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Patel J, Deschler E, Galang E. Spinal cord stimulation for the symptomatic treatment of rigidity and painful spasm in a case of stiff person syndrome. Pain Pract 2024. [PMID: 38185725 DOI: 10.1111/papr.13340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
BACKGROUND Stiff person syndrome (SPS) is a rare neuroimmunological disorder characterized by rigidity and painful spasm primarily affecting the truncal and paraspinal musculature due to autoimmune-mediated neuronal hyperexcitability. Spinal cord stimulation (SCS) is an approved therapy for managing painful neuropathic conditions, including diabetic peripheral neuropathy and refractory angina pectoris. We describe the novel use of SCS for the treatment of spasm and rigidity in a 49-year-old man with seropositive stiff person syndrome (SPS). The patient was treated with intravenous immunoglobulin (IVIG) and oral medications over a 13-month period with minimal improvement, prompting consideration of SCS. To our knowledge, this is the first report of the successful use of SCS in SPS with the demonstration of multifaceted clinical improvement. METHODS Following a successful temporary SCS trial, permanent implantation was performed. Spasm/stiffness (Distribution of Stiffness Index; Heightened Sensitivity Scale; Penn Spasm Frequency Scale, PSFS), disability (Oswestry Disability Index, ODI; Pain Disability Index, PDI), depression (Patient Health Questionnaire-9, PHQ-9), sleep (Pittsburgh Sleep Quality Index, PSQI), fatigue (Fatigue Severity Scale, FSS), pain (Numerical Pain Rating Scale, NPRS), quality of life (EuroQoL 5 Dimension 5 Level, EQ-5D-5L), and medication usage were assessed at baseline, 6-month, and 10-month postimplantation. RESULTS ODI, PHQ-9, FSS, NPRS, PSQI, and EQ-5D-5L scores showed a notable change from baseline and surpassed the defined minimal clinically important difference (MCID) at 6-month and 10-month follow-up. Oral medication dosages were reduced. CONCLUSIONS The novel use of SCS therapy in seropositive SPS resulted in functional improvement and attenuation of symptoms. We present possible mechanisms by which SCS may produce clinical response in patients with SPS and aim to demonstrate proof-of-concept for a future comprehensive pilot study evaluating SCS-mediated response in SPS.
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Affiliation(s)
- Janus Patel
- Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Emily Deschler
- Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
| | - Enrique Galang
- Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina, USA
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Petersen EA. Spinal cord stimulation in painful diabetic neuropathy: An overview. Diabetes Res Clin Pract 2023; 206 Suppl 1:110760. [PMID: 38245324 DOI: 10.1016/j.diabres.2023.110760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 05/30/2023] [Indexed: 01/22/2024]
Abstract
Up to 25% of people with diabetes develop painful diabetic neuropathy (PDN). The standard of care pharmacotherapies for PDN have limited efficacy with a considerable side effect profile. Spinal cord stimulation (SCS) is a form of electrical neurostimulation that modulates neural function via electrodes implanted into the spinal epidural space. While low frequency SCS has been shown to be potentially effective for treating pain associated with neuropathies, it masks pain perception by inducing paresthesia. Compared to low frequency SCS, high frequency (10 kHz) SCS delivers paresthesia-free therapy. As was shown in a randomized controlled trial, SENZA-PDN (NCT03228420), 10 kHz SCS is safe and effective for the treatment of painful diabetic neuropathy. 10 kHz SCS offered a comprehensive treatment that improved pain levels, sleep, quality of life, and neurological function. These improvements correlated with a high degree of patient satisfaction. 10 kHz SCS provides a safe, durable and effective treatment for PDN with the unique potential to improve neurological function. In patients for whom durable, effective treatments have been limited thus far, the findings of the SENZA-PDN study are encouraging.
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Affiliation(s)
- Erika A Petersen
- University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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3
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Paladini A, Vallejo R, Guerrero M, Pasqualucci A, Peppin JF, Pergolizzi J, Varrassi G. Answering Big Questions in Pain Medicine. Cureus 2023; 15:e43561. [PMID: 37719539 PMCID: PMC10502917 DOI: 10.7759/cureus.43561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 08/16/2023] [Indexed: 09/19/2023] Open
Abstract
The future of pain medicine is marked by many questions. What can other nations around the world learn from the opioid crisis that is still affecting the United States? The American opioid experience was mischaracterized and wrongly described, and its causes were misdiagnosed from the outset, leading to its mismanagement and the abandonment of many chronic pain patients to their suffering. There are a few new drugs in the analgesic armamentarium. What new targets do we have in pain medicine? There are many breakthroughs, discoveries, and potential new targets that could add to our analgesic prescribing choices. These include sigma receptors, d-amino acid oxidase, endoplasmic reticulum stress receptors, histone deacetylase, and others. Neuromodulation had been used with varying degrees of success for years, but with a simplistic approach based on the gate theory of pain. Despite our familiarity with neuromodulation and spinal cord stimulators, neuromodulation research indicates that the activation of glial cells may activate the immune system and enhance analgesia. Neuromodulation studies have concentrated on how electricity affects neuronal activity rather than how electrical activity could reduce pain. There are still more frontiers in our battle against pain and some promising avenues for treatments. This narrative review will try to summarize what can be done from the perspective of recent technological and pharmacological developments.
