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Marino S, Le Cause M, De Salvo S, Cardia L, Corallo F, Anfuso C, Di Lorenzo G, Morabito R, Cammaroto S, Smorto C, Militi A, Sorbera C, Brigandì A, Maugeri R, Lavano A, Quartarore A, La Torre D. Transcranial magnetic resonance imaging-guided focused ultrasound for neuropathic pain treatment. Expert Rev Med Devices 2025; 22:455-465. [PMID: 40331426 DOI: 10.1080/17434440.2025.2485289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2024] [Accepted: 03/21/2025] [Indexed: 05/08/2025]
Abstract
INTRODUCTION Magnetic resonance imaging-guided focused ultrasound (MRgFUS) has shown promising results for a variety of neurological conditions, including movement disorders, brain tumors, and degenerative diseases. Recent clinical trials have demonstrated that MRgFUS can produce therapeutic effects in essential tremor (ET) and Parkinson's disease (PD), comparable to those achieved with other neurosurgical interventions. Furthermore, there has been increasing attention on the development of FUS technology and its clinical applications, aimed at exploring new uses and enhancing existing ones. AREAS COVERED In this review, a comprehensive search was conducted across multiple platforms, including PubMed, Scopus, and the Cochrane Library. Filters were applied to include studies based on publication year and clinical trials involving human subjects (excluding animal studies). A thorough analysis of the results was crucial for achieving the objectives of our research. While some studies are still awaiting results, they show promise; others have already been completed. EXPERT OPINION The authors specifically selected six studies that yielded excellent results, covering aspects such as treatment side effects, pain location, key findings, ultrasound temperature, and sample size. he aim of this review is to provide an overview of the recent literature and ongoing clinical trials regarding the application of MRgFUS in the treatment of neuropathic pain.
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Affiliation(s)
- Silvia Marino
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | | | | | | | | | | | | | - Rosa Morabito
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | | | - Chiara Smorto
- IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | | | | | | | - Rosario Maugeri
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Angelo Lavano
- Department of Medical and Surgical Science, University of Magna Graecia, Palermo, Italy
| | | | - Domenico La Torre
- Department of Medical and Surgical Science, University of Magna Graecia, Palermo, Italy
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2
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Sindoni M, Grandl J. A closed-loop system for millisecond readout and control of membrane tension. Biophys J 2025:S0006-3495(25)00199-7. [PMID: 40165372 DOI: 10.1016/j.bpj.2025.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2024] [Revised: 03/06/2025] [Accepted: 03/25/2025] [Indexed: 04/02/2025] Open
Abstract
Characterizing the function of force-gated ion channels is essential for understanding their molecular mechanisms and how they are affected by disease-causing mutations, lipids, or small molecules. Pressure-clamp electrophysiology is a method that is established and widely used to characterize the mechanical sensitivity of force-gated ion channels. However, the physical stimulus many force-gated ion channels sense is not pressure but membrane tension. Here, we further develop the approach of combining patch-clamp electrophysiology with differential interference contrast microscopy into a system that controls membrane tension in real time. The system uses machine learning object detection for millisecond analysis of membrane curvature and control of pipette pressure to produce a closed-loop membrane tension clamp. The analysis of membrane tension is fully automated and includes the propagation of experimental errors, thereby increasing throughput and reducing bias. A dynamic control program clamps membrane tension with at least 93% accuracy and 0.3 mN/m precision. Additionally, the absence of tension drift enables averaging open probabilities of ion channels with low expression and/or unitary conductance over long durations. Using this system, we apply a tension step protocol and show that TMEM63A responds to tension with a tension of half-maximal activation of T50 = 5.5 ± 0.1 mN/m. Overall, this system allows for precise and efficient generation of tension-response relationships of force-gated ion channels.
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Affiliation(s)
- Michael Sindoni
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina
| | - Jörg Grandl
- Department of Neurobiology, Duke University Medical Center, Durham, North Carolina.
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Hehlert P, Effertz T, Gu RX, Nadrowski B, Geurten BRH, Beutner D, de Groot BL, Göpfert MC. NOMPC ion channel hinge forms a gating spring that initiates mechanosensation. Nat Neurosci 2025; 28:259-267. [PMID: 39762662 DOI: 10.1038/s41593-024-01849-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/12/2024] [Indexed: 02/08/2025]
Abstract
The sensation of mechanical stimuli is initiated by elastic gating springs that pull open mechanosensory transduction channels. Searches for gating springs have focused on force-conveying protein tethers such as the amino-terminal ankyrin tether of the Drosophila mechanosensory transduction channel NOMPC. Here, by combining protein domain duplications with mechanical measurements, electrophysiology, molecular dynamics simulations and modeling, we identify the NOMPC gating-spring as the short linker between the ankyrin tether and the channel gate. This linker acts as a Hookean hinge that is ten times more elastic than the tether, with the linker hinge dictating channel gating and the intrinsic stiffness of the gating spring. Our study shows how mechanosensation is initiated molecularly; disentangles gating springs and tethers, and respective paradigms of channel gating; and puts forward gating springs as core ion channel constituents that enable efficient gating by diverse stimuli and in a wide variety of channels.
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Affiliation(s)
- Philip Hehlert
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Thomas Effertz
- Department of Otorhinolaryngology, Head and Neck Surgery and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Ruo-Xu Gu
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Björn Nadrowski
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
| | - Bart R H Geurten
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Dirk Beutner
- Department of Otorhinolaryngology, Head and Neck Surgery and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Bert L de Groot
- Computational Biomolecular Dynamics Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, Göttingen, Germany
| | - Martin C Göpfert
- Department of Cellular Neurobiology, University of Göttingen, Göttingen, Germany.
- Multiscale Bioimaging Cluster of Excellence (MBExC), University of Göttingen, Göttingen, Germany.
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4
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Giese APJ, Weng WH, Kindt KS, Chang HHV, Montgomery JS, Ratzan EM, Beirl AJ, Aponte Rivera R, Lotthammer JM, Walujkar S, Foster MP, Zobeiri OA, Holt JR, Riazuddin S, Cullen KE, Sotomayor M, Ahmed ZM. Complexes of vertebrate TMC1/2 and CIB2/3 proteins form hair-cell mechanotransduction cation channels. eLife 2025; 12:RP89719. [PMID: 39773557 PMCID: PMC11709434 DOI: 10.7554/elife.89719] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2025] Open
Abstract
Calcium and integrin-binding protein 2 (CIB2) and CIB3 bind to transmembrane channel-like 1 (TMC1) and TMC2, the pore-forming subunits of the inner-ear mechano-electrical transduction (MET) apparatus. These interactions have been proposed to be functionally relevant across mechanosensory organs and vertebrate species. Here, we show that both CIB2 and CIB3 can form heteromeric complexes with TMC1 and TMC2 and are integral for MET function in mouse cochlea and vestibular end organs as well as in zebrafish inner ear and lateral line. Our AlphaFold 2 models suggest that vertebrate CIB proteins can simultaneously interact with at least two cytoplasmic domains of TMC1 and TMC2 as validated using nuclear magnetic resonance spectroscopy of TMC1 fragments interacting with CIB2 and CIB3. Molecular dynamics simulations of TMC1/2 complexes with CIB2/3 predict that TMCs are structurally stabilized by CIB proteins to form cation channels. Overall, our work demonstrates that intact CIB2/3 and TMC1/2 complexes are integral to hair-cell MET function in vertebrate mechanosensory epithelia.
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Affiliation(s)
- Arnaud PJ Giese
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of MedicineBaltimoreUnited States
| | - Wei-Hsiang Weng
- Department of Chemistry and Biochemistry, The Ohio State UniversityColumbusUnited States
- Biophysics Graduate Program, The Ohio State UniversityColumbusUnited States
| | - Katie S Kindt
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | | | - Jonathan S Montgomery
- Department of Chemistry and Biochemistry, The Ohio State UniversityColumbusUnited States
- Ohio State Biochemistry Program, The Ohio State UniversityColumbusUnited States
| | - Evan M Ratzan
- Departments of Otolaryngology and Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Alisha J Beirl
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Roberto Aponte Rivera
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Jeffrey M Lotthammer
- Department of Chemistry and Biochemistry, The Ohio State UniversityColumbusUnited States
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State UniversityColumbusUnited States
| | - Mark P Foster
- Department of Chemistry and Biochemistry, The Ohio State UniversityColumbusUnited States
- Biophysics Graduate Program, The Ohio State UniversityColumbusUnited States
- Ohio State Biochemistry Program, The Ohio State UniversityColumbusUnited States
| | - Omid A Zobeiri
- Department of Biomedical Engineering, McGill UniversityMontrealCanada
| | - Jeffrey R Holt
- Departments of Otolaryngology and Neurology, F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical SchoolBostonUnited States
| | - Saima Riazuddin
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of MedicineBaltimoreUnited States
| | - Kathleen E Cullen
- Departments of Biomedical Engineering, Neuroscience, and Otolaryngology and Head and Neck Surgery, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State UniversityColumbusUnited States
- Biophysics Graduate Program, The Ohio State UniversityColumbusUnited States
- Ohio State Biochemistry Program, The Ohio State UniversityColumbusUnited States
| | - Zubair M Ahmed
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of MedicineBaltimoreUnited States
- Department of Biochemistry and Molecular Biology, University of Maryland School of MedicineBaltimoreUnited States
- Department of Ophthalmology and Visual Sciences, University of Maryland School of MedicineBaltimoreUnited States
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Xu T, Zhang Y, Li D, Lai C, Wang S, Zhang S. Mechanosensitive Ion Channels Piezo1 and Piezo2 Mediate Motor Responses In Vivo During Transcranial Focused Ultrasound Stimulation of the Rodent Cerebral Motor Cortex. IEEE Trans Biomed Eng 2024; 71:2900-2910. [PMID: 38748529 DOI: 10.1109/tbme.2024.3401136] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2024]
Abstract
OBJECTIVE Transcranial focused ultrasound (tFUS) neuromodulation offers a noninvasive, safe, deep brain stimulation with high precision, presenting potential in understanding neural circuits and treating brain disorders. This in vivo study investigated the mechanism of tFUS in activating the opening of the mechanosensitive ion channels Piezo1 and Piezo2 in the mouse motor cortex to induce motor responses. METHODS Piezo1 and Piezo2 were knocked down separately in the mouse motor cortex, followed by EMG and motor cortex immunofluorescence comparisons before and after knockdown under tFUS stimulation. RESULTS The results demonstrated that the stimulation-induced motor response success rates in Piezo knockdown mice were lower compared to the control group (Piezo1 knockdown: 57.63% ± 14.62%, Piezo2 knockdown: 73.71% ± 13.10%, Control mice: 85.69% ± 10.23%). Both Piezo1 and Piezo2 knockdowns showed prolonged motor response times (Piezo1 knockdown: 0.62 ± 0.19 s, Piezo2 knockdown: 0.60 ± 0.13 s, Control mice: 0.44 ± 0.12 s) compared to controls. Additionally, Piezo knockdown animals subjected to tFUS showed reduced immunofluorescent c-Fos expression in the target area when measured in terms of cells per unit area compared to the control group. CONCLUSION This in vivo study confirms the pivotal role of Piezo channels in tFUS-induced neuromodulation, highlighting their influence on motor response efficacy and timing. SIGNIFICANCE This study provides insights into the mechanistic underpinnings of noninvasive brain stimulation techniques and opens avenues for developing targeted therapies for neural disorders.
