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Chaudhari SD, Sharma KK, Marchetto JJ, Hydren JR, Burton BM, Moreno AP. Modulating OPG and TGF-β1 mRNA expression via bioelectrical stimulation. Bone Rep 2021; 15:101141. [PMID: 34692946 PMCID: PMC8517839 DOI: 10.1016/j.bonr.2021.101141] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 09/29/2021] [Accepted: 10/05/2021] [Indexed: 12/05/2022] Open
Abstract
BACKGROUND Bone remodeling is a lifelong process that ranges from orthodontic tooth movement/alignment to bone damage/healing, to overall bone health. Osteoprotegerin (OPG) and transforming growth factor β1 (TGF-β1) are secreted by osteoblasts and participate in bone remodeling. OPG promotes bone remineralization and stabilization prominent in post-mechanical repositioning of the teeth in the dental alveolus. TGF-β1 participates in regulatory processes to promote osteoblast and osteoclast equilibrium. In the context of orthodontic tooth movement, post-treatment fixation requires additional, exogenous, stabilization support. Recent research showcases supplementary solutions, in conjunction to standard tooth fixation techniques, such as OPG injections into gum and periodontal tissues to accelerate tooth anchorage; however, injections are prone to post-procedure complications and discomfort. This study utilizes noninvasive bioelectric stimulation (BES) to modulate OPG and TGF-β1 as a novel solution to regulate bone remineralization specifically in the context of post-orthodontic tooth movement. PURPOSE The aim of this study was to investigate a spectrum of BES parameters that would modulate OPG and TGF-β1 expression in osteoblasts. METHODS Osteoblasts were cultured and stimulated using frequencies from 25 Hz to 3 MHz. RT-qPCR was used to quantify changes in OPG and TGFb-1 mRNA expression. RESULTS OPG mRNA expression was significantly increased at frequencies above 10,000 Hz with a maximum expression increase of 332 ± 8% at 100 kHz. Conversely, OPG mRNA expression was downregulated at frequencies lower than 1000 Hz. TGF-β1 mRNA expression increased throughout all stimulation frequencies with a peak of 332 ± 72% at 250 kHz. Alizarin Red tests for calcium, indicated that mineralization of stimulated osteoblasts in vitro increased 28% after 6 weeks in culture. DISCUSSION Results support the working hypothesis that OPG and TGF-β1 mRNA expression can be modulated through BES. Noninvasive BES approaches have the potential to accelerate bone remineralization by providing a novel tool to supplement the anchorage process, reduce complications, and promote patient compliance and reduce post-treatment relapse. Noninvasive BES may be applicable to other clinical applications as a novel therapeutic tool to modulate bone remodeling.
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Affiliation(s)
- Sejal D. Chaudhari
- OrthodontiCell Inc., Leonhardt Launchpads Utah, Inc., Salt Lake City, UT 84115, United States of America
| | - Kapil K. Sharma
- OrthodontiCell Inc., Leonhardt Launchpads Utah, Inc., Salt Lake City, UT 84115, United States of America
| | - John J. Marchetto
- OrthodontiCell Inc., Leonhardt Launchpads Utah, Inc., Salt Lake City, UT 84115, United States of America
- John J. Marchetto DMD, Weston, FL 33326, United States of America
| | - Jay R. Hydren
- OrthodontiCell Inc., Leonhardt Launchpads Utah, Inc., Salt Lake City, UT 84115, United States of America
| | - Brett M. Burton
- OrthodontiCell Inc., Leonhardt Launchpads Utah, Inc., Salt Lake City, UT 84115, United States of America
| | - Alonso P. Moreno
- OrthodontiCell Inc., Leonhardt Launchpads Utah, Inc., Salt Lake City, UT 84115, United States of America
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Darvishi M, Mashati P, Kandala S, Paridar M, Takhviji V, Ebrahimi H, Zibara K, Khosravi A. Electromagnetic radiation: a new charming actor in hematopoiesis? Expert Rev Hematol 2021; 14:47-58. [PMID: 32951483 DOI: 10.1080/17474086.2020.1826301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Electromagnetic waves play indispensable roles in life. Many studies addressed the outcomes of Electromagnetic field (EMF) on various biological functions such as cell proliferation, gene expression, epigenetic alterations, genotoxic, and carcinogenic effects, and its therapeutic applications in medicine. The impact of EMF on bone marrow (BM) is of high importance; however, EMF effects on BM hematopoiesis are not well understood. AREAS COVERED Publications in English were searched in ISI Web of Knowledge and Google Scholar with no restriction on publication date. A literature review has been conducted on the consequences of EMF exposure on BM non-hematopoietic stem cells, mesenchymal stem cells, and the application of these waves in regenerative medicine. Human blood cells such as lymphocytes, red blood cells and their precursors are altered qualitatively and quantitatively following electromagnetic radiation. Therefore, studying the impact of EMF on related signaling pathways in hematopoiesis and hematopoietic stem cell (HSC) differentiation could give a better insight into its efficacy on hematopoiesis and its potential therapeutic usage. EXPERT OPINION In this review, authors evaluated the possible biologic consequences of EMF on the hematopoiesis process in addition to its probable application in the treatment of hematologic disorders.