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Affiliation(s)
- Antonella Paladini
- Department of Life, Health & Environmental Sciences (MESVA), University of L'Aquila, L'Aquila, ITA
| | - Ricardo Vallejo
- Department of Research, Millennium Pain Center, Bloomington, USA
| | - Marixa Guerrero
- Department of Pain Medicine/ Pain Management, Clínica del Country, Bogota, COL
| | - Alberto Pasqualucci
- Department of Anesthesia and Critical Care, University of Perugia, Perugia, ITA
| | - John F Peppin
- Department of Osteopathic Medicine, Marian University, Indianapolis, USA
| | - Joseph Pergolizzi
- Department of Anesthesiology, Pain Medicine, and Critical Care Medicine, Nema Research, Naples, USA
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Sivanesan E, Sanchez KR, Zhang C, He SQ, Linderoth B, Stephens KE, Raja SN, Guan Y. Spinal Cord Stimulation Increases Chemoefficacy and Prevents Paclitaxel-Induced Pain via CX3CL1. Neuromodulation 2023; 26:938-949. [PMID: 37045646 PMCID: PMC10330336 DOI: 10.1016/j.neurom.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/19/2023] [Accepted: 03/13/2023] [Indexed: 04/14/2023]
Abstract
INTRODUCTION Despite increasing utilization of spinal cord stimulation (SCS), its effects on chemoefficacy, cancer progression, and chemotherapy-induced peripheral neuropathy (CIPN) pain remain unclear. Up to 30% of adults who are cancer survivors may suffer from CIPN, and there are currently no effective preventative treatments. MATERIALS AND METHODS Through a combination of bioluminescent imaging, behavioral, biochemical, and immunohistochemical approaches, we investigated the role of SCS and paclitaxel (PTX) on tumor growth and PTX-induced peripheral neuropathy (PIPN) pain development in T-cell-deficient male rats (Crl:NIH-Foxn1rnu) with xenograft human non-small cell lung cancer. We hypothesized that SCS can prevent CIPN pain and enhance chemoefficacy partially by modulating macrophages, fractalkine (CX3CL1), and inflammatory cytokines. RESULTS We show that preemptive SCS enhanced the antitumor efficacy of PTX and prevented PIPN pain. Without SCS, rats with and without tumors developed robust PIPN pain-related mechanical hypersensitivity, but only those with tumors developed cold hypersensitivity, suggesting T-cell dependence for different PIPN pain modalities. SCS increased soluble CX3CL1 and macrophages and decreased neuronal and nonneuronal insoluble CX3CL1 expression and inflammation in dorsal root ganglia. CONCLUSION Collectively, our findings suggest that preemptive SCS is a promising strategy to increase chemoefficacy and prevent PIPN pain via CX3CL1-macrophage modulation.
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Affiliation(s)
- Eellan Sivanesan
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| | - Karla R Sanchez
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Chi Zhang
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Shao-Qiu He
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Bengt Linderoth
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Kimberly E Stephens
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Arkansas Children's Research Institute, Little Rock, AR, USA
| | - Srinivasa N Raja
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA; Department of Neurological Surgery, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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Williams NP, Kushwah N, Dhawan V, Zheng XS, Cui XT. Effects of central nervous system electrical stimulation on non-neuronal cells. Front Neurosci 2022; 16:967491. [PMID: 36188481 PMCID: PMC9521315 DOI: 10.3389/fnins.2022.967491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 08/10/2022] [Indexed: 11/13/2022] Open
Abstract
Over the past few decades, much progress has been made in the clinical use of electrical stimulation of the central nervous system (CNS) to treat an ever-growing number of conditions from Parkinson's disease (PD) to epilepsy as well as for sensory restoration and many other applications. However, little is known about the effects of microstimulation at the cellular level. Most of the existing research focuses on the effects of electrical stimulation on neurons. Other cells of the CNS such as microglia, astrocytes, oligodendrocytes, and vascular endothelial cells have been understudied in terms of their response to stimulation. The varied and critical functions of these cell types are now beginning to be better understood, and their vital roles in brain function in both health and disease are becoming better appreciated. To shed light on the importance of the way electrical stimulation as distinct from device implantation impacts non-neuronal cell types, this review will first summarize common stimulation modalities from the perspective of device design and stimulation parameters and how these different parameters have an impact on the physiological response. Following this, what is known about the responses of different cell types to different stimulation modalities will be summarized, drawing on findings from both clinical studies as well as clinically relevant animal models and in vitro systems.
