence of an EF and toward the cathode. Application of an EF led to activation of the Erk1/2, p38 MAPK, and Akt signaling pathways. Pharmacological inhibition of Erk1/2, p38 MAPK, and Akt impaired EF-induced migratory responses, such as motility rate and directedness. In addition, exposure of the monolayers to EF enhanced EF-induced HK-2 wound healing. Our results suggest that EFs augment the rate of single renal epithelium migration and induce cell cathodal migration through activation of Erk1/2, p38 MAPK, and Akt signaling. Moreover, exposure of the renal epithelium to EF facilitated closure of in vitro small wounds by enhancing cell migration.
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Affiliation(s)
- Linbo Guan
- Laboratory of Genetic Disease and Perinatal Medicine, Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Ping Fan
- Laboratory of Genetic Disease and Perinatal Medicine, Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Xinghui Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, China
| | - Rui Liu
- Division of Peptides Related with Human Disease, West China Hospital, Sichuan University, Chengdu, China
| | - Yu Liu
- Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, China
| | - Huai Bai
- Laboratory of Genetic Disease and Perinatal Medicine, Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, China
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Liu Z, Wan X, Wang ZL, Li L. Electroactive Biomaterials and Systems for Cell Fate Determination and Tissue Regeneration: Design and Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2007429. [PMID: 34117803 DOI: 10.1002/adma.202007429] [Citation(s) in RCA: 104] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/19/2020] [Indexed: 06/12/2023]
Abstract
During natural tissue regeneration, tissue microenvironment and stem cell niche including cell-cell interaction, soluble factors, and extracellular matrix (ECM) provide a train of biochemical and biophysical cues for modulation of cell behaviors and tissue functions. Design of functional biomaterials to mimic the tissue/cell microenvironment have great potentials for tissue regeneration applications. Recently, electroactive biomaterials have drawn increasing attentions not only as scaffolds for cell adhesion and structural support, but also as modulators to regulate cell/tissue behaviors and function, especially for electrically excitable cells and tissues. More importantly, electrostimulation can further modulate a myriad of biological processes, from cell cycle, migration, proliferation and differentiation to neural conduction, muscle contraction, embryogenesis, and tissue regeneration. In this review, endogenous bioelectricity and piezoelectricity are introduced. Then, design rationale of electroactive biomaterials is discussed for imitating dynamic cell microenvironment, as well as their mediated electrostimulation and the applying pathways. Recent advances in electroactive biomaterials are systematically overviewed for modulation of stem cell fate and tissue regeneration, mainly including nerve regeneration, bone tissue engineering, and cardiac tissue engineering. Finally, the significance for simulating the native tissue microenvironment is emphasized and the open challenges and future perspectives of electroactive biomaterials are concluded.
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Affiliation(s)
- Zhirong Liu
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Xingyi Wan
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Zhong Lin Wang
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332-0245, USA
| | - Linlin Li
- Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing, 100083, P. R. China
- School of Nanoscience and Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
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Ferson ND, Uhl AM, Andrew JS. Piezoelectric and Magnetoelectric Scaffolds for Tissue Regeneration and Biomedicine: A Review. IEEE TRANSACTIONS ON ULTRASONICS, FERROELECTRICS, AND FREQUENCY CONTROL 2021; 68:229-241. [PMID: 32866097 DOI: 10.1109/tuffc.2020.3020283] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Electric fields are ubiquitous throughout the body, playing important role in a multitude of biological processes including osteo-regeneration, cell signaling, nerve regeneration, cardiac function, and DNA replication. An increased understanding of the role of electric fields in the body has led to the development of devices for biomedical applications that incorporate electromagnetic fields as an intrinsically novel functionality (e.g., bioactuators, biosensors, cardiac/neural electrodes, and tissues scaffolds). However, in the majority of the aforementioned devices, an implanted power supply is necessary for operation, and therefore requires highly invasive procedures. Thus, the ability to apply electric fields in a minimally invasive manner to remote areas of the body remains a critical and unmet need. Here, we report on the potential of magnetoelectric (ME)-based composites to overcome this challenge. ME materials are capable of producing localized electric fields in response to an applied magnetic field, which the body is permeable to. Yet, the use of ME materials for biomedical applications is just beginning to be explored. Here, we present on the potential of ME materials to be utilized in biomedical applications. This will be presented alongside current state-of-the-art for in vitro and in vivo electrical stimulation of cells and tissues. We will discuss key findings in the field, while also identifying challenges, such as the synthesis and characterization of biocompatible ME materials, challenges in experimental design, and opportunities for future research that would lead to the increased development of ME biomaterials and their applications.
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Mohana Sundaram P, Rangharajan KK, Akbari E, Hadick TJ, Song JW, Prakash S. Direct current electric field regulates endothelial permeability under physiologically relevant fluid forces in a microfluidic vessel bifurcation model. LAB ON A CHIP 2021; 21:319-330. [PMID: 33319218 PMCID: PMC7855772 DOI: 10.1039/d0lc00507j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Previous in vitro studies have reported on the use of direct current electric fields (DC-EFs) to regulate vascular endothelial permeability, which is important for tissue regeneration and wound healing. However, these studies have primarily used static 2D culture models that lack the fluid mechanical forces associated with blood flow experienced by endothelial cells (ECs) in vivo. Hence, the effect of DC-EF on ECs under physiologically relevant fluid forces is yet to be systematically evaluated. Using a 3D microfluidic model of a bifurcating vessel, we report the role of DC-EF on regulating endothelial permeability when co-applied with physiologically relevant fluid forces that arise at the vessel bifurcation. The application of a 70 V m-1 DC-EF simultaneously with 1 μL min-1 low perfusion rate (generating 3.8 dyn cm-2 stagnation pressure at the bifurcation point and 0.3 dyn cm-2 laminar shear stress in the branched vessel) increased the endothelial permeability 7-fold compared to the static control condition (i.e., without flow and DC-EF). When the perfusion rate was increased to 10 μL min-1 (generating 38 dyn cm-2 stagnation pressure at the bifurcation point and 3 dyn cm-2 laminar shear stress in the branched vessel) while maintaining the same electrical stimulation, a 4-fold increase in endothelial permeability compared to the static control was observed. The lower increase in endothelial permeability for the higher fluid forces but the same DC-EF suggests a competing role between fluid forces and the applied DC-EF. Moreover, the observed increase in endothelial permeability due to combined DC-EF and flow was transient and dependent on the Akt signalling pathway. Collectively, these findings provide significant new insights into how the endothelium serves as an electro-mechanical interface for regulating vessel permeability.
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Cui S, Mao J, Rouabhia M, Elkoun S, Zhang Z. A biocompatible polypyrrole membrane for biomedical applications. RSC Adv 2021; 11:16996-17006. [PMID: 35479716 PMCID: PMC9031619 DOI: 10.1039/d1ra01338f] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 04/26/2021] [Indexed: 01/22/2023] Open
Abstract
Polypyrrole (PPy) is the most widely investigated electrically conductive biomaterial. However, because of its intrinsic rigidity, PPy has only been used either in the form of a composite or a thin coating. This work presents a pure and soft PPy membrane that is synergically reinforced with the electrospun polyurethane (PU) and poly-l-lactic acid (PLLA) fibers. This particular reinforcement not only renders the originally rather fragile PPy membrane easy to manipulate, it also prevents the membrane from deformation in an aqueous environment. Peel and mechanical tests confirmed the strong adhesion of the fibers and the significantly increased tensile strength of the reinforced membrane. Surface electrical conductivity and long-term electrical stability were tested, showing that these properties were not affected by the reinforcement. Surface morphology and chemistry were analyzed with scanning electron spectroscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). Material thermal stability was investigated with thermogravimetric analysis (TGA). Finally, the adhesion and proliferation of human skin keratinocytes on the membrane were assessed by Hoechst staining and the methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. In conclusion, this membrane proves to be the first PPy-based soft conductive biomaterial that can be practically used. Its electrical conductivity and cytocompatibility promise a wide range of biomedical applications. A reinforced soft polypyrrole membrane.![]()
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Affiliation(s)
- Shujun Cui
- Research Group on Oral Ecology
- Faculty of Dentistry
- Université Laval
- Québec (QC)
- Canada
| | - Jifu Mao
- Key Laboratory of Textile Science & Technology of Ministry of Education and College of Textiles
- Donghua University
- Shanghai
- China
| | - Mahmoud Rouabhia
- Research Group on Oral Ecology
- Faculty of Dentistry
- Université Laval
- Québec (QC)
- Canada
| | - Saïd Elkoun
- Department of Mechanical Engineering
- Université de Sherbrooke
- Sherbrooke (QC)
- Canada
| | - Ze Zhang
- Department of Surgery
- Faculty of Medicine
- Université Laval
- Québec (QC)
- Canada
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Chen J, Guan L, Fan P, Liu X, Liu R, Liu Y, Bai H. In vitro study of the effects of DC electric fields on cell activities and gene expression in human choriocarcinoma cells. Electromagn Biol Med 2020; 40:49-64. [PMID: 33179558 DOI: 10.1080/15368378.2020.1846555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Physiological electric fields (EFs), as one of the environmental cues influencing both normal and tumor cells, have profound effects on tumor cell malignancy potential. The cellular responses to EFs by choriocarcinoma cells and their underlying mechanisms are unknown. In this study, the migration/motility, cell cycle progression and proliferation of choriocarcinoma cells in electric field culture showed that choriocarcinoma cells migrated cathodally in an applied EF, and EF stimulation influenced cell cycle progression through G2/M arrest and therefore induced a reduction in cellular proliferation. The transcriptome of choriocarcinoma cells subjected to EF stimulation (150 mV/mm) was analyzed using RNA sequencing (RNA-Seq), and the results were verified by reverse transcription quantitative polymerase chain reaction. A Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that ErbB and HIF-1 signaling pathways that are involved in cell migration/motility, cell cycle progression and proliferation were significantly altered in cells treated with an EF of 150 mV/mm compared with control cells, and in addition, the downstream pathways of these signaling pathways such as AKT and P42/P44 MAPK (ERK1/2) showed primary activation by Western blotting. This study's results suggest that an applied EF is an effective cue in regulating cellular phenotypes of choriocarcinoma cells and that transcriptional analysis contributes to the understanding of the mechanism of EF-guided cell functions.