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Affiliation(s)
- Mina Darvishi
- Department of Laboratory Hematology and Blood Bank, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Pargol Mashati
- Department of Laboratory Hematology and Blood Bank, School of Allied Medical Sciences, Shahid Beheshti University of Medical Sciences , Tehran, Iran
| | - Sahithi Kandala
- University of Colorado, Boulder Department: Electrical, Computer and Energy Engineering , Colarada, USA
| | - Mostafa Paridar
- Deputy of Management and Resources Development, Ministry of Health and Medical Education , Tehran, Iran
| | - Vahideh Takhviji
- Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine , Tehran, Iran
| | - Hossein Ebrahimi
- School of Nursing, Ahvaz Jundishapur University of Medical Sciences , Ahvaz, Iran
| | - Kazem Zibara
- PRASE & Biology Department, Faculty of Sciences I, Lebanese University , Beirut, Lebanon
| | - Abbas Khosravi
- Transfusion Research Center, High Institute for Research and Education in Transfusion Medicine , Tehran, Iran
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Zhang B, Xie Y, Ni Z, Chen L. Effects and Mechanisms of Exogenous Electromagnetic Field on Bone Cells: A Review. Bioelectromagnetics 2020; 41:263-278. [PMID: 32159242 DOI: 10.1002/bem.22258] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 02/25/2020] [Indexed: 12/16/2022]
Abstract
Osteoporosis, fractures, and other bone diseases or injuries represent serious health problems in modern society. A variety of treatments including drugs, surgeries, physical therapies, etc. have been used to prevent or delay the progression of these diseases/injuries with limited effects. Electromagnetic field (EMF) has been used to non-invasively treat bone diseases, such as fracture and osteoporosis, for many years. However, because a variety of cellular and molecular events can be affected by EMF with various parameters, the precise bioeffects and underlying mechanisms of specific EMF on bone cells are still obscure. Here, we summarize the common therapeutic parameters (frequency and intensity) of major types of EMF used to treat bone cells taken from 32 papers we selected from the PubMed database published in English from 1991 to 2018. Briefly, pulse EMF promotes the proliferation of osteoblasts when its frequency is 7.5-15 Hz or 50-75 Hz and the intensity is 0.40-1.55 mT or 3.8-4 mT. Sinusoidal EMF, with 0.9-4.8 mT and 45-60 Hz, and static magnetic field with 0.1-0.4 mT or 400 mT, can promote osteoblast differentiation and maturation. Finally, we summarize the latest advances on the molecular signaling pathways influenced by EMF in osteoblasts and osteoclasts. A variety of molecules such as adenosine receptors, calcium channels, BMP2, Notch, Wnt1, etc., can be influenced by EMF in osteoblasts. For osteoclasts, EMF affects RANK, NF-κB, MAPK, etc. We speculate that EMF with different frequencies and intensities exert distinct bioeffects on specific bone cells. More high-quality work is required to explore the detailed effects and underlying mechanisms of EMF on bone cells/skeleton to optimize the application of EMF on bone diseases/injuries. Bioelectromagnetics. 2020;41:263-278 © 2020 Bioelectromagnetics Society.
