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Kopach O, Pivneva T, Fedirko N, Voitenko N. Mitochondrial malfunction mediates impaired cholinergic Ca 2+ signalling and submandibular salivary gland dysfunction in diabetes. Neuropharmacology 2024; 243:109789. [PMID: 37972885 DOI: 10.1016/j.neuropharm.2023.109789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/23/2023] [Accepted: 11/09/2023] [Indexed: 11/19/2023]
Abstract
Xerostomia (dry-mouth syndrome) is a painful and debilitating condition that frequently occurs in individuals with diabetes and is associated with impaired saliva production and salivary gland hypofunction. Saliva fluid production relies on Ca2+-coupled secretion driven by neurotransmitter stimulation of submandibular acinar cells. Although impairments in intracellular Ca2+ signalling have been reported in various xerostomia models, the specific Ca2+-dependent mechanisms underlying saliva fluid hypofunction in diabetes remain unclear. In this study, we show that diabetic animals exhibit severe xerostomia, evident by reduced saliva flow rate, diminished total protein content, and decreased amylase activity in the saliva secreted by submandibular glands. These impairments remained resistant to exogenous cholinergic stimulation. In submandibular acinar cells, the intracellular Ca2+ signals evoked by cholinergic stimulation were reduced and delayed in diabetes, caused by malfunctioning mitochondria. Upon initiation of cholinergic-evoked Ca2+ signals, mitochondria accumulate higher Ca2+ and fail to redistribute Ca2+ influx and facilitate the store-operated Ca2+ entry effectively. Structural damage to mitochondria was evident in the acinar cells in diabetes. These findings provide insights into the potential targeting of malfunctioning mitochondria for the treatment of diabetic xerostomia as an alternative strategy to the existing pharmacotherapeutic approaches. This article is part of the Special Issue on "Ukrainian Neuroscience".
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Affiliation(s)
- Olga Kopach
- Bogomoletz Institute of Physiology, Kyiv, Ukraine; Queen Square Institute of Neurology, University College London, London, UK.
| | - Tetyana Pivneva
- Bogomoletz Institute of Physiology, Kyiv, Ukraine; Kyiv Academic University, Kyiv, Ukraine
| | | | - Nana Voitenko
- Kyiv Academic University, Kyiv, Ukraine; Dobrobut Academy Medical School, Kyiv, Ukraine
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Ivasiuk A, Matvieienko M, Kononenko NI, Duzhyy DE, Korogod SM, Voitenko N, Belan P. Diabetes-Induced Amplification of Nociceptive DRG Neuron Output by Upregulation of Somatic T-Type Ca 2+ Channels. Biomolecules 2023; 13:1320. [PMID: 37759720 PMCID: PMC10526307 DOI: 10.3390/biom13091320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 08/23/2023] [Accepted: 08/23/2023] [Indexed: 09/29/2023] Open
Abstract
The development of pain symptoms in peripheral diabetic neuropathy (PDN) is associated with the upregulation of T-type Ca2+ channels (T-channels) in the soma of nociceptive DRG neurons. Moreover, a block of these channels in DRG neurons effectively reversed mechanical and thermal hyperalgesia in animal diabetic models, indicating that T-channel functioning in these neurons is causally linked to PDN. However, no particular mechanisms relating the upregulation of T-channels in the soma of nociceptive DRG neurons to the pathological pain processing in PDN have been suggested. Here we have electrophysiologically identified voltage-gated currents expressed in nociceptive DRG neurons and developed a computation model of the neurons, including peripheral and central axons. Simulations showed substantially stronger sensitivity of neuronal excitability to diabetes-induced T-channel upregulation at the normal body temperature compared to the ambient one. We also found that upregulation of somatic T-channels, observed in these neurons under diabetic conditions, amplifies a single action potential invading the soma from the periphery into a burst of multiple action potentials further propagated to the end of the central axon. We have concluded that the somatic T-channel-dependent amplification of the peripheral nociceptive input to the spinal cord demonstrated in this work may underlie abnormal nociception at different stages of diabetes development.
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Affiliation(s)
- Arsentii Ivasiuk
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology of NAS of Ukraine, 01024 Kyiv, Ukraine; (A.I.); (M.M.); (N.I.K.); (S.M.K.)
| | - Maksym Matvieienko
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology of NAS of Ukraine, 01024 Kyiv, Ukraine; (A.I.); (M.M.); (N.I.K.); (S.M.K.)
| | - Nikolai I. Kononenko
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology of NAS of Ukraine, 01024 Kyiv, Ukraine; (A.I.); (M.M.); (N.I.K.); (S.M.K.)
| | - Dmytro E. Duzhyy
- Department of Sensory Signaling, Bogomoletz Institute of Physiology of NAS of Ukraine, 01024 Kyiv, Ukraine;
| | - Sergiy M. Korogod
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology of NAS of Ukraine, 01024 Kyiv, Ukraine; (A.I.); (M.M.); (N.I.K.); (S.M.K.)
| | - Nana Voitenko
- Department of Biomedicine and Neuroscience, Kyiv Academic University of NAS of Ukraine, 03142 Kyiv, Ukraine
- Research Center, Dobrobut Academy Medical School, 03022 Kyiv, Ukraine
| | - Pavel Belan
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology of NAS of Ukraine, 01024 Kyiv, Ukraine; (A.I.); (M.M.); (N.I.K.); (S.M.K.)
- Department of Biomedicine and Neuroscience, Kyiv Academic University of NAS of Ukraine, 03142 Kyiv, Ukraine
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Krotov V, Agashkov K, Romanenko S, Koroid K, Krasniakova M, Belan P, Voitenko N. Neuropathic pain changes the output of rat lamina I spino-parabrachial neurons. BBA Advances 2023; 3:100081. [PMID: 37082260 PMCID: PMC10074952 DOI: 10.1016/j.bbadva.2023.100081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/07/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
• Spared nerve injury (SNI) altered the action potential (AP) output of lamina I spino-parabrachial neurons (SPNs) without affecting their resting potential or membrane resistance. • In one-third of SPNs, high-threshold dorsal root stimulation elicited persistent AP firing which was never observed in cells from naïve animals. • 38% of SPNs from SNI rats showed spontaneous persistent AP firing. • After SNI low- and high-output SPNs were no longer nociceptive-specific as part of them responded with APs to low-threshold stimulation. • These SNI-induced changes of SPN output might represent cellular mechanisms for neuropathy-associated allodynia, hyperalgesia, and spontaneous pain.
