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Cody P, Kumar M, Tzounopoulos T. Cortical Zinc Signaling Is Necessary for Changes in Mouse Pupil Diameter That Are Evoked by Background Sounds with Different Contrasts. J Neurosci 2024; 44:e0939232024. [PMID: 38242698 PMCID: PMC10941062 DOI: 10.1523/jneurosci.0939-23.2024] [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: 05/22/2023] [Revised: 12/29/2023] [Accepted: 01/14/2024] [Indexed: 01/21/2024] Open
Abstract
Luminance-independent changes in pupil diameter (PD) during wakefulness influence and are influenced by neuromodulatory, neuronal, and behavioral responses. However, it is unclear whether changes in neuromodulatory activity in a specific brain area are necessary for the associated changes in PD or whether some different mechanisms cause parallel fluctuations in both PD and neuromodulation. To answer this question, we simultaneously recorded PD and cortical neuronal activity in male and female mice. Namely, we measured PD and neuronal activity during adaptation to sound contrast, which is a well-described adaptation conserved in many species and brain areas. In the primary auditory cortex (A1), increases in the variability of sound level (contrast) induce a decrease in the slope of the neuronal input-output relationship, neuronal gain, which depends on cortical neuromodulatory zinc signaling. We found a previously unknown modulation of PD by changes in background sensory context: high stimulus contrast sounds evoke larger increases in evoked PD compared with low-contrast sounds. To explore whether these changes in evoked PD are controlled by cortical neuromodulatory zinc signaling, we imaged single-cell neural activity in A1, manipulated zinc signaling in the cortex, and assessed PD in the same awake mouse. We found that cortical synaptic zinc signaling is necessary for increases in PD during high-contrast background sounds compared with low-contrast sounds. This finding advances our knowledge about how cortical neuromodulatory activity affects PD changes and thus advances our understanding of the brain states, circuits, and neuromodulatory mechanisms that can be inferred from pupil size fluctuations.
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Affiliation(s)
- Patrick Cody
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Manoj Kumar
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
| | - Thanos Tzounopoulos
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
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2
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Bizup B, Brutsaert S, Cunningham CL, Thathiah A, Tzounopoulos T. Cochlear zinc signaling dysregulation is associated with noise-induced hearing loss, and zinc chelation enhances cochlear recovery. Proc Natl Acad Sci U S A 2024; 121:e2310561121. [PMID: 38354264 PMCID: PMC10895357 DOI: 10.1073/pnas.2310561121] [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: 06/22/2023] [Accepted: 01/08/2024] [Indexed: 02/16/2024] Open
Abstract
Exposure to loud noise triggers sensory organ damage and degeneration that, in turn, leads to hearing loss. Despite the troublesome impact of noise-induced hearing loss (NIHL) in individuals and societies, treatment strategies that protect and restore hearing are few and insufficient. As such, identification and mechanistic understanding of the signaling pathways involved in NIHL are required. Biological zinc is mostly bound to proteins, where it plays major structural or catalytic roles; however, there is also a pool of unbound, mobile (labile) zinc. Labile zinc is mostly found in vesicles in secretory tissues, where it is released and plays a critical signaling role. In the brain, labile zinc fine-tunes neurotransmission and sensory processing. However, injury-induced dysregulation of labile zinc signaling contributes to neurodegeneration. Here, we tested whether zinc dysregulation occurs and contributes to NIHL in mice. We found that ZnT3, the vesicular zinc transporter responsible for loading zinc into vesicles, is expressed in cochlear hair cells and the spiral limbus, with labile zinc also present in the same areas. Soon after noise trauma, ZnT3 and zinc levels are significantly increased, and their subcellular localization is vastly altered. Disruption of zinc signaling, either via ZnT3 deletion or pharmacological zinc chelation, mitigated NIHL, as evidenced by enhanced auditory brainstem responses, distortion product otoacoustic emissions, and number of hair cell synapses. These data reveal that noise-induced zinc dysregulation is associated with cochlear dysfunction and recovery after NIHL, and point to zinc chelation as a potential treatment for mitigating NIHL.
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Affiliation(s)
- Brandon Bizup
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Sofie Brutsaert
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Christopher L Cunningham
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Amantha Thathiah
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15261
| | - Thanos Tzounopoulos
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA 15261
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3
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Shim M, Yi J, Pak JH, Chung JW. Zinc deficiency triggers hearing loss by reducing ribbon synapses of inner hair cells in CBA/N mice. Biochem Biophys Res Commun 2024; 693:149396. [PMID: 38118309 DOI: 10.1016/j.bbrc.2023.149396] [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: 11/24/2023] [Accepted: 12/15/2023] [Indexed: 12/22/2023]
Abstract
Zinc plays a vital role in our metabolism, encompassing antioxidant regulation, immune response, and auditory function. Several studies have reported that zinc levels correlate with hearing loss. We have previously demonstrated that the auditory brainstem response (ABR) threshold increased in mice fed a zinc-deficient diet. However, the effects of zinc deficiency on hearing were not fully elucidated. The present study investigated whether zinc deficiency affects hearing in association with neuronal components or cochlear structures. CBA/N mice were fed a normal or zinc-deficient diet for 8 weeks and assessed for ABR and distortion product otoacoustic emissions (DPOAE). The cochlear sections were stained with hematoxylin and eosin solution. Also, we observed the expression of synaptic ribbons, neurofilaments, and alpha-synuclein (α-Syn). The 8-week zinc-deficient diet mice had an elevated ABR threshold but no changed DPOAE threshold or cochlear structures. A reduced number of synaptic ribbons of inner hair cells (IHCs) and impaired efferent nerve fibers were observed in the zinc-deficient diet mice. The number of outer hair cells (OHCs) and expression of α-Syn remained unchanged. Our results suggest that zinc-mediated hearing loss is associated with the loss of neuronal components of IHCs.
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Affiliation(s)
- Myungjoo Shim
- Department of Otorhinolaryngology, University of Ulsan Graduate School, Seoul, South Korea
| | - Junyeong Yi
- Department of Otorhinolaryngology-Head and Neck Surgery, AMIST, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea; Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jhang Ho Pak
- Department of Biochemistry, University of Ulsan College of Medicine and Asan Institute for Life Sciences, Asan Medical Center, Seoul, South Korea
| | - Jong Woo Chung
- Department of Otorhinolaryngology-Head and Neck Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
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4
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Chen B, Yu P, Chan WN, Xie F, Zhang Y, Liang L, Leung KT, Lo KW, Yu J, Tse GMK, Kang W, To KF. Cellular zinc metabolism and zinc signaling: from biological functions to diseases and therapeutic targets. Signal Transduct Target Ther 2024; 9:6. [PMID: 38169461 PMCID: PMC10761908 DOI: 10.1038/s41392-023-01679-y] [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: 05/27/2023] [Revised: 09/15/2023] [Accepted: 10/10/2023] [Indexed: 01/05/2024] Open
Abstract
Zinc metabolism at the cellular level is critical for many biological processes in the body. A key observation is the disruption of cellular homeostasis, often coinciding with disease progression. As an essential factor in maintaining cellular equilibrium, cellular zinc has been increasingly spotlighted in the context of disease development. Extensive research suggests zinc's involvement in promoting malignancy and invasion in cancer cells, despite its low tissue concentration. This has led to a growing body of literature investigating zinc's cellular metabolism, particularly the functions of zinc transporters and storage mechanisms during cancer progression. Zinc transportation is under the control of two major transporter families: SLC30 (ZnT) for the excretion of zinc and SLC39 (ZIP) for the zinc intake. Additionally, the storage of this essential element is predominantly mediated by metallothioneins (MTs). This review consolidates knowledge on the critical functions of cellular zinc signaling and underscores potential molecular pathways linking zinc metabolism to disease progression, with a special focus on cancer. We also compile a summary of clinical trials involving zinc ions. Given the main localization of zinc transporters at the cell membrane, the potential for targeted therapies, including small molecules and monoclonal antibodies, offers promising avenues for future exploration.