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Affiliation(s)
- Bin Zhang
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Wound Repair and Rehabilitation, Center of Bone Metabolism and Repair, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China.,Center of Rehabilitation, Xingcheng Sanatorium of PLA Strategic Support Force, Xingcheng, China
| | - Yangli Xie
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Wound Repair and Rehabilitation, Center of Bone Metabolism and Repair, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Zhenhong Ni
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Wound Repair and Rehabilitation, Center of Bone Metabolism and Repair, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
| | - Lin Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Wound Repair and Rehabilitation, Center of Bone Metabolism and Repair, Trauma Center, Research Institute of Surgery, Daping Hospital, Army Medical University (Third Military Medical University), Chongqing, China
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Mohajerani H, Tabeie F, Vossoughi F, Jafari E, Assadi M. Effect of pulsed electromagnetic field on mandibular fracture healing: A randomized control trial, (RCT). JOURNAL OF STOMATOLOGY, ORAL AND MAXILLOFACIAL SURGERY 2019; 120:390-396. [PMID: 30836195 DOI: 10.1016/j.jormas.2019.02.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 02/06/2019] [Accepted: 02/25/2019] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Currently, the pulsed electromagnetic field (PEMF) method is utilized for the treatment of nonunion long bone fractures. Considering the established effect of the PEMF on the acceleration of the bone healing process, we conducted this study to evaluate the effect of PEMF on the healing process in mandibular bone fractures. MATERIAL AND METHODS This research was a randomized control trial (RCT) study. The sample consisted of patients with a mandibular fracture who were hospitalized in order to receive closed reduction treatment. The participants were randomly selected and then sequentially divided into two groups of 16 participants each (controls = 16, cases = 16). The patients in the control group received conventional therapy without any extra treatment, while the patients in the case group received PEMF therapy in addition to conventional therapy. For the PEMF therapy, patients in the case group received immediate post-surgery PEMF therapy for 6 h. Next, they received 3 h of exposure for the next 6 d, and finally, the same process was repeated for 1.5 h for post-surgery days 8-13. The maxillomandibular fixation (MMF) device was removed at post-surgery week 4. The patients in the control group, however, did not receive any extra treatment. The efficiency of the treatment modalities was evaluated clinically and radiographically. For the radiographical assessment, we employed a direct digital panoramic machine to calculate the computerized density of the bone, and those measurements were used for comparison of the results between the control group and the study patients. RESULTS There was no significant difference in the mean bone density values between the two groups (P > 0.05). However, the percentage of changes in bone density of the two groups revealed that the case group had insignificant decreases at post-surgery day 14 and a significant increase at post-surgery day 28 compared with the control group (P < 0.05). After releasing the MMF, a bimanual mobility test of the fractured segments showed the stability of the segments in all patients. In the case group, the mouth opening was significantly more stable than that of the control group (P < 0.05). CONCLUSION PEMF therapy postoperatively leads to increased bone density, faster recovery, increased formation of new bone, a further opening of the mouth, and decreased pain.
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Affiliation(s)
- H Mohajerani
- Department of Oral and Maxillofacial Surgery, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - F Tabeie
- Department of Nuclear Medicine, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - F Vossoughi
- Department of Oral and Maxillofacial Surgery, School of dentistry, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - E Jafari
- The Persian Gulf Nuclear Medicine Research Center, Bushehr University Of Medical Sciences, Bushehr, Iran
| | - M Assadi
- The Persian Gulf Nuclear Medicine Research Center, Bushehr University Of Medical Sciences, Bushehr, Iran.