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Affiliation(s)
- Jinxin Chen
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University , Chengdu, P. R. China.,Department of Biochemistry, North Sichuan Medical College , Nanchong, P. R. China
| | - Linbo Guan
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University , Chengdu, P. R. China
| | - Ping Fan
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University , Chengdu, P. R. China
| | - Xinghui Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University , Chengdu, P. R. China
| | - Rui Liu
- Division of Peptides Related with Human Disease, West China Hospital, Sichuan University , Chengdu, P. R. China
| | - Yu Liu
- Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University , Chengdu, P. R. China
| | - Huai Bai
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University , Chengdu, P. R. China
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10
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Application of stable continuous external electric field promotes wound healing in pig wound model. Bioelectrochemistry 2020; 135:107578. [DOI: 10.1016/j.bioelechem.2020.107578] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 05/25/2020] [Accepted: 05/31/2020] [Indexed: 12/13/2022]
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11
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Hub Proteins Involved in RAW 264.7 Macrophages Exposed to Direct Current Electric Field. Int J Mol Sci 2020; 21:ijms21124505. [PMID: 32599940 PMCID: PMC7352442 DOI: 10.3390/ijms21124505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/14/2020] [Accepted: 06/22/2020] [Indexed: 01/08/2023] Open
Abstract
At present, studies on macrophage proteins mainly focus on biological stimuli, with less attention paid to the responses of macrophage proteins to physical stimuli, such as electric fields. Here, we exploited the electric field-sensitive hub proteins of macrophages. RAW 264.7 macrophages were treated with a direct current electric field (dcEF) (200 mV/mm) for four hours, followed by RNA-Seq analysis. Differentially expressed genes (DEGs) were obtained, followed by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) and protein–protein interaction (PPI) analysis. Eight qPCR-verified DEGs were selected. Subsequently, three-dimensional protein models of DEGs were modeled by Modeller and Rosetta, followed by molecular dynamics simulation for 200 ns with GROMACS. Finally, dcEFs (10, 50, and 500 mV/mm) were used to simulate the molecular dynamics of DEG proteins for 200 ns, followed by trajectory analysis. The dcEF has no obvious effect on RAW 264.7 morphology. A total of 689 DEGs were obtained, and enrichment analysis showed that the steroid biosynthesis pathway was most affected by the dcEF. Moreover, the three-dimensional protein structures of hub proteins were constructed, and trajectory analysis suggested that the dcEF caused an increase in the atomic motion of the protein in a dcEF-intensity-dependent manner. Overall, we provide new clues and a basis for investigating the hub proteins of macrophages in response to electric field stimulation.
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12
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Luu KY, Zhao M, Mannis MJ. The Use of Electrotherapeutics in Ophthalmology. Am J Ophthalmol 2020; 211:4-14. [PMID: 31738895 PMCID: PMC7949834 DOI: 10.1016/j.ajo.2019.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE To present a perspective on the use of electrotherapeutics in the history of ophthalmology along with the development of novel contemporary ophthalmic instrumentation. DESIGN Perspective study. METHODS We reviewed historical journals, articles, and books discussing the use of electricity and electrotherapeutics in ophthalmology. RESULTS Electrotherapeutic applications have been researched and used to treat ocular diseases as far back as the 18th century. By the 20th century, research in electrotherapeutics in ophthalmology had caught the eye of Edward Jackson, the first president of the American Academy of Ophthalmology and Otolaryngology and first editor of the present (third) series American Journal of Ophthalmology. Edward Jackson published an extensive review on this topic and reported a variety of modalities used to treat ocular diseases. CONCLUSIONS While many early therapeutic uses of electricity did not produce effective and replicable results, studies on electrical stimulation of the eye provided the foundation for the development of clinically significant vision enhancing and restoring instrumentation.
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Affiliation(s)
- Kieu-Yen Luu
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, California, USA
| | - Min Zhao
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, California, USA; Department of Dermatology, University of California, Davis, Sacramento, California, USA
| | - Mark J Mannis
- Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, California, USA.
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13
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Xiong S, Gao H, Qin L, Jia YG, Ren L. Engineering topography: Effects on corneal cell behavior and integration into corneal tissue engineering. Bioact Mater 2019; 4:293-302. [PMID: 31709312 PMCID: PMC6829100 DOI: 10.1016/j.bioactmat.2019.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/23/2019] [Accepted: 10/07/2019] [Indexed: 12/13/2022] Open
Abstract
Cell-material interactions are important to tissue engineering. Inspired by the natural topographic structures on the extracellular matrix, a growing number of studies have integrated engineering topography into investigations of cell behavior on biomaterials. Engineering topography has a significant influence on cell behaviors. These cell-topography interactions play an important role in regenerative medicine and tissue engineering. Similarly, cell-topography interactions are important to corneal reconstruction and regeneration. In this review, we primarily summarized the effects of topographic cues on the behaviors of corneal cells, including cell morphology, adhesion, migration, and proliferation. Furthermore, the integration of engineering surface topography into corneal tissue engineering was also discussed.
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Affiliation(s)
- Sijia Xiong
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, Guangzhou, 510006, China
| | - HuiChang Gao
- School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Lanfeng Qin
- National Engineering Research Centre for Tissue Restoration and Reconstruction, Guangzhou, 510006, China
- School of Biology and Biological Engineering, South China University of Technology, Guangzhou, 510006, China
| | - Yong-Guang Jia
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, Guangzhou, 510006, China
| | - Li Ren
- School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, China
- National Engineering Research Centre for Tissue Restoration and Reconstruction, Guangzhou, 510006, China
- Sino-Singapore International Joint Research Institute, Guangzhou, 510555, China
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14
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Aplin FP, Fridman GY. Implantable Direct Current Neural Modulation: Theory, Feasibility, and Efficacy. Front Neurosci 2019; 13:379. [PMID: 31057361 PMCID: PMC6482222 DOI: 10.3389/fnins.2019.00379] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/02/2019] [Indexed: 12/25/2022] Open
Abstract
Implantable neuroprostheses such as cochlear implants, deep brain stimulators, spinal cord stimulators, and retinal implants use charge-balanced alternating current (AC) pulses to recover delivered charge and thus mitigate toxicity from electrochemical reactions occurring at the metal-tissue interface. At low pulse rates, these short duration pulses have the effect of evoking spikes in neural tissue in a phase-locked fashion. When the therapeutic goal is to suppress neural activity, implants typically work indirectly by delivering excitation to populations of neurons that then inhibit the target neurons, or by delivering very high pulse rates that suffer from a number of undesirable side effects. Direct current (DC) neural modulation is an alternative methodology that can directly modulate extracellular membrane potential. This neuromodulation paradigm can excite or inhibit neurons in a graded fashion while maintaining their stochastic firing patterns. DC can also sensitize or desensitize neurons to input. When applied to a population of neurons, DC can modulate synaptic connectivity. Because DC delivered to metal electrodes inherently violates safe charge injection criteria, its use has not been explored for practical applicability of DC-based neural implants. Recently, several new technologies and strategies have been proposed that address this safety criteria and deliver ionic-based direct current (iDC). This, along with the increased understanding of the mechanisms behind the transcutaneous DC-based modulation of neural targets, has caused a resurgence of interest in the interaction between iDC and neural tissue both in the central and the peripheral nervous system. In this review we assess the feasibility of in-vivo iDC delivery as a form of neural modulation. We present the current understanding of DC/neural interaction. We explore the different design methodologies and technologies that attempt to safely deliver iDC to neural tissue and assess the scope of application for direct current modulation as a form of neuroprosthetic treatment in disease. Finally, we examine the safety implications of long duration iDC delivery. We conclude that DC-based neural implants are a promising new modulation technology that could benefit from further chronic safety assessments and a better understanding of the basic biological and biophysical mechanisms that underpin DC-mediated neural modulation.
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Affiliation(s)
- Felix P Aplin
- Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States
| | - Gene Y Fridman
- Department of Otolaryngology Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, United States.,Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, United States
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15
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Cunha F, Rajnicek AM, McCaig CD. Electrical Stimulation Directs Migration, Enhances and Orients Cell Division and Upregulates the Chemokine Receptors CXCR4 and CXCR2 in Endothelial Cells. J Vasc Res 2019; 56:39-53. [PMID: 30995642 DOI: 10.1159/000495311] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 11/09/2018] [Indexed: 11/19/2022] Open
Abstract
Natural direct current electric fields (DC EFs) within tissues undergoing angiogenesis have the potential to influence vessel formation, but how they affect endothelial cells is not clear. We therefore quantified behaviours of human umbilical vein endothelial cells (HUVEC) and human microvasculature endothelial cells (HMEC) stimulated by EFsin vitro. Both cell types migrated faster and toward the cathode; HUVECs responded to fields as low as 50mV/mm, but the HMEC threshold was 100 mV/mm. Mitosis was stimulated at 50 mV/mm for HMEC and at 150 mV/mm for HUVECs, but the cleavage plane was oriented orthogonal to the field vector at 200 mV/mm for both cell types. That different field strengths induced different cell responses suggests distinct underlying cellular mechanisms. A physiological electric field also upregulated expression of CXCR4 and CXCR2 chemokine receptors and upregulated phosphorylation of both chemokines in HUVEC and HMEC cells. Evidence that DC EFs direct endothelial cell migration, proliferation and upregulate chemokines involved in wound healing suggests a key role for electrical control of capillary production during healing. Our data contribute to the molecular mechanisms by which DC EFs direct endothelial cell behaviour and present a novel signalling paradigm in wound healing, tissue regeneration and angiogenesis-related diseases.