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Krotov V, Agashkov K, Romanenko S, Halaidych O, Andrianov Y, Safronov BV, Belan P, Voitenko N. Elucidating afferent-driven presynaptic inhibition of primary afferent input to spinal laminae I and X. Front Cell Neurosci 2023; 16:1029799. [PMID: 36713779 PMCID: PMC9874151 DOI: 10.3389/fncel.2022.1029799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 12/14/2022] [Indexed: 01/13/2023] Open
Abstract
Although spinal processing of sensory information greatly relies on afferent-driven (AD) presynaptic inhibition (PI), our knowledge about how it shapes peripheral input to different types of nociceptive neurons remains insufficient. Here we examined the AD-PI of primary afferent input to spinal neurons in the marginal layer, lamina I, and the layer surrounding the central canal, lamina X; two nociceptive-processing regions with similar patterns of direct supply by Aδ- and C-afferents. Unmyelinated C-fibers were selectively activated by electrical stimuli of negative polarity that induced an anodal block of myelinated Aβ/δ-fibers. Combining this approach with the patch-clamp recording in an ex vivo spinal cord preparation, we found that attenuation of the AD-PI by the anodal block of Aβ/δ-fibers resulted in the appearance of new mono- and polysynaptic C-fiber-mediated excitatory postsynaptic current (EPSC) components. Such homosegmental Aβ/δ-AD-PI affected neurons in the segment of the dorsal root entrance as well as in the adjacent rostral segment. In their turn, C-fibers from the L5 dorsal root induced heterosegmental AD-PI of the inputs from the L4 Aδ- and C-afferents to the neurons in the L4 segment. The heterosegmental C-AD-PI was reciprocal since the L4 C-afferents inhibited the L5 Aδ- and C-fiber inputs, as well as some direct L5 Aβ-fiber inputs. Moreover, the C-AD-PI was found to control the spike discharge in spinal neurons. Given that the homosegmental Aβ/δ-AD-PI and heterosegmental C-AD-PI affected a substantial percentage of lamina I and X neurons, we suggest that these basic mechanisms are important for shaping primary afferent input to the neurons in the spinal nociceptive-processing network.
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Affiliation(s)
- Volodymyr Krotov
- Department of Sensory Signaling, Bogomoletz Institute of Physiology, Kyiv, Ukraine,Department of Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine,*Correspondence: Volodymyr Krotov,
| | - Kirill Agashkov
- Department of Sensory Signaling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Sergii Romanenko
- Department of Sensory Signaling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Oleh Halaidych
- Department of Sensory Signaling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Yaroslav Andrianov
- Department of Sensory Signaling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Boris V. Safronov
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal,Neuronal Networks Group, Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Pavel Belan
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine,Department of Biomedicine and Neuroscience, Kyiv Academic University, Kyiv, Ukraine
| | - Nana Voitenko
- Department of Sensory Signaling, Bogomoletz Institute of Physiology, Kyiv, Ukraine,Department of Biomedicine and Neuroscience, Kyiv Academic University, Kyiv, Ukraine,Dobrobut Academy Medical School, Kyiv, Ukraine
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Krotov V, Agashkov K, Krasniakova M, Safronov BV, Belan P, Voitenko N. Segmental and descending control of primary afferent input to the spinal lamina X. Pain 2022; 163:2014-2020. [PMID: 35297816 PMCID: PMC9339045 DOI: 10.1097/j.pain.0000000000002597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 01/03/2022] [Accepted: 01/20/2022] [Indexed: 02/04/2023]
Abstract
ABSTRACT Despite being involved in a number of functions, such as nociception and locomotion, spinal lamina X remains one of the least studied central nervous system regions. Here, we show that Aδ- and C-afferent inputs to lamina X neurons are presynaptically inhibited by homo- and heterosegmental afferents as well as by descending fibers from the corticospinal tract, dorsolateral funiculus, and anterior funiculus. Activation of descending tracts suppresses primary afferent-evoked action potentials and also elicits excitatory (mono- and polysynaptic) and inhibitory postsynaptic responses in lamina X neurons. Thus, primary afferent input to lamina X is subject to both spinal and supraspinal control being regulated by at least 5 distinct pathways.
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Affiliation(s)
- Volodymyr Krotov
- Departments of Sensory Signaling and
- Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | | | | | - Boris V. Safronov
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal
- Neuronal Networks Group, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Pavel Belan
- Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine
- Kyiv Academic University, Kyiv, Ukraine
| | - Nana Voitenko
- Departments of Sensory Signaling and
- Kyiv Academic University, Kyiv, Ukraine
- Private Institution Dobrobut Academy, Kyiv, Ukraine
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Kopach O, Voitenko N. Spinal AMPA receptors: Amenable players in central sensitization for chronic pain therapy? Channels (Austin) 2021; 15:284-297. [PMID: 33565904 PMCID: PMC7889122 DOI: 10.1080/19336950.2021.1885836] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 02/01/2021] [Accepted: 02/01/2021] [Indexed: 02/08/2023] Open
Abstract
The activity-dependent trafficking of AMPA receptors (AMPAR) mediates synaptic strength and plasticity, while the perturbed trafficking of the receptors of different subunit compositions has been linked to memory impairment and to causing neuropathology. In the spinal cord, nociceptive-induced changes in AMPAR trafficking determine the central sensitization of the dorsal horn (DH): changes in AMPAR subunit composition compromise the balance between synaptic excitation and inhibition, rendering interneurons hyperexcitable to afferent inputs, and promoting Ca2+ influx into the DH neurons, thereby amplifying neuronal hyperexcitability. The DH circuits become over-excitable and carry out aberrant sensory processing; this causes an increase in pain sensation in central sensory pathways, giving rise to chronic pain syndrome. Current knowledge of the contribution of spinal AMPAR to the cellular mechanisms relating to chronic pain provides opportunities for developing target-based therapies for chronic pain intervention.