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Enhancement of osteogenic differentiation of rat adipose tissue-derived mesenchymal stem cells by zinc sulphate under electromagnetic field via the PKA, ERK1/2 and Wnt/β-catenin signaling pathways. PLoS One 2017; 12:e0173877. [PMID: 28339498 PMCID: PMC5365128 DOI: 10.1371/journal.pone.0173877] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Accepted: 02/28/2017] [Indexed: 01/22/2023] Open
Abstract
Zinc ion as an essential trace element and electromagnetic fields (EMFs) has been reported to be involved in the regulation of bone metabolism. The aim of this study was to elucidate the effects of zinc sulphate (ZnSO4) on the osteogenic differentiation of adipose tissue-derived mesenchymal stem cells (ADSCs) in the presence of EMF as a strategy in osteoporosis therapy. Alkaline phophatase (ALP) activity measurement, calcium assay and expression of several osteoblastic marker genes were examined to assess the effect of ZnSO4 on the osteogenic differentiation of ADSCs under EMF. The expression of cAMP and PKA was evaluated by ELISA. The expression of β-catenin, Wnt1, Wnt3a, low-density lipoprotein receptor-related protein 5 (LRP5) and reduced dickkopf1 (DKK1) genes were used to detect the Wnt/β-catenin pathway. It was found that ZnSO4, in the presence of EMF, resulted in an increase in the expression of osteogenic genes, ALP activity and calcium levels. EMF, in the presence of ZnSO4, increased the cAMP level and protein kinase A (PKA) activity. Treatment of ADSCs with (MAPK)/ERK kinase 1/2 inhibitor, or PKA inhibitor, significantly inhibited the promotion of osteogenic markers, indicating that the induction of osteogenesis was dependent on the ERK and PKA signaling pathways. Real-time PCR analysis showed that ZnSO4, in the presence of EMF, increased the mRNA expressions of β-catenin, Wnt1, Wnt3a, LRP5 and DKK1. In this study, it was shown that 0.432 μg/ml ZnSO4, in the presence of 50 Hz, 20 mT EMF, induced the osteogenic differentiation of ADSCs via PKA, ERK1/2 and Wnt/β-catenin signaling pathways.
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Bilgin HM, Çelik F, Gem M, Akpolat V, Yıldız İ, Ekinci A, Özerdem MS, Tunik S. Effects of local vibration and pulsed electromagnetic field on bone fracture: A comparative study. Bioelectromagnetics 2017; 38:339-348. [DOI: 10.1002/bem.22043] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 02/08/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Hakkı Murat Bilgin
- Department of Physiology; Faculty of Medicine; Dicle University; Diyarbakir Turkey
| | - Ferhat Çelik
- Department of Physiology; Faculty of Medicine; Dicle University; Diyarbakir Turkey
| | - Mehmet Gem
- Orthopedics and Traumatology; Dicle University; Diyarbakir Turkey
| | | | | | - Aysun Ekinci
- Biochemistry; Dicle University; Diyarbakir Turkey
| | - Mehmet Siraç Özerdem
- Department of Electrical & Electronics Engineering; Faculty of Engineering; Dicle University; Diyarbakir Turkey
| | - Selçuk Tunik
- Histology and Embryology; Dicle University; Diyarbakir Turkey
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7
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Cellular processes involved in human epidermal cells exposed to extremely low frequency electric fields. Cell Signal 2015; 27:889-98. [DOI: 10.1016/j.cellsig.2015.02.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Accepted: 02/08/2015] [Indexed: 01/18/2023]
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8
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Yong Y, Ming ZD, Feng L, Chun ZW, Hua W. Electromagnetic fields promote osteogenesis of rat mesenchymal stem cells through the PKA and ERK1/2 pathways. J Tissue Eng Regen Med 2014; 10:E537-E545. [PMID: 24634418 DOI: 10.1002/term.1864] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 08/27/2013] [Accepted: 12/01/2013] [Indexed: 11/08/2022]
Abstract
It has been reported that electromagnetic fields (EMFs) can promote the healing of non-union, osteogenesis and differentiation of the osteoblasts. However, its mechanism has not been unravelled. In this study, we detected some response induced by EMF and evaluated the importance of these signals for EMF-induced osteogenesis in bone marrow mesenchymal stem cells (MSCs). We characterized the expression of EMF-induced osteogenesis markers in MSCs, using RT-PCR and real-time PCR. Western blot was used to detect the signalling pathways. We found that EMF could promote osteogenesis in MSCs, along with the expression of several osteogenic markers. EMF-induced cyclic adenosine monophosphate (cAMP) level increase causes protein kinase A (PKA) and extracellular signal-regulated kinase (ERK)1/2 phosphorylation. Pretreating the MSCs with the mitogen-activated protein kinase (MAPK)/ERK kinase 1/2 (MEK1/2) inhibitor PD98059, or the PKA inhibitor H-89, significantly inhibited the induction of osteogenic markers, showing that EMF induction of osteogenesis was dependent on the ERK and PKA signalling pathways. Therefore, our study showed that EMF promoted MSC osteogenesis and that the EMF-induced osteogenic markers were mediated by both the PKA and MAPK signalling pathways. Copyright © 2014 John Wiley & Sons, Ltd.