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Affiliation(s)
- Filipa Cunha
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, United Kingdom,
| | - Ann M Rajnicek
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Colin D McCaig
- Institute of Medical Sciences, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen, Aberdeen, United Kingdom
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16
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Sun Y, Reid B, Ferreira F, Luxardi G, Ma L, Lokken KL, Zhu K, Xu G, Sun Y, Ryzhuk V, Guo BP, Lebrilla CB, Maverakis E, Mogilner A, Zhao M. Infection-generated electric field in gut epithelium drives bidirectional migration of macrophages. PLoS Biol 2019; 17:e3000044. [PMID: 30964858 PMCID: PMC6456179 DOI: 10.1371/journal.pbio.3000044] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2018] [Accepted: 03/05/2019] [Indexed: 12/13/2022] Open
Abstract
Many bacterial pathogens hijack macrophages to egress from the port of entry to the lymphatic drainage and/or bloodstream, causing dissemination of life-threatening infections. However, the underlying mechanisms are not well understood. Here, we report that Salmonella infection generates directional electric fields (EFs) in the follicle-associated epithelium of mouse cecum. In vitro application of an EF, mimicking the infection-generated electric field (IGEF), induces directional migration of primary mouse macrophages to the anode, which is reversed to the cathode upon Salmonella infection. This infection-dependent directional switch is independent of the Salmonella pathogenicity island 1 (SPI-1) type III secretion system. The switch is accompanied by a reduction of sialic acids on glycosylated surface components during phagocytosis of bacteria, which is absent in macrophages challenged by microspheres. Moreover, enzymatic cleavage of terminally exposed sialic acids reduces macrophage surface negativity and severely impairs directional migration of macrophages in response to an EF. Based on these findings, we propose that macrophages are attracted to the site of infection by a combination of chemotaxis and galvanotaxis; after phagocytosis of bacteria, surface electrical properties of the macrophage change, and galvanotaxis directs the cells away from the site of infection.
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Affiliation(s)
- Yaohui Sun
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
- Courant Institute and Department of Biology, New York University, New York, New York, United States of America
| | - Brian Reid
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Fernando Ferreira
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
- Departamento de Biologia, Centro de Biologia Molecular e Ambiental (CBMA), Universidade do Minho, Braga, Portugal
| | - Guillaume Luxardi
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Li Ma
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
- Skin and Cosmetic Research Department, Shanghai Skin Disease Hospital, Shanghai, China
| | - Kristen L. Lokken
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Kan Zhu
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Gege Xu
- Department of Chemistry, University of California, Davis, Davis, California, United States of America
| | - Yuxin Sun
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Volodymyr Ryzhuk
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Betty P. Guo
- Office of Research, School of Medicine, University of California, Davis, Davis, California, United States of America
| | - Carlito B. Lebrilla
- Department of Chemistry, University of California, Davis, Davis, California, United States of America
| | - Emanual Maverakis
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
| | - Alex Mogilner
- Courant Institute and Department of Biology, New York University, New York, New York, United States of America
| | - Min Zhao
- Department of Dermatology, School of Medicine, University of California, Davis, Sacramento, California, United States of America
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17
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Li J. Weak direct current (DC) electric fields as a therapy for spinal cord injuries: review and advancement of the oscillating field stimulator (OFS). Neurosurg Rev 2019; 42:825-834. [DOI: 10.1007/s10143-018-01068-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/07/2018] [Accepted: 12/07/2018] [Indexed: 12/14/2022]
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18
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Electric field-responsive nanoparticles and electric fields: physical, chemical, biological mechanisms and therapeutic prospects. Adv Drug Deliv Rev 2019; 138:56-67. [PMID: 30414494 DOI: 10.1016/j.addr.2018.10.017] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 10/05/2018] [Accepted: 10/31/2018] [Indexed: 12/18/2022]
Abstract
Electric fields are among physical stimuli that have revolutionized therapy. Occurring endogenously or exogenously, the electric field can be used as a trigger for controlled drug release from electroresponsive drug delivery systems, can stimulate wound healing and cell proliferation, may enhance endocytosis or guide stem cell differentiation. Electric field pulses may be applied to induce cell fusion, can increase the penetration of therapeutic agents into cells, or can be applied as a standalone therapy to ablate tumors. This review describes the main therapeutic trends and overviews the main physical, chemical and biological mechanisms underlying the actions of electric fields. Overall, the electric field can be used in therapeutic approaches in several ways. The electric field can act on drug carriers, cells and tissues. Understanding the multiple effects of this powerful tool will help harnessing its full therapeutic potential in an efficient and safe way.
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19
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Cao L, Liu J, Pu J, Milne G, Chen M, Xu H, Shipley A, Forrester JV, McCaig CD, Lois N. Polarized retinal pigment epithelium generates electrical signals that diminish with age and regulate retinal pathology. J Cell Mol Med 2018; 22:5552-5564. [PMID: 30160348 PMCID: PMC6201363 DOI: 10.1111/jcmm.13829] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 07/06/2018] [Accepted: 07/10/2018] [Indexed: 12/21/2022] Open
Abstract
The transepithelial potential difference (TEP) across the retinal pigment epithelial (RPE) is dependent on ionic pumps and tight junction "seals" between epithelial cells. RPE cells release neurotrophic growth factors such as pigment epithelial derived factor (PEDF), which is reduced in age-related macular degeneration (AMD). The mechanisms that control the secretion of PEDF from RPE cells are not well understood. Using the CCL2/CX3CR1 double knockout mouse model (DKO), which demonstrates RPE damage and retinal degeneration, we uncovered an interaction between PEDF and the TEP which is likely to play an important role in retinal ageing and in the pathogenesis of AMD. We found that: (a) the expression of ATP1B1 (the Na+ /K+ -ATPase β1 subunit) was reduced significantly in RPE from aged mice, in patients with CNV (Choroidal Neovascularization) and in DKO mice; (b) the expression of PEDF also was decreased in aged persons and in DKO mice; (c) the TEP across RPE was reduced markedly in RPE cells from DKO mice and (d) an applied electric field (EF) of 50-100 mV/mm, used to mimic the natural TEP, increased the expression and secretion of PEDF in primary RPE cells. In conclusion, the TEP across the RPE depends on the expression of ATP1B1 and this regulates the secretion of PEDF by RPE cells and so may regulate the onset of retinal disease. Increasing the expression of PEDF using an applied EF to replenish a disease or age-reduced TEP may offer a new way of preventing or reversing retinal dysfunction.
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Affiliation(s)
- Lin Cao
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
- Yizhou International Proton Medical Centre and Cancer HospitalHe BeiChina
| | - Jie Liu
- Department of OphthalmologyFrist Hospital Affiliated to the Chinese PLA General HospitalBeijingChina
| | - Jin Pu
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Gillian Milne
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Mei Chen
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's UniversityBelfastUK
| | - Heping Xu
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's UniversityBelfastUK
| | - Alan Shipley
- Biological Research & DevelopmentUniversity of New EnglandBiddefordMaine
| | - John V Forrester
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Colin D McCaig
- School of MedicineMedical Sciences and NutritionInstitute of Medical SciencesUniversity of AberdeenAberdeenUK
| | - Noemi Lois
- Wellcome‐Wolfson Institute for Experimental MedicineQueen's UniversityBelfastUK
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20
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Ye L, Guan L, Fan P, Liu Y, Xiong W, Liu R, Wei X, Zhu Y, Liu Y, Bai H. Effect of a Small Physiological Electric Field on Angiogenic Activity in First-Trimester Extravillous Trophoblast Cells. Reprod Sci 2018; 26:745-756. [PMID: 30111245 DOI: 10.1177/1933719118792102] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Electrical stimulation induces significant angiogenesis in vivo. We have shown that electrical stimulation of trophoblast cells has important functions in aspects of angiogenesis. In this study, we investigated the effects of a direct current electrical field on trophoblast angiogenic tube formation. A 6-hour exposure to electric fields ranging from 50 to 150 mV/mm dose dependently increased tube growth and network formation. Additionally, the effect was time dependent, with increased tube formation occurring between 4 and 8 hours, indicating stimulation of trophoblast cell angiogenesis. Electrical fields of small physiological magnitude stimulated vascular endothelial growth factor expression by trophoblast cells in the culture. Electric field treatment also resulted in activation of Akt, while the activity of extracellular-regulated kinase 1/2, p38, and c-Jun NH2-terminal kinase was not significantly changed. Pretreatment with the vascular endothelial growth factor receptor (VEGFR)-2 inhibitor, SU1498, resulted in potent inhibition of tube growth, and the Akt inhibitor, MK-2206 2HCl, significantly reduced electric field-stimulated tubulogenesis. These data suggest the importance of the VEGFR-2 signaling pathway during electric field-induced trophoblastic angiogenesis. This novel evidence indicates that endogenous electrical fields may promote angiogenesis of trophoblast cells by stimulating the VEGFR signaling pathway.
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Affiliation(s)
- Liyan Ye
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China
| | - Linbo Guan
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China
| | - Ping Fan
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China
| | - Yinghui Liu
- Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Wei Xiong
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Rui Liu
- Division of Peptides Related with Human Disease, West China Hospital, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Xing Wei
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China
| | - Yue Zhu
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China
| | - Yu Liu
- Department of Biochemistry and Molecular Biology, West China School of Preclinical and Forensic Medicine, Sichuan University, Chengdu, Sichuan, People's Republic of China
| | - Huai Bai
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of the Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, 610041, People's Republic of China.
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21
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Electric Pulses Can Influence Galvanotaxis of Dictyostelium discoideum. BIOMED RESEARCH INTERNATIONAL 2018; 2018:2534625. [PMID: 30186854 PMCID: PMC6112078 DOI: 10.1155/2018/2534625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/02/2018] [Accepted: 07/31/2018] [Indexed: 01/14/2023]
Abstract
Galvanotaxis, or electrotaxis, plays an essential role in wound healing, embryogenesis, and nerve regeneration. Up until now great efforts have been made to identify the underlying mechanism related to galvanotaxis in various cells under direct current electric field (DCEF) in laboratory studies. However, abundant clinical research shows that non-DCEFs including monopolar or bipolar electric field may also contribute to wound healing and regeneration, although the mechanism remains elusive. Here, we designed a novel electric stimulator and applied DCEF, pulsed DCEF (pDCEF), and bipolar pulse electric field (bpEF) to the cells of Dictyostelium discoideum. The cells had better directional performance under asymmetric 90% duty cycle pDCEF and 80% duty cycle bpEF compared to DCEF, with 10 Hz frequency electric fields eliciting a better cell response than 5 Hz. Interestingly, electrically neutral 50% duty cycle bpEF triggered the highest migration speed, albeit in random directions. The results suggest that electric pulses are vital to galvanotaxis and non-DCEF is promising in both basic and clinical researches.