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Curk T, Leyva SG, Pagonabarraga I. Discontinuous Transition in Electrolyte Flow through Charge-Patterned Nanochannels. PHYSICAL REVIEW LETTERS 2024; 133:078201. [PMID: 39213551 DOI: 10.1103/physrevlett.133.078201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 06/26/2024] [Indexed: 09/04/2024]
Abstract
We investigate the flow of an electrolyte through a rigid nanochannel decorated with a surface charge pattern. Employing lattice Boltzmann and dissipative particle dynamics methods, as well as analytical theory, we show that the electrohydrodynamic coupling leads to two distinct flow regimes. The accompanying discontinuous transition between slow, ionic, and fast, Poiseuille flows is observed at intermediate ion concentrations, channel widths, and electrostatic coupling strengths. These findings indicate routes to design nanochannels containing a typical aqueous electrolyte that exhibit a digital on-off flux response, which could be useful for nanofluidics and ionotronic applications.
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7
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Chen G, Yu F, Shi L, Marar C, Du Z, Jia D, Cheng J, Yang C. High-Precision Photoacoustic Neural Modulation Uses a Non-Thermal Mechanism. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2403205. [PMID: 38923780 PMCID: PMC11348214 DOI: 10.1002/advs.202403205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/24/2024] [Indexed: 06/28/2024]
Abstract
Neuromodulation is a powerful tool for fundamental studies in neuroscience and potential treatments of neurological disorders. Both photoacoustic (PA) and photothermal (PT) effects are harnessed for non-genetic high-precision neural stimulation. Using a fiber-based device excitable by a nanosecond pulsed laser and a continuous wave laser for PA and PT stimulation, respectively, PA and PT neuromodulation is systematically investigated at the single neuron level. These results show that to achieve the same level of neuron activation recorded by Ca2+ imaging, the laser energy needed for PA stimulation is 1/40 of that needed for PT stimulation. The threshold energy for PA stimulation is found to be further reduced in neurons overexpressing mechano-sensitive channels, indicating direct involvement of mechano-sensitive channels in PA stimulation. Electrophysiology study of single neurons upon PA and PT stimulation is performed by patch clamp recordings. Electrophysiological features induced by PA are distinct from those by PT, confirming that PA and PT stimulation operate through different mechanisms. These insights offer a foundation for the rational design of more efficient and safer non-genetic neural modulation approaches.
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Affiliation(s)
- Guo Chen
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
| | - Feiyuan Yu
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
| | - Linli Shi
- Department of ChemistryBoston UniversityBostonMA02215USA
| | - Carolyn Marar
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
| | - Zhiyi Du
- Department of ChemistryBoston UniversityBostonMA02215USA
| | - Danchen Jia
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
| | - Ji‐Xin Cheng
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
- Department of Biomedical EngineeringBoston UniversityBostonMA02215USA
| | - Chen Yang
- Department of Electrical and Computer EngineeringBoston UniversityBostonMA02215USA
- Department of ChemistryBoston UniversityBostonMA02215USA
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8
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Giese APJ, Weng WH, Kindt KS, Chang HHV, Montgomery JS, Ratzan EM, Beirl AJ, Rivera RA, Lotthammer JM, Walujkar S, Foster MP, Zobeiri OA, Holt JR, Riazuddin S, Cullen KE, Sotomayor M, Ahmed ZM. Complexes of vertebrate TMC1/2 and CIB2/3 proteins form hair-cell mechanotransduction cation channels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.26.542533. [PMID: 37398045 PMCID: PMC10312449 DOI: 10.1101/2023.05.26.542533] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Calcium and integrin-binding protein 2 (CIB2) and CIB3 bind to transmembrane channel-like 1 (TMC1) and TMC2, the pore-forming subunits of the inner-ear mechano-electrical transduction (MET) apparatus. These interactions have been proposed to be functionally relevant across mechanosensory organs and vertebrate species. Here we show that both CIB2 and CIB3 can form heteromeric complexes with TMC1 and TMC2 and are integral for MET function in mouse cochlea and vestibular end organs as well as in zebrafish inner ear and lateral line. Our AlphaFold 2 models suggest that vertebrate CIB proteins can simultaneously interact with at least two cytoplasmic domains of TMC1 and TMC2 as validated using nuclear magnetic resonance spectroscopy of TMC1 fragments interacting with CIB2 and CIB3. Molecular dynamics simulations of TMC1/2 complexes with CIB2/3 predict that TMCs are structurally stabilized by CIB proteins to form cation channels. Overall, our work demonstrates that intact CIB2/3 and TMC1/2 complexes are integral to hair-cell MET function in vertebrate mechanosensory epithelia.
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Affiliation(s)
- Arnaud P J Giese
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Wei-Hsiang Weng
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
- Biophysics Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Katie S Kindt
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | | | - Jonathan S Montgomery
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
| | - Evan M Ratzan
- Departments of Otolaryngology and Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Alisha J Beirl
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Roberto Aponte Rivera
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
| | - Jeffrey M Lotthammer
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Mark P Foster
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
- Biophysics Graduate Program, The Ohio State University, Columbus, OH, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
| | - Omid A Zobeiri
- Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Jeffrey R Holt
- Departments of Otolaryngology and Neurology, F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Saima Riazuddin
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kathleen E Cullen
- Departments of Biomedical Engineering, Neuroscience, and Otolaryngology and Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
- Biophysics Graduate Program, The Ohio State University, Columbus, OH, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
| | - Zubair M Ahmed
- Department of Otorhinolaryngology - Head & Neck Surgery, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
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Sorum B, Docter T, Panico V, Rietmeijer RA, Brohawn SG. Tension activation of mechanosensitive two-pore domain K+ channels TRAAK, TREK-1, and TREK-2. Nat Commun 2024; 15:3142. [PMID: 38605031 PMCID: PMC11009253 DOI: 10.1038/s41467-024-47208-5] [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: 10/17/2023] [Accepted: 03/22/2024] [Indexed: 04/13/2024] Open
Abstract
TRAAK, TREK-1, and TREK-2 are mechanosensitive two-pore domain K+ (K2P) channels that contribute to action potential propagation, sensory transduction, and muscle contraction. While structural and functional studies have led to models that explain their mechanosensitivity, we lack a quantitative understanding of channel activation by membrane tension. Here, we define the tension response of mechanosensitive K2Ps using patch-clamp recording and imaging. All are low-threshold mechanosensitive channels (T10%/50% 0.6-2.7 / 4.4-6.4 mN/m) with distinct response profiles. TRAAK is most sensitive, TREK-1 intermediate, and TREK-2 least sensitive. TRAAK and TREK-1 are activated broadly over a range encompassing nearly all physiologically relevant tensions. TREK-2, in contrast, activates over a narrower range like mechanosensitive channels Piezo1, MscS, and MscL. We further show that low-frequency, low-intensity focused ultrasound increases membrane tension to activate TRAAK and MscS. This work provides insight into tension gating of mechanosensitive K2Ps relevant to understanding their physiological roles and potential applications for ultrasonic neuromodulation.
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Affiliation(s)
- Ben Sorum
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, CA, 94720, USA
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, 94720, USA
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, NJ, 08103, USA
| | - Trevor Docter
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, CA, 94720, USA
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, 94720, USA
| | - Vincent Panico
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, CA, 94720, USA
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, 94720, USA
| | - Robert A Rietmeijer
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, CA, 94720, USA
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, 94720, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, 94720, USA
| | - Stephen G Brohawn
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, CA, 94720, USA.
- Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA, 94720, USA.
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, 94720, USA.
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10
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Mulhall EM, Gharpure A, Lee RM, Dubin AE, Aaron JS, Marshall KL, Spencer KR, Reiche MA, Henderson SC, Chew TL, Patapoutian A. Direct observation of the conformational states of PIEZO1. Nature 2023; 620:1117-1125. [PMID: 37587339 PMCID: PMC10468401 DOI: 10.1038/s41586-023-06427-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 07/11/2023] [Indexed: 08/18/2023]
Abstract
PIEZOs are mechanosensitive ion channels that convert force into chemoelectric signals1,2 and have essential roles in diverse physiological settings3. In vitro studies have proposed that PIEZO channels transduce mechanical force through the deformation of extensive blades of transmembrane domains emanating from a central ion-conducting pore4-8. However, little is known about how these channels interact with their native environment and which molecular movements underlie activation. Here we directly observe the conformational dynamics of the blades of individual PIEZO1 molecules in a cell using nanoscopic fluorescence imaging. Compared with previous structural models of PIEZO1, we show that the blades are significantly expanded at rest by the bending stress exerted by the plasma membrane. The degree of expansion varies dramatically along the length of the blade, where decreased binding strength between subdomains can explain increased flexibility of the distal blade. Using chemical and mechanical modulators of PIEZO1, we show that blade expansion and channel activation are correlated. Our findings begin to uncover how PIEZO1 is activated in a native environment. More generally, as we reliably detect conformational shifts of single nanometres from populations of channels, we expect that this approach will serve as a framework for the structural analysis of membrane proteins through nanoscopic imaging.