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Affiliation(s)
- Yang Yong
- Department of Orthopaedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, People's Republic of China
| | - Zhao Dong Ming
- Department of Orthopaedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, People's Republic of China
| | - Li Feng
- Department of Orthopaedics, Optical Valley School District, Hubei Hospital of Traditional Chinese Medicine, People's Republic of China
| | - Zhao Wen Chun
- Department of Engineering, Navy University of Engineering, Wuhan of Hubei province, People's Republic of China
| | - Wu Hua
- Department of Orthopaedics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, People's Republic of China.
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Hilz FM, Ahrens P, Grad S, Stoddart MJ, Dahmani C, Wilken FL, Sauerschnig M, Niemeyer P, Zwingmann J, Burgkart R, von Eisenhart-Rothe R, Südkamp NP, Weyh T, Imhoff AB, Alini M, Salzmann GM. Influence of extremely low frequency, low energy electromagnetic fields and combined mechanical stimulation on chondrocytes in 3-D constructs for cartilage tissue engineering. Bioelectromagnetics 2013; 35:116-28. [PMID: 24203577 DOI: 10.1002/bem.21822] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 09/16/2013] [Indexed: 12/21/2022]
Abstract
Articular cartilage, once damaged, has very low regenerative potential. Various experimental approaches have been conducted to enhance chondrogenesis and cartilage maturation. Among those, non-invasive electromagnetic fields have shown their beneficial influence for cartilage regeneration and are widely used for the treatment of non-unions, fractures, avascular necrosis and osteoarthritis. One very well accepted way to promote cartilage maturation is physical stimulation through bioreactors. The aim of this study was the investigation of combined mechanical and electromagnetic stress affecting cartilage cells in vitro. Primary articular chondrocytes from bovine fetlock joints were seeded into three-dimensional (3-D) polyurethane scaffolds and distributed into seven stimulated experimental groups. They either underwent mechanical or electromagnetic stimulation (sinusoidal electromagnetic field of 1 mT, 2 mT, or 3 mT; 60 Hz) or both within a joint-specific bioreactor and a coil system. The scaffold-cell constructs were analyzed for glycosaminoglycan (GAG) and DNA content, histology, and gene expression of collagen-1, collagen-2, aggrecan, cartilage oligomeric matrix protein (COMP), Sox9, proteoglycan-4 (PRG-4), and matrix metalloproteinases (MMP-3 and -13). There were statistically significant differences in GAG/DNA content between the stimulated versus the control group with highest levels in the combined stimulation group. Gene expression was significantly higher for combined stimulation groups versus static control for collagen 2/collagen 1 ratio and lower for MMP-13. Amongst other genes, a more chondrogenic phenotype was noticed in expression patterns for the stimulated groups. To conclude, there is an effect of electromagnetic and mechanical stimulation on chondrocytes seeded in a 3-D scaffold, resulting in improved extracellular matrix production.
