1
|
Kelly AR, Glover DJ. Information Transmission through Biotic-Abiotic Interfaces to Restore or Enhance Human Function. ACS APPLIED BIO MATERIALS 2024; 7:3605-3628. [PMID: 38729914 DOI: 10.1021/acsabm.4c00435] [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] [Indexed: 05/12/2024]
Abstract
Advancements in reliable information transfer across biotic-abiotic interfaces have enabled the restoration of lost human function. For example, communication between neuronal cells and electrical devices restores the ability to walk to a tetraplegic patient and vision to patients blinded by retinal disease. These impactful medical achievements are aided by tailored biotic-abiotic interfaces that maximize information transfer fidelity by considering the physical properties of the underlying biological and synthetic components. This Review develops a modular framework to define and describe the engineering of biotic and abiotic components as well as the design of interfaces to facilitate biotic-abiotic information transfer using light or electricity. Delineating the properties of the biotic, interface, and abiotic components that enable communication can serve as a guide for future research in this highly interdisciplinary field. Application of synthetic biology to engineer light-sensitive proteins has facilitated the control of neural signaling and the restoration of rudimentary vision after retinal blindness. Electrophysiological methodologies that use brain-computer interfaces and stimulating implants to bypass spinal column injuries have led to the rehabilitation of limb movement and walking ability. Cellular interfacing methodologies and on-chip learning capability have been made possible by organic transistors that mimic the information processing capacity of neurons. The collaboration of molecular biologists, material scientists, and electrical engineers in the emerging field of biotic-abiotic interfacing will lead to the development of prosthetics capable of responding to thought and experiencing touch sensation via direct integration into the human nervous system. Further interdisciplinary research will improve electrical and optical interfacing technologies for the restoration of vision, offering greater visual acuity and potentially color vision in the near future.
Collapse
Affiliation(s)
- Alexander R Kelly
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Dominic J Glover
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| |
Collapse
|
2
|
Gidado IM, Nwokoye II, Triantis IF, Qassem M, Kyriacou PA. Multi-Modal Spectroscopic Assessment of Skin Hydration. SENSORS (BASEL, SWITZERLAND) 2024; 24:1419. [PMID: 38474955 DOI: 10.3390/s24051419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 02/14/2024] [Accepted: 02/16/2024] [Indexed: 03/14/2024]
Abstract
Human skin acts as a protective barrier, preserving bodily functions and regulating water loss. Disruption to the skin barrier can lead to skin conditions and diseases, emphasizing the need for skin hydration monitoring. The gold-standard sensing method for assessing skin hydration is the Corneometer, monitoring the skin's electrical properties. It relies on measuring capacitance and has the advantage of precisely detecting a wide range of hydration levels within the skin's superficial layer. However, measurement errors due to its front end requiring contact with the skin, combined with the bipolar configuration of the electrodes used and discrepancies due to variations in various interfering analytes, often result in significant inaccuracy and a need to perform measurements under controlled conditions. To overcome these issues, we explore the merits of a different approach to sensing electrical properties, namely, a tetrapolar bioimpedance sensing approach, with the merits of a novel optical sensing modality. Tetrapolar bioimpedance allows for the elimination of bipolar measurement errors, and optical spectroscopy allows for the identification of skin water absorption peaks at wavelengths of 970 nm and 1450 nm. Employing both electrical and optical sensing modalities through a multimodal approach enhances skin hydration measurement sensitivity and validity. This layered approach may be particularly beneficial for minimising errors, providing a more robust and comprehensive tool for skin hydration assessment. An ex vivo desorption experiment was carried out on fresh porcine skin, and an in vivo indicative case study was conducted utilising the developed optical and bioimpedance sensing devices. Expected outcomes were expressed from both techniques, with an increase in the output of the optical sensor voltage and a decrease in bioimpedance as skin hydration decreased. MLR models were employed, and the results presented strong correlations (R-squared = 0.996 and p-value = 6.45 × 10-21), with an enhanced outcome for hydration parameters when both modalities were combined as opposed to independently, highlighting the advantage of the multimodal sensing approach for skin hydration assessment.