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22
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Bashirzadeh Y, Poole J, Qian S, Maruthamuthu V. Effect of pharmacological modulation of actin and myosin on collective cell electrotaxis. Bioelectromagnetics 2018; 39:289-298. [PMID: 29663474 DOI: 10.1002/bem.22119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 02/14/2018] [Indexed: 01/10/2023]
Abstract
Electrotaxis-the directional migration of cells in response to an electric field-is most evident in multicellular collectives and plays an important role in physiological contexts. While most cell types respond to applied electric fields of the order of a Volt per centimeter, our knowledge of the factors influencing this response is limited. This is especially true for collective cell electrotaxis, in which the subcellular migration response within a cell has to be coordinated with coupled neighboring cells. Here, we investigated the effect of the level of actin cytoskeleton polymerization and myosin activity on collective cell electrotaxis of Madin-Darby Canine Kidney (MDCK) cells in response to a weak electric field of physiologically relevant magnitude. We modulated the polymerization state of the actin cytoskeleton using the depolymerizing agent cytochalasin D or the polymerizing agent jasplakinolide. We also modulated the contractility of the cell using the myosin motor inhibitor blebbistatin or the phosphatase inhibitor calyculin A. While all the above pharmacological treatments altered cell speed to various extents, we found that only increasing the contractility and a high level of increase/stabilization of polymerized actin had a strong inhibitory effect specifically on the directedness of collective cell electrotaxis. On the other hand, even as the effect of the actin modulators on collective cell migration was varied, most conditions of actin and myosin pharmacological modulation-except for high level of actin polymerization/stabilization-resulted in cell speeds that were similar in the absence or presence of the electric field. Our results led us to speculate that the applied electric field may largely impact the cellular apparatus specifying the polarity of collective cell migration, rather than the functioning of the migratory apparatus. Bioelectromagnetics. 39:289-298, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Yashar Bashirzadeh
- Department of Mechanical & Aerospace Engineering, Old Dominion University, Norfolk, Virginia
| | - Jonathan Poole
- Department of Mechanical & Aerospace Engineering, Old Dominion University, Norfolk, Virginia
| | - Shizhi Qian
- Department of Mechanical & Aerospace Engineering, Old Dominion University, Norfolk, Virginia
| | - Venkat Maruthamuthu
- Department of Mechanical & Aerospace Engineering, Old Dominion University, Norfolk, Virginia
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23
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Yao L, Li Y. The Role of Direct Current Electric Field-Guided Stem Cell Migration in Neural Regeneration. Stem Cell Rev Rep 2017; 12:365-75. [PMID: 27108005 DOI: 10.1007/s12015-016-9654-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Effective directional axonal growth and neural cell migration are crucial in the neural regeneration of the central nervous system (CNS). Endogenous currents have been detected in many developing nervous systems. Experiments have demonstrated that applied direct current (DC) electric fields (EFs) can guide axonal growth in vitro, and attempts have been made to enhance the regrowth of damaged spinal cord axons using DC EFs in in vivo experiments. Recent work has revealed that the migration of stem cells and stem cell-derived neural cells can be guided by DC EFs. These studies have raised the possibility that endogenous and applied DC EFs can be used to direct neural tissue regeneration. Although the mechanism of EF-directed axonal growth and cell migration has not been fully understood, studies have shown that the polarization of cell membrane proteins and the activation of intracellular signaling molecules are involved in the process. The application of EFs is a promising biotechnology for regeneration of the CNS.
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Affiliation(s)
- Li Yao
- Department of Biological Sciences, Wichita State University, Wichita, KS, 67260, USA.
| | - Yongchao Li
- Department of Biological Sciences, Wichita State University, Wichita, KS, 67260, USA
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24
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Abstract
Endogenous electric fields (EFs) are involved in developmental regulation and wound healing. Although the phenomenon is known for more than a century, it is not clear how cells perceive the external EF. Membrane proteins, responding to electrophoretic and electroosmotic forces, have long been proposed as the sensing molecules. However, specific charge modification of surface proteins did not change cell migration motility nor directionality in EFs. Moreover, symmetric alternating current (AC) EF directs cell migration in a frequency-dependent manner. Due to their charge and ability to coalesce, glycolipids are therefore the likely primary EF sensor driving polarization of membrane proteins and intracellular signaling. We demonstrate that detergent-resistant membrane nanodomains, also known as lipid rafts, are the primary response element in EF sensing. The clustering and activation of caveolin and signaling proteins further stabilize raft structure and feed-forward downstream signaling events, such as rho and PI3K activation. Theoretical modeling supports the experimental results and predicts AC frequency-dependent cell and raft migration. Our results establish a fundamental mechanism for cell electrosensing and provide a role in lipid raft mechanotransduction.
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25
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Environmental Factors That Influence Stem Cell Migration: An "Electric Field". Stem Cells Int 2017; 2017:4276927. [PMID: 28588621 PMCID: PMC5447312 DOI: 10.1155/2017/4276927] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 03/21/2017] [Accepted: 04/11/2017] [Indexed: 01/14/2023] Open
Abstract
Environmental Stimulus of Electric Fields on Stem Cell Migration. The movement of cells in response to electric potential gradients is called galvanotaxis. In vivo galvanotaxis, powered by endogenous electric fields (EFs), plays a critical role during development and wound healing. This review aims to provide a perspective on how stem cells transduce EFs into directed migration and an understanding of the current literature relating to the mechanisms by which cells sense and transduce EFs. We will comment on potential EF-based regenerative medicine therapeutics.
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26
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Electric field-induced suppression of PTEN drives epithelial-to-mesenchymal transition via mTORC1 activation. J Dermatol Sci 2016; 85:96-105. [PMID: 27919618 DOI: 10.1016/j.jdermsci.2016.11.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 11/03/2016] [Accepted: 11/17/2016] [Indexed: 01/05/2023]
Abstract
BACKGROUND Naturally occurring electric fields (EFs) are an intrinsic property of wounds. Endogenous EFs in skin wounds play critical roles in the dynamic and well-ordered biological process of wound healing. The epithelial-to-mesenchymal transition (EMT) allows keratinocytes to transition from sedentary cells to motile cells, facilitating wound healing. However, EMT-related studies have been performed without considering endogenous EFs. Thus, the relationship between electrical signals and the EMT remain elusive. OBJECTIVE Phosphatase and tension homolog (PTEN) and mammalian target of rapamycin complex 1 (mTORC1) are key molecules in sensing electrical cues, and they play significant roles in cellular responses to EFs. In addition, these molecules are closely related to the occurrence of the EMT in other cells. We used primary human keratinocytes to investigate the influence of EFs on the EMT as well as the roles of PTEN and mTORC1 in this process. METHODS The effects of EFs on the EMT were investigated by analyzing the levels of specific proteins and transcription factors. The roles of mTORC1 and PTEN and their relationship with each other were studied via pharmacological inhibition or genetic knockdown. A Zeiss imaging system and scratch assays were used to study single-cell motility and monolayer cell migration. RESULTS EFs induced a range of both biochemical changes (e.g., increased Snail, Slug, vimentin, and N-cadherin expression, decreased E-cadherin expression) and functional changes (e.g., enhanced migratory capacity) that are characteristic of the EMT. EF-stimulated cells exhibited suppressed PTEN expression, and further PTEN downregulation led to the acquisition of more mesenchymal features and the loss of epithelial characteristics, which was accompanied by increased migratory capacity. PTEN overexpression reversed the EF-induced EMT and inhibited the migratory capacity of keratinocytes. EF-induced mTORC1 activation was a required component of the causal relationship between PTEN suppression and the EMT, as mTORC1 inhibition reversed the EMT induced by PTEN downregulation. CONCLUSIONS Our data demonstrate that the EF-induced suppression of PTEN drives the EMT via mTORC1 activation, thereby revealing a new and promising role of EFs in facilitating wound reepithelialization. These results provide a novel perspective regarding the significance of EFs in wound healing; therefore, electrical stimulation offers a new avenue of wound management for improved and accelerated wound healing.
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27
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Wang X, Gao Y, Shi H, Liu N, Zhang W, Li H. Influence of the intensity and loading time of direct current electric field on the directional migration of rat bone marrow mesenchymal stem cells. Front Med 2016; 10:286-96. [PMID: 27324024 DOI: 10.1007/s11684-016-0456-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 05/05/2016] [Indexed: 10/21/2022]
Abstract
Exogenic electric fields can effectively accelerate bone healing and remodeling through the enhanced migration of bone marrow mesenchymal stem cells (BMSCs) toward the injured area. This study aimed to determine the following: (1) the direction of rat BMSC (rBMSC) migration upon exposure to a direct current electric field (DCEF), (2) the optimal DCEF intensity and duration, and (3) the possible regulatory role of SDF-1/CXCR4 axis in rBMSC migration as induced by DCEF. Results showed that rBMSCs migrated to the positive electrode of the DCEF, and that the DCEF of 200 mV/mm for 4 h was found to be optimal in enhancing rBMSC migration. This DCEF strength and duration also upregulated the expression of osteoblastic genes, including ALP and OCN, and upregulated the expression of ALP and Runx2 proteins. Moreover, when CXCR4 was inhibited, rBMSC migration due to DCEF was partially blocked. These findings indicated that DCEF can effectively induce rBMSC migration. A DCEF of 200 mV/mm for 4 h was recommended because of its ability to promote rBMSC migration, proliferation, and osteogenic differentiation. The SDF-1/CXCR4 signaling pathway may play an important role in regulating the DCEF-induced migration of rBMSCs.
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Affiliation(s)
- Xiaoyu Wang
- Department of Stomatology, Chinese PLA General Hospital, Beijing, 100853, China
| | - Yuxuan Gao
- Department of Stomatology, Chinese PLA General Hospital, Beijing, 100853, China
| | - Haigang Shi
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Na Liu
- Department of Stomatology, Chinese PLA General Hospital, Beijing, 100853, China
| | - Wei Zhang
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Hongbo Li
- Department of Stomatology, Chinese PLA General Hospital, Beijing, 100853, China.