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Affiliation(s)
- Eric M Mulhall
- Howard Hughes Medical Institute, Department of Neuroscience, Dorris Neuroscience Center, Scripps Research, La Jolla, CA, USA
| | - Anant Gharpure
- Howard Hughes Medical Institute, Department of Neuroscience, Dorris Neuroscience Center, Scripps Research, La Jolla, CA, USA
| | - Rachel M Lee
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Adrienne E Dubin
- Howard Hughes Medical Institute, Department of Neuroscience, Dorris Neuroscience Center, Scripps Research, La Jolla, CA, USA
| | - Jesse S Aaron
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Kara L Marshall
- Howard Hughes Medical Institute, Department of Neuroscience, Dorris Neuroscience Center, Scripps Research, La Jolla, CA, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | - Kathryn R Spencer
- Department of Neuroscience, Dorris Neuroscience Center, Scripps Research, La Jolla, CA, USA
| | - Michael A Reiche
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Scott C Henderson
- Department of Molecular Medicine, Scripps Research, La Jolla, CA, USA
| | - Teng-Leong Chew
- Advanced Imaging Center, Howard Hughes Medical Institute Janelia Research Campus, Ashburn, VA, USA
| | - Ardem Patapoutian
- Howard Hughes Medical Institute, Department of Neuroscience, Dorris Neuroscience Center, Scripps Research, La Jolla, CA, USA.
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11
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Goodman MB, Haswell ES, Vásquez V. Mechanosensitive membrane proteins: Usual and unusual suspects in mediating mechanotransduction. J Gen Physiol 2023; 155:e202213248. [PMID: 36696153 PMCID: PMC9930137 DOI: 10.1085/jgp.202213248] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This Viewpoint, which accompanies a Special Issue focusing on membrane mechanosensors, discusses unifying and unique features of both established and emerging mechanosensitive (MS) membrane proteins, their distribution across protein families and phyla, and current and future challenges in the study of these important proteins and their partners. MS membrane proteins are essential for tissue development, cellular motion, osmotic homeostasis, and sensing external and self-generated mechanical cues like those responsible for touch and proprioception. Though researchers' attention and this Viewpoint focus on a few famous ion channels that are considered the usual suspects as MS mechanosensors, we also discuss some of the more unusual suspects, such as G-protein coupled receptors. As the field continues to grow, so too will the list of proteins suspected to function as mechanosensors and the diversity of known MS membrane proteins.
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Affiliation(s)
- Miriam B. Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Elizabeth S. Haswell
- Department of Biology, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Valeria Vásquez
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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12
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Sorum B, Docter T, Panico V, Rietmeijer RA, Brohawn SG. Pressure and ultrasound activate mechanosensitive TRAAK K + channels through increased membrane tension. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.11.523644. [PMID: 36712118 PMCID: PMC9882092 DOI: 10.1101/2023.01.11.523644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
TRAAK is a mechanosensitive two-pore domain K + (K2P) channel found in nodes of Ranvier within myelinated axons. It displays low leak activity at rest and is activated up to one hundred-fold by increased membrane tension. Structural and functional studies have led to physical models for channel gating and mechanosensitivity, but no quantitative analysis of channel activation by tension has been reported. Here, we use simultaneous patch-clamp recording and fluorescent imaging to determine the tension response characteristics of TRAAK. TRAAK shows high sensitivity and a broad response to tension spanning nearly the entire physiologically relevant tension range. This graded response profile distinguishes TRAAK from similarly low-threshold mechanosensitive channels Piezo1 and MscS, which activate in a step-like fashion over a narrow tension range. We further use patch imaging to show that ultrasonic activation of TRAAK and MscS is due to increased membrane tension. Together, these results provide mechanistic insight into TRAAK tension gating, a framework for exploring the role of mechanosensitive K + channels at nodes of Ranvier, and biophysical context for developing ultrasound as a mechanical stimulation technique for neuromodulation.
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Affiliation(s)
- Ben Sorum
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, California 94720, USA.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California 94720, USA.,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA 94720, USA
| | - Trevor Docter
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, California 94720, USA.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California 94720, USA.,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA 94720, USA
| | - Vincent Panico
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, California 94720, USA.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California 94720, USA.,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA 94720, USA
| | - Robert A. Rietmeijer
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, California 94720, USA.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California 94720, USA.,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA 94720, USA
| | - Stephen G. Brohawn
- Department of Molecular & Cell Biology, University of California Berkeley, Berkeley, California 94720, USA.,Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, California 94720, USA.,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA 94720, USA.,Correspondence:
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13
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Badadhe JD, Roh H, Lee BC, Kim JH, Im M. Ultrasound stimulation for non-invasive visual prostheses. Front Cell Neurosci 2022; 16:971148. [PMID: 35990889 PMCID: PMC9382087 DOI: 10.3389/fncel.2022.971148] [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: 06/16/2022] [Accepted: 07/18/2022] [Indexed: 12/04/2022] Open
Abstract
Globally, it is estimated there are more than 2.2 billion visually impaired people. Visual diseases such as retinitis pigmentosa, age-related macular degeneration, glaucoma, and optic neuritis can cause irreversible profound vision loss. Many groups have investigated different approaches such as microelectronic prostheses, optogenetics, stem cell therapy, and gene therapy to restore vision. However, these methods have some limitations such as invasive implantation surgery and unknown long-term risk of genetic manipulation. In addition to the safety of ultrasound as a medical imaging modality, ultrasound stimulation can be a viable non-invasive alternative approach for the sight restoration because of its ability to non-invasively control neuronal activities. Indeed, recent studies have demonstrated ultrasound stimulation can successfully modulate retinal/brain neuronal activities without causing any damage to the nerve cells. Superior penetration depth and high spatial resolution of focused ultrasound can open a new avenue in neuromodulation researches. This review summarizes the latest research results about neural responses to ultrasound stimulation. Also, this work provides an overview of technical viewpoints in the future design of a miniaturized ultrasound transducer for a non-invasive acoustic visual prosthesis for non-surgical and painless restoration of vision.
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Affiliation(s)
- Jaya Dilip Badadhe
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology (UST), Seoul, South Korea
| | - Hyeonhee Roh
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- School of Electrical Engineering, College of Engineering, Korea University, Seoul, South Korea
| | - Byung Chul Lee
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology (UST), Seoul, South Korea
- KHU-KIST Department of Converging Science and Technology, Kyung Hee University, Seoul, South Korea
| | - Jae Hun Kim
- Sensor System Research Center, Korea Institute of Science and Technology (KIST), Seoul, South Korea
| | - Maesoon Im
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul, South Korea
- Division of Bio-Medical Science & Technology, KIST School, University of Science and Technology (UST), Seoul, South Korea
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14
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Prospero AG, Pinto LA, Matos RVR, Soares GA, Oliveira RB, Mascarenhas S, Miranda JRDA. New device for active gastric mechanical stimulation. Neurogastroenterol Motil 2021; 33:e14169. [PMID: 33969918 DOI: 10.1111/nmo.14169] [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] [Revised: 04/16/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Gastroparesis is a chronic stomach disorder and effective treatment is the aim of different strategies. Alternative therapies consist of an electrical stimulation of the stomach to evoke a response in the gastric activity. We present the development and in vivo application of an electromagnet system to induce a mechanical stimulus in the stomach aiming for gastric contractile responses. METHODS The electromagnet system consisted of an implantable magnet and an external drive coil. We implanted the magnet at the greater curvature of the gastric body in rats. We applied an alternating current to the drive coils, inducing mechanical stimulation of the gastric wall. We measured the gastric contraction activity and gastric electrical activity in response to the stimulus using AC biosusceptometry and electrogastrography. Moreover, we used the phenol red to evaluate the stimulus effects on gastrointestinal transit. KEY RESULTS The stimulus increased the spectral intensity and signal-to-noise ratio significantly of gastric contraction activity and gastric electrical activity. Furthermore, we found a lower phenol red retention in the stomach in rats without stimulus. No significant differences were found in frequency and root mean square amplitude. CONCLUSIONS & INFERENCES We developed a new simple electromagnet system that evoked a contraction and gastric electrical response using a mechanical stimulus and decreased gastric emptying time. The system is an accessible tool and may contribute to gastroparesis studies in animals.
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Affiliation(s)
- Andre Gonçalves Prospero
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Leonardo Antonio Pinto
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Ronaldo Vitor Reis Matos
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Guilherme Augusto Soares
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
| | - Ricardo Brandt Oliveira
- Faculdade de Medicina de Ribeirão Preto, USP/University of São Paulo, Ribeirão Preto, Brazil
| | | | - José Ricardo de Arruda Miranda
- Departamento de Biofísica e Farmacologia, Laboratório de Biomagnetismo, UNESP/São Paulo State University, Botucatu, Brazil
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15
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Shah V, Patel S, Shah J. Emerging Role of Piezo Ion Channels in Cardiovascular Development. Dev Dyn 2021; 251:276-286. [PMID: 34255896 DOI: 10.1002/dvdy.401] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 06/12/2021] [Accepted: 07/09/2021] [Indexed: 12/23/2022] Open
Abstract
Mechanical cues are crucial for vascular development and the proper differentiation of various cell types. Piezo1 and Piezo2 are mechanically activated cationic channels expressed in various cell types, especially in vascular smooth muscle and endothelial cells. It is present as a transmembrane homotrimeric complex, regulating calcium influx. Local blood flow associated shear stress, in addition to blood pressure associated cell membrane stretching are key Piezo channel activators. There is rising proof, showcasing Piezo channels significance in myocytes, cardiac fibroblast, vascular tone maintenance, atherosclerosis, hypertension, NO generation, and baroreceptor reflex. Here, we review the role of Piezo channels in cardiovascular development and its associated clinical disorders. Also, emphasizing on Piezo channel modulators which might lead to novel therapies for cardiovascular diseases. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Vandit Shah
- Department of Pharmacology, L.M. College of Pharmacy, Navrangpura, Ahmedabad, Gujarat, India
| | - Sandip Patel
- Department of Pharmacology, L.M. College of Pharmacy, Navrangpura, Ahmedabad, Gujarat, India
| | - Jigna Shah
- Department of Pharmacology, Institute of Pharmacy Nirma University, Ahmedabad, Gujarat, India
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16
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Kärki T, Tojkander S. TRPV Protein Family-From Mechanosensing to Cancer Invasion. Biomolecules 2021; 11:1019. [PMID: 34356643 PMCID: PMC8301805 DOI: 10.3390/biom11071019] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/30/2021] [Accepted: 07/09/2021] [Indexed: 02/08/2023] Open
Abstract
Biophysical cues from the cellular microenvironment are detected by mechanosensitive machineries that translate physical signals into biochemical signaling cascades. At the crossroads of extracellular space and cell interior are located several ion channel families, including TRP family proteins, that are triggered by mechanical stimuli and drive intracellular signaling pathways through spatio-temporally controlled Ca2+-influx. Mechanosensitive Ca2+-channels, therefore, act as critical components in the rapid transmission of physical signals into biologically compatible information to impact crucial processes during development, morphogenesis and regeneration. Given the mechanosensitive nature of many of the TRP family channels, they must also respond to the biophysical changes along the development of several pathophysiological conditions and have also been linked to cancer progression. In this review, we will focus on the TRPV, vanilloid family of TRP proteins, and their connection to cancer progression through their mechanosensitive nature.