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Affiliation(s)
- Nathaniel P. Williams
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, Pittsburgh, PA, United States
| | - Neetu Kushwah
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Vaishnavi Dhawan
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, Pittsburgh, PA, United States
| | - Xin Sally Zheng
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition, Pittsburgh, PA, United States
- McGowan Institute for Regenerative Medicine, Pittsburgh, PA, United States
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Chakravarthy K, Reddy R, Al-Kaisy A, Yearwood T, Grider J. A Call to Action Toward Optimizing the Electrical Dose Received by Neural Targets in Spinal Cord Stimulation Therapy for Neuropathic Pain. J Pain Res 2021; 14:2767-2776. [PMID: 34522135 PMCID: PMC8434932 DOI: 10.2147/jpr.s323372] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/16/2021] [Indexed: 12/20/2022] Open
Abstract
Spinal cord stimulation has seen unprecedented growth in new technology in the 50 years since the first subdural implant. As we continue to grow our understanding of spinal cord stimulation and relevant mechanisms of action, novel questions arise as to electrical dosing optimization. Programming adjustment — dose titration — is often a process of trial and error that can be time-consuming and frustrating for both patient and clinician. In this report, we review the current preclinical and clinical knowledge base in order to provide insights that may be helpful in developing more rational approaches to spinal cord stimulation dosing. We also provide key conclusions that may help in directing future research into electrical dosing, given the advent of newer waveforms outside traditional programming parameters.
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Affiliation(s)
- Krishnan Chakravarthy
- Department of Anesthesiology and Pain Medicine, University of California San Diego Health Sciences, San Diego, CA, USA.,VA San Diego Healthcare System, San Diego, Ca, USA
| | - Rajiv Reddy
- Department of Anesthesiology and Pain Medicine, University of California San Diego Health Sciences, San Diego, CA, USA
| | - Adnan Al-Kaisy
- Pain Management and Neuromodulation Centre at Guy's and St. Thomas' NHS Trust, London, UK
| | - Thomas Yearwood
- Pain Management and Neuromodulation Centre at Guy's and St. Thomas' NHS Trust, London, UK
| | - Jay Grider
- Division of Pain Medicine, Department of Anesthesiology, University of Kentucky College of Medicine, Lexington, KY, 40536, USA
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Cedeño DL, Kelley CA, Chakravarthy K, Vallejo R. Modulation of Glia-Mediated Processes by Spinal Cord Stimulation in Animal Models of Neuropathic Pain. FRONTIERS IN PAIN RESEARCH 2021; 2:702906. [PMID: 35295479 PMCID: PMC8915735 DOI: 10.3389/fpain.2021.702906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/31/2021] [Indexed: 12/23/2022] Open
Abstract
Glial cells play an essential role in maintaining the proper functioning of the nervous system. They are more abundant than neurons in most neural tissues and provide metabolic and catabolic regulation, maintaining the homeostatic balance at the synapse. Chronic pain is generated and sustained by the disruption of glia-mediated processes in the central nervous system resulting in unbalanced neuron–glial interactions. Animal models of neuropathic pain have been used to demonstrate that changes in immune and neuroinflammatory processes occur in the course of pain chronification. Spinal cord stimulation (SCS) is an electrical neuromodulation therapy proven safe and effective for treating intractable chronic pain. Traditional SCS therapies were developed based on the gate control theory of pain and rely on stimulating large Aβ neurons to induce paresthesia in the painful dermatome intended to mask nociceptive input carried out by small sensory neurons. A paradigm shift was introduced with SCS treatments that do not require paresthesia to provide effective pain relief. Efforts to understand the mechanism of action of SCS have considered the role of glial cells and the effect of electrical parameters on neuron–glial interactions. Recent work has provided evidence that SCS affects expression levels of glia-related genes and proteins. This inspired the development of a differential target multiplexed programming (DTMP) approach using electrical signals that can rebalance neuroglial interactions by targeting neurons and glial cells differentially. Our group pioneered the utilization of transcriptomic and proteomic analyses to identify the mechanism of action by which SCS works, emphasizing the DTMP approach. This is an account of evidence demonstrating the effect of SCS on glia-mediated processes using neuropathic pain models, emphasizing studies that rely on the evaluation of large sets of genes and proteins. We show that SCS using a DTMP approach strongly affects the expression of neuron and glia-specific transcriptomes while modulating them toward expression levels of healthy animals. The ability of DTMP to modulate key genes and proteins involved in glia-mediated processes affected by pain toward levels found in uninjured animals demonstrates a shift in the neuron–glial environment promoting analgesia.