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Affiliation(s)
- Olga Kopach
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
- Present Address: Department of Clinical and Experimental Epilepsy, Queen Square Institute of Neurology, University College London, London, UK
| | - Nana Voitenko
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
- Kyiv Academic University, Kyiv, Ukraine
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Kopach O, Zheng K, Dong L, Sapelkin A, Voitenko N, Sukhorukov GB, Rusakov DA. Nano-engineered microcapsules boost the treatment of persistent pain. Drug Deliv 2018; 25:435-447. [PMID: 29383961 PMCID: PMC5796488 DOI: 10.1080/10717544.2018.1431981] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/16/2018] [Accepted: 01/21/2018] [Indexed: 11/17/2022] Open
Abstract
Persistent pain remains a major health issue: common treatments relying on either repeated local injections or systemic drug administration are prone to concomitant side-effects. It is thought that an alternative could be a multifunctional cargo system to deliver medicine to the target site and release it over a prolonged time window. We nano-engineered microcapsules equipped with adjustable cargo release properties and encapsulated the sodium-channel blocker QX-314 using the layer-by-layer (LbL) technology. First, we employed single-cell electrophysiology to establish in vitro that microcapsule application can dampen neuronal excitability in a controlled fashion. Secondly, we used two-photon excitation imaging to monitor and adjust long-lasting release of encapsulated cargo in target tissue in situ. Finally, we explored an established peripheral inflammation model in rodents to find that a single local injection of QX-314-containing microcapsules could provide robust pain relief lasting for over a week. This was accompanied by a recovery of the locomotive deficit and the amelioration of anxiety in animals with persistent inflammation. Post hoc immunohistology confirmed biodegradation of microcapsules over a period of several weeks. The overall remedial effect lasted 10-20 times longer than that of a single focal drug injection. It depended on the QX-314 encapsulation levels, involved TRPV1-channel-dependent cell permeability of QX-314, and showed no detectable side-effects. Our data suggest that nano-engineered encapsulation provides local drug delivery suitable for prolonged pain relief, which could be highly advantageous compared to existing treatments.
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Affiliation(s)
- Olga Kopach
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK
| | - Kayiu Zheng
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK
| | - Luo Dong
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - Andrei Sapelkin
- Centre for Condensed Matter and Materials Physics, Queen Mary University of London, London, UK
| | - Nana Voitenko
- Department of Sensory Signaling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Gleb B. Sukhorukov
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - Dmitri A. Rusakov
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, University College London, London, UK
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Kopach O, Krotov V, Shysh A, Sotnic A, Viatchenko-Karpinski V, Dosenko V, Voitenko N. Spinal PKCα inhibition and gene-silencing for pain relief: AMPAR trafficking at the synapses between primary afferents and sensory interneurons. Sci Rep 2018; 8:10285. [PMID: 29980697 PMCID: PMC6035211 DOI: 10.1038/s41598-018-28512-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 06/22/2018] [Indexed: 01/21/2023] Open
Abstract
Upregulation of Ca2+-permeable AMPA receptors (CP-AMPARs) in dorsal horn (DH) neurons has been causally linked to persistent inflammatory pain. This upregulation, demonstrated for both synaptic and extrasynaptic AMPARs, depends on the protein kinase C alpha (PKCα) activation; hence, spinal PKC inhibition has alleviated peripheral nociceptive hypersensitivity. However, whether targeting the spinal PKCα would alleviate both pain development and maintenance has not been explored yet (essential to pharmacological translation). Similarly, if it could balance the upregulated postsynaptic CP-AMPARs also remains unknown. Here, we utilized pharmacological and genetic inhibition of spinal PKCα in various schemes of pain treatment in an animal model of long-lasting peripheral inflammation. Pharmacological inhibition (pre- or post-treatment) reduced the peripheral nociceptive hypersensitivity and accompanying locomotive deficit and anxiety in rats with induced inflammation. These effects were dose-dependent and observed for both pain development and maintenance. Gene-therapy (knockdown of PKCα) was also found to relieve inflammatory pain when applied as pre- or post-treatment. Moreover, the revealed therapeutic effects were accompanied with the declined upregulation of CP-AMPARs at the DH synapses between primary afferents and sensory interneurons. Our results provide a new focus on the mechanism-based pain treatment through interference with molecular mechanisms of AMPAR trafficking in central pain pathways.
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Affiliation(s)
- Olga Kopach
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine. .,Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, UK.
| | - Volodymyr Krotov
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Angela Shysh
- Department of General and Molecular Pathophysiology, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Andrij Sotnic
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Viacheslav Viatchenko-Karpinski
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine.,The University of Alabama at Birmingham, Birmingham, United States
| | - Victor Dosenko
- Department of General and Molecular Pathophysiology, Bogomoletz Institute of Physiology, Kyiv, Ukraine.,Kyiv Academic University, Kyiv, Ukraine
| | - Nana Voitenko
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine. .,Kyiv Academic University, Kyiv, Ukraine.
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Kopach O, Rybachuk O, Krotov V, Kyryk V, Voitenko N, Pivneva T. Maturation of neural stem cells and integration into hippocampal circuits - a functional study in an in situ model of cerebral ischemia. J Cell Sci 2018; 131:jcs.210989. [PMID: 29361548 DOI: 10.1242/jcs.210989] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/29/2017] [Indexed: 12/16/2022] Open
Abstract
The hippocampus is the region of the brain that is most susceptible to ischemic lesion because it contains pyramidal neurons that are highly vulnerable to ischemic cell death. A restricted brain neurogenesis limits the possibility of reversing massive cell death after stroke and, hence, endorses cell-based therapies for neuronal replacement strategies following cerebral ischemia. Neurons differentiated from neural stem/progenitor cells (NSPCs) can mature and integrate into host circuitry, improving recovery after stroke. However, how the host environment regulates the NSPC behavior in post-ischemic tissue remains unknown. Here, we studied functional maturation of NSPCs in control and post-ischemic hippocampal tissue after modelling cerebral ischemia in situ We traced the maturation of electrophysiological properties and integration of the NSPC-derived neurons into the host circuits, with these cells developing appropriate activity 3 weeks or less after engraftment. In the tissue subjected to ischemia, the NSPC-derived neurons exhibited functional deficits, and differentiation of embryonic NSPCs to glial types - oligodendrocytes and astrocytes - was boosted. Our findings of the delayed neuronal maturation in post-ischemic conditions, while the NSPC differentiation was promoted towards glial cell types, provide new insights that could be applicable to stem cell therapy replacement strategies used after cerebral ischemia.