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Affiliation(s)
- Tytti Kärki
- Department of Applied Physics, School of Science, Aalto University, 00076 Espoo, Finland;
| | - Sari Tojkander
- Department of Veterinary Biosciences, Section of Pathology, University of Helsinki, 00014 Helsinki, Finland
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17
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Richardson J, Kotevski A, Poole K. From stretch to deflection: the importance of context in the activation of mammalian, mechanically activated ion channels. FEBS J 2021; 289:4447-4469. [PMID: 34060230 DOI: 10.1111/febs.16041] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/11/2021] [Accepted: 05/28/2021] [Indexed: 01/21/2023]
Abstract
The ability of cells to convert mechanical perturbations into biochemical information is an essential aspect of mammalian physiology. The molecules that mediate such mechanotransduction include mechanically activated ion channels, which directly convert mechanical inputs into electrochemical signals. The unifying feature of these channels is that their open probability increases with the application of a mechanical input. However, the structure, activation profile and sensitivity of distinct mechanically activated ion channels vary from channel to channel. In this review, we discuss how ionic currents can be mechanically evoked and monitored in vitro, and describe the distinct activation profiles displayed by a range of mammalian channels. In addition, we discuss the various mechanisms by which the best-characterized mammalian, mechanically activated ion channel, PIEZO1, can be modulated. The diversity of activation and modulation of these mammalian ion channels suggest that these molecules may facilitate a finely controlled and diverse ability to sense mechanical inputs in mammalian cells.
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Affiliation(s)
- Jessica Richardson
- EMBL Australia node in Single Molecule Science, School of Medical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia.,Cellular and Systems Physiology, School of Medical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
| | - Adrian Kotevski
- EMBL Australia node in Single Molecule Science, School of Medical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia.,Cellular and Systems Physiology, School of Medical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
| | - Kate Poole
- EMBL Australia node in Single Molecule Science, School of Medical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia.,Cellular and Systems Physiology, School of Medical Sciences, Faculty of Medicine & Health, University of New South Wales, Sydney, NSW, Australia
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18
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Liu Y, Wang G, Cao C, Zhang G, Tanzi EB, Zhang Y, Zhou W, Li Y. Neuromodulation Effect of Very Low Intensity Transcranial Ultrasound Stimulation on Multiple Nuclei in Rat Brain. Front Aging Neurosci 2021; 13:656430. [PMID: 33935688 PMCID: PMC8081960 DOI: 10.3389/fnagi.2021.656430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/02/2021] [Indexed: 11/13/2022] Open
Abstract
Objective Low-intensity transcranial ultrasound stimulation (TUS) is a non-invasive neuromodulation technique with high spatial resolution and feasible penetration depth. To date, the mechanisms of TUS modulated neural oscillations are not fully understood. This study designed a very low acoustic intensity (AI) TUS system that produces considerably reduced AI Ultrasound pulses (ISPTA < 0.5 W/cm2) when compared to previous methods used to measure regional neural oscillation patterns under different TUS parameters. Methods We recorded the local field potential (LFP) of five brain nuclei under TUS with three groups of simulating parameters. Spectrum estimation, time-frequency analysis (TFA), and relative power analysis methods have been applied to investigate neural oscillation patterns under different stimulation parameters. Results Under PRF, 500 Hz and 1 kHz TUS, high-amplitude LFP activity with the auto-rhythmic pattern appeared in selected nuclei when ISPTA exceeded 12 mW/cm2. With TFA, high-frequency energy (slow gamma and high gamma) was significantly increased during the auto-rhythmic patterns. We observed an initial plateau in nuclei response when ISPTA reached 16.4 mW/cm2 for RPF 500 Hz and 20.8 mW/cm2 for RPF 1 kHz. The number of responding nuclei started decreasing while ISPTA continued increasing. Under 1.5 kHz TUS, no auto-rhythmic patterns have been observed, but slow frequency power was increased during TUS. TUS inhibited most of the frequency band and generated obvious slow waves (theta and delta band) when stimulated at RPF = 1.5 kHz, ISPTA = 8.8 mW/cm2. Conclusion These results demonstrate that very low intensity Transcranial Ultrasound Stimulation (VLTUS) exerts significant neuromodulator effects under specific parameters in rat models and may be a valid tool to study neuronal physiology.
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Affiliation(s)
- Yingjian Liu
- School of Microelectronics, Shandong University, Jinan, China
| | - Gang Wang
- School of Microelectronics, Shandong University, Jinan, China
| | - Chao Cao
- School of Microelectronics, Shandong University, Jinan, China
| | - Gaorui Zhang
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China.,School of Medical Imaging, Weifang Medical University, Weifang, China
| | | | - Yang Zhang
- Department of Radiology, Qilu Hospital of Shandong University, Jinan, China
| | - Weidong Zhou
- School of Microelectronics, Shandong University, Jinan, China
| | - Yi Li
- Weill Cornell Medicine, New York, NY, United States
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19
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Cox CD, Bavi N, Martinac B. Biophysical Principles of Ion-Channel-Mediated Mechanosensory Transduction. Cell Rep 2020; 29:1-12. [PMID: 31577940 DOI: 10.1016/j.celrep.2019.08.075] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 06/09/2019] [Accepted: 08/22/2019] [Indexed: 01/12/2023] Open
Abstract
Recent rapid progress in the field of mechanobiology has been driven by novel emerging tools and methodologies and growing interest from different scientific disciplines. Specific progress has been made toward understanding how cell mechanics is linked to intracellular signaling and the regulation of gene expression in response to a variety of mechanical stimuli. There is a direct link between the mechanoreceptors at the cell surface and intracellular biochemical signaling, which in turn controls downstream effector molecules. Among the mechanoreceptors in the cell membrane, mechanosensitive (MS) ion channels are essential for the ultra-rapid (millisecond) transduction of mechanical stimuli into biologically relevant signals. The three decades of research on mechanosensitive channels resulted in the formulation of two basic principles of mechanosensitive channel gating: force-from-lipids and force-from-filament. In this review, we revisit the biophysical principles that underlie the innate force-sensing ability of mechanosensitive channels as contributors to the force-dependent evolution of life forms.
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Affiliation(s)
- Charles D Cox
- Victor Chang Cardiac Research Institute, Lowy Packer Building, Darlinghurst, NSW 2010, Australia; St. Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW 2010, Australia
| | - Navid Bavi
- Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA
| | - Boris Martinac
- Victor Chang Cardiac Research Institute, Lowy Packer Building, Darlinghurst, NSW 2010, Australia; St. Vincent's Clinical School, University of New South Wales, Darlinghurst, NSW 2010, Australia.
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20
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Ventre DM, Cluff A, Gagnon C, Diaz Vera D, Koppes RA, Koppes AN. The effects of low intensity focused ultrasonic stimulation on dorsal root ganglion neurons and Schwann cells in vitro. J Neurosci Res 2020; 99:374-391. [PMID: 32743823 DOI: 10.1002/jnr.24700] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 01/14/2023]
Abstract
Satisfactory treatment of peripheral nerve injury (PNI) faces difficulties owing to the intrinsic biological barriers in larger injuries and invasive surgical interventions. Injury gaps >3 cm have low chances of full motor and sensory recovery, and the unmet need for PNI repair techniques which increase the likelihood of functional recovery while limiting invasiveness motivate this work. Building upon prior work in ultrasound stimulation (US) of dorsal root ganglion (DRG) neurons, the effects of US on DRG neuron and Schwann cell (SC) cocultures were investigated to uncover the role of SCs in mediating the neuronal response to US in vitro. Acoustic intensity-dependent alteration in selected neuromorphometrics of DRG neurons in coculture with SCs was observed in total outgrowth, primary neurites, and length compared to previously reported DRG monoculture in a calcium-independent manner. SC viability and proliferation were not impacted by US. Conditioned medium studies suggest secreted factors from SCs subjected to US impact DRG neuron morphology. These findings advance the current understanding of mechanisms by which these cell types respond to US, which may lead to new noninvasive US therapies for treating PNI.
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Affiliation(s)
- Daniel M Ventre
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | - Avery Cluff
- Department of Bioengineering, Northeastern University, Boston, MA, USA
| | | | - David Diaz Vera
- Department of Chemical Engineering, Northeastern University, Boston, MA, USA
| | - Ryan A Koppes
- Department of Biology, Northeastern University, Boston, MA, USA
| | - Abigail N Koppes
- Department of Biology, Northeastern University, Boston, MA, USA.,Department of Chemical Engineering, Northeastern University, Boston, MA, USA
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21
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Wang S, Meng W, Ren Z, Li B, Zhu T, Chen H, Wang Z, He B, Zhao D, Jiang H. Ultrasonic Neuromodulation and Sonogenetics: A New Era for Neural Modulation. Front Physiol 2020; 11:787. [PMID: 32765294 PMCID: PMC7378787 DOI: 10.3389/fphys.2020.00787] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 06/15/2020] [Indexed: 12/19/2022] Open
Abstract
Non-invasive ultrasonic neural modulation (UNM), a non-invasive technique with enhanced spatial focus compared to conventional electrical neural modulation, has attracted much attention in recent decades and might become the mainstream regimen for neurological disorders. However, as ultrasonic bioeffects and its adjustments are still unclear, it remains difficult to be extensively applied for therapeutic purpose, much less in the setting of human skull. Hence to comprehensively understand the way ultrasound exerts bioeffects, we explored UNM from a basic perspective by illustrating the parameter settings and the underlying mechanisms. In addition, although the spatial resolution and precision of UNM are considerable, UNM is relatively non-specific to tissue or cell type and shows very low specificity at the molecular level. Surprisingly, Ibsen et al. (2015) first proposed the concept of sonogenetics, which combined UNM and mechanosensitive (MS) channel protein. This emerging approach is a valuable improvement, as it may markedly increase the precision and spatial resolution of UNM. It seemed to be an inspiring tool with high accuracy and specificity, however, little information about sonogenetics is currently available. Thus, in order to provide an overview of sonogenetics and prompt the researches on UNM, we summarized the potential mechanisms from a molecular level.