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Affiliation(s)
- David L. Cedeño
- Research and Development, Lumbrera LLC, Bloomington, IL, United States
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, United States
- *Correspondence: David L. Cedeño
| | - Courtney A. Kelley
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, United States
| | - Krishnan Chakravarthy
- Deparment of Anesthesiology and Pain Medicine, University of California, San Diego, La Jolla, CA, United States
| | - Ricardo Vallejo
- Research and Development, Lumbrera LLC, Bloomington, IL, United States
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL, United States
- Research Department, National Spine and Pain Center, Bloomington, IL, United States
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8
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Zheng XS, Yang Q, Vazquez AL, Tracy Cui X. Imaging the Efficiency of Poly(3,4-ethylenedioxythiophene) Doped with Acid-Functionalized Carbon Nanotube and Iridium Oxide Electrode Coatings for Microstimulation. ADVANCED NANOBIOMED RESEARCH 2021; 1:2000092. [PMID: 34746928 PMCID: PMC8552016 DOI: 10.1002/anbr.202000092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 03/18/2021] [Indexed: 12/02/2022] Open
Abstract
Electrical microstimulation has shown promise in restoring neural deficits in humans. Electrodes coated with materials like the conducting polymer poly(3,4-ethylenedioxythiophene) doped with acid-functionalized carbon nanotubes (PEDOT/CNTs, or PC) exhibit superior charge injection than traditional metals like platinum. However, the stimulation performance of PC remains to be fully characterized. Advanced imaging techniques and transgenic tools allow for real-time observations of neural activity in vivo. Herein, microelectrodes coated with PC and iridium oxide (IrOx) (a commonly used high-charge-injection material) are implanted in GCaMP6s mice and electrical stimulation is applied while imaging neuronal calcium responses. Results show that PC-coated electrodes stimulate more intense and broader GCaMP responses than IrOx. Two-photon microscopy reveals that PC-coated electrodes activate significantly more neuronal soma and neuropil than IrOx-coated electrodes in constant-voltage stimulation and significantly more neuronal soma in constant-current stimulation. Furthermore, with the same injected charge, both materials activate more spatially confined neural elements with shorter pulses than longer pulses, providing a means to tune stimulation selectivity. Finite element analyses reveal that the PC coating creates a denser and nonuniform electric field, increasing the likelihood of activating nearby neural elements. PC coating can significantly improve energy efficiency for electrical stimulation applications.
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Affiliation(s)
- Xin S. Zheng
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Qianru Yang
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
| | - Alberto L. Vazquez
- Departments of Radiology and BioengineeringUniversity of Pittsburgh3025 E. Carson St.PittsburghPA15203USA
| | - Xinyan Tracy Cui
- Department of BioengineeringUniversity of Pittsburgh3501 Fifth Ave.PittsburghPA15213USA
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Exploration of the Supraspinal Hypotheses about Spinal Cord Stimulation and Dorsal Root Ganglion Stimulation: A Systematic Review. J Clin Med 2021; 10:jcm10132766. [PMID: 34201877 PMCID: PMC8268298 DOI: 10.3390/jcm10132766] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/19/2021] [Accepted: 06/20/2021] [Indexed: 12/27/2022] Open
Abstract
Despite the established efficacy and effectiveness of Spinal Cord Stimulation (SCS), there is still no consensus on the supraspinal mechanisms of action of this therapy. The purpose of this study was to systematically review previously raised hypotheses concerning supraspinal mechanisms of action of SCS based on human, animal and computational studies. Searches were conducted using four electronic databases (PubMed, EMBASE, SCOPUS and Web of Science), backward reference searching and consultation with experts. The study protocol was registered prior to initiation of the review process (PROSPERO CRD42020161531). A total of 54 publications were included, 21 of which were animal studies, and 33 were human studies. The supraspinal hypotheses (n = 69) identified from the included studies could be categorized into six groups concerning the proposed supraspinal hypothesis, namely descending pathways (n = 24); ascending medial pathway (n = 13); ascending lateral pathway (n = 10); affective/motivational influences (n = 8); spinal–cerebral (thalamic)-loop (n = 3) and miscellaneous (n = 11). Scientific support is provided for the hypotheses identified. Modulation of the descending nociceptive inhibitory pathways, medial and lateral pathways were the most frequently reported hypotheses about the supraspinal mechanisms of action of SCS. These hypotheses were mainly supported by studies with a high or moderate confidence in the body of evidence.
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Zheng XS, Tan C, Castagnola E, Cui XT. Electrode Materials for Chronic Electrical Microstimulation. Adv Healthc Mater 2021; 10:e2100119. [PMID: 34029008 PMCID: PMC8257249 DOI: 10.1002/adhm.202100119] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/20/2021] [Indexed: 02/06/2023]
Abstract
Electrical microstimulation has enabled partial restoration of vision, hearing, movement, somatosensation, as well as improving organ functions by electrically modulating neural activities. However, chronic microstimulation is faced with numerous challenges. The implantation of an electrode array into the neural tissue triggers an inflammatory response, which can be exacerbated by the delivery of electrical currents. Meanwhile, prolonged stimulation may lead to electrode material degradation., which can be accelerated by the hostile inflammatory environment. Both material degradation and adverse tissue reactions can compromise stimulation performance over time. For stable chronic electrical stimulation, an ideal microelectrode must present 1) high charge injection limit, to efficiently deliver charge without exceeding safety limits for both tissue and electrodes, 2) small size, to gain high spatial selectivity, 3) excellent biocompatibility that ensures tissue health immediately next to the device, and 4) stable in vivo electrochemical properties over the application period. In this review, the challenges in chronic microstimulation are described in detail. To aid material scientists interested in neural stimulation research, the in vitro and in vivo testing methods are introduced for assessing stimulation functionality and longevity and a detailed overview of recent advances in electrode material research and device fabrication for improving chronic microstimulation performance is provided.