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Affiliation(s)
- Olga Kopach
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv 01024, Ukraine .,Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Oksana Rybachuk
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv 01024, Ukraine.,State Institute of Genetic and Regenerative Medicine, Kyiv 04114, Ukraine
| | - Volodymyr Krotov
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv 01024, Ukraine
| | - Vitalii Kyryk
- State Institute of Genetic and Regenerative Medicine, Kyiv 04114, Ukraine
| | - Nana Voitenko
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv 01024, Ukraine.,Kyiv Academic University, Kyiv 03142, Ukraine
| | - Tatyana Pivneva
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv 01024, Ukraine.,State Institute of Genetic and Regenerative Medicine, Kyiv 04114, Ukraine.,Kyiv Academic University, Kyiv 03142, Ukraine
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Krotov V, Tokhtamysh A, Kopach O, Dromaretsky A, Sheremet Y, Belan P, Voitenko N. Functional Characterization of Lamina X Neurons in ex-Vivo Spinal Cord Preparation. Front Cell Neurosci 2017; 11:342. [PMID: 29163053 PMCID: PMC5672841 DOI: 10.3389/fncel.2017.00342] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/16/2017] [Indexed: 11/25/2022] Open
Abstract
Functional properties of lamina X neurons in the spinal cord remain unknown despite the established role of this area for somatosensory integration, visceral nociception, autonomic regulation and motoneuron output modulation. Investigations of neuronal functioning in the lamina X have been hampered by technical challenges. Here we introduce an ex-vivo spinal cord preparation with both dorsal and ventral roots still attached for functional studies of the lamina X neurons and their connectivity using an oblique LED illumination for resolved visualization of lamina X neurons in a thick tissue. With the elaborated approach, we demonstrate electrophysiological characteristics of lamina X neurons by their membrane properties, firing pattern discharge and fiber innervation (either afferent or efferent). The tissue preparation has been also probed using Ca2+ imaging with fluorescent Ca2+ dyes (membrane-impermeable or -permeable) to demonstrate the depolarization-induced changes in intracellular calcium concentration in lamina X neurons. Finally, we performed visualization of subpopulations of lamina X neurons stained by retrograde labeling with aminostilbamidine dye to identify sympathetic preganglionic and projection neurons in the lamina X. Thus, the elaborated approach provides a reliable tool for investigation of functional properties and connectivity in specific neuronal subpopulations, boosting research of lamina X of the spinal cord.
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Affiliation(s)
- Volodymyr Krotov
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine.,Department of Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Anastasia Tokhtamysh
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Olga Kopach
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Andrew Dromaretsky
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Yevhenii Sheremet
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine
| | - Pavel Belan
- Department of Molecular Biophysics, Bogomoletz Institute of Physiology, Kyiv, Ukraine.,Chair of Biophysics and Molecular Physiology, Kyiv Academic University, Kyiv, Ukraine
| | - Nana Voitenko
- Department of Sensory Signalling, Bogomoletz Institute of Physiology, Kyiv, Ukraine.,Chair of Biophysics and Molecular Physiology, Kyiv Academic University, Kyiv, Ukraine
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Kopach O, Krotov V, Voitenko N. Atlanto-occipital catheterization of young rats for long-term drug delivery into the lumbar subarachnoid space combined with in vivo testing and electrophysiology in situ. J Neurosci Methods 2017; 290:125-132. [PMID: 28780368 DOI: 10.1016/j.jneumeth.2017.08.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 07/30/2017] [Accepted: 08/01/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Catheterization has been widely used in neuroscience and pain research for local drug delivery. Though different modifications were developed, the use of young animals for spinal catheterization remains limited because of a little success rate. A reliable technique is needed to catheterize young animals aimed for in vivo testing combined with spinal cord electrophysiology, often limited by animal age, to facilitate pain research. NEW METHODS We describe intrathecal catheterization of young rats (3-week-old) through atlanto-occipical approach for long-lasting drug delivery into the lumbar subarachnoid space. The technique represents a surgical approach of minimized invasiveness that requires PE-10 catheter and few equipment of standard laboratory use. RESULTS Behavioral assessments revealed that spinal catheterization does not change peripheral sensitivity of different modalities (thermal and mechanical) and gives no rise to locomotive deficit or anxiety-like behavior in young rats. The long-term administration of genetic material (oligodeoxynucleotides given up to 4days), examined both in vivo and in situ, produced no adverse effects on basal peripheral sensitivity, but changed the AMPA receptor-mediated currents in sensory interneurons of the spinal cord. COMPARISON WITH EXISTING METHODS Dissimilar to already described methods, the method is designed for the use of young rats for behavioral testing in vivo and/or spinal cord electrophysiology in situ. CONCLUSIONS A practical method for spinal catheterization of young animals designed for studies in vivo and in situ is proposed. The method is rapid and effective and should facilitate investigation of therapeutic effects on both systemic and subcellular levels, as an advantage over the existing methods.
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Affiliation(s)
- Olga Kopach
- Bogomoletz Institute of Physiology, Bogomoletz str. 4, Kyiv 01024, Ukraine; Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.
| | - Volodymyr Krotov
- Bogomoletz Institute of Physiology, Bogomoletz str. 4, Kyiv 01024, Ukraine
| | - Nana Voitenko
- Bogomoletz Institute of Physiology, Bogomoletz str. 4, Kyiv 01024, Ukraine
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Rybachuk O, Kopach O, Krotov V, Voitenko N, Pivneva T. Optimized Model of Cerebral Ischemia In situ for the Long-Lasting Assessment of Hippocampal Cell Death. Front Neurosci 2017; 11:388. [PMID: 28729821 PMCID: PMC5498507 DOI: 10.3389/fnins.2017.00388] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/20/2017] [Indexed: 12/29/2022] Open
Abstract
Among all the brain, the hippocampus is the most susceptible region to ischemic lesion, with the highest vulnerability of CA1 pyramidal neurons to ischemic damage. This damage may cause either prompt neuronal death (within hours) or with a delayed appearance (over days), providing a window for applying potential therapies to reduce or prevent ischemic impairments. However, the time course when ischemic damage turns to neuronal death strictly depends on experimental modeling of cerebral ischemia and, up to now, studies were predominantly focused on a short time-window—from hours to up to a few days post-lesion. Using different schemes of oxygen-glucose deprivation (OGD), the conditions taking place upon cerebral ischemia, we optimized a model of mimicking ischemic conditions in organotypical hippocampal slices for the long-lasting assessment of CA1 neuronal death (at least 3 weeks). By combining morphology and electrophysiology, we show that prolonged (30-min duration) OGD results in a massive neuronal death and overwhelmed astrogliosis within a week post-OGD whereas OGD of a shorter duration (10-min) triggered programmed CA1 neuronal death with a significant delay—within 2 weeks—accompanied with drastically impaired CA1 neuron functions. Our results provide a rationale toward optimized modeling of cerebral ischemia for reliable examination of potential treatments for brain neuroprotection, neuro-regeneration, or testing neuroprotective compounds in situ.