Collapse
Affiliation(s)
- Iman M Gidado
- Research Centre for Biomedical Engineering, University of London, London EC1V 0HB, UK
| | - Ifeabunike I Nwokoye
- Research Centre for Biomedical Engineering, University of London, London EC1V 0HB, UK
| | - Iasonas F Triantis
- Research Centre for Biomedical Engineering, University of London, London EC1V 0HB, UK
| | - Meha Qassem
- Research Centre for Biomedical Engineering, University of London, London EC1V 0HB, UK
| | - Panicos A Kyriacou
- Research Centre for Biomedical Engineering, University of London, London EC1V 0HB, UK
| |
Collapse
|
3
|
Kwon JW, Jeon YK, Kim J, Kim SJ, Kim SJ. Intramolecular Disulfide Bonds for Biogenesis of CALHM1 Ion Channel Are Dispensable for Voltage-Dependent Activation. Mol Cells 2021; 44:758-769. [PMID: 34711692 PMCID: PMC8560582 DOI: 10.14348/molcells.2021.0131] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 08/19/2021] [Accepted: 09/06/2021] [Indexed: 11/27/2022] Open
Abstract
Calcium homeostasis modulator 1 (CALHM1) is a membrane protein with four transmembrane helices that form an octameric ion channel with voltage-dependent activation. There are four conserved cysteine (Cys) residues in the extracellular domain that form two intramolecular disulfide bonds. We investigated the roles of C42-C127 and C44-C161 in human CALHM1 channel biogenesis and the ionic current (ICALHM1). Replacing Cys with Ser or Ala abolished the membrane trafficking as well as ICALHM1. Immunoblotting analysis revealed dithiothreitol-sensitive multimeric CALHM1, which was markedly reduced in C44S and C161S, but preserved in C42S and C127S. The mixed expression of C42S and wild-type did not show a dominant-negative effect. While the heteromeric assembly of CALHM1 and CALHM3 formed active ion channels, the co-expression of C42S and CALHM3 did not produce functional channels. Despite the critical structural role of the extracellular cysteine residues, a treatment with the membrane-impermeable reducing agent tris(2-carboxyethyl) phosphine (TCEP, 2 mM) did not affect ICALHM1 for up to 30 min. Interestingly, incubation with TCEP (2 mM) for 2-6 h reduced both ICALHM1 and the surface expression of CALHM1 in a time-dependent manner. We propose that the intramolecular disulfide bonds are essential for folding, oligomerization, trafficking and maintenance of CALHM1 in the plasma membrane, but dispensable for the voltage-dependent activation once expressed on the plasma membrane.
Collapse
Affiliation(s)
- Jae Won Kwon
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Young Keul Jeon
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Jinsung Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Sang Jeong Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul 03080, Korea
- Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Korea
- Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 03080, Korea
| |
Collapse
|
4
|
Choi SW, Choi SW, Jeon YK, Moon SH, Zhang YH, Kim SJ. Suppression of hERG K + current and cardiac action potential prolongation by 4-hydroxynonenal via dual mechanisms. Redox Biol 2018; 19:190-199. [PMID: 30172983 PMCID: PMC6122396 DOI: 10.1016/j.redox.2018.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 08/20/2018] [Accepted: 08/23/2018] [Indexed: 01/08/2023] Open
Abstract
Oxidative stress under pathological conditions, such as ischemia/reperfusion and inflammation, results in the production of various reactive chemicals. Of these chemicals, 4-hydroxynonenal (4-HNE), a peroxidation product of ω6-polyunsaturated fatty acid, has garnered significant attention. However, the effect of 4-HNE on cardiac electrophysiology has not yet been reported. In the present study, we investigated the effects of 4-HNE on several cardiac ion channels, including human ether-a-go-go-related (hERG) channels, using the whole-cell patch clamp technique. Short-term exposure to 100 μM 4-HNE (4-HNE100S), which mimics local levels under oxidative stress, decreased the amplitudes of rapidly activating delayed rectifier K+ current (IKr) in guinea pig ventricular myocytes (GPVMs) and HEK293T cells overexpressing hERG (IhERG). MS analysis revealed the formation of 4-HNE-hERG adduct on specific amino acid residues, including C276, K595, H70, and H687. Long-term treatment (1–3 h) with 10 μM 4-HNE (4-HNE10L), suppressed IKr and IhERG, but not IKs and ICa,L. Action potential duration (APD) of GPVMs was prolonged by 37% and 64% by 4-HNE100S and 4-HNE10L, respectively. Western blot analysis using surface biotinylation revealed a reduction in mature membrane hERG protein after treatment with 4-HNE10L. Proteasomal degradation inhibitors, such as bortezomib, prevented the 4-HNE10L-induced decrease in mature hERG, suggesting a retrograde degradation of membrane hERG due to 4-HNE. Taken together, 4-HNE100S and 4-HNE10L suppressed IhERG via functional inhibition and downregulation of membrane expression of hERG, respectively. The exposure of 4-HNE under pathological oxidative stress may increase the risk of proarrhythmic events via APD prolongation. 4-HNE-mediated hERG channel modification causes cardiac action potential prolongation. 4-HNE inhibits hERG channel by post-translational modification at Cys276, Lys595, His70, and His687. Long-term exposure to 4-HNE decreases membrane hERG channel expression.
