1
|
Zhang XD, Thai PN, Ren L, Perez Flores MC, Ledford HA, Park S, Lee JH, Sihn CR, Chang CW, Chen WC, Timofeyev V, Zuo J, Chan JW, Yamoah EN, Chiamvimonvat N. Prestin amplifies cardiac motor functions. Cell Rep 2021; 35:109097. [PMID: 33951436 PMCID: PMC8720583 DOI: 10.1016/j.celrep.2021.109097] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/27/2020] [Accepted: 04/16/2021] [Indexed: 02/06/2023] Open
Abstract
Cardiac cells generate and amplify force in the context of cardiac load, yet the membranous sheath enclosing the muscle fibers-the sarcolemma-does not experience displacement. That the sarcolemma sustains beat-to-beat pressure changes without experiencing significant distortion is a muscle-contraction paradox. Here, we report that an elastic element-the motor protein prestin (Slc26a5)-serves to amplify actin-myosin force generation in mouse and human cardiac myocytes, accounting partly for the nonlinear capacitance of cardiomyocytes. The functional significance of prestin is underpinned by significant alterations of cardiac contractility in Prestin-knockout mice. Prestin was previously considered exclusive to the inner ear's outer hair cells; however, our results show that prestin serves a broader cellular motor function.
Collapse
Affiliation(s)
- Xiao-Dong Zhang
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA; Department of Veterans Affairs, VA Northern California Health Care System, Mather, CA 95655, USA.
| | - Phung N Thai
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Lu Ren
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Maria Cristina Perez Flores
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Hannah A Ledford
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Seojin Park
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Jeong Han Lee
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA
| | - Choong-Ryoul Sihn
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Che-Wei Chang
- Department of Pathology and Laboratory Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Wei Chun Chen
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Valeriy Timofeyev
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA
| | - Jian Zuo
- Department of Biomedical Sciences, Creighton University, Omaha, NE 68178, USA
| | - James W Chan
- Department of Pathology and Laboratory Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Ebenezer N Yamoah
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV 89557, USA.
| | - Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, University of California, Davis, Davis, CA 95616, USA; Department of Veterans Affairs, VA Northern California Health Care System, Mather, CA 95655, USA.
| |
Collapse
|
2
|
Stasiunas A, Verikas A, Kemesis P, Bacauskiene M, Miliauskas R, Stasiuniene N, Malmqvist K. A non-linear circuit for simulating OHC of the cochlea. Med Eng Phys 2003; 25:591-601. [PMID: 12835072 DOI: 10.1016/s1350-4533(03)00071-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In the present paper, referring to known characteristics of the outer hair cells functioning in the cochlea of the inner ear, a functional model of the outer hair cells is constructed. It consists of a linear feed-forward circuit and a non-linear positive feedback circuit. The feed-forward circuit reflects the contribution of local basilar and tectorial membrane areas and passive outer hair cells' physical parameters to the forming of low-selectivity resonance characteristics. The non-linear positive feedback circuit reflects the non-linear outer hair cell signal transduction processes and the active role of efferents from the medial superior olive in altering circuit sensitivity and selectivity. Referring to an analytical description of the circuit model and computer simulation results, an explanation is given over the biological meaning of the outer hair cells' non-linearities in signal transduction processes and the role of the non-linearities in achieving the following: signal compression, the dependency of circuit sensitivity and frequency selectivity upon the input signal amplitude, the compatibility of high-frequency selectivity and short transient response of the biological filtering circuits.
Collapse
Affiliation(s)
- Antanas Stasiunas
- Department of Applied Electronics, Kaunas University of Technology, LT-3031 Kaunas, Lithuania
| | | | | | | | | | | | | |
Collapse
|
3
|
Abstract
The role of the cochlea is to transduce complex sound waves into electrical neural activity in the auditory nerve. Hair cells of the organ of Corti are the sensory cells of hearing. The inner hair cells perform the transduction and initiate the depolarization of the spiral ganglion neurons. The outer hair cells are accessory sensory cells that enhance the sensitivity and selectivity of the cochlea. Neural feedback loops that bring efferent signals to the outer hair cells assist in sharpening and amplifying the signals. The stria vascularis generates the endocochlear potential and maintains the ionic composition of the endolymph, the fluid in which the apical surface of the hair cells is bathed. The mechanical characteristics of the basilar membrane and its related structures further enhance the frequency selectivity of the auditory transduction mechanism. The tectorial membrane is an extracellular matrix, which provides mass loading on top of the organ of Corti, facilitating deflection of the stereocilia. This review deals with the structure of the normal mature mammalian cochlea and includes recent data on the molecular organization of the main cell types within the cochlea.
Collapse
Affiliation(s)
- Yehoash Raphael
- Kresge Hearing Research Institute, The University of Michigan, MSRB 3, Rm 9303, 1150 W. Medical Center Drive, Ann Arbor, MI 48109-0648, USA.
| | | |
Collapse
|
4
|
Järlebark LE, Housley GD, Raybould NP, Vlajkovic S, Thorne PR. ATP-gated ion channels assembled from P2X2 receptor subunits in the mouse cochlea. Neuroreport 2002; 13:1979-84. [PMID: 12395104 DOI: 10.1097/00001756-200210280-00030] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Extracellular ATP has several neuro-humoral actions on cochlear physiology, many of which involve P2X receptor-mediated signal transduction. The present study extends the molecular physiology of P2X receptor gene expression in the cochlea to the principal platform for transgenic studies, the mouse model. P2X receptor subunits, which assemble to form ATP-gated ion channels, were localised in cryosections and whole-mount tissues from the adult mouse cochlea using a specific antiserum and immunoperoxidase histochemistry. Whole-cell voltage clamp recordings functionally correlated immunolocalisation of ATP-gated ion channels in isolated hair cells and supporting cells. P2X immunoreactivity was widespread throughout the epithelial lining of the cochlea (except vascular stria); spiral ganglion neurons, organ of Corti supporting cells, and outer hair cell (OHC) stereocilia exhibited strong P2X immunolabelling. Localisation of ATP-gated ion channels on the endolymphatic surface (cuticular plates and stereocilia) of outer hair cells was confirmed electrophysiologically. In contrast, Deiters' cells exhibited an even distribution of both immunolabelling over the whole cell membrane and inward currents could be evoked by localised ATP application anywhere on these cells. In both OHC and Deiters' cells, the slowly-desensitising inward currents were blocked by the P2X-selective antagonist pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), compatible with P2X subunits contributing to the ATP-gated ion channels. Our immunohistochemical and functional localisation of P2X receptors in the mouse cochlea extends previous studies to verify and characterise extracellular ATP signalling in the cochlea and extends support for P2X receptor-mediated regulation of endolymphatic ionic homeostasis, sound transduction, auditory neurotransmission and cochlear mechanics.
Collapse
Affiliation(s)
- Leif E Järlebark
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Private Bag 92019, Auckland
| | | | | | | | | |
Collapse
|