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Affiliation(s)
- Oksana Rybachuk
- Department of Sensory Signaling, Bogomoletz Institute of PhysiologyKyiv, Ukraine
| | - Olga Kopach
- Department of Sensory Signaling, Bogomoletz Institute of PhysiologyKyiv, Ukraine
| | - Volodymyr Krotov
- Department of Sensory Signaling, Bogomoletz Institute of PhysiologyKyiv, Ukraine
| | - Nana Voitenko
- Department of Sensory Signaling, Bogomoletz Institute of PhysiologyKyiv, Ukraine
| | - Tatyana Pivneva
- Department of Sensory Signaling, Bogomoletz Institute of PhysiologyKyiv, Ukraine
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Kopach O, Maistrenko A, Lushnikova I, Belan P, Skibo G, Voitenko N. HIF-1α-mediated upregulation of SERCA2b: The endogenous mechanism for alleviating the ischemia-induced intracellular Ca2+ store dysfunction in CA1 and CA3 hippocampal neurons. Cell Calcium 2016; 59:251-61. [DOI: 10.1016/j.ceca.2016.02.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/11/2016] [Accepted: 02/22/2016] [Indexed: 01/27/2023]
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Viatchenko-Karpinski V, Novosolova N, Ishchenko Y, Azhar MA, Wright M, Tsintsadze V, Kamal A, Burnashev N, Miller AD, Voitenko N, Giniatullin R, Lozovaya N. Stable, synthetic analogs of diadenosine tetraphosphate inhibit rat and human P2X3 receptors and inflammatory pain. Mol Pain 2016; 12:1744806916637704. [PMID: 27030723 PMCID: PMC4955970 DOI: 10.1177/1744806916637704] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 12/08/2015] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND A growing body of evidence suggests that ATP-gated P2X3 receptors (P2X3Rs) are implicated in chronic pain. We address the possibility that stable, synthetic analogs of diadenosine tetraphosphate (Ap4A) might induce antinociceptive effects by inhibiting P2X3Rs in peripheral sensory neurons. RESULTS The effects of two stable, synthetic Ap4A analogs (AppNHppA and AppCH2ppA) are studied firstly in vitro on HEK293 cells expressing recombinant rat P2XRs (P2X2Rs, P2X3Rs, P2X4Rs, and P2X7Rs) and then using native rat brain cells (cultured trigeminal, nodose, or dorsal root ganglion neurons). Thereafter, the action of these stable, synthetic Ap4A analogs on inflammatory pain and thermal hyperalgesia is studied through the measurement of antinociceptive effects in formalin and Hargreaves plantar tests in rats in vivo. In vitro inhibition of rat P2X3Rs (not P2X2Rs, P2X4Rs nor P2X7Rs) is shown to take place mediated by high-affinity desensitization (at low concentrations; IC50 values 100-250 nM) giving way to only weak partial agonism at much higher concentrations (EC50 values ≥ 10 µM). Similar inhibitory activity is observed with human recombinant P2X3Rs. The inhibitory effects of AppNHppA on nodose, dorsal root, and trigeminal neuron whole cell currents suggest that stable, synthetic Ap4A analogs inhibit homomeric P2X3Rs in preference to heteromeric P2X2/3Rs. Both Ap4A analogs mediate clear inhibition of pain responses in both in vivo inflammation models. CONCLUSIONS Stable, synthetic Ap4A analogs (AppNHppA and AppCH2ppA) being weak partial agonist provoke potent high-affinity desensitization-mediated inhibition of homomeric P2X3Rs at low concentrations. Therefore, both analogs demonstrate clear potential as potent analgesic agents for use in the management of chronic pain associated with heightened P2X3R activation.
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Affiliation(s)
- Viacheslav Viatchenko-Karpinski
- Laboratory of Sensory Signaling, Bogomoletz Institute of Physiology, Kiev, Ukraine International Center for Molecular Physiology, Kiev, Ukraine
| | | | | | - M Ameruddin Azhar
- Indian Institute of Chemical Technology, Hyderabad, India Imperial College Genetic Therapies Centre, Department of Chemistry, Imperial College London, London, UK
| | - Michael Wright
- Imperial College Genetic Therapies Centre, Department of Chemistry, Imperial College London, London, UK Institute of Pharmaceutical Science, King's College London, London, UK
| | - Vera Tsintsadze
- INSERM UMR901 Aix-Marseille Université, Marseille, France INMED, Institut de Neurobiologie de la Méditerranée, Marseille, France
| | - Ahmed Kamal
- Indian Institute of Chemical Technology, Hyderabad, India
| | - Nail Burnashev
- INSERM UMR901 Aix-Marseille Université, Marseille, France INMED, Institut de Neurobiologie de la Méditerranée, Marseille, France
| | - Andrew D Miller
- Institute of Pharmaceutical Science, King's College London, London, UK GlobalAcorn Ltd, London, UK
| | - Nana Voitenko
- Laboratory of Sensory Signaling, Bogomoletz Institute of Physiology, Kiev, Ukraine International Center for Molecular Physiology, Kiev, Ukraine
| | - Rashid Giniatullin
- Department of Neurobiology, A. I. Virtanen Institute, Kuopio, Finland Kazan Federal University, Kazan, Russia
| | - Natalia Lozovaya
- INSERM UMR901 Aix-Marseille Université, Marseille, France INMED, Institut de Neurobiologie de la Méditerranée, Marseille, France Neurochlore, Marseille, France
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Kopach O, Krotov V, Goncharenko J, Voitenko N. Inhibition of Spinal Ca(2+)-Permeable AMPA Receptors with Dicationic Compounds Alleviates Persistent Inflammatory Pain without Adverse Effects. Front Cell Neurosci 2016; 10:50. [PMID: 26973464 PMCID: PMC4770326 DOI: 10.3389/fncel.2016.00050] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 02/13/2016] [Indexed: 11/17/2022] Open
Abstract
Upregulation of Ca2+-permeable AMPA receptors (CP-AMPARs) in the dorsal horn (DH) neurons of the spinal cord has been causally linked to the maintenance of persistent inflammatory pain. Therefore, inhibition of CP-AMPARs could potentially alleviate an, otherwise, poorly treatable chronic pain. However, a loss of CP-AMPARs could produce considerable side effects because of the crucial role of CP-AMPARs in synaptic plasticity. Here we have tested whether the inhibition of spinal CP-AMPARs with dicationic compounds, the open-channel antagonists acting in an activity-dependent manner, can relieve inflammatory pain without adverse effects being developed. Dicationic compounds, N1-(1-phenylcyclohexyl)pentane-1,5-diaminium bromide (IEM-1925) and 1-trimethylammonio-5-1-adamantane-methyl-ammoniopentane dibromide (IEM-1460) were applied intrathecally (i.t.) as a post-treatment for inflammatory pain in the model of complete Freund’s adjuvant (CFA)-induced long-lasting peripheral inflammation. The capability of dicationic compounds to ameliorate inflammatory pain was tested in rats in vivo using the Hargreaves, the von Frey and the open-field tests. Treatment with IEM-1460 or IEM-1925 resulted in profound alleviation of inflammatory pain. The pain relief appeared shortly after compound administration. The effects were concentration-dependent, displaying a high potency of dicationic compounds for alleviation of inflammatory hyperalgesia in the micromolar range, for both acute and long-lasting responses. The period of pain maintenance was shortened following treatment. Treatment with IEM-1460 or IEM-1925 changed neither thermal and mechanical basal sensitivities nor animal locomotion, suggesting that inhibition of CP-AMPARs with dicationic compounds does not give rise to detectable side effects. Thus, the ability of dicationic compounds to alleviate persistent inflammatory pain may provide new routes in the treatment of chronic pain.