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28
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Shen Y, Pfluger T, Ferreira F, Liang J, Navedo MF, Zeng Q, Reid B, Zhao M. Diabetic cornea wounds produce significantly weaker electric signals that may contribute to impaired healing. Sci Rep 2016; 6:26525. [PMID: 27283241 PMCID: PMC4901296 DOI: 10.1038/srep26525] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/04/2016] [Indexed: 12/26/2022] Open
Abstract
Wounds naturally produce electric signals which serve as powerful cues that stimulate and guide cell migration during wound healing. In diabetic patients, impaired wound healing is one of the most challenging complications in diabetes management. A fundamental gap in knowledge is whether diabetic wounds have abnormal electric signaling. Here we used a vibrating probe to demonstrate that diabetic corneas produced significantly weaker wound electric signals than the normal cornea. This was confirmed in three independent animal models of diabetes: db/db, streptozotocin-induced and mice fed a high-fat diet. Spatial measurements illustrated that diabetic cornea wound currents at the wound edge but not wound center were significantly weaker than normal. Time lapse measurements revealed that the electric currents at diabetic corneas lost the normal rising and plateau phases. The abnormal electric signals correlated significantly with impaired wound healing. Immunostaining suggested lower expression of chloride channel 2 and cystic fibrosis transmembrane regulator in diabetic corneal epithelium. Acute high glucose exposure significantly (albeit moderately) reduced electrotaxis of human corneal epithelial cells in vitro, but did not affect the electric currents at cornea wounds. These data suggest that weaker wound electric signals and impaired electrotaxis may contribute to the impaired wound healing in diabetes.
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Affiliation(s)
- Yunyun Shen
- Department of Dermatology, University of California, Davis, CA, USA.,Bioelectromagnetics Laboratory, Department of Occupational and Environmental Health, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, China
| | - Trisha Pfluger
- Department of Dermatology, University of California, Davis, CA, USA
| | - Fernando Ferreira
- Department of Dermatology, University of California, Davis, CA, USA.,Department of Biology, Centre of Molecular and Environmental Biology (CBMA), University of Minho, Braga, Portugal
| | - Jiebing Liang
- Department of Biology, California State University, Northridge, CA, USA
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Qunli Zeng
- Bioelectromagnetics Laboratory, Department of Occupational and Environmental Health, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, China
| | - Brian Reid
- Department of Dermatology, University of California, Davis, CA, USA
| | - Min Zhao
- Department of Dermatology, University of California, Davis, CA, USA.,Department of Ophthalmology and Vision Science, University of California, Davis, CA, USA
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Banks TA, Luckman PSB, Frith JE, Cooper-White JJ. Effects of electric fields on human mesenchymal stem cell behaviour and morphology using a novel multichannel device. Integr Biol (Camb) 2016; 7:693-712. [PMID: 25988194 DOI: 10.1039/c4ib00297k] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The intrinsic piezoelectric nature of collagenous-rich tissues, such as bone and cartilage, can result in the production of small, endogenous electric fields (EFs) during applied mechanical stresses. In vivo, these EFs may influence cell migration, a vital component of wound healing. As a result, the application of small external EFs to bone fractures and cutaneous wounds is actively practiced clinically. Due to the significant regenerative potential of stem cells in bone and cartilage healing, and their potential role in the observed improved healing in vivo post applied EFs, using a novel medium throughput device, we investigated the impacts of physiological and aphysiological EFs on human bone marrow-derived mesenchymal stem cells (hBM-MSCs) for up to 15 hours. The applied EFs had significant impacts on hBM-MSC morphology and migration; cells displayed varying degrees of conversion to a highly elongated phenotype dependent on the EF strength, consistent perpendicular alignment to the EF vector, and definitive cathodal migration in response to EF strengths ≥0.5 V cm(-1), with the fastest migration speeds observed at between 1.7 and 3 V cm(-1). We observed variability in hBM-MSC donor-to-donor responses and overall tolerances to applied EFs. This study thus confirms hBM-MSCs are responsive to applied EFs, and their rate of migration towards the cathode is controllable depending on the EF strength, providing new insight into the physiology of hBM-MSCs and possibly a significant opportunity for the utilisation of EFs in directed scaffold colonisation in vitro for tissue engineering applications or in vivo post implantation.
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Affiliation(s)
- T A Banks
- Tissue Engineering and Microfluidics Laboratory, Australian Institute for Bioengineering & Nanotechnology, The University of Queensland, St. Lucia, Qld 4072, Australia.
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Baer ML, Henderson SC, Colello RJ. Elucidating the Role of Injury-Induced Electric Fields (EFs) in Regulating the Astrocytic Response to Injury in the Mammalian Central Nervous System. PLoS One 2015; 10:e0142740. [PMID: 26562295 PMCID: PMC4643040 DOI: 10.1371/journal.pone.0142740] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 10/25/2015] [Indexed: 12/22/2022] Open
Abstract
Injury to the vertebrate central nervous system (CNS) induces astrocytes to change their morphology, to increase their rate of proliferation, and to display directional migration to the injury site, all to facilitate repair. These astrocytic responses to injury occur in a clear temporal sequence and, by their intensity and duration, can have both beneficial and detrimental effects on the repair of damaged CNS tissue. Studies on highly regenerative tissues in non-mammalian vertebrates have demonstrated that the intensity of direct-current extracellular electric fields (EFs) at the injury site, which are 50-100 fold greater than in uninjured tissue, represent a potent signal to drive tissue repair. In contrast, a 10-fold EF increase has been measured in many injured mammalian tissues where limited regeneration occurs. As the astrocytic response to CNS injury is crucial to the reparative outcome, we exposed purified rat cortical astrocytes to EF intensities associated with intact and injured mammalian tissues, as well as to those EF intensities measured in regenerating non-mammalian vertebrate tissues, to determine whether EFs may contribute to the astrocytic injury response. Astrocytes exposed to EF intensities associated with uninjured tissue showed little change in their cellular behavior. However, astrocytes exposed to EF intensities associated with injured tissue showed a dramatic increase in migration and proliferation. At EF intensities associated with regenerating non-mammalian vertebrate tissues, these cellular responses were even more robust and included morphological changes consistent with a regenerative phenotype. These findings suggest that endogenous EFs may be a crucial signal for regulating the astrocytic response to injury and that their manipulation may be a novel target for facilitating CNS repair.
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Affiliation(s)
- Matthew L. Baer
- Department of Anatomy & Neurobiology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Scott C. Henderson
- Department of Anatomy & Neurobiology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Raymond J. Colello
- Department of Anatomy & Neurobiology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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Saltukoglu D, Grünewald J, Strohmeyer N, Bensch R, Ulbrich MH, Ronneberger O, Simons M. Spontaneous and electric field-controlled front-rear polarization of human keratinocytes. Mol Biol Cell 2015; 26:4373-86. [PMID: 26424799 PMCID: PMC4666133 DOI: 10.1091/mbc.e14-12-1580] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 09/21/2015] [Indexed: 01/23/2023] Open
Abstract
It has long been known that electrical fields (EFs) are able to influence the direction of migrating cells, a process commonly referred to as electrotaxis or galvanotaxis. Most studies have focused on migrating cells equipped with an existing polarity before EF application, making it difficult to delineate EF-specific pathways. Here we study the initial events in front-rear organization of spreading keratinocytes to dissect the molecular requirements for random and EF-controlled polarization. We find that Arp2/3-dependent protrusive forces and Rac1/Cdc42 activity were generally required for both forms of polarization but were dispensable for controlling the direction of EF-controlled polarization. By contrast, we found a crucial role for extracellular pH as well as G protein coupled-receptor (GPCR) or purinergic signaling in the control of directionality. The normal direction of polarization toward the cathode was reverted by lowering extracellular pH. Polarization toward the anode was also seen at neutral pH when GPCR or purinergic signaling was inhibited. However, the stepwise increase of extracellular pH in this scenario led to restoration of cathodal polarization. Overall our work puts forward a model in which the EF uses distinct polarization pathways. The cathodal pathway involves GPCR/purinergic signaling and is dominant over the anodal pathway at neutral pH.
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Affiliation(s)
- Deniz Saltukoglu
- Center for Systems Biology, University of Freiburg, 79104 Freiburg, Germany Renal Division, University Hospital Freiburg, 79106 Freiburg, Germany Spemann Graduate School of Biology and Medicine, University of Freiburg, 79104 Freiburg, Germany BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Julian Grünewald
- Center for Systems Biology, University of Freiburg, 79104 Freiburg, Germany Renal Division, University Hospital Freiburg, 79106 Freiburg, Germany
| | - Nico Strohmeyer
- Center for Systems Biology, University of Freiburg, 79104 Freiburg, Germany Renal Division, University Hospital Freiburg, 79106 Freiburg, Germany
| | - Robert Bensch
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany Institute for Computer Science, Faculty of Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Maximilian H Ulbrich
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany Institute of Physiology II, University of Freiburg, 79106 Freiburg, Germany
| | - Olaf Ronneberger
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany Institute for Computer Science, Faculty of Engineering, University of Freiburg, 79110 Freiburg, Germany
| | - Matias Simons
- Center for Systems Biology, University of Freiburg, 79104 Freiburg, Germany Renal Division, University Hospital Freiburg, 79106 Freiburg, Germany BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany Imagine Institute, Paris Descartes University-Sorbonne Paris Cité, 75015 Paris, France
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Mousavi SJ, Hamdy Doweidar M. Three-dimensional numerical model of cell morphology during migration in multi-signaling substrates. PLoS One 2015; 10:e0122094. [PMID: 25822332 PMCID: PMC4379188 DOI: 10.1371/journal.pone.0122094] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Accepted: 02/21/2015] [Indexed: 12/19/2022] Open
Abstract
Cell Migration associated with cell shape changes are of central importance in many biological processes ranging from morphogenesis to metastatic cancer cells. Cell movement is a result of cyclic changes of cell morphology due to effective forces on cell body, leading to periodic fluctuations of the cell length and cell membrane area. It is well-known that the cell can be guided by different effective stimuli such as mechanotaxis, thermotaxis, chemotaxis and/or electrotaxis. Regulation of intracellular mechanics and cell's physical interaction with its substrate rely on control of cell shape during cell migration. In this notion, it is essential to understand how each natural or external stimulus may affect the cell behavior. Therefore, a three-dimensional (3D) computational model is here developed to analyze a free mode of cell shape changes during migration in a multi-signaling micro-environment. This model is based on previous models that are presented by the same authors to study cell migration with a constant spherical cell shape in a multi-signaling substrates and mechanotaxis effect on cell morphology. Using the finite element discrete methodology, the cell is represented by a group of finite elements. The cell motion is modeled by equilibrium of effective forces on cell body such as traction, protrusion, electrostatic and drag forces, where the cell traction force is a function of the cell internal deformations. To study cell behavior in the presence of different stimuli, the model has been employed in different numerical cases. Our findings, which are qualitatively consistent with well-known related experimental observations, indicate that adding a new stimulus to the cell substrate pushes the cell to migrate more directionally in more elongated form towards the more effective stimuli. For instance, the presence of thermotaxis, chemotaxis and electrotaxis can further move the cell centroid towards the corresponding stimulus, respectively, diminishing the mechanotaxis effect. Besides, the stronger stimulus imposes a greater cell elongation and more cell membrane area. The present model not only provides new insights into cell morphology in a multi-signaling micro-environment but also enables us to investigate in more precise way the cell migration in the presence of different stimuli.