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Affiliation(s)
- Xin Sally Zheng
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Chao Tan
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Elisa Castagnola
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Xinyan Tracy Cui
- Department of Bioengineering, University of Pittsburgh, 3501 Fifth Ave. Pittsburgh, Pittsburgh, PA, 15213, USA
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11
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Safety and efficacy of umbilical cord-derived Wharton's jelly compared to hyaluronic acid and saline for knee osteoarthritis: study protocol for a randomized, controlled, single-blind, multi-center trial. J Orthop Surg Res 2021; 16:352. [PMID: 34059080 PMCID: PMC8165766 DOI: 10.1186/s13018-021-02475-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/06/2021] [Indexed: 12/15/2022] Open
Abstract
Background Osteoarthritis (OA) is the most common joint disorder in the United States of America (USA) with a fast-rising prevalence. Current treatment modalities are limited, and total knee replacement surgeries have shown disadvantages, especially for grade II/III OA. The interest in the use of biologics, including umbilical cord (UC)-derived Wharton’s jelly (WJ), has grown in recent years. The results from a preliminary study demonstrated the presence of essential components of regenerative medicine, namely growth factors, cytokines, hyaluronic acid (HA), and extracellular vesicles, including exosomes, in WJ. The proposed study aims to evaluate the safety and efficacy of intra-articular injection of UC-derived WJ for the treatment of knee OA symptoms. Methods A randomized, controlled, single-blind, multi-center, prospective study will be conducted in which the safety and efficacy of intra-articular administration of UC-derived WJ are compared to HA (control) and saline (placebo control) in patients suffering from grade II/III knee OA. A total of 168 participants with grade II or III knee OA on the KL scale will be recruited across 53 sites in the USA with 56 participants in each arm and followed for 1 year post-injection. Patient satisfaction, Numeric Pain Rating Scale, Knee Injury and Osteoarthritis Outcome Score, 36-Item Short Form Survey (SF-36), and 7-point Likert Scale will be used to assess the participants. Physical exams, X-rays, and MRI with Magnetic Resonance Observation of Cartilage Repair Tissue score will be used to assess improvement in associated anatomy. Discussion The study results will provide valuable information into the safety and efficacy of intra-articular administration of Wharton’s jelly for grade II/III knee osteoarthritis. The results of this study will also add to the treatment options available for grade II/III OA as well as help facilitate the development of a more focused treatment strategy for patients. Trial registration ClinicalTrials.gov, NCT04711304. Registered on January 15, 2021
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12
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Spinal cord stimulation in chronic neuropathic pain: mechanisms of action, new locations, new paradigms. Pain 2021; 161 Suppl 1:S104-S113. [PMID: 33090743 PMCID: PMC7434213 DOI: 10.1097/j.pain.0000000000001854] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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13
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Smith WJ, Cedeño DL, Thomas SM, Kelley CA, Vetri F, Vallejo R. Modulation of microglial activation states by spinal cord stimulation in an animal model of neuropathic pain: Comparing high rate, low rate, and differential target multiplexed programming. Mol Pain 2021; 17:1744806921999013. [PMID: 33626981 PMCID: PMC7925954 DOI: 10.1177/1744806921999013] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
While numerous studies and patient experiences have demonstrated the efficacy of spinal cord stimulation as a treatment for chronic neuropathic pain, the exact mechanism underlying this therapy is still uncertain. Recent studies highlighting the importance of microglial cells in chronic pain and characterizing microglial activation transcriptomes have created a focus on microglia in pain research. Our group has investigated the modulation of gene expression in neurons and glial cells after spinal cord stimulation (SCS), specifically focusing on transcriptomic changes induced by varying SCS stimulation parameters. Previous work showed that, in rodents subjected to the spared nerve injury (SNI) model of neuropathic pain, a differential target multiplexed programming (DTMP) approach provided significantly better relief of pain-like behavior compared to high rate (HRP) and low rate programming (LRP). While these studies demonstrated the importance of transcriptomic changes in SCS mechanism of action, they did not specifically address the role of SCS in microglial activation. The data presented herein utilizes microglia-specific activation transcriptomes to further understand how an SNI model of chronic pain and subsequent continuous SCS treatment with either DTMP, HRP, or LRP affects microglial activation. Genes for each activation transcriptome were identified within our dataset and gene expression levels were compared with that of healthy animals, naïve to injury and interventional procedures. Pearson correlations indicated that DTMP yields the highest significant correlations to expression levels found in the healthy animals across all microglial activation transcriptomes. In contrast, HRP or LRP yielded weak or very weak correlations for these transcriptomes. This work demonstrates that chronic pain and subsequent SCS treatments can modulate microglial activation transcriptomes, supporting previous research on microglia in chronic pain. Furthermore, this study provides evidence that DTMP is more effective than HRP and LRP at modulating microglial transcriptomes, offering potential insight into the therapeutic efficacy of DTMP.
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Affiliation(s)
- William J Smith
- Research and Development, Lumbrera LLC, Bloomington, IL, USA.,Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - David L Cedeño
- Research and Development, Lumbrera LLC, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Samuel M Thomas
- College of Osteopathic Medicine, Des Moines University, Des Moines, IA, USA
| | - Courtney A Kelley
- Research and Development, Lumbrera LLC, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | | | - Ricardo Vallejo
- Research and Development, Lumbrera LLC, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA.,National Spine and Pain Centers, Bloomington, IL, USA
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Vallejo R, Kelley CA, Gupta A, Smith WJ, Vallejo A, Cedeño DL. Modulation of neuroglial interactions using differential target multiplexed spinal cord stimulation in an animal model of neuropathic pain. Mol Pain 2021; 16:1744806920918057. [PMID: 32290778 PMCID: PMC7160773 DOI: 10.1177/1744806920918057] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The development and maintenance of chronic neuropathic pain involves distorted
neuroglial interactions, which result in prolonged perturbations of immune and
inflammatory response, as well as disrupted synapses and cellular interactions.