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Affiliation(s)
- Olga Kopach
- Laboratory of Sensory Signaling, Bogomoletz Institute of PhysiologyKyiv, Ukraine; Laboratory of Synaptic Imaging, Institute of Neurology, University College LondonLondon, UK
| | - Volodymyr Krotov
- Laboratory of Sensory Signaling, Bogomoletz Institute of Physiology Kyiv, Ukraine
| | - Julia Goncharenko
- Laboratory of Sensory Signaling, Bogomoletz Institute of Physiology Kyiv, Ukraine
| | - Nana Voitenko
- Laboratory of Sensory Signaling, Bogomoletz Institute of PhysiologyKyiv, Ukraine; International Center for Molecular Physiology, Bogomoletz Institute of PhysiologyKyiv, Ukraine
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Kopach O, Viatchenko-Karpinski V, Atianjoh FE, Belan P, Tao YX, Voitenko N. PKCα is required for inflammation-induced trafficking of extrasynaptic AMPA receptors in tonically firing lamina II dorsal horn neurons during the maintenance of persistent inflammatory pain. J Pain 2013; 14:182-92. [PMID: 23374940 DOI: 10.1016/j.jpain.2012.10.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 08/29/2012] [Accepted: 10/31/2012] [Indexed: 10/27/2022]
Abstract
UNLABELLED Persistent inflammation promotes internalization of synaptic GluR2-containing, Ca(2+)-impermeable AMPA receptors (AMPARs) and insertion of GluR1-containing, Ca(2+)-permeable AMPARs at extrasynaptic sites in dorsal horn neurons. Previously we have shown that internalization of synaptic GluR2-containing AMPARs requires activation of spinal cord protein kinase C alpha (PKCα), but molecular mechanisms that underlie altered trafficking of extrasynaptic AMPARs are unclear. Here, using antisense (AS) oligodeoxynucleotides (ODN) that specifically knock down PKCα, we found that a decrease in dorsal horn PKCα expression prevents complete Freund's adjuvant (CFA)-induced increase in functional expression of extrasynaptic Ca(2+)-permeable AMPARs in substantia gelatinosa (SG) neurons of the rat spinal cord. Augmented AMPA-induced currents and associated [Ca(2+)](i) transients were abolished, and the current rectification 1 day post-CFA was reversed. These changes were observed specifically in SG neurons characterized by intrinsic tonic firing properties, but not in those that exhibited strong adaptation. Finally, dorsal horn PKCα knockdown produced an antinociceptive effect on CFA-induced thermal and mechanical hypersensitivity during the maintenance period of inflammatory pain, indicating a role for PKCα in persistent inflammatory pain maintenance. Our results indicate that inflammation-induced trafficking of extrasynaptic Ca(2+)-permeable AMPARs in tonically firing SG neurons depends on PKCα, and that this PKCα-dependent trafficking may contribute to persistent inflammatory pain maintenance. PERSPECTIVE This study shows that PKCα knockdown blocks inflammation-induced upregulation of extrasynaptic Ca(2+)-permeable AMPARs in dorsal horn neurons and produces an antinociceptive effect during the maintenance period of inflammatory pain. These findings have potential implications for use of PKCα gene-silencing therapy to prevent and/or treat persistent inflammatory pain.
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Affiliation(s)
- Olga Kopach
- State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology, Kiev, Ukraine
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Kopach O, Viatchenko-Karpinski V, Belan P, Voitenko N. Development of inflammation-induced hyperalgesia and allodynia is associated with the upregulation of extrasynaptic AMPA receptors in tonically firing lamina II dorsal horn neurons. Front Physiol 2012; 3:391. [PMID: 23060815 PMCID: PMC3462428 DOI: 10.3389/fphys.2012.00391] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 09/13/2012] [Indexed: 11/29/2022] Open
Abstract
Persistent peripheral inflammation changes AMPA receptor (AMPAR) trafficking in dorsal horn neurons by promoting internalization of GluR2-containing, Ca2+-impermeable AMPARs from the synapses and by increasing insertion of GluR1-containing, Ca2+-permeable AMPARs in extrasynaptic plasma membrane. These changes contribute to the maintenance of persistent inflammatory pain. However, much less is known about AMPAR trafficking during development of persistent inflammatory pain and direct studies of extrasynaptic AMPARs functioning during this period are still lacking. Using Complete Freund's adjuvant (CFA)-induced model of long-lasting peripheral inflammation, we showed that remarkable hyperalgesia and allodynia developes in 1–3 h after intraplantar CFA injection. By utilizing patch-clamp recording combined with Ca2+ imaging, we found a significant upregulation of extrasynaptic AMPARs in substantia gelatinosa (SG) neurons of the rat spinal cord 2–3 h after CFA injection. This upregulation was manifested as a robust increase in the amplitude of AMPAR-mediated currents 2–3 h post-CFA. These changes were observed specifically in SG neurons characterized by intrinsic tonic firing properties, but not in those that exhibited strong adaptation. Our results indicate that CFA-induced inflammation increases functional expression of extrasynaptic AMPARs in tonically firing SG neurons during development of pain hypersensitivity and that this increase may contribute to the development of peripheral persistent pain.