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Affiliation(s)
- Florian M Hilz
- Department of Orthopaedic Sports Medicine, Technical University of Munich, Munich, Germany; AO Research Institute, Davos, Switzerland; Clinic of Orthopaedics and Sport Orthopaedics, Technical University of Munich, Munich, Germany
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Caputo M, Zirpoli H, De Rosa MC, Rescigno T, Chiadini F, Scaglione A, Stellato C, Giurato G, Weisz A, Tecce MF, Bisceglia B. Effect of low frequency (LF) electric fields on gene expression of a bone human cell line. Electromagn Biol Med 2013; 33:289-95. [PMID: 23977831 DOI: 10.3109/15368378.2013.822387] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We evaluated the effects, on cultured human SaOS-2 cells, of exposures to the low frequency (LF) electric signal (60 kHz sinusoidal wave, 24.5 V peak-to-peak voltage, amplitude modulated by a 12.5 Hz square wave, 50% duty cycle) from an apparatus of current clinical use in bone diseases requiring regenerating processes. Cells in flasks were exposed to a capacitively coupled electric field giving electric current density in the sample of 4 µA/cm(2). The whole expressed cellular mRNAs were systematically analyzed by "DNA microchips" technology to identify all individual species quantitatively affected by field exposure. Comparisons were made between RNA samples from exposed and control sham-exposed cells. Results indicated that immediately and 4 h after exposure there were almost no differentially modulated mRNA species. However, samples obtained at 24 h after exposure showed a small number of limitedly differential signals (7 down-regulated and 3 up-regulated with a cut-off value of ±1.5; 38 and 11, respectively, with a cut-off value of ±1.3), which included mostly mRNA encoding transcription factors and DNA binding proteins. Nevertheless, in identical experimental conditions, we previously demonstrated enzymatic changes of alkaline phosphatase occurring immediately after exposure and declining in a few hours. Therefore, since enzymatic changes occur before those observed at gene regulation level, it is conceivable that only earlier effects are directly due the treatment and then these effects are later able to affect gene expression only indirectly.
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Sundelacruz S, Levin M, Kaplan DL. Depolarization alters phenotype, maintains plasticity of predifferentiated mesenchymal stem cells. Tissue Eng Part A 2013; 19:1889-908. [PMID: 23738690 DOI: 10.1089/ten.tea.2012.0425.rev] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Although adult stem cell transplantation has been implemented as a therapy for tissue repair, it is limited by the availability of functional adult stem cells. A potential approach to generate stem and progenitor cells may be to modulate the differentiated status of somatic cells. Therefore, there is a need for a better understanding of how the differentiated phenotype of mature cells is regulated. We hypothesize that bioelectric signaling plays an important role in the maintenance of the differentiated state, as it is a functional regulator of the differentiation process in various cells and tissues. In this study, we asked whether the mature phenotype of osteoblasts and adipocytes derived from human mesenchymal stem cells (hMSCs) could be altered by modulation of their membrane potential. hMSC-derived osteoblasts and adipocytes were depolarized by treatment with ouabain, a Na(+)/K(+) ATPase inhibitor, or by treatment with high concentrations of extracellular K(+). To characterize the effect of voltage modulation on the differentiated state, the depolarized cells were evaluated for (1) the loss of differentiation markers; (2) the up-regulation of stemness markers and stem properties; and (3) differences in gene expression profiles in response to voltage modulation. hMSC-derived osteoblasts and adipocytes exhibited significant down-regulation of bone and fat tissue markers in response to depolarization, despite the presence of differentiation-inducing soluble factors, suggesting that bioelectric signaling overrides biochemical signaling in the maintenance of cell state. Suppression of the osteoblast or adipocyte phenotype was not accompanied by up-regulation of genes associated with the stem state. Thus, depolarization does not activate the stem cell genetic signature and, therefore, does not induce a full reprogramming event. However, after transdifferentiating the depolarized cells to evaluate for multi-lineage potential, depolarized osteoblasts demonstrated improved ability to achieve correct adipocyte morphology compared with nondepolarized osteoblasts. The present study thus demonstrates that depolarization reduces the differentiated phenotype of hMSC-derived cells and improves their transdifferentiation capacity, but does not restore a stem-like genetic profile. Through global transcript profiling of depolarized osteoblasts, we identified pathways that may mediate the effects of voltage signaling on cell state, which will require a detailed mechanistic inquiry in future studies.