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Affiliation(s)
- Seyed Jamaleddin Mousavi
- Group of Structural Mechanics and Materials Modeling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
- Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Mohamed Hamdy Doweidar
- Group of Structural Mechanics and Materials Modeling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
- Mechanical Engineering Department, School of Engineering and Architecture (EINA), University of Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomédica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
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Thompson DM, Koppes AN, Hardy JG, Schmidt CE. Electrical stimuli in the central nervous system microenvironment. Annu Rev Biomed Eng 2015; 16:397-430. [PMID: 25014787 DOI: 10.1146/annurev-bioeng-121813-120655] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Electrical stimulation to manipulate the central nervous system (CNS) has been applied as early as the 1750s to produce visual sensations of light. Deep brain stimulation (DBS), cochlear implants, visual prosthetics, and functional electrical stimulation (FES) are being applied in the clinic to treat a wide array of neurological diseases, disorders, and injuries. This review describes the history of electrical stimulation of the CNS microenvironment; recent advances in electrical stimulation of the CNS, including DBS to treat essential tremor, Parkinson's disease, and depression; FES for the treatment of spinal cord injuries; and alternative electrical devices to restore vision and hearing via neuroprosthetics (retinal and cochlear implants). It also discusses the role of electrical cues during development and following injury and, importantly, manipulation of these endogenous cues to support regeneration of neural tissue.
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Affiliation(s)
- Deanna M Thompson
- Department of Biomedical Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York 12180;
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Gao J, Raghunathan VK, Reid B, Wei D, Diaz RC, Russell P, Murphy CJ, Zhao M. Biomimetic stochastic topography and electric fields synergistically enhance directional migration of corneal epithelial cells in a MMP-3-dependent manner. Acta Biomater 2015; 12:102-112. [PMID: 25311684 DOI: 10.1016/j.actbio.2014.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 10/02/2014] [Accepted: 10/04/2014] [Indexed: 01/14/2023]
Abstract
Directed migration of corneal epithelial cells (CECs) is critical for maintenance of corneal homeostasis as well as wound healing. Soluble cytoactive factors and the intrinsic chemical attributes of the underlying extracellular matrix (ECM) participate in stimulating and directing migration. The central importance of the intrinsic biophysical attributes of the microenvironment of the cell in modulating an array of fundamental epithelial behaviors including migration has been widely documented. Among the best measures of these attributes are the intrinsic topography and stiffness of the ECM and electric fields (EFs). How cells integrate these multiple simultaneous inputs is not well understood. Here, we present a method that combines the use of (i) topographically patterned substrates (mean pore diameter 800nm) possessing features that approximate those found in the native corneal basement membrane; and (ii) EFs (0-150mVmm(-1)) mimicking those at corneal epithelial wounds that the cells experience in vivo. We found that topographic cues and EFs synergistically regulated directional migration of human CECs and that this was associated with upregulation of matrix metalloproteinase-3 (MMP3). MMP3 expression and activity were significantly elevated with 150mVmm(-1) applied-EF while MMP2/9 remained unaltered. MMP3 expression was elevated in cells cultured on patterned surfaces against planar surfaces. The highest single-cell migration rate was observed with 150mVmm(-1) applied EF on patterned and planar surfaces. When cultured as a confluent sheet, EFs induced collective cell migration on stochastically patterned surfaces compared with dissociated single-cell migration on planar surfaces. These results suggest significant interaction of biophysical cues in regulating cell behaviors and will help define design parameters for corneal prosthetics and help to better understand corneal wound healing.
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Tyler SEB. The Work Surfaces of Morphogenesis: The Role of the Morphogenetic Field. ACTA ACUST UNITED AC 2014. [DOI: 10.1007/s13752-014-0177-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhang J, Ren R, Luo X, Fan P, Liu X, Liang S, Ma L, Yu P, Bai H. A small physiological electric field mediated responses of extravillous trophoblasts derived from HTR8/SVneo cells: involvement of activation of focal adhesion kinase signaling. PLoS One 2014; 9:e92252. [PMID: 24643246 PMCID: PMC3958492 DOI: 10.1371/journal.pone.0092252] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/18/2014] [Indexed: 11/18/2022] Open
Abstract
Moderate invasion of trophoblast cells into endometrium is essential for the placental development and normal pregnancy. Electric field (EF)-induced effects on cellular behaviors have been observed in many cell types. This study was to investigate the effect of physiological direct current EF (dc EF) on cellular responses such as elongation, orientation and motility of trophoblast cells. Immortalized first trimester extravillous trophoblast cells (HTR-8/SVneo) were exposed to the dc EF at physiological magnitude. Cell images were recorded and analyzed by image analyzer. Cell lysates were used to detect protein expression by Western blot. Cultured in the dc EFs the cells showed elongation, orientation and enhanced migration rate compared with non-EF stimulated cells at field strengths of 100 mV/mm to 200 mV/mm. EF exposure increased focal adhesion kinase (FAK) phosphorylation in a time-dependent manner and increased expression levels of MMP-2. Pharmacological inhibition of FAK impaired the EF-induced responses including motility and abrogated the elevation of MMP-2 expression. However, the expression levels of integrins like integrin α1, α5, αV and β1 were not affected by EF stimulation. Our results demonstrate the importance of FAK activation in migration/motility of trophobalst cells driven by EFs. In addition, it raises the feasibility of using applied EFs to promote placentation through effects on trophoblast cells.
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Affiliation(s)
- Juan Zhang
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Rongmei Ren
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Xuefeng Luo
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Ping Fan
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Xinghui Liu
- Department of Obstetrics and Gynecology, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Shanshan Liang
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Lei Ma
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Ping Yu
- Laboratory of Cell and Gene Therapy, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
| | - Huai Bai
- Laboratory of Genetic Disease and Perinatal Medicine and Key Laboratory of Birth Defects and Related Diseases of Women and Children of Ministry of Education, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, P. R. China
- * E-mail:
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Reid B, Zhao M. The Electrical Response to Injury: Molecular Mechanisms and Wound Healing. Adv Wound Care (New Rochelle) 2014; 3:184-201. [PMID: 24761358 DOI: 10.1089/wound.2013.0442] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 06/21/2013] [Indexed: 01/06/2023] Open
Abstract
Significance: Natural, endogenous electric fields (EFs) and currents arise spontaneously after wounding of many tissues, especially epithelia, and are necessary for normal healing. This wound electrical activity is a long-lasting and regulated response. Enhancing or inhibiting this electrical activity increases or decreases wound healing, respectively. Cells that are responsible for wound closure such as corneal epithelial cells or skin keratinocytes migrate directionally in EFs of physiological magnitude. However, the mechanisms of how the wound electrical response is initiated and regulated remain unclear. Recent Advances: Wound EFs and currents appear to arise by ion channel up-regulation and redistribution, which are perhaps triggered by an intracellular calcium wave or cell depolarization. We discuss the possibility of stimulation of wound healing via pharmacological enhancement of the wound electric signal by stimulation of ion pumping. Critical Issues: Chronic wounds are a major problem in the elderly and diabetic patient. Any strategy to stimulate wound healing in these patients is desirable. Applying electrical stimulation directly is problematic, but pharmacological enhancement of the wound signal may be a promising strategy. Future Directions: Understanding the molecular regulation of wound electric signals may reveal some fundamental mechanisms in wound healing. Manipulating fluxes of ions and electric currents at wounds might offer new approaches to achieve better wound healing and to heal chronic wounds.
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Affiliation(s)
- Brian Reid
- Departments of Dermatology and Ophthalmology, School of Medicine, University of California, Davis, California
| | - Min Zhao
- Departments of Dermatology and Ophthalmology, School of Medicine, University of California, Davis, California
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Haan N, Song B. Therapeutic Application of Electric Fields in the Injured Nervous System. Adv Wound Care (New Rochelle) 2014; 3:156-165. [PMID: 24761356 DOI: 10.1089/wound.2013.0450] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 04/07/2013] [Indexed: 12/23/2022] Open
Abstract
Significance: Nervous system injuries, both in the peripheral nervous system (PNS) and central nervous system are a major cause for pain, loss-of-function, and impairment of daily life. As nervous system injuries commonly heal slowly or incompletely, new therapeutic approaches may be required. Recent Advances: The observation that cultured neurons are able to respond to exogenous electric fields (EFs) by sprouting more neurites and directing growth along the field, along with the presence of endogenous EFs in the developing vertebrate nervous system have led to the suggestion of the use of EFs in a regenerative therapeutic setting. This review discusses the effects of EFs on nervous cells, and their use in the treatment of nervous injuries in the eye, limb nerves, and the spinal cord. Exogenous EFs have been shown to be neuroprotective in various injury models of the eye, including traumatic injury, congenital degenerative retinopathy, and glaucoma. In the PNS, EFs are able to stimulate regrowth and functional recovery in damaged limb nerves. In the spinal cord, axonal regeneration and improved quality of life may be achieved using EF stimulation. Critical Issues: The optimal paradigm for electrical stimulation has not been determined, and the mechanisms behind the effect of EF are still largely unknown. Future Directions: Although the therapeutic use of EFs in the nervous system is still in its infancy, it is a promising therapeutic avenue for otherwise hard to treat injuries. The cellular/molecular mechanisms of such regulation need to be fully investigated, and the efficiency of applied EFs during wound healing needs to be optimized in a systematic approach in both animal models and future clinical trials.