Spinal cord stimulation (SCS) has proven effective and safe for more than
40 years, but comprehensive understanding of its mode of action remains elusive.
Previous work in our laboratory provided evidence that conventional SCS
parameters modulate biological processes associated with neuropathic pain in
animals. This inspired the development of differential target multiplexed
programming (DTMP) in which multiple electrical signals are used for modulating
glial cells and neurons in order to rebalance their interactions. This work
compares DTMP with both low rate and high rate programming using an animal model
of neuropathic pain. The spared nerve injury model was implemented in 48 rats
equally randomized into four experimental groups: No-SCS, DTMP, low rate, and
high rate. Naive animals (N = 7) served as a reference control. SCS was applied
continuously for 48 h and pain-related behavior assessed before and after SCS.
RNA from the spinal cord exposed to SCS was sequenced to determine changes in
gene expression as a result of injury (No-SCS vs. naïve) and as a result of SCS
(SCS vs. No-SCS). Bioinformatics tools (Weighted Gene Co-expression Network
Analysis and Gene Ontology Enrichment Analysis) were used to evaluate the
significance of the results. All three therapies significantly reduced
mechanical hypersensitivity, although DTMP provided statistically better results
overall. DTMP also reduced thermal hypersensitivity significantly.
RNA-sequencing corroborated the complex effects of nerve injury on the
transcriptome. In addition, DTMP provided significantly more effective
modulation of genes associated with pain-related processes in returning their
expression toward levels observed in naïve, noninjured animals. DTMP provides a
more effective way of modulating the expression of genes involved in
pain-relevant biological processes associated with neuroglial interactions.
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Affiliation(s)
- Ricardo Vallejo
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Courtney A Kelley
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Ashim Gupta
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA.,Department of Research, South Texas Orthopaedic Research Institute, Laredo, TX, USA
| | - William J Smith
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Alejandro Vallejo
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA
| | - David L Cedeño
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
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15
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Gupta A, Maffulli N, Rodriguez HC, Lee CE, Levy HJ, El-Amin SF. Umbilical cord-derived Wharton's jelly for treatment of knee osteoarthritis: study protocol for a non-randomized, open-label, multi-center trial. J Orthop Surg Res 2021; 16:143. [PMID: 33602286 PMCID: PMC7890617 DOI: 10.1186/s13018-021-02300-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 02/10/2021] [Indexed: 12/15/2022] Open
Abstract
Background Osteoarthritis (OA) is the most common joint disorder in the USA, and knee OA has the highest prevalence. Inflammation and decrease in vascularization are key factors in the degeneration of articular cartilage and the associated pain and decrease in function. To combat this process, the use of biologics including umbilical cord-derived Wharton’s Jelly (UC-derived WJ) has grown. UC-derived WJ contains large quantities of regenerative factors, including growth factors (GFs), cytokines (CKs), hyaluronic acid (HA), and extracellular vesicles (EVs). The proposed study evaluates the safety and efficacy of intraarticular injection of UC-derived WJ for treatment of knee OA symptoms. Methods and analysis This is a non-randomized, open-label, multi-center, prospective study in which the safety and efficacy of intraarticular UC-derived WJ in patients suffering from grade II/III OA will be assessed. Twelve patients with grade II/III OA who meet the inclusion and exclusion criteria will be recruited for this study which will be conducted at up to two sites within the USA. The participants will be followed for 1 s. Participants will be assessed using the Numeric Pain Rating Scale (NPRS), Knee Injury and Osteoarthritis Outcome Score (KOOS), 36-item short form survey (SF-36), Single Assessment Numeric Evaluation (SANE), physical exams, plain radiography, and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score for improvements in pain, satisfaction, function, and cartilage regeneration. Discussion This prospective study will contribute to the limited amount of data on UC-derived WJ, particularly with regard to its safety and efficacy. The outcomes from this study will also lay the groundwork for a large placebo-controlled trial of intraarticular UC-derived WJ for symptomatic knee OA. Trial registration ClinicalTrials.gov NCT04719793. Registered on 22 January 2021
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Affiliation(s)
- Ashim Gupta
- BioIntegrate, Lawrenceville, GA, USA.,Future Biologics, Lawrenceville, GA, USA.,South Texas Orthopedic Research Institute (STORI Inc.), Laredo, TX, USA.,Veterans in Pain (V.I.P.), Los Angeles, CA, USA
| | - Nicola Maffulli
- Department of Musculoskeletal Disorders, School of Medicine and Surgery, University of Salerno, Fisciano, Italy.,San Giovanni di Dio e Ruggi D'Aragona Hospital "Clinica Orthopedica" Department, Hospital of Salerno, Salerno, Italy.,Barts and the London School of Medicine and Dentistry, Centre for Sports and Exercise Medicine, Queen Mary University of London, London, UK.,School of Pharmacy and Bioengineering, Keele University School of Medicine, Stoke on Trent, UK
| | - Hugo C Rodriguez
- Future Biologics, Lawrenceville, GA, USA.,South Texas Orthopedic Research Institute (STORI Inc.), Laredo, TX, USA.,School of Osteopathic Medicine, University of The Incarnate Word, San Antonio, TX, USA.,Future Physicians of South Texas, San Antonio, TX, USA
| | - Cassidy E Lee
- El-Amin Orthopaedic and Sports Medicine Institute, 2505 Newpoint Pkwy, Suite 100B, Lawrenceville, GA, 30043, USA
| | - Howard J Levy
- BioIntegrate, Lawrenceville, GA, USA.,Department of Orthopaedic Surgery, Lenox Hill Hospital, Northwell Health, New York, NY, USA
| | - Saadiq F El-Amin
- BioIntegrate, Lawrenceville, GA, USA. .,El-Amin Orthopaedic and Sports Medicine Institute, 2505 Newpoint Pkwy, Suite 100B, Lawrenceville, GA, 30043, USA.