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Affiliation(s)
- Bonan Chen
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Peiyao Yu
- Department of Pathology, Nanfang Hospital and Basic Medical College, Southern Medical University, Guangdong Province Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Wai Nok Chan
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Fuda Xie
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Yigan Zhang
- Institute of Biomedical Research, Taihe Hospital, Hubei University of Medicine, Shiyan, China
| | - Li Liang
- Department of Pathology, Nanfang Hospital and Basic Medical College, Southern Medical University, Guangdong Province Key Laboratory of Molecular Tumor Pathology, Guangzhou, China
| | - Kam Tong Leung
- Department of Pediatrics, The Chinese University of Hong Kong, Hong Kong, China
| | - Kwok Wai Lo
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Jun Yu
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | - Gary M K Tse
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Wei Kang
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China.
- CUHK-Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China.
| | - Ka Fai To
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.
- State Key Laboratory of Digestive Disease, Institute of Digestive Disease, The Chinese University of Hong Kong, Hong Kong, China.
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5
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Bender PTR, McCollum M, Boyd-Pratt H, Mendelson BZ, Anderson CT. Synaptic zinc potentiates AMPA receptor function in mouse auditory cortex. Cell Rep 2023; 42:112932. [PMID: 37585291 PMCID: PMC10514716 DOI: 10.1016/j.celrep.2023.112932] [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: 04/05/2023] [Revised: 06/23/2023] [Accepted: 07/18/2023] [Indexed: 08/18/2023] Open
Abstract
Synaptic zinc signaling modulates synaptic activity and is present in specific populations of cortical neurons, suggesting that synaptic zinc contributes to the diversity of intracortical synaptic microcircuits and their functional specificity. To understand the role of zinc signaling in the cortex, we performed whole-cell patch-clamp recordings from intratelencephalic (IT)-type neurons and pyramidal tract (PT)-type neurons in layer 5 of the mouse auditory cortex during optogenetic stimulation of specific classes of presynaptic neurons. Our results show that synaptic zinc potentiates AMPA receptor (AMPAR) function in a synapse-specific manner. We performed in vivo 2-photon calcium imaging of the same classes of neurons in awake mice and found that changes in synaptic zinc can widen or sharpen the sound-frequency tuning bandwidth of IT-type neurons but only widen the tuning bandwidth of PT-type neurons. These results provide evidence for synapse- and cell-type-specific actions of synaptic zinc in the cortex.
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Affiliation(s)
- Philip T R Bender
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Mason McCollum
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Helen Boyd-Pratt
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Benjamin Z Mendelson
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Charles T Anderson
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA.
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6
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Kumar M, Handy G, Kouvaros S, Zhao Y, Brinson LL, Wei E, Bizup B, Doiron B, Tzounopoulos T. Cell-type-specific plasticity of inhibitory interneurons in the rehabilitation of auditory cortex after peripheral damage. Nat Commun 2023; 14:4170. [PMID: 37443148 PMCID: PMC10345144 DOI: 10.1038/s41467-023-39732-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Peripheral sensory organ damage leads to compensatory cortical plasticity that is associated with a remarkable recovery of cortical responses to sound. The precise mechanisms that explain how this plasticity is implemented and distributed over a diverse collection of excitatory and inhibitory cortical neurons remain unknown. After noise trauma and persistent peripheral deficits, we found recovered sound-evoked activity in mouse A1 excitatory principal neurons (PNs), parvalbumin- and vasoactive intestinal peptide-expressing neurons (PVs and VIPs), but reduced activity in somatostatin-expressing neurons (SOMs). This cell-type-specific recovery was also associated with cell-type-specific intrinsic plasticity. These findings, along with our computational modelling results, are consistent with the notion that PV plasticity contributes to PN stability, SOM plasticity allows for increased PN and PV activity, and VIP plasticity enables PN and PV recovery by inhibiting SOMs.
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Affiliation(s)
- Manoj Kumar
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
| | - Gregory Handy
- Departments of Neurobiology and Statistics, University of Chicago, Chicago, IL, 60637, USA
| | - Stylianos Kouvaros
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Yanjun Zhao
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Lovisa Ljungqvist Brinson
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Eric Wei
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Brandon Bizup
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Brent Doiron
- Departments of Neurobiology and Statistics, University of Chicago, Chicago, IL, 60637, USA
| | - Thanos Tzounopoulos
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA, 15261, USA.
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7
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Kouvaros S, Bizup B, Solis O, Kumar M, Ventriglia E, Curry FP, Michaelides M, Tzounopoulos T. A CRE/DRE dual recombinase transgenic mouse reveals synaptic zinc-mediated thalamocortical neuromodulation. SCIENCE ADVANCES 2023; 9:eadf3525. [PMID: 37294760 PMCID: PMC10256168 DOI: 10.1126/sciadv.adf3525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 05/05/2023] [Indexed: 06/11/2023]
Abstract
Synaptic zinc is a neuromodulator that shapes synaptic transmission and sensory processing. The maintenance of synaptic zinc is dependent on the vesicular zinc transporter, ZnT3. Hence, the ZnT3 knockout mouse has been a key tool for studying the mechanisms and functions of synaptic zinc. However, the use of this constitutive knockout mouse has notable limitations, including developmental, compensatory, and brain and cell type specificity issues. To overcome these limitations, we developed and characterized a dual recombinase transgenic mouse, which combines the Cre and Dre recombinase systems. This mouse allows for tamoxifen-inducible Cre-dependent expression of exogenous genes or knockout of floxed genes in ZnT3-expressing neurons and DreO-dependent region and cell type-specific conditional ZnT3 knockout in adult mice. Using this system, we reveal a neuromodulatory mechanism whereby zinc release from thalamic neurons modulates N-methyl-d-aspartate receptor activity in layer 5 pyramidal tract neurons, unmasking previously unknown features of cortical neuromodulation.