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Affiliation(s)
- Olga Kopach
- State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology Kiev, Ukraine
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Kopach O, Vats J, Netsyk O, Voitenko N, Irving A, Fedirko N. Cannabinoid receptors in submandibular acinar cells: functional coupling between saliva fluid and electrolytes secretion and Ca2+ signalling. J Cell Sci 2012; 125:1884-95. [PMID: 22366450 DOI: 10.1242/jcs.088930] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Cannabinoid receptors (CBRs) belong to the G protein-coupled receptor superfamily, and activation of CBRs in salivary cells inhibits agonist-stimulated salivation and modifies saliva content. However, the role of different CBR subtypes in acinar cell physiology and in intracellular signalling remains unclear. Here, we uncover functional CB(1)Rs and CB(2)Rs in acinar cells of rat submandibular gland and their essential role in saliva secretion. Pharmacological activation of CB(1)Rs and CB(2)Rs in the submandibular gland suppressed saliva outflow and modified saliva content produced by the submandibular gland in vivo. Using Na(+)-selective microelectrodes to record secretory Na(+) responses in the lumen of acini, we observed a reduction in Na(+) transport following the activation of CBRs, which was counteracted by the selective CB(1)R antagonist AM251. In addition, activation of CB(1)Rs or CB Rs caused inhibition of Na(+)-K(+) 2 -ATPase activity in microsomes derived from the gland tissue as well as in isolated acinar cells. Using a Ca(2+) imaging technique, we showed that activation of CB(1)Rs and CB(2)Rs alters [Ca(2+)](cyt) signalling in acinar cells by distinct pathways, involving Ca(2+) release from the endoplasmic reticulum (ER) and store-operated Ca(2+) entry (SOCE), respectively. Our data demonstrate the expression of CB(1)Rs and CB(2)Rs in acinar cells, and their involvement in the regulation of salivary gland functioning.
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Affiliation(s)
- Olga Kopach
- State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
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Kopach O, Kao SC, Petralia RS, Belan P, Tao YX, Voitenko N. Inflammation alters trafficking of extrasynaptic AMPA receptors in tonically firing lamina II neurons of the rat spinal dorsal horn. Pain 2011; 152:912-923. [PMID: 21282008 DOI: 10.1016/j.pain.2011.01.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Revised: 11/02/2010] [Accepted: 01/10/2011] [Indexed: 12/17/2022]
Abstract
Peripheral inflammation alters AMPA receptor (AMPAR) subunit trafficking and increases AMPAR Ca(2+) permeability at synapses of spinal dorsal horn neurons. However, it is unclear whether AMPAR trafficking at extrasynaptic sites of these neurons also changes under persistent inflammatory pain conditions. Using patch-clamp recording combined with Ca(2+) imaging and cobalt staining, we found that, under normal conditions, an extrasynaptic pool of AMPARs in rat substantia gelatinosa (SG) neurons of spinal dorsal horn predominantly consists of GluR2-containing Ca(2+)-impermeable receptors. Maintenance of complete Freund's adjuvant (CFA)-induced inflammation was associated with a marked enhancement of AMPA-induced currents and [Ca(2+)](i) transients in SG neurons, while, as we previously showed, the amplitude of synaptically evoked AMPAR-mediated currents was not changed 24 h after CFA. These findings indicate that extrasynaptic AMPARs are upregulated and their Ca(2+) permeability increases dramatically. This increase occurred in SG neurons characterized by intrinsic tonic firing properties, but not in those exhibited strong adaptation. This increase was also accompanied by an inward rectification of AMPA-induced currents and enhancement of sensitivity to a highly selective Ca(2+)-permeable AMPAR blocker, IEM-1460. Electron microcopy and biochemical assays additionally showed an increase in the amount of GluR1 at extrasynaptic membranes in dorsal horn neurons 24h post-CFA. Taken together, our findings indicate that CFA-induced inflammation increases functional expression and proportion of extrasynaptic GluR1-containing Ca(2+)-permeable AMPARs in tonically firing excitatory dorsal horn neurons, suggesting that the altered extrasynaptic AMPAR trafficking might participate in the maintenance of persistent inflammatory pain.
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Affiliation(s)
- Olga Kopach
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA Department of Anesthesiology, Lin-Kou Medical Center, Chung Gung Memorial Hospital, Taoyaun County, Taiwan 333, ROC Laboratory of Neurochemistry, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
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Tsiklauri N, Viatchenko-Karpinski V, Voitenko N, Tsagareli MG. Non-opioid tolerance in juvenile and adult rats. Eur J Pharmacol 2010; 629:68-72. [DOI: 10.1016/j.ejphar.2009.12.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 12/03/2009] [Accepted: 12/15/2009] [Indexed: 10/20/2022]
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Kopach O, Voitenko N, Fedirko N. Impaired Mitochondria Fail to Ensure Sustained Soce: Possible Mechanism for Decreased Salivary Secretion Under Diabetes. Biophys J 2010. [DOI: 10.1016/j.bpj.2009.12.549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Park JS, Voitenko N, Petralia RS, Guan X, Xu JT, Steinberg JP, Takamiya K, Sotnik A, Kopach O, Huganir RL, Tao YX. Persistent inflammation induces GluR2 internalization via NMDA receptor-triggered PKC activation in dorsal horn neurons. J Neurosci 2009; 29:3206-19. [PMID: 19279258 PMCID: PMC2664544 DOI: 10.1523/jneurosci.4514-08.2009] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2008] [Revised: 02/04/2009] [Accepted: 02/09/2009] [Indexed: 01/23/2023] Open
Abstract
Spinal cord GluR2-lacking AMPA receptors (AMPARs) contribute to nociceptive hypersensitivity in persistent pain, but the molecular mechanisms underlying this event are not completely understood. We report that complete Freund's adjuvant (CFA)-induced peripheral inflammation induces synaptic GluR2 internalization in dorsal horn neurons during the maintenance of CFA-evoked nociceptive hypersensitivity. This internalization is initiated by GluR2 phosphorylation at Ser(880) and subsequent disruption of GluR2 binding to its synaptic anchoring protein (GRIP), resulting in a switch of GluR2-containing AMPARs to GluR2-lacking AMPARs and an increase of AMPAR Ca(2+) permeability at the synapses in dorsal horn neurons. Spinal cord NMDA receptor-mediated triggering of protein kinase C (PKC) activation is required for the induction and maintenance of CFA-induced dorsal horn GluR2 internalization. Moreover, preventing CFA-induced spinal GluR2 internalization through targeted mutation of the GluR2 PKC phosphorylation site impairs CFA-evoked nociceptive hypersensitivity during the maintenance period. These results suggest that dorsal horn GluR2 internalization might participate in the maintenance of NMDA receptor/PKC-dependent nociceptive hypersensitivity in persistent inflammatory pain.