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Affiliation(s)
- Niels Haan
- Tissue Engineering and Reparative Dentistry, School of Dentistry, College of Biomedical & Life Sciences, Cardiff University, Cardiff, United Kingdom
| | - Bing Song
- Tissue Engineering and Reparative Dentistry, School of Dentistry, College of Biomedical & Life Sciences, Cardiff University, Cardiff, United Kingdom
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Stock C, Ludwig FT, Hanley PJ, Schwab A. Roles of ion transport in control of cell motility. Compr Physiol 2013; 3:59-119. [PMID: 23720281 DOI: 10.1002/cphy.c110056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell motility is an essential feature of life. It is essential for reproduction, propagation, embryonic development, and healing processes such as wound closure and a successful immune defense. If out of control, cell motility can become life-threatening as, for example, in metastasis or autoimmune diseases. Regardless of whether ciliary/flagellar or amoeboid movement, controlled motility always requires a concerted action of ion channels and transporters, cytoskeletal elements, and signaling cascades. Ion transport across the plasma membrane contributes to cell motility by affecting the membrane potential and voltage-sensitive ion channels, by inducing local volume changes with the help of aquaporins and by modulating cytosolic Ca(2+) and H(+) concentrations. Voltage-sensitive ion channels serve as voltage detectors in electric fields thus enabling galvanotaxis; local swelling facilitates the outgrowth of protrusions at the leading edge while local shrinkage accompanies the retraction of the cell rear; the cytosolic Ca(2+) concentration exerts its main effect on cytoskeletal dynamics via motor proteins such as myosin or dynein; and both, the intracellular and the extracellular H(+) concentration modulate cell migration and adhesion by tuning the activity of enzymes and signaling molecules in the cytosol as well as the activation state of adhesion molecules at the cell surface. In addition to the actual process of ion transport, both, channels and transporters contribute to cell migration by being part of focal adhesion complexes and/or physically interacting with components of the cytoskeleton. The present article provides an overview of how the numerous ion-transport mechanisms contribute to the various modes of cell motility.
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Affiliation(s)
- Christian Stock
- Institute of Physiology II, University of Münster, Münster, Germany.
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Rouabhia M, Park H, Meng S, Derbali H, Zhang Z. Electrical stimulation promotes wound healing by enhancing dermal fibroblast activity and promoting myofibroblast transdifferentiation. PLoS One 2013; 8:e71660. [PMID: 23990967 PMCID: PMC3747189 DOI: 10.1371/journal.pone.0071660] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 07/01/2013] [Indexed: 01/15/2023] Open
Abstract
Electrical stimulation (ES) has long been used as an alternative clinical treatment and an effective approach to modulate cellular behaviours. In this work we investigated the effects of ES on human skin fibroblast activity, myofibroblast transdifferentiation and the consequence on wound healing. Normal human fibroblasts were seeded on heparin-bioactivated PPy/PLLA conductive membranes, cultured for 24 h, and then exposed to ES of 50 or 200 mV/mm for 2, 4, or 6 h. Following ES, the cells were either subjected to various analyses or re-seeded to investigate their healing capacity. Our findings show that ES had no cytotoxic effect on the fibroblasts, as demonstrated by the similar LDH activity levels in the ES-exposed and non-exposed cultures, and by the comparable cell viability under both conditions. Furthermore, the number of viable fibroblasts was higher following exposure to 6 h of ES than in the non-exposed culture. This enhanced cell growth was likely due to the ES up-regulated secretion of FGF-1 and FGF-2. In an in vitro scratch-wound assay where cell monolayer was used as a healing model, the electrically stimulated dermal fibroblasts migrated faster following exposure to ES and recorded a high contractile behaviour toward the collagen gel matrix. This enhanced contraction was supported by the high level of α-smooth muscle actin expressed by the fibroblasts following exposure to ES, indicating the characteristics of myofibroblasts. Remarkably, the modulation of fibroblast growth continued long after ES. In conclusion, this work demonstrates for the first time that exposure to ES promoted skin fibroblast growth and migration, increased growth factor secretion, and promoted fibroblast to myofibroblast transdifferentiation, thus promoting wound healing.
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Affiliation(s)
- Mahmoud Rouabhia
- Faculty of Dentistry, Research Group on Oral Ecology, Laval University, Quebec City, Quebec, Canada
| | - Hyunjin Park
- Faculty of Dentistry, Research Group on Oral Ecology, Laval University, Quebec City, Quebec, Canada
- Faculty of Medicine, Department of Surgery, Laval University, Saint-François d’Assise Hospital Research Center, CHU, Quebec City, Quebec, Canada
| | - Shiyun Meng
- College of Environment and Biotechnology, Chongqing Technology and Business University, Chongqing, China
| | - Habib Derbali
- Faculty of Dentistry, Research Group on Oral Ecology, Laval University, Quebec City, Quebec, Canada
- Faculty of Medicine, Department of Surgery, Laval University, Saint-François d’Assise Hospital Research Center, CHU, Quebec City, Quebec, Canada
| | - Ze Zhang
- Faculty of Medicine, Department of Surgery, Laval University, Saint-François d’Assise Hospital Research Center, CHU, Quebec City, Quebec, Canada
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Rudell JC, Gao J, Sun Y, Sun Y, Chodosh J, Schwab I, Zhao M. Acanthamoeba migration in an electric field. Invest Ophthalmol Vis Sci 2013; 54:4225-33. [PMID: 23716626 DOI: 10.1167/iovs.13-11968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
PURPOSE We investigated the in vitro response of Acanthamoeba trophozoites to electric fields (EFs). METHODS Acanthamoeba castellanii were exposed to varying strengths of an EF. During EF exposure, cell migration was monitored using an inverted microscope equipped with a CCD camera and the SimplePCI 5.3 imaging system to capture time-lapse images. The migration of A. castellanii trophozoites was analyzed and quantified with ImageJ software. For analysis of cell migration in a three-dimensional culture system, Acanthamoeba trophozoites were cultured in agar, exposed to an EF, digitally video recorded, and analyzed at various Z focal planes. RESULTS Acanthamoeba trophozoites move at random in the absence of an EF, but move directionally in response to an EF. Directedness in the absence of an EF is 0.08 ± 0.01, while in 1200 mV/mm EF, directedness is significantly higher at -0.65 ± 0.01 (P < 0.001). We find that the trophozoite migration response is voltage-dependent, with higher directionality with higher voltage application. Acanthamoeba move directionally in a three-dimensional (3D) agar system as well when exposed to an EF. CONCLUSIONS Acanthamoeba trophozoites move directionally in response to an EF in a two-dimensional and 3D culture system. Acanthamoeba trophozoite migration is also voltage-dependent, with increased directionality with increasing voltage. This may provide new treatment modalities for Acanthamoeba keratitis.
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Affiliation(s)
- Jolene Chang Rudell
- Department of Dermatology, Institute for Regenerative Cures, School of Medicine, University of California at Davis, Davis, California, USA
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Sundelacruz S, Li C, Choi YJ, Levin M, Kaplan DL. Bioelectric modulation of wound healing in a 3D in vitro model of tissue-engineered bone. Biomaterials 2013; 34:6695-705. [PMID: 23764116 DOI: 10.1016/j.biomaterials.2013.05.040] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 05/21/2013] [Indexed: 12/15/2022]
Abstract
Long-standing interest in bioelectric regulation of bone fracture healing has primarily focused on exogenous stimulation of bone using applied electromagnetic fields. Endogenous electric signals, such as spatial gradients of resting potential among non-excitable cells in vivo, have also been shown to be important in cell proliferation, differentiation, migration, and tissue regeneration, and may therefore have as-yet unexplored therapeutic potential for regulating wound healing in bone tissue. To study this form of bioelectric regulation, there is a need for three-dimensional (3D) in vitro wound tissue models that can overcome limitations of current in vivo models. We present a 3D wound healing model in engineered bone tissue that serves as a pre-clinical experimental platform for studying electrophysiological regulation of wound healing. Using this system, we identified two electrophysiology-modulating compounds, glibenclamide and monensin, that augmented osteoblast mineralization. Of particular interest, these compounds displayed differential effects in the wound area compared to the surrounding tissue. Several hypotheses are proposed to account for these observations, including the existence of heterogeneous subpopulations of osteoblasts that respond differently to bioelectric signals, or the capacity of the wound-specific biochemical and biomechanical environment to alter cell responses to electrophysiological treatments. These data indicate that a comprehensive characterization of the cellular, biochemical, biomechanical, and bioelectrical components of in vitro wound models is needed to develop bioelectric strategies to control cell functions for improved bone regeneration.
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Affiliation(s)
- Sarah Sundelacruz
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
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Tran V, Zhang X, Cao L, Li H, Lee B, So M, Sun Y, Chen W, Zhao M. Synchronization modulation increases transepithelial potentials in MDCK monolayers through Na/K pumps. PLoS One 2013; 8:e61509. [PMID: 23585907 PMCID: PMC3621860 DOI: 10.1371/journal.pone.0061509] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 03/09/2013] [Indexed: 01/13/2023] Open
Abstract
Transepithelial potential (TEP) is the voltage across a polarized epithelium. In epithelia that have active transport functions, the force for transmembrane flux of an ion is dictated by the electrochemical gradient in which TEP plays an essential role. In epithelial injury, disruption of the epithelial barrier collapses the TEP at the wound edge, resulting in the establishment of an endogenous wound electric field (∼100 mV/mm) that is directed towards the center of the wound. This endogenous electric field is implicated to enhance wound healing by guiding cell migration. We thus seek techniques to enhance the TEP, which may increase the wound electric fields and enhance wound healing. We report a novel technique, termed synchronization modulation (SM) using a train of electric pulses to synchronize the Na/K pump activity, and then modulating the pumping cycles to increase the efficiency of the Na/K pumps. Kidney epithelial monolayers (MDCK cells) maintain a stable TEP and transepithelial resistance (TER). SM significantly increased TEP over four fold. Either ouabain or digoxin, which block Na/K pump, abolished SM-induced TEP increases. In addition to the pump activity, basolateral distribution of Na/K pumps is essential for an increase in TEP. Our study for the first time developed an electrical approach to significantly increase the TEP. This technique targeting the Na/K pump may be used to modulate TEP, and may have implication in wound healing and in diseases where TEP needs to be modulated.