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Affiliation(s)
- Stylianos Kouvaros
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Brandon Bizup
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Oscar Solis
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Manoj Kumar
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Emilya Ventriglia
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Fallon P. Curry
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
| | - Michael Michaelides
- Biobehavioral Imaging and Molecular Neuropsychopharmacology Unit, National Institute on Drug Abuse Intramural Research Program, Baltimore, MD 21224, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Thanos Tzounopoulos
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, PA 15261, USA
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8
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Wu T, Kumar M, Zhang J, Zhao S, Drobizhev M, McCollum M, Anderson CT, Wang Y, Pokorny A, Tian X, Zhang Y, Tzounopoulos T, Ai HW. A genetically encoded far-red fluorescent indicator for imaging synaptically released Zn 2. SCIENCE ADVANCES 2023; 9:eadd2058. [PMID: 36857451 PMCID: PMC9977179 DOI: 10.1126/sciadv.add2058] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 02/01/2023] [Indexed: 06/18/2023]
Abstract
Synaptic zinc ion (Zn2+) has emerged as a key neuromodulator in the brain. However, the lack of research tools for directly tracking synaptic Zn2+ in the brain of awake animals hinders our rigorous understanding of the physiological and pathological roles of synaptic Zn2+. In this study, we developed a genetically encoded far-red fluorescent indicator for monitoring synaptic Zn2+ dynamics in the nervous system. Our engineered far-red fluorescent indicator for synaptic Zn2+ (FRISZ) displayed a substantial Zn2+-specific turn-on response and low-micromolar affinity. We genetically anchored FRISZ to the mammalian extracellular membrane via a transmembrane (TM) ⍺ helix and characterized the resultant FRISZ-TM construct at the mammalian cell surface. We used FRISZ-TM to image synaptic Zn2+ in the auditory cortex in acute brain slices and awake mice in response to electric and sound stimuli, respectively. Thus, this study establishes a technology for studying the roles of synaptic Zn2+ in the nervous system.
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Affiliation(s)
- Tianchen Wu
- Department of Molecular Physiology and Biological Physics, and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Manoj Kumar
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Jing Zhang
- Department of Molecular Physiology and Biological Physics, and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Shengyu Zhao
- Department of Molecular Physiology and Biological Physics, and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| | - Mikhail Drobizhev
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717-384, USA
| | - Mason McCollum
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Charles T. Anderson
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV 26506, USA
| | - Ying Wang
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28403, USA
| | - Antje Pokorny
- Department of Chemistry and Biochemistry, University of North Carolina Wilmington, Wilmington, NC 28403, USA
| | - Xiaodong Tian
- Department of Molecular Physiology and Biological Physics, and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Yiyu Zhang
- Department of Molecular Physiology and Biological Physics, and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
| | - Thanos Tzounopoulos
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Hui-wang Ai
- Department of Molecular Physiology and Biological Physics, and Center for Membrane and Cell Physiology, University of Virginia School of Medicine, Charlottesville, VA 22908, USA
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
- The UVA Comprehensive Cancer Center, University of Virginia, Charlottesville, VA 22908, USA
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9
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Ikejiri Y, Tanimoto Y, Fujita K, Hiramatsu F, Yamazaki SJ, Endo Y, Iwatani Y, Fujimoto K, Kimura KD. Neural mechanism of experience-dependent sensory gain control in C. elegans. Neurosci Res 2023; 191:77-90. [PMID: 36681153 DOI: 10.1016/j.neures.2023.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/15/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Animals' sensory systems adjust their responsiveness to environmental stimuli that vary greatly in their intensity. Here we report the neural mechanism of experience-dependent sensory adjustment, especially gain control, in the ASH nociceptive neurons in Caenorhabditis elegans. Using calcium imaging under gradual changes in stimulus intensity, we find that the ASH neurons of naive animals respond to concentration increases in a repulsive odor 2-nonanone regardless of the magnitude of the concentration increase. However, after preexposure to the odor, the ASH neurons exhibit significantly weak responses to a small gradual increase in odor concentration while their responses to a large gradual increase remain strong. Thus, preexposure changes the slope of stimulus-response relationships (i.e., gain control). Behavioral analysis suggests that this gain control contributes to the preexposure-dependent enhancement of odor avoidance behavior. Mathematical analysis reveals that the ASH response consists of fast and slow components, and that the fast component is specifically suppressed by preexposure for the gain control. In addition, genetic analysis suggests that G protein signaling may be required for the regulation of fast component. We propose how prior experience dynamically and specifically modulates stimulus-response relationships in sensory neurons, eventually leading to adaptive modulation of behavior.
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Affiliation(s)
- Yosuke Ikejiri
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuki Tanimoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Kosuke Fujita
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Fumie Hiramatsu
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Shuhei J Yamazaki
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuto Endo
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yasushi Iwatani
- Department of Science and Technology, Graduate School of Science and Technology, Hirosaki University, Hirosaki, Aomori 036-8561, Japan
| | - Koichi Fujimoto
- Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Koutarou D Kimura
- Department of Information and Basic Science, Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; Department of Biological Sciences, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
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10
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Jelen LA, Green MS, King S, Morris AG, Zhang X, Lythgoe DJ, Young AH, De Belleroche J, Stone JM. Variants in the zinc transporter-3 encoding gene (SLC30A3) in schizophrenia and bipolar disorder: Effects on brain glutamate-A pilot study. Front Psychiatry 2022; 13:929306. [PMID: 36203844 PMCID: PMC9531870 DOI: 10.3389/fpsyt.2022.929306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/23/2022] [Indexed: 11/25/2022] Open
Abstract
Zinc transporter 3 (ZnT3) has been implicated in the aetiopathology of schizophrenia. In this pilot study, we tested the hypothesis that the presence of a minor allele of two variants in the gene encoding ZnT3 (SLC30A3) affects brain glutamate and cognitive activity in patients with schizophrenia and bipolar affective disorder. Fifteen patients with schizophrenia (SCZ), 15 with bipolar affective disorder type 2 (BD), and 14 healthy volunteers (HV) were genotyped for two SLC30A3 single nucleotide polymorphisms (rs11126936 and rs11126929). They also underwent structural and functional MRI (n-back) imaging as well as static (PRESS) and functional magnetic resonance spectroscopy (n-back) on a 3 Tesla MRI system. SCZ with at least one copy of the minor allele showed reductions in dorsal anterior cingulate cortex glutamate during the n-back task, whereas SCZ without the minor allele showed an increase in glutamate. BD with the minor allele had reduced glutamate in the anterior cingulate cortex (p < 0.05). There was no effect of SLC30A3 genotype on BOLD activation during n-back or on cortical brain volume. This study supports the further investigation of SLC30A3 and its role in glutamatergic neurotransmission and in the neuropathology of mental illness.
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Affiliation(s)
- Luke A. Jelen
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- South London and Maudsley NHS Foundation Trust, Bethlem Royal Hospital, Beckenham, United Kingdom
| | - Mark S. Green
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Sinead King
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- Department of Psychiatry and Behavioural Sciences, Stanford University, Palo Alto, CA, United States
- Centre for Neuroimaging and Cognitive Genomics, National University of Ireland, Galway, Ireland
| | - Alex G. Morris
- Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - Xinyuan Zhang
- Imperial College London, Hammersmith Hospital Campus, London, United Kingdom
| | - David J. Lythgoe
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Allan H. Young
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- South London and Maudsley NHS Foundation Trust, Bethlem Royal Hospital, Beckenham, United Kingdom
| | | | - James M. Stone
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
- South London and Maudsley NHS Foundation Trust, Bethlem Royal Hospital, Beckenham, United Kingdom
- Psychiatry, Department of Neuroscience, Brighton and Sussex Medical School (BSMS), University of Sussex, Brighton, United Kingdom
- Department of Psychiatry, Sussex Partnership Foundation Trust, Eastbourne DGH, Eastbourne, United Kingdom
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11
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Zhang C, Dischler A, Glover K, Qin Y. Neuronal signalling of zinc: from detection and modulation to function. Open Biol 2022; 12:220188. [PMID: 36067793 PMCID: PMC9448499 DOI: 10.1098/rsob.220188] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Zinc is an essential trace element that stabilizes protein structures and allosterically modulates a plethora of enzymes, ion channels and neurotransmitter receptors. Labile zinc (Zn2+) acts as an intracellular and intercellular signalling molecule in response to various stimuli, which is especially important in the central nervous system. Zincergic neurons, characterized by Zn2+ deposits in synaptic vesicles and presynaptic Zn2+ release, are found in the cortex, hippocampus, amygdala, olfactory bulb and spinal cord. To provide an overview of synaptic Zn2+ and intracellular Zn2+ signalling in neurons, the present paper summarizes the fluorescent sensors used to detect Zn2+ signals, the cellular mechanisms regulating the generation and buffering of Zn2+ signals, as well as the current perspectives on their pleiotropic effects on phosphorylation signalling, synapse formation, synaptic plasticity, as well as sensory and cognitive function.