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Affiliation(s)
- Songyun Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Weilun Meng
- Department of Cardiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Medical Department, Nanjing Medical University, Nanjing, China
| | - Zhongyuan Ren
- Department of Cardiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Medical Department, Soochow University Medical College, Suzhou, China
| | - Binxun Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Tongjian Zhu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Hui Chen
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Zhen Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Bo He
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Dongdong Zhao
- Department of Cardiology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Hong Jiang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
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22
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The role of Piezo proteins and cellular mechanosensing in tuning the fate of transplanted stem cells. Cell Tissue Res 2020; 381:1-12. [DOI: 10.1007/s00441-020-03191-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 02/19/2020] [Indexed: 12/18/2022]
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23
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F B, B M, R S, H G. Transcranial Focused Ultrasound Modulates Electrical Behavior of the Neurons: Design and Implementation of a Model. J Biomed Phys Eng 2020; 10:65-74. [PMID: 32158713 PMCID: PMC7036408 DOI: 10.31661/jbpe.v0i0.1052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 12/15/2018] [Indexed: 11/16/2022]
Abstract
Background: Recently, ultrasonic neuromodulation research has been an important and interesting issue. Ultrasonic neuromodulation is possible by the use of low-intensity transcranial focused ultrasound (tFUS) to stimulate or inhibit the neural structures. The primary capability of this method is the improvement in the treatment progress of certain neurological and psychiatric disorders noninvasively. tFUS is able to modulate ionic currents and neural depolarization, causing the alteration in electrical properties of neurons Objective: The study aims to investigate the effect of tFUS waves on the electrical behavior of neurons using the simulation method Material and Methods: In the first part of this simulation study, the propagation of tFUS waves throughout the head was simulated to calculate the value of acoustic pressure at the cortex. In the second part, cortical neurons were simulated by a simple model of spiking neurons proposed by Izhikevich for three common dynamics. Then, the capacitance model was proposed to determine the alteration in the electrical behavior of the neurons during tFUS stimulation. Results: At the resting state, the electric potential of the neuron’s membrane through the tFUS stimulation has an amplitude of about 30 mv with the similar oscillatory behavior of the acoustic waveform; while,the ultimate electrical behavior of the neuron’s membrane indicates a decrease in the electric potential when the neurons fire Conclusion: The electrical behavior of the neuron and the range of its membrane voltage modulated during ultrasonic stimulation. The reduction in the amplitude of membrane potential was observed while neuron spikes
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Affiliation(s)
- Baniasad F
- MSc, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
- MSc, Research Center for Molecular and Cellular Imaging (RCMCI), Tehran University of Medical Sciences, Tehran, Iran
| | - Makkiabadi B
- PhD, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
- PhD, Research Center for Biomedical Technologies and Robotics (RCBTR), Tehran University of Medical Sciences, Tehran, Iran
| | - Solgi R
- MSc, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
- MSc, Research Center for Molecular and Cellular Imaging (RCMCI), Tehran University of Medical Sciences, Tehran, Iran
| | - Ghadiri H
- PhD, Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
- PhD, Research Center for Molecular and Cellular Imaging (RCMCI), Tehran University of Medical Sciences, Tehran, Iran
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24
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Reddy B, Bavi N, Lu A, Park Y, Perozo E. Molecular basis of force-from-lipids gating in the mechanosensitive channel MscS. eLife 2019; 8:50486. [PMID: 31880537 PMCID: PMC7299334 DOI: 10.7554/elife.50486] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/27/2019] [Indexed: 12/28/2022] Open
Abstract
Prokaryotic mechanosensitive (MS) channels open by sensing the physical state of the membrane. As such, lipid-protein interactions represent the defining molecular process underlying mechanotransduction. Here, we describe cryo-electron microscopy (cryo-EM) structures of the E. coli small-conductance mechanosensitive channel (MscS) in nanodiscs (ND). They reveal a novel membrane-anchoring fold that plays a significant role in channel activation and establish a new location for the lipid bilayer, shifted ~14 Å from previous consensus placements. Two types of lipid densities are explicitly observed. A phospholipid that ‘hooks’ the top of each TM2-TM3 hairpin and likely plays a role in force sensing, and a bundle of acyl chains occluding the permeation path above the L105 cuff. These observations reshape our understanding of force-from-lipids gating in MscS and highlight the key role of allosteric interactions between TM segments and phospholipids bound to key dynamic components of the channel.
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Affiliation(s)
- Bharat Reddy
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States
| | - Navid Bavi
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States
| | - Allen Lu
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States
| | - Yeonwoo Park
- Department of Ecology and Evolution, The University of Chicago, Chicago, United States
| | - Eduardo Perozo
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, United States.,Institute for Biophysical Dynamics, The University of Chicago, Chicago, United States
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25
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Bertucci C, Koppes R, Dumont C, Koppes A. Neural responses to electrical stimulation in 2D and 3D in vitro environments. Brain Res Bull 2019; 152:265-284. [PMID: 31323281 DOI: 10.1016/j.brainresbull.2019.07.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/29/2019] [Accepted: 07/12/2019] [Indexed: 12/17/2022]
Abstract
Electrical stimulation (ES) to manipulate the central (CNS) and peripheral nervous system (PNS) has been explored for decades, recently gaining momentum as bioelectronic medicine advances. The application of ES in vitro to modulate a variety of cellular functions, including regenerative potential, migration, and stem cell fate, are being explored to aid neural degeneration, dysfunction, and injury. This review describes the materials and approaches for the application of ES to the PNS and CNS microenvironments, towards an improved understanding of how ES can be harnessed for beneficial clinical applications. Emphasized are some recent advances in ES, including conductive polymers, methods of charge transfer, impact on neural cells, and a brief overview of alternative methodologies for cellular targeting including magneto, ultrasonic, and optogenetic stimulation. This review will examine how heterogenous cell populations, including neurons, glia, and neural stem cells respond to a wide range of conductive 2D and 3D substrates, stimulation regimes, known mechanisms of response, and how cellular sources impact the response to ES.
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Affiliation(s)
- Christopher Bertucci
- Northeastern University, Department of Chemical Engineering, Boston, MA, 02115, United States.
| | - Ryan Koppes
- Northeastern University, Department of Chemical Engineering, Boston, MA, 02115, United States.
| | - Courtney Dumont
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, 33146, United States.
| | - Abigail Koppes
- Northeastern University, Department of Chemical Engineering, Boston, MA, 02115, United States; Department of Biology, Boston, 02115, MA, United States.
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26
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Tajhya R, Delling M. New insights into ion channel-dependent signalling during left-right patterning. J Physiol 2019; 598:1741-1752. [PMID: 31106399 DOI: 10.1113/jp277835] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/23/2019] [Indexed: 01/20/2023] Open
Abstract
The left-right organizer (LRO) in the mouse consists of pit cells within the depression, located at the end of the developing notochord, also known as the embryonic node and crown cells lining the outer periphery of the node. Cilia on pit cells are posteriorly tilted, rotate clockwise and generate leftward fluid flow. Primary cilia on crown cells are required to interpret the directionality of fluid movement and initiate flow-dependent gene transcription. Crown cells express PC1-L1 and PC2, which may form a heteromeric polycystin channel complex on primary cilia. It is still only poorly understood how fluid flow activates the ciliary polycystin complex. Besides polycystin channels voltage gated channels like HCN4 and KCNQ1 have been implicated in establishing asymmetry. How this electrical network of ion channels initiates left-sided signalling cascades and differential gene expression is currently only poorly defined.
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Affiliation(s)
- Rajeev Tajhya
- Department of Physiology, University of California, 1550 4th Street, San Francisco, CA, 94518, USA
| | - Markus Delling
- Department of Physiology, University of California, 1550 4th Street, San Francisco, CA, 94518, USA
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27
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di Biase L, Falato E, Di Lazzaro V. Transcranial Focused Ultrasound (tFUS) and Transcranial Unfocused Ultrasound (tUS) Neuromodulation: From Theoretical Principles to Stimulation Practices. Front Neurol 2019; 10:549. [PMID: 31244747 PMCID: PMC6579808 DOI: 10.3389/fneur.2019.00549] [Citation(s) in RCA: 97] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 05/07/2019] [Indexed: 01/28/2023] Open
Abstract
Transcranial focused ultrasound is an emerging technique for non-invasive neurostimulation. Compared to magnetic or electric non-invasive brain stimulation, this technique has a higher spatial resolution and can reach deep structures. In addition, both animal and human studies suggest that, potentially, different sites of the central and peripheral nervous system can be targeted by this technique. Depending on stimulation parameters, transcranial focused ultrasound is able to determine a wide spectrum of effects, ranging from suppression or facilitation of neural activity to tissue ablation. The aim is to review the state of the art of the human transcranial focused ultrasound neuromodulation literature, including the theoretical principles which underlie the explanation of the bioeffects on neural tissues, and showing the stimulation techniques and parameters used and their outcomes in terms of clinical, neurophysiological or neuroimaging results and safety.
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Affiliation(s)
- Lazzaro di Biase
- Neurology, Neurophysiology, and Neurobiology Unit, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy.,Unit of Neurophysiology and Neuroengineering of Human-Technology Interaction, School of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Emma Falato
- Neurology, Neurophysiology, and Neurobiology Unit, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy.,Unit of Neurophysiology and Neuroengineering of Human-Technology Interaction, School of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Vincenzo Di Lazzaro
- Neurology, Neurophysiology, and Neurobiology Unit, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
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28
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Fan YL, Zhao HC, Li B, Zhao ZL, Feng XQ. Mechanical Roles of F-Actin in the Differentiation of Stem Cells: A Review. ACS Biomater Sci Eng 2019; 5:3788-3801. [PMID: 33438419 DOI: 10.1021/acsbiomaterials.9b00126] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In the development and differentiation of stem cells, mechanical forces associated with filamentous actin (F-actin) play a crucial role. The present review aims to reveal the relationship among the chemical components, microscopic structures, mechanical properties, and biological functions of F-actin. Particular attention is given to the functions of the cytoplasmic and nuclear microfilament cytoskeleton and their regulation mechanisms in the differentiation of stem cells. The distributions of different types of actin monomers in mammal cells and the functions of actin-binding proteins are summarized. We discuss how the fate of stem cells is regulated by intra/extracellular mechanical and chemical cues associated with microfilament-related proteins, intercellular adhesion molecules, etc. In addition, we also address the differentiation-induced variation in the stiffness of stem cells and the correlation between the fate and geometric shape change of stem cells. This review not only deepens our understanding of the biophysical mechanisms underlying the fates of stem cells under different culture conditions but also provides inspirations for the tissue engineering of stem cells.