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Affiliation(s)
- Vu Tran
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
| | - Xiaodong Zhang
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
| | - Lin Cao
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
| | - Hanqing Li
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
| | - Benjamin Lee
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
| | - Michelle So
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
| | - Yaohui Sun
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
| | - Wei Chen
- Cellular and Molecular Biophysics, Department of Physics, University of South Florida, Tampa, Florida, United States of America
| | - Min Zhao
- Institute for Regenerative Cures, Departments of Dermatology and Ophthalmology, University of California Davis, Davis, California, United States of America
- Center for Neurosciences, University of California Davis, Davis, California, United States of America
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Mousavi SJ, Doweidar MH, Doblaré M. 3D computational modelling of cell migration: a mechano-chemo-thermo-electrotaxis approach. J Theor Biol 2013; 329:64-73. [PMID: 23571009 DOI: 10.1016/j.jtbi.2013.03.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 02/14/2013] [Accepted: 03/22/2013] [Indexed: 11/26/2022]
Abstract
Single cell migration constitutes a fundamental phenomenon involved in many biological events such as wound healing, cancer development and tissue regeneration. Several experiments have demonstrated that, besides the mechanical driving force (mechanotaxis), cell migration may be also influenced by chemical, thermal and/or electrical cues. In this paper, we present an extension of a previous model of the same authors adding the effects of chemotaxis, thermotaxis and electrotaxis to the initial mechanotaxis model of cell migration, allowing us to predict cell migration behaviour under different conditions and substrate properties. The present model is based on the balance of effective forces during cell motility in the presence of the several guiding cues. This model has been applied to several numerical experiments to demonstrate the effect of the different drivers onto the cell path and final location within a certain three-dimensional substrate with heterogeneous properties. Our findings indicate that the presence of the chemotaxis, thermotaxis and/or electrotaxis reduce, in general, the random component of cell movement, being this reduction more important in the case of electrotaxis that can be considered a dominating signal during cell migration (besides the underlying mechanical effects). These results are qualitatively in agreement with well-known experimental ones.
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Affiliation(s)
- Seyed Jamaleddin Mousavi
- Group of Structural Mechanics and Materials Modelling (GEMM), Aragón Institute of Engineering Research (I3A), University of Zaragoza, Spain
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Effect of Transcutaneous Electrical Stimulation on Rabbit Corneal Epithelial Cell Migration. Cornea 2012; 31:559-63. [DOI: 10.1097/ico.0b013e31823f8b2a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nuccitelli R, Nuccitelli P, Li C, Narsing S, Pariser DM, Lui K. The electric field near human skin wounds declines with age and provides a noninvasive indicator of wound healing. Wound Repair Regen 2012; 19:645-55. [PMID: 22092802 DOI: 10.1111/j.1524-475x.2011.00723.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Due to the transepidermal potential of 15-50 mV, inside positive, an injury current is driven out of all human skin wounds. The flow of this current generates a lateral electric field within the epidermis that is more negative at the wound edge than at regions more lateral from the wound edge. Electric fields in this region could be as large as 40 mV/mm, and electric fields of this magnitude have been shown to stimulate human keratinocyte migration toward the wounded region. After flowing out of the wound, the current returns through the space between the epidermis and stratum corneum, generating a lateral field above the epidermis in the opposite direction. Here, we report the results from the first clinical trial designed to measure this lateral electric field adjacent to human skin wounds noninvasively. Using a new instrument, the Dermacorder®, we found that the mean lateral electric field in the space between the epidermis and stratum corneum adjacent to a lancet wound in 18-25-year-olds is 107-148 mV/mm, 48% larger on average than that in 65-80-year-olds. We also conducted extensive measurements of the lateral electric field adjacent to mouse wounds as they healed and compared this field with histological sections through the wound to determine the correlation between the electric field and the rate of epithelial wound closure. Immediately after wounding, the average lateral electric field was 122 ± 9 mV/mm. When the wound is filled in with a thick, disorganized epidermal layer, the mean field falls to 79 ± 4 mV/mm. Once this epidermis forms a compact structure with only three cell layers, the mean field is 59 ± 5 mV/mm. Thus, the peak-to-peak spatial variation in surface potential is largest in fresh wounds and slowly declines as the wound closes. The rate of wound healing is slightly greater when wounds are kept moist as expected, but we could find no correlation between the amplitude of the electric field and the rate of wound healing.
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Zhao M, Chalmers L, Cao L, Vieira AC, Mannis M, Reid B. Electrical signaling in control of ocular cell behaviors. Prog Retin Eye Res 2011; 31:65-88. [PMID: 22020127 DOI: 10.1016/j.preteyeres.2011.10.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 10/01/2011] [Accepted: 10/04/2011] [Indexed: 12/13/2022]
Abstract
Epithelia of the cornea, lens and retina contain a vast array of ion channels and pumps. Together they produce a polarized flow of ions in and out of cells, as well as across the epithelia. These naturally occurring ion fluxes are essential to the hydration and metabolism of the ocular tissues, especially for the avascular cornea and lens. The directional transport of ions generates electric fields and currents in those tissues. Applied electric fields affect migration, division and proliferation of ocular cells which are important in homeostasis and healing of the ocular tissues. Abnormalities in any of those aspects may underlie many ocular diseases, for example chronic corneal ulcers, posterior capsule opacity after cataract surgery, and retinopathies. Electric field-inducing cellular responses, termed electrical signaling here, therefore may be an unexpected yet powerful mechanism in regulating ocular cell behavior. Both endogenous electric fields and applied electric fields could be exploited to regulate ocular cells. We aim to briefly describe the physiology of the naturally occurring electrical activities in the corneal, lens, and retinal epithelia, to provide experimental evidence of the effects of electric fields on ocular cell behaviors, and to suggest possible clinical implications.
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Affiliation(s)
- Min Zhao
- Department of Dermatology, UC Davis School of Medicine, 2921 Stockton Blvd., Sacramento, CA 95817, USA.
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Directing migration of endothelial progenitor cells with applied DC electric fields. Stem Cell Res 2011; 8:38-48. [PMID: 22099019 PMCID: PMC3238468 DOI: 10.1016/j.scr.2011.08.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 07/11/2011] [Accepted: 08/05/2011] [Indexed: 12/22/2022] Open
Abstract
Naturally-occurring, endogenous electric fields (EFs) have been detected at skin wounds, damaged tissue sites and vasculature. Applied EFs guide migration of many types of cells, including endothelial cells to migrate directionally. Homing of endothelial progenitor cells (EPCs) to an injury site is important for repair of vasculature and also for angiogenesis. However, it has not been reported whether EPCs respond to applied EFs. Aiming to explore the possibility to use electric stimulation to regulate the progenitor cells and angiogenesis, we tested the effects of direct-current (DC) EFs on EPCs. We first used immunofluorescence to confirm the expression of endothelial progenitor markers in three lines of EPCs. We then cultured the progenitor cells in EFs. Using time-lapse video microscopy, we demonstrated that an applied DC EF directs migration of the EPCs toward the cathode. The progenitor cells also align and elongate in an EF. Inhibition of vascular endothelial growth factor (VEGF) receptor signaling completely abolished the EF-induced directional migration of the progenitor cells. We conclude that EFs are an effective signal that guides EPC migration through VEGF receptor signaling in vitro. Applied EFs may be used to control behaviors of EPCs in tissue engineering, in homing of EPCs to wounds and to an injury site in the vasculature.
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Messerli MA, Graham DM. Extracellular electrical fields direct wound healing and regeneration. THE BIOLOGICAL BULLETIN 2011; 221:79-92. [PMID: 21876112 DOI: 10.1086/bblv221n1p79] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Endogenous DC electric fields (EFs) are important, fundamental components of development, regeneration, and wound healing. The fields are the result of polarized ion transport and current flow through electrically conductive pathways. Nullification of endogenous EFs with pharmacological agents or applied EFs of opposite polarity disturbs the aforementioned processes, while enhancement increases the rate of wound closure and the extent of regeneration. EFs are applied to humans in the clinic, to provide an overwhelming signal for the enhancement of healing of chronic wounds. Although clinical trials, spanning a course of decades, have shown that applied EFs enhance healing of chronic wounds, the mechanisms by which cells sense and respond to these weak cues remains unknown. EFs are thought to influence many different processes in vivo. However, under more rigorously controlled conditions in vitro, applied EFs induce cellular polarity and direct migration and outgrowth. Here we review the generation of endogenous EFs, the results of their alteration, and the mechanisms by which cells may sense these weak fields. Understanding the mechanisms by which native and applied EFs direct development and repair will enable current and future therapeutic applications to be optimized.
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Affiliation(s)
- Mark A Messerli
- The Eugene Bell Center for Regenerative Biology and Tissue Engineering.
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50
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Sun YH, Reid B, Fontaine JH, Miller LA, Hyde DM, Mogilner A, Zhao M. Airway epithelial wounds in rhesus monkey generate ionic currents that guide cell migration to promote healing. J Appl Physiol (1985) 2011; 111:1031-41. [PMID: 21719726 DOI: 10.1152/japplphysiol.00915.2010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Damage to the respiratory epithelium is one of the most critical steps to many life-threatening diseases, such as acute respiratory distress syndrome and chronic obstructive pulmonary disease. The mechanisms underlying repair of the damaged epithelium have not yet been fully elucidated. Here we provide experimental evidence suggesting a novel mechanism for wound repair: endogenous electric currents. It is known that the airway epithelium maintains a voltage difference referred to as the transepithelial potential. Using a noninvasive vibrating probe, we demonstrate that wounds in the epithelium of trachea from rhesus monkeys generate significant outward electric currents. A small slit wound produced an outward current (1.59 μA/cm(2)), which could be enhanced (nearly doubled) by the ion transport stimulator aminophylline. In addition, inhibiting cystic fibrosis transmembrane conductance regulator (CFTR) with CFTR(Inh)-172 significantly reduced wound currents (0.17 μA/cm(2)), implicating an important role of ion transporters in wound induced electric potentials. Time-lapse video microscopy showed that applied electric fields (EFs) induced robust directional migration of primary tracheobronchial epithelial cells from rhesus monkeys, towards the cathode, with a threshold of <23 mV/mm. Reversal of the field polarity induced cell migration towards the new cathode. We further demonstrate that application of an EF promoted wound healing in a monolayer wound healing assay. Our results suggest that endogenous electric currents at sites of tracheal epithelial injury may direct cell migration, which could benefit restitution of damaged airway mucosa. Manipulation of ion transport may lead to novel therapeutic approaches to repair damaged respiratory epithelium.
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Affiliation(s)
- Yao-Hui Sun
- Department of Dermatology, School of Medicine, Univ. of California at Davis CA, Sacramento, CA 95817, USA
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