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Affiliation(s)
- Chen Zhang
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Anna Dischler
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Kaitlyn Glover
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
| | - Yan Qin
- Department of Biological Sciences, University of Denver, Denver, CO 80210, USA
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12
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Cody PA, Tzounopoulos T. Neuromodulatory Mechanisms Underlying Contrast Gain Control in Mouse Auditory Cortex. J Neurosci 2022; 42:5564-5579. [PMID: 35998293 PMCID: PMC9295830 DOI: 10.1523/jneurosci.2054-21.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 05/11/2022] [Accepted: 05/11/2022] [Indexed: 01/16/2023] Open
Abstract
Neural adaptation enables the brain to efficiently process sensory signals despite large changes in background noise. Previous studies have established that recent background spectro- or spatio-temporal statistics scale neural responses to sensory stimuli via a canonical normalization computation, which is conserved among species and sensory domains. In the auditory pathway, one major form of normalization, termed contrast gain control, presents as decreasing instantaneous firing-rate gain, the slope of the neural input-output relationship, with increasing variability of background sound levels (contrast) across time and frequency. Despite this gain rescaling, mean firing-rates in auditory cortex become invariant to sound level contrast, termed contrast invariance. The underlying neuromodulatory mechanisms of these two phenomena remain unknown. To study these mechanisms in male and female mice, we used a 2-photon calcium imaging preparation in layer 2/3 neurons of primary auditory cortex (A1), along with pharmacological and genetic KO approaches. We found that neuromodulatory cortical synaptic zinc signaling is necessary for contrast gain control but not contrast invariance in mouse A1.SIGNIFICANCE STATEMENT When sound levels in the acoustic environment become more variable across time and frequency, the brain decreases response gain to maintain dynamic range and thus stimulus discriminability. This gain adaptation accounts for changes in perceptual judgments in humans and mice; however, the underlying neuromodulatory mechanisms remain poorly understood. Here, we report context-dependent neuromodulatory effects of synaptic zinc that are necessary for contrast gain control in A1. Understanding context-specific neuromodulatory mechanisms, such as contrast gain control, provides insight into A1 cortical mechanisms of adaptation and also into fundamental aspects of perceptual changes that rely on gain modulation, such as attention.
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Affiliation(s)
- Patrick A Cody
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Thanos Tzounopoulos
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
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13
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Morabito A, Zerlaut Y, Serraz B, Sala R, Paoletti P, Rebola N. Activity-dependent modulation of NMDA receptors by endogenous zinc shapes dendritic function in cortical neurons. Cell Rep 2022; 38:110415. [PMID: 35196488 PMCID: PMC8889438 DOI: 10.1016/j.celrep.2022.110415] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 12/08/2021] [Accepted: 01/31/2022] [Indexed: 11/11/2022] Open
Abstract
NMDA receptors (NMDARs) have been proposed to control single-neuron computations in vivo. However, whether specific mechanisms regulate the function of such receptors and modulate input-output transformations performed by cortical neurons under in vivo-like conditions is understudied. Here, we report that in layer 2/3 pyramidal neurons (L2/3 PNs), repeated synaptic stimulation results in an activity-dependent decrease in NMDAR function by vesicular zinc. Such a mechanism shifts the threshold for dendritic non-linearities and strongly reduces LTP. Modulation of NMDARs is cell and pathway specific, being present selectively in L2/3-L2/3 connections but absent in inputs originating from L4 neurons. Numerical simulations highlight that activity-dependent modulation of NMDARs influences dendritic computations, endowing L2/3 PN dendrites with the ability to sustain non-linear integrations constant across different regimes of synaptic activity like those found in vivo. Our results unveil vesicular zinc as an important endogenous modulator of dendritic function in cortical PNs. Vesicular zinc release downregulates function of synaptic NMDARs in cortical neurons Zinc modulation of NMDARs is activity dependent, pathway and cell specific Endogenous zinc controls dendritic non-linearities and synaptic plasticity in L2/3 PNs Modulation of NMDARs normalizes dendritic function during ongoing synaptic activity
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Affiliation(s)
- Annunziato Morabito
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de l'Hôpital, 75013 Paris, France
| | - Yann Zerlaut
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de l'Hôpital, 75013 Paris, France
| | - Benjamin Serraz
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, 75005 Paris, France
| | - Romain Sala
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de l'Hôpital, 75013 Paris, France
| | - Pierre Paoletti
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, 75005 Paris, France
| | - Nelson Rebola
- Sorbonne Université, Institut Du Cerveau-Paris Brain Institute-ICM, Inserm U1127, CNRS UMR 7225, 47 Boulevard de l'Hôpital, 75013 Paris, France.
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14
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Tan CH, Kornfeld K. Zinc is an intracellular signal during sperm activation in Caenorhabditis elegans. Development 2021; 148:273336. [PMID: 34739028 DOI: 10.1242/dev.199836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/28/2021] [Indexed: 11/20/2022]
Abstract
Sperm activation is a rapid and dramatic cell differentiation event that does not involve changes in transcription, and the signaling cascades that mediate this process have not been fully defined. zipt-7.1 encodes a zinc transporter, and zipt-7.1(lf) mutants display sperm-activation defects, leading to the hypothesis that zinc signaling mediates sperm activation in Caenorhabditis elegans. Here, we describe the development of a method for dynamic imaging of labile zinc during sperm activation using the zinc-specific fluorescence probe FluoZin-3 AM and time-lapse confocal imaging. Two phases of dynamic changes in labile zinc levels were observed during sperm activation. Forced zinc entry using the zinc ionophore pyrithione activated sperm in vitro, and it suppressed the defects of zipt-7.1(lf) mutants, indicating that high levels of cytosolic zinc are sufficient for sperm activation. We compared activation by zinc pyrithione to activation by extracellular zinc, the Na+/H+ antiporter monensin and the protease cocktail pronase in multiple mutant backgrounds. These results indicate that the protease pathway does not require zinc signaling, suggesting that zinc signaling is sufficient to activate sperm but is not always necessary.