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16
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Main BJ, Valk JA, Maffulli N, Rodriguez HC, Gupta M, Stone IW, El-Amin SF, Gupta A. Umbilical cord-derived Wharton's jelly for regenerative medicine applications in orthopedic surgery: a systematic review protocol. J Orthop Surg Res 2020; 15:527. [PMID: 33176838 PMCID: PMC7659052 DOI: 10.1186/s13018-020-02067-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 11/04/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Musculoskeletal injuries and conditions affect millions of individuals. These ailments are typically managed by immobilization, physiotherapy, or activity modification. Regenerative medicine has experienced tremendous growth in the past decades, especially in musculoskeletal medicine. Umbilical cord-derived Wharton's jelly is an exciting new option for such therapies. Wharton's jelly is a connective tissue located within the umbilical cord largely composed of mesenchymal stem cells and extracellular matrix components, including collagen, chondroitin sulfate, hyaluronic acid, and sulfated proteoglycans. Wharton's jelly is a promising and applicable biologic source for orthopedic regenerative application. METHODS A systematic search will be conducted in PubMed, ScienceDirect, and Google Scholar databases of English, Italian, French, Spanish, and Portuguese language articles published to date. References will be screened and assessed for eligibility by two independent reviewers as per PRISMA guidelines. Articles will be considered without exclusion to sex, activity, or age. Studies will be included if they used culture-expanded, mesenchymal stem/stromal cells of mesenchymal stem cells and/or connective tissue obtained from Wharton's jelly. Studies will be excluded if Wharton's jelly is not the sole experimental examined cell type. Placebos, conventional non-operative therapies including steroid injections, exercise, and NSAIDs will be compared. The study selection process will be performed independently by two reviewers using a reference software. Data synthesis and meta-analysis will be performed separately for clinical and pre-clinical studies. DISCUSSION The results will be published in relevant peer-reviewed scientific journals. Investigators will present results at national or international conferences. TRIAL REGISTRATION The protocol was registered on PROSPERO international prospective register of systematic reviews prior to commencement, CRD42020182487 .
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Affiliation(s)
- Benjamin J Main
- Beaumont Hospital Farmington Hills, Farmington Hills, MI, USA
| | - Josiah A Valk
- Beaumont Hospital Farmington Hills, Farmington Hills, MI, USA
| | - Nicola Maffulli
- Department of Musculoskeletal Disorders, School of Medicine and Surgery, University of Salerno, Fisciano, Italy
- San Giovanni di Dio e Ruggi D'Aragona Hospital "Clinica Orthopedica" Department, Hospital of Salerno, Salerno, Italy
- Queen Mary University of London, Barts and the London School of Medicine and Dentistry, Centre for Sports and Exercise Medicine, London, England
| | - Hugo C Rodriguez
- School of Osteopathic Medicine, University of the Incarnate Word, San Antonio, TX, USA
- South Texas Orthopaedic Research Institute, Laredo, TX, USA
| | - Manu Gupta
- Future Biologics, Lawrenceville, GA, USA
| | - Ian W Stone
- School of Osteopathic Medicine, University of the Incarnate Word, San Antonio, TX, USA
| | - Saadiq F El-Amin
- El-Amin Orthopaedic and Sports Medicine Institute, Duluth, GA, USA
- BioIntegrate Inc., 2505 Newpoint Pkwy, Suite 100-A, Lawrenceville, GA, 30043, USA
| | - Ashim Gupta
- South Texas Orthopaedic Research Institute, Laredo, TX, USA.
- Future Biologics, Lawrenceville, GA, USA.
- BioIntegrate Inc., 2505 Newpoint Pkwy, Suite 100-A, Lawrenceville, GA, 30043, USA.