Collapse
Affiliation(s)
- Seong Woo Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea; Department of Stem Cell Biology, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Si Won Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young Keul Jeon
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sung-Hwan Moon
- Department of Stem Cell Biology, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Yin-Hua Zhang
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
| |
Collapse
|
5
|
Abstract
Epithelial cells are polarized and have tight junctions that contribute to barrier function. Assessment of barrier function typically involves measurement of electrophysiological parameters or movement of nonionic particles across an epithelium. Here, we describe measurement of transepithelial electrical conductance or resistance, determination of dilution potential, and assessment of flux of nonionic particles such as dextran or mannitol, with particular emphasis on Ussing chamber techniques.
Collapse
|
6
|
Berman JM, Awayda RG, Awayda MS. Interacting domains in the epithelial sodium channel that mediate proteolytic activation. Channels (Austin) 2015. [PMID: 26218672 DOI: 10.1080/19336950.2015.1073869] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Epithelial Sodium Channel (ENaC) proteolysis at sites in the extracellular loop of the α and γ subunits leads to marked activation. The mechanism of this effect remains debated, as well as the role of the N- and C-terminal fragments of these subunits created by cleavage. We introduced cysteines at sites bracketing upstream and downstream the cleavage regions in α and γ ENaC to examine the role of these fragments in the activated channel. Using thiol modifying reagents, as well as examining the effects of cleavage by exogenous proteases we constructed a functional model that determines the potential interactions of the termini near the cleavage regions. We report that the N-terminal fragments of both α and γ ENaC interact with the channel complex; with interactions between the N-terminal γ and the C-terminal α fragments being the most critical to channel function and activation by exogenous cleavage by subtilisin. Positive charge modification at a.a.135 in the N-terminal fragment of γ exhibited the largest inhibition of channel function. This region was found to interact with the C-terminal α fragment between a.a. 205 and 221; a tract which was previously identified to be the site of subtilisin's action. These data provide the first evidence for the functional channel rearrangement caused by proteolysis of the α and γ subunit and indicate that the untethered N-terminal fragments of these subunits interact with the channel complex.
Collapse
Affiliation(s)
- Jonathan M Berman
- a Department of Physiology and Biophysics ; State University of New York at Buffalo ; Buffalo NY USA
| | - Ryan G Awayda
- a Department of Physiology and Biophysics ; State University of New York at Buffalo ; Buffalo NY USA
| | - Mouhamed S Awayda
- a Department of Physiology and Biophysics ; State University of New York at Buffalo ; Buffalo NY USA
| |
Collapse
|
7
|
Hogg DW, Pamenter ME, Dukoff DJ, Buck LT. Decreases in mitochondrial reactive oxygen species initiate GABA(A) receptor-mediated electrical suppression in anoxia-tolerant turtle neurons. J Physiol 2015; 593:2311-26. [PMID: 25781154 DOI: 10.1113/jp270474] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 03/12/2015] [Indexed: 12/16/2022] Open
Abstract
Anoxia induces hyper-excitability and cell death in mammalian brain but in the anoxia-tolerant western painted turtle (Chrysemys picta bellii) neuronal electrical activity is suppressed (i.e. spike arrest), adenosine triphosphate (ATP) consumption is reduced, and cell death does not occur. Electrical suppression is primarily the result of enhanced γ-aminobutyric acid (GABA) transmission; however, the underlying mechanism responsible for initiating oxygen-sensitive GABAergic spike arrest is unknown. In turtle cortical pyramidal neurons there are three types of GABA(A) receptor-mediated currents: spontaneous inhibitory postsynaptic currents (IPSCs), giant IPSCs and tonic currents. The aim of this study was to assess the effects of reactive oxygen species (ROS) scavenging on these three currents since ROS levels naturally decrease with anoxia and may serve as a redox signal to initiate spike arrest. We found that anoxia, pharmacological ROS scavenging, or inhibition of mitochondrial ROS generation enhanced all three types of GABA currents, with tonic currents comprising ∼50% of the total current. Application of hydrogen peroxide inhibited all three GABA currents, demonstrating a reversible redox-sensitive signalling mechanism. We conclude that anoxia-mediated decreases in mitochondrial ROS production are sufficient to initiate a redox-sensitive inhibitory GABA signalling cascade that suppresses electrical activity when oxygen is limited. This unique strategy for reducing neuronal ATP consumption during anoxia represents a natural mechanism in which to explore therapies to protect mammalian brain from low-oxygen insults.