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Affiliation(s)
- Chieh-Hsiang Tan
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kerry Kornfeld
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA
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15
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Krall RF, Tzounopoulos T, Aizenman E. The Function and Regulation of Zinc in the Brain. Neuroscience 2021; 457:235-258. [PMID: 33460731 DOI: 10.1016/j.neuroscience.2021.01.010] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 12/31/2022]
Abstract
Nearly sixty years ago Fredrich Timm developed a histochemical technique that revealed a rich reserve of free zinc in distinct regions of the brain. Subsequent electron microscopy studies in Timm- stained brain tissue found that this "labile" pool of cellular zinc was highly concentrated at synaptic boutons, hinting a possible role for the metal in synaptic transmission. Although evidence for activity-dependent synaptic release of zinc would not be reported for another twenty years, these initial findings spurred decades of research into zinc's role in neuronal function and revealed a diverse array of signaling cascades triggered or regulated by the metal. Here, we delve into our current understanding of the many roles zinc plays in the brain, from influencing neurotransmission and sensory processing, to activating both pro-survival and pro-death neuronal signaling pathways. Moreover, we detail the many mechanisms that tightly regulate cellular zinc levels, including metal binding proteins and a large array of zinc transporters.
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Affiliation(s)
- Rebecca F Krall
- Department of Neurobiology, University of Pittsburgh School of Medicine, USA; Department of Otolaryngology, University of Pittsburgh School of Medicine, USA; Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, USA
| | - Thanos Tzounopoulos
- Department of Otolaryngology, University of Pittsburgh School of Medicine, USA; Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, USA.
| | - Elias Aizenman
- Department of Neurobiology, University of Pittsburgh School of Medicine, USA; Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, USA.
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16
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Pratt EPS, Damon LJ, Anson KJ, Palmer AE. Tools and techniques for illuminating the cell biology of zinc. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118865. [PMID: 32980354 DOI: 10.1016/j.bbamcr.2020.118865] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 09/13/2020] [Accepted: 09/15/2020] [Indexed: 12/19/2022]
Abstract
Zinc (Zn2+) is an essential micronutrient that is required for a wide variety of cellular processes. Tools and methods have been instrumental in revealing the myriad roles of Zn2+ in cells. This review highlights recent developments fluorescent sensors to measure the labile Zn2+ pool, chelators to manipulate Zn2+ availability, and fluorescent tools and proteomics approaches for monitoring Zn2+-binding proteins in cells. Finally, we close with some highlights on the role of Zn2+ in regulating cell function and in cell signaling.
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Affiliation(s)
- Evan P S Pratt
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America
| | - Leah J Damon
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America
| | - Kelsie J Anson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America
| | - Amy E Palmer
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, Boulder, CO 80303, United States of America.
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17
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Krall RF, Moutal A, Phillips MB, Asraf H, Johnson JW, Khanna R, Hershfinkel M, Aizenman E, Tzounopoulos T. Synaptic zinc inhibition of NMDA receptors depends on the association of GluN2A with the zinc transporter ZnT1. SCIENCE ADVANCES 2020; 6:eabb1515. [PMID: 32937457 PMCID: PMC7458442 DOI: 10.1126/sciadv.abb1515] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/20/2020] [Indexed: 05/08/2023]
Abstract
The NMDA receptor (NMDAR) is inhibited by synaptically released zinc. This inhibition is thought to be the result of zinc diffusion across the synaptic cleft and subsequent binding to the extracellular domain of the NMDAR. However, this model fails to incorporate the observed association of the highly zinc-sensitive NMDAR subunit GluN2A with the postsynaptic zinc transporter ZnT1, which moves intracellular zinc to the extracellular space. Here, we report that disruption of ZnT1-GluN2A association by a cell-permeant peptide strongly reduced NMDAR inhibition by synaptic zinc in mouse dorsal cochlear nucleus synapses. Moreover, synaptic zinc inhibition of NMDARs required postsynaptic intracellular zinc, suggesting that cytoplasmic zinc is transported by ZnT1 to the extracellular space in close proximity to the NMDAR. These results challenge a decades-old dogma on how zinc inhibits synaptic NMDARs and demonstrate that presynaptic release and a postsynaptic transporter organize zinc into distinct microdomains to modulate NMDAR neurotransmission.
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Affiliation(s)
- Rebecca F Krall
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Aubin Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Matthew B Phillips
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Hila Asraf
- Department of Physiology and Cell Biology, Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer-Sheva, Israel
| | - Jon W Johnson
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Michal Hershfinkel
- Department of Physiology and Cell Biology, Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer-Sheva, Israel
| | - Elias Aizenman
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Department of Physiology and Cell Biology, Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer-Sheva, Israel
| | - Thanos Tzounopoulos
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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18
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Mechanisms Underlying Long-Term Synaptic Zinc Plasticity at Mouse Dorsal Cochlear Nucleus Glutamatergic Synapses. J Neurosci 2020; 40:4981-4996. [PMID: 32434779 DOI: 10.1523/jneurosci.0175-20.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 11/21/2022] Open
Abstract
In many brain areas, such as the neocortex, limbic structures, and auditory brainstem, synaptic zinc is released from presynaptic terminals to modulate neurotransmission. As such, synaptic zinc signaling modulates sensory processing and enhances acuity for discrimination of different sensory stimuli. Whereas sensory experience causes long-term changes in synaptic zinc signaling, the mechanisms underlying this long-term synaptic zinc plasticity remain unknown. To study these mechanisms in male and female mice, we used in vitro and in vivo models of zinc plasticity observed at the zinc-rich glutamatergic dorsal cochlear nucleus (DCN) parallel fiber synapses onto cartwheel cells. High-frequency stimulation of DCN parallel fiber synapses induced LTD of synaptic zinc signaling (Z-LTD), evidenced by reduced zinc-mediated inhibition of EPSCs. Low-frequency stimulation induced LTP of synaptic zinc signaling (Z-LTP), evidenced by enhanced zinc-mediated inhibition of EPSCs. Pharmacological manipulations of Group 1 metabotropic glutamate receptors (G1 mGluRs) demonstrated that G1 mGluR activation is necessary and sufficient for inducing Z-LTD and Z-LTP. Pharmacological manipulations of Ca2+ dynamics indicated that rises in postsynaptic Ca2+ are necessary and sufficient for Z-LTD induction. Electrophysiological measurements assessing postsynaptic expression mechanisms, and imaging studies with a ratiometric extracellular zinc sensor probing zinc release, supported that Z-LTD is expressed, at least in part, via reductions in presynaptic zinc release. Finally, exposure of mice to loud sound caused G1 mGluR-dependent Z-LTD at DCN parallel fiber synapses, thus validating our in vitro results. Together, our results reveal a novel mechanism underlying activity- and experience-dependent plasticity of synaptic zinc signaling.SIGNIFICANCE STATEMENT In the neocortex, limbic structures, and auditory brainstem, glutamatergic nerve terminals corelease zinc to modulate excitatory neurotransmission and sensory responses. Moreover, sensory experience causes bidirectional, long-term changes in synaptic zinc signaling. However, the mechanisms of this long-term synaptic zinc plasticity remain unknown. Here, we identified a novel Group 1 mGluR-dependent mechanism that causes bidirectional, long-term changes in synaptic zinc signaling. Our results highlight new mechanisms of brain adaptation during sensory processing, and potentially point to mechanisms of disorders associated with pathologic adaptation, such as tinnitus.