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Affiliation(s)
- Yan-Lei Fan
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Hu-Cheng Zhao
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Bo Li
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Zi-Long Zhao
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Xi-Qiao Feng
- Institute of Biomechanics and Medical Engineering, Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
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29
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NOMOTO T, TAKAHASHI M, FUJII T, CHIARI L, TOYOTA T, FUJINAMI M. Effects of Cholesterol Concentration and Osmolarity on the Fluidity and Membrane Tension of Free-standing Black Lipid Membranes. ANAL SCI 2018; 34:1237-1242. [DOI: 10.2116/analsci.18p200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Tomonori NOMOTO
- Department of Applied Chemistry and Biotechnology, Chiba University
| | | | - Takuya FUJII
- Department of Applied Chemistry and Biotechnology, Chiba University
| | - Luca CHIARI
- Department of Applied Chemistry and Biotechnology, Chiba University
| | - Taro TOYOTA
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo
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30
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Jaiganesh A, Narui Y, Araya-Secchi R, Sotomayor M. Beyond Cell-Cell Adhesion: Sensational Cadherins for Hearing and Balance. Cold Spring Harb Perspect Biol 2018; 10:a029280. [PMID: 28847902 PMCID: PMC6008173 DOI: 10.1101/cshperspect.a029280] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cadherins form a large family of proteins often involved in calcium-dependent cellular adhesion. Although classical members of the family can provide a physical bond between cells, a subset of special cadherins use their extracellular domains to interlink apical specializations of single epithelial sensory cells. Two of these cadherins, cadherin-23 (CDH23) and protocadherin-15 (PCDH15), form extracellular "tip link" filaments that connect apical bundles of stereocilia on hair cells essential for inner-ear mechanotransduction. As these bundles deflect in response to mechanical stimuli from sound or head movements, tip links gate hair-cell mechanosensitive channels to initiate sensory perception. Here, we review the unusual and diverse structural properties of these tip-link cadherins and the functional significance of their deafness-related missense mutations. Based on the structural features of CDH23 and PCDH15, we discuss the elasticity of tip links and models that bridge the gap between the nanomechanics of cadherins and the micromechanics of hair-cell bundles during inner-ear mechanotransduction.
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Affiliation(s)
- Avinash Jaiganesh
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Yoshie Narui
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Raul Araya-Secchi
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210
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31
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Lin Z, Zhou W, Huang X, Wang K, Tang J, Niu L, Meng L, Zheng H. On-Chip Ultrasound Modulation of Pyramidal Neuronal Activity in Hippocampal Slices. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/adbi.201800041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Zhengrong Lin
- Institute of Biomedical and Health Engineering; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; 1068 Xueyuan Avenue Shenzhen 518055 China
| | - Wei Zhou
- Institute of Biomedical and Health Engineering; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; 1068 Xueyuan Avenue Shenzhen 518055 China
| | - Xiaowei Huang
- Institute of Biomedical and Health Engineering; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; 1068 Xueyuan Avenue Shenzhen 518055 China
| | - Kaiyue Wang
- Institute of Biomedical and Health Engineering; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; 1068 Xueyuan Avenue Shenzhen 518055 China
| | - Jie Tang
- Department of Physiology; School of Basic Medical Sciences; Southern Medical University; 1023-1063 Shatai South Avenue Guangzhou 510515 China
| | - Lili Niu
- Institute of Biomedical and Health Engineering; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; 1068 Xueyuan Avenue Shenzhen 518055 China
| | - Long Meng
- Institute of Biomedical and Health Engineering; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; 1068 Xueyuan Avenue Shenzhen 518055 China
| | - Hairong Zheng
- Institute of Biomedical and Health Engineering; Shenzhen Institutes of Advanced Technology; Chinese Academy of Sciences; 1068 Xueyuan Avenue Shenzhen 518055 China
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32
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Ultrasound Elicits Behavioral Responses through Mechanical Effects on Neurons and Ion Channels in a Simple Nervous System. J Neurosci 2018; 38:3081-3091. [PMID: 29463641 DOI: 10.1523/jneurosci.1458-17.2018] [Citation(s) in RCA: 199] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 01/11/2018] [Accepted: 01/27/2018] [Indexed: 01/07/2023] Open
Abstract
Focused ultrasound has been shown to stimulate excitable cells, but the biophysical mechanisms behind this phenomenon remain poorly understood. To provide additional insight, we devised a behavioral-genetic assay applied to the well-characterized nervous system of Caenorhabditis elegans nematodes. We found that pulsed ultrasound elicits robust reversal behavior in wild-type animals in a pressure-, duration-, and pulse protocol-dependent manner. Responses were preserved in mutants unable to sense thermal fluctuations and absent in mutants lacking neurons required for mechanosensation. Additionally, we found that the worm's response to ultrasound pulses rests on the expression of MEC-4, a DEG/ENaC/ASIC ion channel required for touch sensation. Consistent with prior studies of MEC-4-dependent currents in vivo, the worm's response was optimal for pulses repeated 300-1000 times per second. Based on these findings, we conclude that mechanical, rather than thermal, stimulation accounts for behavioral responses. Further, we propose that acoustic radiation force governs the response to ultrasound in a manner that depends on the touch receptor neurons and MEC-4-dependent ion channels. Our findings illuminate a complete pathway of ultrasound action, from the forces generated by propagating ultrasound to an activation of a specific ion channel. The findings further highlight the importance of optimizing ultrasound pulsing protocols when stimulating neurons via ion channels with mechanosensitive properties.SIGNIFICANCE STATEMENT How ultrasound influences neurons and other excitable cells has remained a mystery for decades. Although it is widely understood that ultrasound can heat tissues and induce mechanical strain, whether or not neuronal activation depends on heat, mechanical force, or both physical factors is not known. We harnessed Caenorhabditis elegans nematodes and their extraordinary sensitivity to thermal and mechanical stimuli to address this question. Whereas thermosensory mutants respond to ultrasound similar to wild-type animals, mechanosensory mutants were insensitive to ultrasound stimulation. Additionally, stimulus parameters that accentuate mechanical effects were more effective than those producing more heat. These findings highlight a mechanical nature of the effect of ultrasound on neurons and suggest specific ways to optimize stimulation protocols in specific tissues.
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33
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Tang Z, Li X, Tan Y, Fan H, Zhang X. The material and biological characteristics of osteoinductive calcium phosphate ceramics. Regen Biomater 2018; 5:43-59. [PMID: 29423267 PMCID: PMC5798025 DOI: 10.1093/rb/rbx024] [Citation(s) in RCA: 164] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/16/2017] [Accepted: 07/20/2017] [Indexed: 12/14/2022] Open
Abstract
The discovery of osteoinductivity of calcium phosphate (Ca-P) ceramics has set an enduring paradigm of conferring biological regenerative activity to materials with carefully designed structural characteristics. The unique phase composition and porous structural features of osteoinductive Ca-P ceramics allow it to interact with signaling molecules and extracellular matrices in the host system, creating a local environment conducive to new bone formation. Mounting evidence now indicate that the osteoinductive activity of Ca-P ceramics is linked to their physicochemical and three-dimensional structural properties. Inspired by this conceptual breakthrough, many laboratories have shown that other materials can be also enticed to join the rank of tissue-inducing biomaterials, and besides the bones, other tissues such as cartilage, nerves and blood vessels were also regenerated with the assistance of biomaterials. Here, we give a brief historical recount about the discovery of the osteoinductivity of Ca-P ceramics, summarize the underlying material factors and biological characteristics, and discuss the mechanism of osteoinduction concerning protein adsorption, and the interaction with different types of cells, and the involvement of the vascular and immune systems.
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Affiliation(s)
- Zhurong Tang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P.R. China
| | - Xiangfeng Li
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P.R. China
| | - Yanfei Tan
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P.R. China
| | - Hongsong Fan
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P.R. China
| | - Xingdong Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P.R. China
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34
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Nourse JL, Pathak MM. How cells channel their stress: Interplay between Piezo1 and the cytoskeleton. Semin Cell Dev Biol 2017; 71:3-12. [PMID: 28676421 DOI: 10.1016/j.semcdb.2017.06.018] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/23/2017] [Accepted: 06/25/2017] [Indexed: 11/17/2022]
Abstract
Cells constantly encounter mechanical stimuli in their environment, such as dynamic forces and mechanical features of the extracellular matrix. These mechanical cues are transduced into biochemical signals, and integrated with genetic and chemical signals to modulate diverse physiological processes. Cells also actively generate forces to internally transport cargo, to explore the physical properties of their environment and to spatially position themselves and other cells during development. Mechanical forces are therefore central to development, homeostasis, and repair. Several molecular and biophysical strategies are utilized by cells for detecting and generating mechanical forces. Here we discuss an important class of molecules involved in sensing and transducing mechanical forces - mechanically-activated ion channels. We focus primarily on the Piezo1 ion channel, and examine its relationship with the cellular cytoskeleton.
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Affiliation(s)
- Jamison L Nourse
- Department of Physiology & Biophysics, Sue & Bill Gross Stem Cell Research Center, 835 Health Sciences Road, Room 275B, UC Irvine, Irvine, CA 92697, United States
| | - Medha M Pathak
- Department of Physiology & Biophysics, Sue & Bill Gross Stem Cell Research Center, 835 Health Sciences Road, Room 275B, UC Irvine, Irvine, CA 92697, United States.