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Affiliation(s)
- Sarah Sundelacruz
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, USA
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12
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Sundelacruz S, Levin M, Kaplan DL. Depolarization alters phenotype, maintains plasticity of pre-differentiated mesenchymal stem cells. Tissue Eng Part A 2013. [DOI: 10.1089/ten.tea.2012.0425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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13
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Collard JF, Lazar C, Nowé A, Hinsenkamp M. Statistical validation of the acceleration of the differentiation at the expense of the proliferation in human epidermal cells exposed to extremely low frequency electric fields. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 111:37-45. [PMID: 23257322 DOI: 10.1016/j.pbiomolbio.2012.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 12/06/2012] [Accepted: 12/07/2012] [Indexed: 11/26/2022]
Abstract
An acceleration of differentiation at the expense of proliferation is observed in our previous publications and in the literature after exposure of various biological models to low frequency and low-amplitude electric and electromagnetic fields. This observation is related with a significant modification of genes expression. We observed and compared over time this modification. This study use microarray data obtained on epidermis cultures harvested from human abdominoplasty exposed to ELF electric fields. This protocol is repeated with samples collected on three different healthy patients. The sampling over time allows comparison of the effect of the stimulus at a given time with the evolution of control group. After 4 days, we observed a significant difference of the genes expression between control (D4C) and stimulated (D4S) (p < 0.05). On the control between day 4 and 7, we observed another group of genes with significant difference (p < 0.05) in their expression. We identify the common genes between these two groups and we select from them those expressing no difference between stimulate at 4 days (D4S) and control after 7 days (D7C). The same analysis was performed with D4S-D4C-D12C and D7S-D7C-D12C. The lists of genes which follow this pattern show acceleration in their expressions under stimulation appearing on control at a later time. In this list, genes such as DKK1, SPRR3, NDRG4, and CHEK1 are involved in cell proliferation or differentiation. Numerous other genes are also playing a function in mitosis, cell cycle or in the DNA replication transcription and translation.
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Affiliation(s)
- J-F Collard
- Laboratoire de Recherche en Orthopédie Traumatologie (LROT), Hôpital Erasme, Université Libre de Bruxelles (ULB), 808, route de Lennik, B-1070 Brussels, Belgium
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Systemic treatment with pulsed electromagnetic fields do not affect bone microarchitecture in osteoporotic rats. INTERNATIONAL ORTHOPAEDICS 2012; 36:1501-6. [PMID: 22249842 PMCID: PMC3385882 DOI: 10.1007/s00264-011-1471-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 12/19/2011] [Indexed: 12/01/2022]
Abstract
Purpose Pulsed electromagnetic fields (PEMF) are currently used in the treatment of spinal fusions and non-unions. There are indications that PEMF might also be effective in the treatment of osteoporosis. In this study we examined whether whole-body PEMF treatment affects the bone microarchitecture in an osteoporotic rat model. Methods Twenty-week-old female rats were ovariectomised (n = 20). Four different PEMF treatment protocols based on previous experimental studies and based on clinically used PEMF signals were examined (2 h/day, 5 days/week). A control group did not receive PEMF. At zero, three and six weeks cancellous and cortical bone architectural changes at the proximal tibia were evaluated using in vivo microCT scanning. Results PEMF treatment did not induce any changes in cancellous or cortical bone compared to untreated controls. Conclusions Although previous studies have shown strong effects of PEMF in osteoporosis we were unable to demonstrate this in any of the treatment protocols. Using in vivo microCT scanning we were able to identify small bone changes in time. Subtle differences in the experimental set-up might explain the differences in study outcomes in the literature. Since PEMF treatment is safe, future experimental studies on the effect of PEMF on bone can better be performed directly on humans, eliminating the potential translation issues between animals and humans. In this study we found no support for the use of PEMF in the treatment of osteoporosis.
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