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19
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Kouvaros S, Kumar M, Tzounopoulos T. Synaptic Zinc Enhances Inhibition Mediated by Somatostatin, but not Parvalbumin, Cells in Mouse Auditory Cortex. Cereb Cortex 2020; 30:3895-3909. [PMID: 32090251 DOI: 10.1093/cercor/bhaa005] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/23/2019] [Accepted: 01/06/2020] [Indexed: 11/13/2022] Open
Abstract
Cortical inhibition is essential for brain activity and behavior. Yet, the mechanisms that modulate cortical inhibition and their impact on sensory processing remain less understood. Synaptically released zinc, a neuromodulator released by cortical glutamatergic synaptic vesicles, has emerged as a powerful modulator of sensory processing and behavior. Despite the puzzling finding that the vesicular zinc transporter (ZnT3) mRNA is expressed in cortical inhibitory interneurons, the actions of synaptic zinc in cortical inhibitory neurotransmission remain unknown. Using in vitro electrophysiology and optogenetics in mouse brain slices containing the layer 2/3 (L2/3) of auditory cortex, we discovered that synaptic zinc increases the quantal size of inhibitory GABAergic neurotransmission mediated by somatostatin (SOM)- but not parvalbumin (PV)-expressing neurons. Using two-photon imaging in awake mice, we showed that synaptic zinc is required for the effects of SOM- but not PV-mediated inhibition on frequency tuning of principal neurons. Thus, cell-specific zinc modulation of cortical inhibition regulates frequency tuning.
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Affiliation(s)
- Stylianos Kouvaros
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Manoj Kumar
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Thanos Tzounopoulos
- Department of Otolaryngology, Pittsburgh Hearing Research Center, University of Pittsburgh, Pittsburgh, PA 15261, USA
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20
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Blakemore LJ, Trombley PQ. Zinc Modulates Olfactory Bulb Kainate Receptors. Neuroscience 2020; 428:252-268. [PMID: 31874243 DOI: 10.1016/j.neuroscience.2019.11.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 11/22/2019] [Accepted: 11/26/2019] [Indexed: 10/25/2022]
Abstract
Kainate receptors (KARs) are glutamate receptors with ionotropic and metabotropic activity composed of the GluK1-GluK5 subunits. We previously reported that KARs modulate excitatory and inhibitory transmission in the olfactory bulb (OB). Zinc, which is highly concentrated in the OB, also appears to modulate OB synaptic transmission via actions at other ionotropic glutamate receptors (i.e., AMPA, NMDA). However, few reports of effects of zinc on recombinant and/or native KARs exist and none have involved the OB. In the present study, we investigated the effects of exogenously applied zinc on OB KARs expressed by mitral/tufted (M/T) cells. We found that 100 µM zinc inhibits currents evoked by various combinations of KAR agonists (kainate or SYM 2081) and the AMPA receptor antagonist SYM 2206. The greatest degree of zinc-mediated inhibition was observed with coapplication of zinc with the GluK1- and GluK2-preferring agonist SYM 2081 plus SYM 2206. This finding is consistent with prior reports of zinc's inhibitory effects on some recombinant (homomeric GluK1 and GluK2 and heteromeric GluK2/GluK4 and GluK2/GluK5) KARs, although potentiation of other (GluK3, GluK2/3) KARs has also been described. It is also of potential importance given our previously reported molecular data suggesting that OB neurons express relatively high levels of GluK1 and GluK2. Our present findings suggest that a physiologically relevant concentration of zinc modulates KARs expressed by M/T cells. As M/T cells are targets of zinc-containing olfactory sensory neurons, synaptically released zinc may influence odor information-encoding synaptic circuits in the OB via actions at KARs.
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Affiliation(s)
- Laura J Blakemore
- Program in Neuroscience, Florida State University, Tallahassee, FL, USA; Department of Biological Science, Florida State University, Tallahassee, FL, USA
| | - Paul Q Trombley
- Program in Neuroscience, Florida State University, Tallahassee, FL, USA; Department of Biological Science, Florida State University, Tallahassee, FL, USA.
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21
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Sikora J, Kieffer BL, Paoletti P, Ouagazzal AM. Synaptic zinc contributes to motor and cognitive deficits in 6-hydroxydopamine mouse models of Parkinson's disease. Neurobiol Dis 2019; 134:104681. [PMID: 31759136 DOI: 10.1016/j.nbd.2019.104681] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/05/2019] [Accepted: 11/19/2019] [Indexed: 12/19/2022] Open
Abstract
Hyperactivity of glutamatergic corticostrial pathways is recognized as a key pathophysiological mechanism contributing to development of PD symptoms and dopaminergic neurotoxicity. Subset of corticostriatal projection neurons uses Zn2+ as a co-transmitter alongside glutamate, but the role of synaptically released Zn2+ in PD remains unexplored. We used genetically modified mice and pharmacological tools in combination with 6-hydroxydopamine (6-OHDA) lesion models of PD to investigate the contribution of synaptic zinc to disease associated behavioral deficits and neurodegeneration. Vesicular zinc transporter-3 (ZnT3) knockout mice lacking releasable Zn2+ were more resistant to locomotor deficit and memory impairment of nigrostriatal dopamine (DA) denervation compared to wildtype littermates. The loss of striatal dopaminergic fibers was comparable between genotypes, indicating that synaptically released Zn2+ contributes to behavioral deficits but not neurotoxic effects of 6-OHDA. To gain further insight into the mechanisms of Zn2+ actions, we used the extracellular Zn2+ chelator CaEDTA and knock-in mice lacking the high affinity Zn2+ inhibition of GluN2A-containing NMDA receptors (GluN2A-NMDARs). Acute chelation of extracellular Zn2+ in the striatum restored locomotor deficit of 6-OHDA lesion, confirming that synaptic Zn2+ suppresses locomotor behavior. Disruption of the Zn2+-GluN2A interaction had, on the other hand, no impact on locomotor deficit or neurotoxic effect of 6-OHDA. Collectively, these findings provide clear evidence for the implication of striatal synaptic Zn2+ in the pathophysiology of PD. They unveil that synaptic Zn2+ plays predominantly a detrimental role by promoting motor and cognitive deficits caused by nigrostriatal DA denervation, pointing towards new therapeutic interventions.
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Affiliation(s)
- Joanna Sikora
- Laboratoire de Neurosciences Cognitives, Aix-Marseille Univ, CNRS, LNC, UMR 7291, 13331 Marseille, France; Aix-marseille Université, Marseille, France
| | - Brigitte L Kieffer
- Douglas Research Center, Department of Psychiatry, McGill University, Montréal, Canada
| | - Pierre Paoletti
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, Université PSL, CNRS, INSERM, Paris, France
| | - Abdel-Mouttalib Ouagazzal
- Laboratoire de Neurosciences Cognitives, Aix-Marseille Univ, CNRS, LNC, UMR 7291, 13331 Marseille, France.