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35
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Jiao R, Cui D, Wang SC, Li D, Wang YF. Interactions of the Mechanosensitive Channels with Extracellular Matrix, Integrins, and Cytoskeletal Network in Osmosensation. Front Mol Neurosci 2017; 10:96. [PMID: 28424587 PMCID: PMC5380722 DOI: 10.3389/fnmol.2017.00096] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 03/21/2017] [Indexed: 01/14/2023] Open
Abstract
Life is maintained in a sea water-like internal environment. The homeostasis of this environment is dependent on osmosensory system translation of hydromineral information into osmotic regulatory machinery at system, tissue and cell levels. In the osmosensation, hydromineral information can be converted into cellular reactions through osmoreceptors, which changes thirst and drinking, secretion of antidiuretic vasopressin (VP), reabsorption of water and salt in the kidneys at systemic level as well as cellular metabolic activity and survival status at tissue level. The key feature of osmosensation is the activation of mechanoreceptors or mechanosensors, particularly transient receptor potential vallinoid (TRPV) and canonical (TRPC) family channels, which increases cytosolic Ca2+ levels, activates osmosensory cells including VP neurons and triggers a series of secondary reactions. TRPV channels are sensitive to both hyperosmotic and hyposmotic stimuli while TRPC channels are more sensitive to hyposmotic challenge in neurons. The activation of TRP channels relies on changes in cell volume, membrane stretch and cytoskeletal reorganization as well as hydration status of extracellular matrix (ECM) and activity of integrins. Different families of TRP channels could be activated differently in response to hyperosmotic and hyposmotic stimuli in different spatiotemporal orders, leading to differential reactions of osmosensory cells. Together, they constitute the osmosensory machinery. The activation of this osmoreceptor complex is also associated with the activity of other osmolarity-regulating organelles, such as water channel protein aquaporins, Na-K-2Cl cotransporters, volume-sensitive anion channels, sodium pump and purinergic receptors in addition to intercellular interactions, typically astrocytic neuronal interactions. In this article, we review our current understandings of the composition of osmoreceptors and the processes of osmosensation.
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Affiliation(s)
- Runsheng Jiao
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical UniversityHarbin, China
| | - Dan Cui
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical UniversityHarbin, China
| | - Stephani C Wang
- Department of Internal Medicine, Albany Medical CollegeAlbany, NY, USA
| | - Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical UniversityHarbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical UniversityHarbin, China
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36
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Effects of a skin-massaging device on the ex-vivo expression of human dermis proteins and in-vivo facial wrinkles. PLoS One 2017; 12:e0172624. [PMID: 28249037 PMCID: PMC5383004 DOI: 10.1371/journal.pone.0172624] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/23/2017] [Indexed: 12/26/2022] Open
Abstract
Mechanical and geometrical cues influence cell behaviour. At the tissue level, almost all organs exhibit immediate mechanical responsiveness, in particular by increasing their stiffness in direct proportion to an applied mechanical stress. It was recently shown in cultured-cell models, in particular with fibroblasts, that the frequency of the applied stress is a fundamental stimulating parameter. However, the influence of the stimulus frequency at the tissue level has remained elusive. Using a device to deliver an oscillating torque that generates cyclic strain at different frequencies, we studied the effect(s) of mild skin massage in an ex vivo model and in vivo. Skin explants were maintained ex vivo for 10 days and massaged twice daily for one minute at various frequencies within the range of 65–85 Hz. Biopsies were analysed at D0, D5 and D10 and processed for immuno-histological staining specific to various dermal proteins. As compared to untreated skin explants, the massaging procedure clearly led to higher rates of expression, in particular for decorin, fibrillin, tropoelastin, and procollagen-1. The mechanical stimulus thus evoked an anti-aging response. Strikingly, the expression was found to depend on the stimulus frequency with maximum expression at 75Hz. We then tested whether this mechanical stimulus had an anti-aging effect in vivo. Twenty Caucasian women (aged 65-75y) applied a commercial anti-aging cream to the face and neck, followed by daily treatments using the anti-aging massage device for 8 weeks. A control group of twenty-two women, with similar ages to the first group, applied the cream alone. At W0, W4 and W8, a blinded evaluator assessed the global facial wrinkles, skin texture, lip area, cheek wrinkles, neck sagging and neck texture using a clinical grading scale. We found that combining the massaging device with a skin anti-aging formulation amplified the beneficial effects of the cream.
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Wu J, Lewis AH, Grandl J. Touch, Tension, and Transduction - The Function and Regulation of Piezo Ion Channels. Trends Biochem Sci 2016; 42:57-71. [PMID: 27743844 DOI: 10.1016/j.tibs.2016.09.004] [Citation(s) in RCA: 377] [Impact Index Per Article: 41.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 09/07/2016] [Accepted: 09/08/2016] [Indexed: 02/03/2023]
Abstract
In 2010, two proteins, Piezo1 and Piezo2, were identified as the long-sought molecular carriers of an excitatory mechanically activated current found in many cells. This discovery has opened the floodgates for studying a vast number of mechanotransduction processes. Over the past 6 years, groundbreaking research has identified Piezos as ion channels that sense light touch, proprioception, and vascular blood flow, ruled out roles for Piezos in several other mechanotransduction processes, and revealed the basic structural and functional properties of the channel. Here, we review these findings and discuss the many aspects of Piezo function that remain mysterious, including how Piezos convert a variety of mechanical stimuli into channel activation and subsequent inactivation, and what molecules and mechanisms modulate Piezo function.
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Affiliation(s)
- Jason Wu
- Duke University Medical Center, Department of Neurobiology, Durham, NC 27710, USA
| | - Amanda H Lewis
- Duke University Medical Center, Department of Neurobiology, Durham, NC 27710, USA
| | - Jörg Grandl
- Duke University Medical Center, Department of Neurobiology, Durham, NC 27710, USA.
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40
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Ventre DM, Koppes AN. The Body Acoustic: Ultrasonic Neuromodulation for Translational Medicine. Cells Tissues Organs 2016; 202:23-41. [DOI: 10.1159/000446622] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2016] [Indexed: 11/19/2022] Open
Abstract
For the greater part of the last century, ultrasound (US) has seen widespread use in applications ranging from materials science to medicine. The history of US in medicine has also seen promising success in clinical diagnostics and regenerative medicine. Recent studies have shown that US is able to manipulate the nervous system, leading toward potential treatment for various neuropathological conditions, a phenomenon known as ultrasonic neuromodulation (NM). Ultrasonic NM is a promising alternative to pharmaceuticals and surgery, due to high spatiotemporal resolution combined with the potentially noninvasive means of application. Current advances have made progress in establishing effective dosage limits, waveform parameters, and stimulus regimes in order to achieve desired effects in a variety of tissue and cell types. However, to date there has been limited systematic analysis of the complex variables involved in creating a therapeutic US stimulation regime specifically tailored to the nervous system. Without a fundamental understanding of the effects of US on neural tissue, including the surrounding bone, musculature, and vasculature, the safety and efficacy of US as an NM tool is yet to be determined. Advances in imaging technology and focusing hardware highlight new avenues for potential clinical applications for therapeutic ultrasonic stimulation. US may be an alternative to electrical and magnetic means of NM for targets in the central nervous system as well as in the peripheral and autonomic nervous systems. This review provides a historical perspective on the past, present, and future of US as a translational therapeutic.
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41
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Localized force application reveals mechanically sensitive domains of Piezo1. Nat Commun 2016; 7:12939. [PMID: 27694883 PMCID: PMC5063965 DOI: 10.1038/ncomms12939] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 08/16/2016] [Indexed: 01/12/2023] Open
Abstract
Piezos are mechanically activated ion channels that function as sensors of touch and pressure in various cell types. However, the precise mechanism and structures mediating mechanical activation and subsequent inactivation have not yet been identified. Here we use magnetic nanoparticles as localized transducers of mechanical force in combination with pressure-clamp electrophysiology to identify mechanically sensitive domains important for activation and inactivation.
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Katta S, Krieg M, Goodman MB. Feeling force: physical and physiological principles enabling sensory mechanotransduction. Annu Rev Cell Dev Biol 2016; 31:347-71. [PMID: 26566115 DOI: 10.1146/annurev-cellbio-100913-013426] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Organisms as diverse as microbes, roundworms, insects, and mammals detect and respond to applied force. In animals, this ability depends on ionotropic force receptors, known as mechanoelectrical transduction (MeT) channels, that are expressed by specialized mechanoreceptor cells embedded in diverse tissues and distributed throughout the body. These cells mediate hearing, touch, and proprioception and play a crucial role in regulating organ function. Here, we attempt to integrate knowledge about the architecture of mechanoreceptor cells and their sensory organs with principles of cell mechanics, and we consider how engulfing tissues contribute to mechanical filtering. We address progress in the quest to identify the proteins that form MeT channels and to understand how these channels are gated. For clarity and convenience, we focus on sensory mechanobiology in nematodes, fruit flies, and mice. These themes are emphasized: asymmetric responses to applied forces, which may reflect anisotropy of the structure and mechanics of sensory mechanoreceptor cells, and proteins that function as MeT channels, which appear to have emerged many times through evolution.
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Affiliation(s)
- Samata Katta
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305;
| | - Michael Krieg
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305;
| | - Miriam B Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305;
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Abstract
Brain stimulation techniques are important in both basic and clinical studies. Majority of well-known brain stimulating techniques have low spatial resolution or entail invasive processes. Low intensity focused ultrasound (LIFU) seems to be a proper candidate for dealing with such deficiencies. This review recapitulates studies which explored the effects of LIFU on brain structures and its function, in both research and clinical areas. Although the mechanism of LIFU action is still unclear, its different effects from molecular level up to behavioral level can be explored in animal and human brain. It can also be coupled with brain imaging assessments in future research.
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Affiliation(s)
- Ehsan Rezayat
- Ultrasound Brain Stimulation Lab, Institute for Cognitive Science Studies, Tehran, Iran
| | - Iman Ghodrati Toostani
- Interunidades Bioengenharia (EESC/FMRP/IQSC), Neurocognitive Engineering Lab, Universidade de São Paulo, São Carlos, SP, Brazil.; Research FGS (Fanavaran Gostaresh Salamat), Research and Development Department, Tehran, Iran
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Sabass B, Stone HA. Role of the Membrane for Mechanosensing by Tethered Channels. PHYSICAL REVIEW LETTERS 2016; 116:258101. [PMID: 27391754 DOI: 10.1103/physrevlett.116.258101] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Indexed: 06/06/2023]
Abstract
Biologically important membrane channels are gated by force at attached tethers. Here, we generically characterize the nontrivial interplay of force, membrane tension, and channel deformations that can affect gating. A central finding is that minute conical channel deformation under force leads to significant energy release during opening. We also calculate channel-channel interactions and show that they can amplify the force sensitivity of tethered channels.