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17
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Graham RD, Bruns TM, Duan B, Lempka SF. The Effect of Clinically Controllable Factors on Neural Activation During Dorsal Root Ganglion Stimulation. Neuromodulation 2020; 24:655-671. [PMID: 32583523 DOI: 10.1111/ner.13211] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Dorsal root ganglion stimulation (DRGS) is an effective therapy for chronic pain, though its mechanisms of action are unknown. Currently, we do not understand how clinically controllable parameters (e.g., electrode position, stimulus pulse width) affect the direct neural response to DRGS. Therefore, the goal of this study was to utilize a computational modeling approach to characterize how varying clinically controllable parameters changed neural activation profiles during DRGS. MATERIALS AND METHODS We coupled a finite element model of a human L5 DRG to multicompartment models of primary sensory neurons (i.e., Aα-, Aβ-, Aδ-, and C-neurons). We calculated the stimulation amplitudes necessary to elicit one or more action potentials in each neuron, and examined how neural activation profiles were affected by varying clinically controllable parameters. RESULTS In general, DRGS predominantly activated large myelinated Aα- and Aβ-neurons. Shifting the electrode more than 2 mm away from the ganglion abolished most DRGS-induced neural activation. Increasing the stimulus pulse width to 500 μs or greater increased the number of activated Aδ-neurons, while shorter pulse widths typically only activated Aα- and Aβ-neurons. Placing a cathode near a nerve root, or an anode near the ganglion body, maximized Aβ-mechanoreceptor activation. Guarded active contact configurations did not activate more Aβ-mechanoreceptors than conventional bipolar configurations. CONCLUSIONS Our results suggest that DRGS applied with stimulation parameters within typical clinical ranges predominantly activates Aβ-mechanoreceptors. In general, varying clinically controllable parameters affects the number of Aβ-mechanoreceptors activated, although longer pulse widths can increase Aδ-neuron activation. Our data support several Neuromodulation Appropriateness Consensus Committee guidelines on the clinical implementation of DRGS.
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Affiliation(s)
- Robert D Graham
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Tim M Bruns
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA
| | - Bo Duan
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Scott F Lempka
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.,Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA.,Department of Anesthesiology, University of Michigan, Ann Arbor, MI, USA
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18
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Vallejo R, Platt DC, Rink JA, Jones MA, Kelley CA, Gupta A, Cass CL, Eichenberg K, Vallejo A, Smith WJ, Benyamin R, Cedeño DL. Electrical Stimulation of C6 Glia-Precursor Cells In Vitro Differentially Modulates Gene Expression Related to Chronic Pain Pathways. Brain Sci 2019; 9:brainsci9110303. [PMID: 31683631 PMCID: PMC6896182 DOI: 10.3390/brainsci9110303] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/27/2019] [Accepted: 10/29/2019] [Indexed: 12/21/2022] Open
Abstract
Glial cells comprise the majority of cells in the central nervous system and exhibit diverse functions including the development of persistent neuropathic pain. While earlier theories have proposed that the applied electric field specifically affects neurons, it has been demonstrated that electrical stimulation (ES) of neural tissue modulates gene expression of the glial cells. This study examines the effect of ES on the expression of eight genes related to oxidative stress and neuroprotection in cultured rodent glioma cells. Concentric bipolar electrodes under seven different ES types were used to stimulate cells for 30 min in the presence and absence of extracellular glutamate. ES consisted of rectangular pulses at 50 Hz in varying proportions of anodic and cathodic phases. Real-time reverse-transcribed quantitative polymerase chain reaction was used to determine gene expression using the ∆∆Cq method. The results demonstrate that glutamate has a significant effect on gene expression in both stimulated and non-stimulated groups. Furthermore, stimulation parameters have differential effects on gene expression, both in the presence and absence of glutamate. ES has an effect on glial cell gene expression that is dependent on waveform composition. Optimization of ES therapy for chronic pain applications can be enhanced by this understanding.
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Affiliation(s)
- Ricardo Vallejo
- Millennium Pain Center, Bloomington, IL 61704, USA.
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL 61701, USA.
| | - David C Platt
- Department of Chemistry, Illinois State University, Normal, IL 61790, USA.
| | - Jonathan A Rink
- Department of Biology, Illinois Wesleyan University, Bloomington, IL 61701, USA.
| | - Marjorie A Jones
- Department of Chemistry, Illinois State University, Normal, IL 61790, USA.
| | - Courtney A Kelley
- Millennium Pain Center, Bloomington, IL 61704, USA.
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL 61701, USA.
| | - Ashim Gupta
- Millennium Pain Center, Bloomington, IL 61704, USA.
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL 61701, USA.
- South Texas Orthopaedic Research Institute, Laredo, TX 78045, USA.
| | - Cynthia L Cass
- Millennium Pain Center, Bloomington, IL 61704, USA.
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL 61701, USA.
| | - Kirk Eichenberg
- Department of Chemistry, Illinois State University, Normal, IL 61790, USA.
| | | | - William J Smith
- Millennium Pain Center, Bloomington, IL 61704, USA.
- Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA.
| | - Ramsin Benyamin
- Millennium Pain Center, Bloomington, IL 61704, USA.
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL 61701, USA.
- College of Medicine, Department of Surgery, University of Illinois at Urbana-Champaign, Champaign-Urbana, IL 61801, USA.
| | - David L Cedeño
- Millennium Pain Center, Bloomington, IL 61704, USA.
- Department of Psychology, Illinois Wesleyan University, Bloomington, IL 61701, USA.
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