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22
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Chen M, Zhang S, Xing Y, Li X, He Y, Wang Y, Oberholzer J, Ai HW. Genetically Encoded, Photostable Indicators to Image Dynamic Zn 2+ Secretion of Pancreatic Islets. Anal Chem 2019; 91:12212-12219. [PMID: 31475537 DOI: 10.1021/acs.analchem.9b01802] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
As an essential element for living organisms, zinc (Zn2+) exerts its biological functions both intracellularly and extracellularly. Previous studies have reported a number of genetically encoded Zn2+ indicators (GEZIs), which have been widely used to monitor Zn2+ in the cytosol and intracellular organelles. However, it is challenging to localize existing GEZIs to the extracellular space to detect secreted Zn2+. Herein, we report two photostable, green fluorescent protein (GFP) based indicators, ZIBG1 and ZIBG2, which respond to Zn2+ selectively and have affinities suited for detecting Zn2+ secretion from intracellular vesicles. In particular, ZIBG2 can be effectively targeted to the extracellular side of plasma membrane. We applied cell surface-localized ZIBG2 to monitor glucose-induced dynamic Zn2+ secretion from mouse insulinoma MIN6 cells and primary mouse and human pancreatic islets. Because Zn2+ is co-released with insulin from β-cells, the fluorescence of cell surface-localized ZIBG2 was shown to be a strong indicator for the functional potency of islets. Our work here has thus expanded the use of GEZIs to image dynamic Zn2+ secretion in live tissue. Because it is convenient to use genetically encoded indicators for expression over extended periods and for in vivo delivery, we envision future applications of ZIBG2 in development of induced β-cells or islets to advance cell replacement therapies for diabetes and in direct imaging of Zn2+ secretion dynamics in vivo.
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Calderón-Garcidueñas L, Kulesza RJ, Mansour Y, Aiello-Mora M, Mukherjee PS, González-González LO. Increased Gain in the Auditory Pathway, Alzheimer’s Disease Continuum, and Air Pollution: Peripheral and Central Auditory System Dysfunction Evolves Across Pediatric and Adult Urbanites. J Alzheimers Dis 2019; 70:1275-1286. [DOI: 10.3233/jad-190405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | - Randy J. Kulesza
- Auditory Research Center, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Yusra Mansour
- Auditory Research Center, Lake Erie College of Osteopathic Medicine, Erie, PA, USA
| | - Mario Aiello-Mora
- Servicio de Otorrinolaringologia, Instituto Nacional de Cardiología, Mexico
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24
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Richardson CER, Nolan EM, Shoulders MD, Lippard SJ. A Sensitive, Nonradioactive Assay for Zn(II) Uptake into Metazoan Cells. Biochemistry 2018; 57:6807-6815. [PMID: 30381945 PMCID: PMC6437758 DOI: 10.1021/acs.biochem.8b01043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sensitive measurements of cellular Zn(II) uptake currently rely on quantitating radioactive emissions from cells treated with 65Zn(II). Here, we describe a straightforward and reliable method employing a stable isotope to sensitively measure Zn(II) uptake by metazoan cells. First, biological medium selectively depleted of natural abundance Zn(II) using A12-resin [Richardson, C. E. R., et al. (2018) J. Am. Chem. Soc. 140, 2413] is restored to physiological levels of Zn(II) by addition of a non-natural Zn(II) isotope distribution comprising 70% 70Zn(II). The resulting 70Zn(II)-enriched medium facilitates quantitation of Zn(II) uptake using inductively coupled plasma-mass spectrometry (ICP-MS). This sensitive and reliable assay assesses Zn(II)-uptake kinetics at early time points and can be used to delineate how chemical and genetic perturbations influence Zn(II) uptake. Further, the use of ICP-MS in a Zn(II)-uptake assay permits simultaneous measurement of multiple metal ion concentrations. We used this capability to show that, across three cell lines, Zn(II) deficiency enhances selectivity for Zn(II) over Cd(II) uptake.
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Affiliation(s)
- Christopher E. R. Richardson
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Matthew D. Shoulders
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Stephen J. Lippard
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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25
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Fine Control of Sound Frequency Tuning and Frequency Discrimination Acuity by Synaptic Zinc Signaling in Mouse Auditory Cortex. J Neurosci 2018; 39:854-865. [PMID: 30504277 DOI: 10.1523/jneurosci.1339-18.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 10/16/2018] [Accepted: 11/16/2018] [Indexed: 11/21/2022] Open
Abstract
Neurons in the auditory cortex are tuned to specific ranges of sound frequencies. Although the cellular and network mechanisms underlying neuronal sound frequency selectivity are well studied and reflect the interplay of thalamocortical and intracortical excitatory inputs and further refinement by cortical inhibition, the precise synaptic signaling mechanisms remain less understood. To gain further understanding on these mechanisms and their effects on sound-driven behavior, we used in vivo imaging as well as behavioral approaches in awake and behaving female and male mice. We discovered that synaptic zinc, a modulator of neurotransmission and responsiveness to sound, sharpened the sound frequency tuning of principal and parvalbumin-expressing neurons and widened the sound frequency tuning of somatostatin-expressing inhibitory neurons in layer 2/3 of the primary auditory cortex. In the absence of cortical synaptic zinc, mice exhibited reduced acuity for detecting changes in sound frequencies. Together, our results reveal that cell-type-specific effects of zinc contribute to cortical sound frequency tuning and enhance acuity for sound frequency discrimination.SIGNIFICANCE STATEMENT Neuronal tuning to specific features of sensory stimuli is a fundamental property of cortical sensory processing that advantageously supports behavior. Despite the established roles of synaptic thalamocortical and intracortical excitation and inhibition in cortical tuning, the precise synaptic signaling mechanisms remain unknown. Here, we investigated these mechanisms in the mouse auditory cortex. We discovered a previously unknown signaling mechanism linking synaptic zinc signaling with cell-specific cortical tuning and enhancement in sound frequency discrimination acuity. Given the abundance of synaptic zinc in all sensory cortices, this newly discovered interaction between synaptic zinc and cortical tuning can provide a general mechanism for modulating neuronal stimulus specificity and sensory-driven behavior.
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26
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Superiority of SpiroZin2 Versus FluoZin-3 for monitoring vesicular Zn 2+ allows tracking of lysosomal Zn 2+ pools. Sci Rep 2018; 8:15034. [PMID: 30302024 PMCID: PMC6177427 DOI: 10.1038/s41598-018-33102-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 09/17/2018] [Indexed: 12/28/2022] Open
Abstract
Small-molecule fluorescent probes are powerful and ubiquitous tools for measuring the concentration and distribution of analytes in living cells. However, accurate characterization of these analytes requires rigorous evaluation of cell-to-cell heterogeneity in fluorescence intensities and intracellular distribution of probes. In this study, we perform a parallel and systematic comparison of two small-molecule fluorescent vesicular Zn2+ probes, FluoZin-3 AM and SpiroZin2, to evaluate each probe for measurement of vesicular Zn2+ pools. Our results reveal that SpiroZin2 is a specific lysosomal vesicular Zn2+ probe and affords uniform measurement of resting Zn2+ levels at the single cell level with proper calibration. In contrast, FluoZin-3 AM produces highly variable fluorescence intensities and non-specifically localizes in the cytosol and multiple vesicular compartments. We further applied SpiroZin2 to lactating mouse mammary epithelial cells and detected a transient increase of lysosomal free Zn2+ at 24-hour after lactation hormone treatment, which implies that lysosomes play a role in the regulation of Zn2+ homeostasis during lactation. This study demonstrates the need for critical characterization of small-molecule fluorescent probes to define the concentration and localization of analytes in different cell populations, and reveals SpiroZin2 to be capable of reporting diverse perturbations to lysosomal Zn2+.