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Affiliation(s)
- Benedikt Sabass
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Howard A Stone
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA
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Freeman EC, Najem JS, Sukharev S, Philen MK, Leo DJ. The mechanoelectrical response of droplet interface bilayer membranes. SOFT MATTER 2016; 12:3021-3031. [PMID: 26905644 DOI: 10.1039/c5sm02779a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mechanotransduction and interfacial properties in unsupported liquid biomimetic membranes are explored using the droplet-interface bilayer technique. The fluidic monolayer-membrane system afforded by this technique allows for dynamic control over the membrane dimensions and curvature, which under periodic deformations generates capacitive currents (akin to a Kelvin probe), and permits a detailed electrostatic characterization of the boundary layers as well as observation of flexoelectric effects. Both high and low displacement frequency regimes are examined, and the results show that the mechanoelectric signals generated by the membranes may be linked to the membrane electrostatic structure. In addition, we show that periodic membrane bending in a high-frequency regime generates tension sufficient to activate reconstituted mechanosensitive channels.
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Affiliation(s)
- E C Freeman
- College of Engineering, University of Georgia, USA.
| | - J S Najem
- Department of Mechanical Engineering, Virginia Tech, USA
| | - S Sukharev
- Department of Biology, University of Maryland, USA
| | - M K Philen
- Department of Aerospace and Ocean Engineering, Virginia Tech, USA
| | - D J Leo
- College of Engineering, University of Georgia, USA.
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Zhu L, Wu J, Liu L, Liu Y, Yan Y, Cui Q, Chen X. Gating mechanism of mechanosensitive channel of large conductance: a coupled continuum mechanical-continuum solvation approach. Biomech Model Mechanobiol 2016; 15:1557-1576. [PMID: 27009075 DOI: 10.1007/s10237-016-0783-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
Gating transition of the mechanosensitive channel of large conductance (MscL) represents a good example of important biological processes that are difficult to describe using atomistic simulations due to the large (submicron) length scale and long (millisecond) time scale. Here we develop a novel computational framework that tightly couples continuum mechanics with continuum solvation models to study the detailed gating behavior of E. coli-MscL. The components of protein molecules are modeled by continuum elements that properly describe their shape, material properties and physicochemical features (e.g., charge distribution). The lipid membrane is modeled as a three-layer material in which the lipid head group and tail regions are treated separately, taking into account the fact that fluidic lipid bilayers do not bear shear stress. Coupling between mechanical and chemical responses of the channel is realized by an iterative integration of continuum mechanics (CM) modeling and continuum solvation (CS) computation. Compared to previous continuum mechanics studies, the present model is capable of capturing the most essential features of the gating process in a much more realistic fashion: due mainly to the apolar solvation contribution, the membrane tension for full opening of MscL is reduced substantially to the experimental measured range. Moreover, the pore size stabilizes constantly during gating because of the intricate interactions of the multiple components of the system, implying the mechanism for sub-conducting states of MscL gating. A significant fraction ([Formula: see text]2/3) of the gating membrane strain is required to reach the first sub-conducting state of our model, which is featured with a relative conductance of 0.115 to the fully opened state. These trends agree well with experimental observations. We anticipate that the coupled CM/CS modeling framework is uniquely suited for the analysis of many biomolecules and their assemblies under external mechanical stimuli.
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Affiliation(s)
- Liangliang Zhu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China.,Columbia Nanomechanics Research Center, Department of Earth and Environmental Engineering, Columbia University, New York, NY, 10027, USA
| | - Jiazhong Wu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Ling Liu
- Department of Mechanical and Aerospace Engineering, Utah State University, Logan, UT, 84322, USA
| | - Yilun Liu
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Yuan Yan
- International Center for Applied Mechanics, State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an, 710049, People's Republic of China
| | - Qiang Cui
- Department of Chemistry and Theoretical Chemistry Institute, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Xi Chen
- Columbia Nanomechanics Research Center, Department of Earth and Environmental Engineering, Columbia University, New York, NY, 10027, USA.
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Jalalvand E, Robertson B, Wallén P, Grillner S. Ciliated neurons lining the central canal sense both fluid movement and pH through ASIC3. Nat Commun 2016; 7:10002. [PMID: 26743691 PMCID: PMC4729841 DOI: 10.1038/ncomms10002] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 10/26/2015] [Indexed: 01/02/2023] Open
Abstract
Cerebrospinal fluid-contacting (CSF-c) cells are found in all vertebrates but their function has remained elusive. We recently identified one type of laterally projecting CSF-c cell in lamprey spinal cord with neuronal properties that expresses GABA and somatostatin. We show here that these CSF-c neurons respond to both mechanical stimulation and to lowered pH. These effects are most likely mediated by ASIC3-channels, since APETx2, a specific antagonist of ASIC3, blocks them both. Furthermore, lowering of pH as well as application of somatostatin will reduce the locomotor burst rate. The somatostatin receptor antagonist counteracts the effects of both a decrease in pH and of somatostatin. Lateral bending movement imposed on the spinal cord, as would occur during natural swimming, activates CSF-c neurons. Taken together, we show that CSF-c neurons act both as mechanoreceptors and as chemoreceptors through ASIC3 channels, and their action may protect against pH-changes resulting from excessive neuronal activity.
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Affiliation(s)
- Elham Jalalvand
- The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institutet, Stockholm SE-171 77, Sweden
| | - Brita Robertson
- The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institutet, Stockholm SE-171 77, Sweden
| | - Peter Wallén
- The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institutet, Stockholm SE-171 77, Sweden
| | - Sten Grillner
- The Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institutet, Stockholm SE-171 77, Sweden
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Lewis AH, Grandl J. Mechanical sensitivity of Piezo1 ion channels can be tuned by cellular membrane tension. eLife 2015; 4. [PMID: 26646186 PMCID: PMC4718726 DOI: 10.7554/elife.12088] [Citation(s) in RCA: 278] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 11/26/2015] [Indexed: 12/17/2022] Open
Abstract
Piezo1 ion channels mediate the conversion of mechanical forces into electrical signals and are critical for responsiveness to touch in metazoans. The apparent mechanical sensitivity of Piezo1 varies substantially across cellular environments, stimulating methods and protocols, raising the fundamental questions of what precise physical stimulus activates the channel and how its stimulus sensitivity is regulated. Here, we measured Piezo1 currents evoked by membrane stretch in three patch configurations, while simultaneously visualizing and measuring membrane geometry. Building on this approach, we developed protocols to minimize resting membrane curvature and tension prior to probing Piezo1 activity. We find that Piezo1 responds to lateral membrane tension with exquisite sensitivity as compared to other mechanically activated channels and that resting tension can drive channel inactivation, thereby tuning overall mechanical sensitivity of Piezo1. Our results explain how Piezo1 can function efficiently and with adaptable sensitivity as a sensor of mechanical stimulation in diverse cellular contexts. DOI:http://dx.doi.org/10.7554/eLife.12088.001 Piezo ion channels are proteins that are embedded in the cell membranes of many types of tissue, including the heart, lung, skin and kidney. These proteins are essential for many biological processes, including sensing gentle touches and ensuring that blood vessels develop properly. When stimulated by mechanical forces, a central pore in the Piezo channel opens to allow positively charged ions to flow into the cell, which triggers electrical and chemical signaling processes inside the cell. However, it was not known exactly what type of mechanical stimulus is sensed by Piezo ion channels. Lewis and Grandl expressed Piezo ion channels in cultured human kidney cells, and opened them by applying pressure to parts of the cell membrane inside a glass pipette. This causes a number of changes to the membrane, including to its curvature and tension, either of which could potentially open the Piezo channels. However, Lewis and Grandl were able to calculate from images of the cell membrane inside the pipette that tension is the activating stimulus. Further experiments unexpectedly revealed that the tension that is usually present in the cell membrane is sufficient to inactivate Piezo channels and prevent them from responding to an additional mechanical stimulus. This suggests that Piezo ion channels are inherently more sensitive to tension than previously realized, which could explain why different cell types appear to have different sensitivities to pressure. Although Lewis and Grandl have now shown that Piezo channels are activated by tension, more work is needed to investigate how the Piezo ion channel senses this force, and how this leads to the channel pore opening. DOI:http://dx.doi.org/10.7554/eLife.12088.002
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Affiliation(s)
- Amanda H Lewis
- Department of Neurobiology, Duke University Medical Center, Durham, United States
| | - Jörg Grandl
- Department of Neurobiology, Duke University Medical Center, Durham, United States
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Hakimova H, Kim S, Chu K, Lee SK, Jeong B, Jeon D. Ultrasound stimulation inhibits recurrent seizures and improves behavioral outcome in an experimental model of mesial temporal lobe epilepsy. Epilepsy Behav 2015; 49:26-32. [PMID: 25940106 DOI: 10.1016/j.yebeh.2015.04.008] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 04/03/2015] [Indexed: 02/06/2023]
Abstract
Current therapies for epilepsy consist mostly of pharmacological agents or invasive surgery. Recently, ultrasound (US) stimulation has been considered a promising tool for the noninvasive treatment of brain diseases, including epilepsy. However, in temporal lobe epilepsy (TLE), a common form of epilepsy, neurophysiological and functional outcomes following US stimulation are not well defined. To address this, we developed a paradigm of transcranial pulsed US stimulation to efficiently suppress seizure activity in the initial/acute period in a kainate (KA)-induced mouse model of mesial TLE. Pulsed US stimulation inhibited acute seizure activity and either delayed the onset of or suppressed status epilepticus (SE). Kainate-treated mice that had received US stimulation in the initial period exhibited fewer spontaneous recurrent seizures (SRSs) and improved performance in behavioral tasks assessing sociability and depression in the chronic period of epilepsy. Our results demonstrate that US stimulation in the acute period of epilepsy can inhibit SRSs and improve behavioral outcomes in a mouse model of mesial TLE. The present study suggests that noninvasive transcranial pulsed US stimulation may be feasible as an adjuvant therapy in patients with epilepsy. This article is part of a Special Issue entitled "Status Epilepticus".
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Affiliation(s)
- Hilola Hakimova
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Sangwoo Kim
- Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital (SNUH), Seoul, Republic of Korea
| | - Kon Chu
- Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital (SNUH), Seoul, Republic of Korea
| | - Sang Kun Lee
- Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital (SNUH), Seoul, Republic of Korea
| | - Bumseok Jeong
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.
| | - Daejong Jeon
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea; Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital (SNUH), Seoul, Republic of Korea.
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