Collapse
Affiliation(s)
- David W Hogg
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5
| | - Matthew E Pamenter
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
| | - David J Dukoff
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5
| | - Leslie T Buck
- Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5.,Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada, M5S 3G5
| |
Collapse
|
8
|
Berman JM, Brand C, Awayda MS. A long isoform of the epithelial sodium channel alpha subunit forms a highly active channel. Channels (Austin) 2015; 9:30-43. [PMID: 25517724 DOI: 10.4161/19336950.2014.985478] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
A long isoform of the human Epithelial Sodium Channel (ENaC) α subunit has been identified, but little data exist regarding the properties or regulation of channels formed by α728. The baseline whole cell conductance of oocytes expressing trimeric α728βγ channels was 898.1±277.2 and 49.59±13.2 µS in low and high sodium solutions, respectively, and was 11 and 2 fold higher than the conductances of α669βγ in same solutions. α728βγ channels were also 2 to 5 fold less sensitive to activation by the serine proteases subtilisin and trypsin than α669βγ in low and high Na+ conditions. The long isoform exhibited lower levels of full length and cleaved protein at the plasma membrane and a rightward shifted sensitivity to inhibition by increases of [Na+]i. Both channels displayed similar single channel conductances of 4 pS, and both were activated to a similar extent by reducing temperature, altogether indicating that activation of baseline conductance of α728βγ was likely mediated by enhanced channel activity or open probability. Expression of α728 in native kidneys was validated in human urinary exosomes. These data demonstrate that the long isoform of αENaC forms the structural basis of a channel with different activity and regulation, which may not be easily distinguishable in native tissue, but may underlie sodium hyperabsorption and salt sensitive differences in humans.
Collapse
Affiliation(s)
- Jonathan M Berman
- a Department of Physiology and Biophysics ; State University of New York at Buffalo ; Buffalo , NY USA
| | | | | |
Collapse
|
9
|
Inoue H, Murayama T, Tashiro M, Sakurai T, Konishi M. Mg(2+)- and ATP-dependent inhibition of transient receptor potential melastatin 7 by oxidative stress. Free Radic Biol Med 2014; 72:257-66. [PMID: 24747489 DOI: 10.1016/j.freeradbiomed.2014.04.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 11/25/2022]
Abstract
Transient receptor potential melastatin 7 (TRPM7) is a Ca(2+)- and Mg(2+)-permeable nonselective cation channel that contains a unique carboxyl-terminal serine/threonine protein kinase domain. It has been reported that reactive oxygen species associated with hypoxia or ischemia activate TRPM7 current and then induce Ca(2+) overload resulting in neuronal cell death in the brain. In this study, we aimed to investigate the molecular mechanisms of TRPM7 regulation by hydrogen peroxide (H2O2) using murine TRPM7 expressed in HEK293 cells. Using the whole-cell patch-clamp technique, it was revealed that the TRPM7 current was inhibited, not activated, by the application of H2O2 to the extracellular solution. This inhibition was not reversed after washout or treatment with dithiothreitol, suggesting irreversible oxidation of TRPM7 or its regulatory factors by H2O2 under whole-cell recording. Application of an electrophile, N-methylmaleimide (NMM), which covalently modifies cysteine residues in proteins, also inhibited TRPM7 current irreversibly. The effects of H2O2 and NMM were dependent on free [Mg(2+)]i; the inhibition was stronger when cells were perfused with higher free [Mg(2+)]i solutions via pipette. In addition, TRPM7 current was not inhibited by H2O2 when millimolar ATP was included in the intracellular solution, even in the presence of substantial free [Mg(2+)]i, which is sufficient for TRPM7 inhibition by H2O2 in the absence of ATP. Moreover, a kinase-deficient mutant of TRPM7 (K1645R) was similarly inhibited by H2O2 just like the wild-type TRPM7 in a [Mg(2+)]i- and [ATP]i-dependent manner, indicating no involvement of the kinase activity of TRPM7. Thus, these data suggest that oxidative stress inhibits TRPM7 current under pathological conditions that accompany intracellular ATP depletion and free [Mg(2+)]i elevation.
Collapse
Affiliation(s)
- Hana Inoue
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan.
| | - Takashi Murayama
- Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Michiko Tashiro
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan
| | - Takashi Sakurai
- Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Masato Konishi
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan
| |
Collapse
|