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27
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Balaram P, Hackett TA, Polley DB. Synergistic Transcriptional Changes in AMPA and GABA A Receptor Genes Support Compensatory Plasticity Following Unilateral Hearing Loss. Neuroscience 2018; 407:108-119. [PMID: 30176318 DOI: 10.1016/j.neuroscience.2018.08.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/02/2018] [Accepted: 08/22/2018] [Indexed: 01/11/2023]
Abstract
Debilitating perceptual disorders including tinnitus, hyperacusis, phantom limb pain and visual release hallucinations may reflect aberrant patterns of neural activity in central sensory pathways following a loss of peripheral sensory input. Here, we explore short- and long-term changes in gene expression that may contribute to hyperexcitability following a sudden, profound loss of auditory input from one ear. We used fluorescence in situ hybridization to quantify mRNA levels for genes encoding AMPA and GABAA receptor subunits (Gria2 and Gabra1, respectively) in single neurons from the inferior colliculus (IC) and auditory cortex (ACtx). Thirty days after unilateral hearing loss, Gria2 levels were significantly increased while Gabra1 levels were significantly decreased. Transcriptional rebalancing was more pronounced in ACtx than IC and bore no obvious relationship to the degree of hearing loss. By contrast to the opposing, synergistic shifts in Gria2 and Gabra1 observed 30 days after hearing loss, we found that transcription levels for both genes were equivalently reduced after 5 days of hearing loss, producing no net change in the excitatory/inhibitory transcriptional balance. Opposing transcriptional shifts in AMPA and GABA receptor genes that emerge several weeks after a peripheral insult could promote both sensitization and disinhibition to support a homeostatic recovery of neural activity following auditory deprivation. Imprecise transcriptional changes could also drive the system toward perceptual hypersensitivity, degraded temporal processing and the irrepressible perception of non-existent environmental stimuli, a trio of perceptual impairments that often accompany chronic sensory deprivation.
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Affiliation(s)
- P Balaram
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston MA 02114, USA; Dept. of Otolaryngology, Harvard Medical School, Boston MA 02114, USA
| | - T A Hackett
- Dept. of Hearing and Speech Sciences, Vanderbilt Bill Wilkerson Center for Otolaryngology and Communication Sciences, Vanderbilt University Medical Center, Nashville TN 37232 USA
| | - D B Polley
- Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston MA 02114, USA; Dept. of Otolaryngology, Harvard Medical School, Boston MA 02114, USA.
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28
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How cellular Zn 2+ signaling drives physiological functions. Cell Calcium 2018; 75:53-63. [PMID: 30145429 DOI: 10.1016/j.ceca.2018.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/16/2018] [Accepted: 08/17/2018] [Indexed: 01/10/2023]
Abstract
Zinc is an essential micronutrient affecting many aspects of human health. Cellular Zn2+ homeostasis is critical for cell function and survival. Zn2+, acting as a first or second messenger, triggers signaling pathways that mediate the physiological roles of Zn2+. Transient changes in Zn2+ concentrations within the cell or in the extracellular region occur following its release from Zn2+ binding metallothioneins, its transport across membranes by the ZnT or ZIP transporters, or release of vesicular Zn2+. These transients activate a distinct Zn2+ sensing receptor, ZnR/GPR39, or modulate numerous proteins and signaling pathways. Importantly, Zn2+ signaling regulates cellular physiological functions such as: proliferation, differentiation, ion transport and secretion. Indeed, novel therapeutic approaches aimed to maintain Zn2+ homeostasis and signaling are evolving. This review focuses on recent findings describing roles of Zn2+ and its transporters in regulating physiological or pathological processes.
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29
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Goldberg JM, Lippard SJ. New Tools Uncover New Functions for Mobile Zinc in the Brain. Biochemistry 2018; 57:3991-3992. [PMID: 29553247 DOI: 10.1021/acs.biochem.8b00108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jacob M Goldberg
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States
| | - Stephen J Lippard
- Department of Chemistry , Massachusetts Institute of Technology , 77 Massachusetts Avenue , Cambridge , Massachusetts 02139 , United States
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30
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Goldberg JM, Wang F, Sessler CD, Vogler NW, Zhang DY, Loucks WH, Tzounopoulos T, Lippard SJ. Photoactivatable Sensors for Detecting Mobile Zinc. J Am Chem Soc 2018; 140:2020-2023. [PMID: 29384658 PMCID: PMC5935517 DOI: 10.1021/jacs.7b12766] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fluorescent sensors for mobile zinc are valuable for studying complex biological systems. Because these sensors typically bind zinc rapidly and tightly, there has been little temporal control over the activity of the probe after its application to a sample. The ability to control the activity of a zinc sensor in vivo during imaging experiments would greatly improve the time resolution of the measurement. Here, we describe photoactivatable zinc sensors that can be triggered with short pulses of UV light. These probes are prepared by functionalizing a zinc sensor with protecting groups that render the probe insensitive to metal ions. Photoinduced removal of the protecting groups restores the binding site, allowing for zinc-responsive changes in fluorescence that can be observed in live cells and tissues.
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Affiliation(s)
- Jacob M. Goldberg
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Fang Wang
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Chanan D. Sessler
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Nathan W. Vogler
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, United States
| | - Daniel Y. Zhang
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - William H. Loucks
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Thanos Tzounopoulos
- Pittsburgh Hearing Research Center, Department of Otolaryngology, University of Pittsburgh, 3501 Fifth Avenue, Pittsburgh, Pennsylvania 15261, United States
| | - Stephen J. Lippard
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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31
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Signaling by Synaptic Zinc is Required for Whisker-Mediated, Fine Texture Discrimination. Neuroscience 2017; 369:242-247. [PMID: 29158108 DOI: 10.1016/j.neuroscience.2017.11.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 11/06/2017] [Accepted: 11/11/2017] [Indexed: 01/08/2023]
Abstract
Zinc-containing terminals are found throughout the neocortex, concentrated predominantly in layers II/III, V, and VI. Synaptic zinc is a potent neurotransmitter/modulator and, therefore, may mediate inter- or intra-cortical integration of sensory information. We have previously shown that levels of synaptic zinc are rapidly modulated in somatosensory (barrel) cortex, in an experience- and activity-dependent manner. Zinc transporter 3 (ZnT3) knockout (KO) mice lack synaptic zinc and provide us with a good model to examine the contribution of synaptic zinc to barrel cortex-dependent behavior. In the present study, we show that ZnT3 KO mice display a marked decrease in acuity for whisker-dependent texture discrimination. ZnT3 KO mice were not able to discriminate between textures having an average particle diameter less than 300 μm while control mice were able to discriminate between textures having particle diameters separated by as little as 25 μm. This loss of texture discrimination acuity in ZnT3 KO mice was whisker-dependent and was observed in young (2 months-of-age) and older mice (12 months-of-age). These results show that zincergic signaling is necessary for the normal integration of somatosensory information.
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32
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Abstract
Certain neurons in the auditory cortex release zinc to influence how the brain processes sounds.
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Affiliation(s)
- Brendan B McAllister
- Department of Psychology, Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
| | - Richard H Dyck
- Department of Psychology, Hotchkiss Brain Institute, University of Calgary, Calgary, Canada
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