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Affiliation(s)
- Jang-Su Park
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Nana Voitenko
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
| | - Ronald S. Petralia
- Laboratory of Neurochemistry, National Institute of Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland 20892, and
| | - Xiaowei Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Ji-Tian Xu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | | | | | - Andrij Sotnik
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
| | - Olga Kopach
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
| | - Richard L. Huganir
- Departments of Neuroscience and
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Yuan-Xiang Tao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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Kopach O, Kruglikov I, Pivneva T, Voitenko N, Fedirko N. Functional coupling between ryanodine receptors, mitochondria and Ca(2+) ATPases in rat submandibular acinar cells. Cell Calcium 2007; 43:469-81. [PMID: 17889347 DOI: 10.1016/j.ceca.2007.08.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2007] [Revised: 08/01/2007] [Accepted: 08/06/2007] [Indexed: 11/17/2022]
Abstract
Agonist stimulation of exocrine cells leads to the generation of intracellular Ca(2+) signals driven by inositol 1,4,5-trisphosphate receptors (IP(3)Rs) that rapidly become global due to propagation throughout the cell. In many types of excitable cells the intracellular Ca(2+) signal is propagated by a mechanism of Ca(2+)-induced Ca(2+) release (CICR), mediated by ryanodine receptors (RyRs). Expression of RyRs in salivary gland cells has been demonstrated immunocytochemically although their functional role is not clear. We used microfluorimetry to measure Ca(2+) signals in the cytoplasm, in the endoplasmic reticulum (ER) and in mitochondria. In permeabilized acinar cells caffeine induced a dose-dependent, transient decrease of Ca(2+) concentration in the endoplasmic reticulum ([Ca(2+)](ER)). This decrease was inhibited by ryanodine but was insensitive to heparin. Application of caffeine, however, did not elevate cytosolic Ca(2+) concentration ([Ca(2+)](i)) suggesting fast local buffering of Ca(2+) released through RyRs. Indeed, activation of RyRs produced a robust mitochondrial Ca(2+) transient that was prevented by addition of Ca(2+) chelator BAPTA but not EGTA. When mitochondrial Ca(2+) uptake was blocked, activation of RyRs evoked only a non-transient increase in [Ca(2+)](i) and substantially smaller Ca(2+) release from the ER. Upon simultaneous inhibition of mitochondrial Ca(2+) uptake and either plasmalemmal or ER Ca(2+) ATPase, activation of RyRs caused a transient rise in [Ca(2+)](i). Collectively, our data suggest that Ca(2+) released through RyRs is mostly "tunnelled" to mitochondria, while Ca(2+) ATPases are responsible for the fast initial sequestration of Ca(2+). Ca(2+) uptake by mitochondria is critical for maintaining continuous CICR. A complex interplay between RyRs, mitochondria and Ca(2+) ATPases is accomplished through strategic positioning of mitochondria close to both Ca(2+) release sites in the ER and Ca(2+) pumping sites of the plasmalemma and the ER.
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Affiliation(s)
- Olga Kopach
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, Kiev , Ukraine
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Shutov L, Kruglikov I, Gryshchenko O, Khomula E, Viatchenko-Karpinski V, Belan P, Voitenko N. The effect of nimodipine on calcium homeostasis and pain sensitivity in diabetic rats. Cell Mol Neurobiol 2006; 26:1541-57. [PMID: 16838100 DOI: 10.1007/s10571-006-9107-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2005] [Accepted: 05/31/2006] [Indexed: 02/05/2023]
Abstract
1. The pathogenesis of diabetic neuropathy is a complex phenomenon, the mechanisms of which are not fully understood. Our previous studies have shown that the intracellular calcium signaling is impaired in primary and secondary nociceptive neurons in rats with streptozotocin (STZ)-induced diabetes. Here, we investigated the effect of prolonged treatment with the L-type calcium channel blocker nimodipine on diabetes-induced changes in neuronal calcium signaling and pain sensitivity. 2. Diabetes was induced in young rats (21 p.d.) by a streptozotocin injection. After 3 weeks of diabetes development, the rats were treated with nimodipine for another 3 weeks. The effect of nimodipine treatment on calcium homeostasis in nociceptive dorsal root ganglion neurons (DRG) and substantia gelatinosa (SG) neurons of the spinal cord slices was examined with fluorescent imaging technique. 3. Nimodipine treatment was not able to normalize elevated resting intracellular calcium ([Ca(2+)]( i )) levels in small DRG neurons. However, it was able to restore impaired Ca(2+) release from the ER, induced by either activation of ryanodine receptors or by receptor-independent mechanism in both DRG and SG neurons. 4. The beneficiary effects of nimodipine treatment on [Ca(2+)]( i ) signaling were paralleled with the reversal of diabetes-induced thermal hypoalgesia and normalization of the acute phase of the response to formalin injection. Nimodipine treatment was also able to shorten the duration of the tonic phase of formalin response to the control values. 5. To separate vasodilating effect of nimodipine Biessels et al., (Brain Res. 1035:86-93) from its effect on neuronal Ca(2+) channels, a group of STZ-diabetic rats was treated with vasodilator - enalapril. Enalapril treatment also have some beneficial effect on normalizing Ca(2+) release from the ER, however, it was far less explicit than the normalizing effect of nimodipine. Effect of enalapril treatment on nociceptive behavioral responses was also much less pronounced. It partially reversed diabetes-induced thermal hypoalgesia, but did not change the characteristics of the response to formalin injection. 6. The results of this study suggest that chronic nimodipine treatment may be effective in restoring diabetes-impaired neuronal calcium homeostasis as well as reduction of diabetes-induced thermal hypoalgesia and noxious stimuli responses. The nimodipine effect is mediated through a direct neuronal action combined with some vascular mechanism.
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Affiliation(s)
- L Shutov
- Bogomoletz Institute of Physiology, Kiev, Ukraine
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Youn DH, Voitenko N, Gerber G, Park YK, Galik J, Randić M. Altered long-term synaptic plasticity and kainate-induced Ca2+ transients in the substantia gelatinosa neurons in GLUK6-deficient mice. ACTA ACUST UNITED AC 2005; 142:9-18. [PMID: 16219388 DOI: 10.1016/j.molbrainres.2005.09.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2005] [Revised: 08/24/2005] [Accepted: 09/05/2005] [Indexed: 11/22/2022]
Abstract
Functional kainate receptors are expressed in the spinal cord substantia gelatinosa region, and their activation contributes to bi-directional regulation of excitatory synaptic transmission at primary afferent synapses with spinal cord substantia gelatinosa neurons. However, no study has reported a role(s) for kainate receptor subtypes in long-term synaptic plasticity phenomena in this region. Using gene-targeted mice lacking glutamate receptor 5 (GLU(K5)) or GLU(K6) subunit, we here show that GLU(K6) subunit, but not GLU(K5) subunit, is involved in the induction of long-term potentiation of excitatory postsynaptic potentials, evoked by two different protocols: (1) high-frequency primary afferent stimulation (100 Hz, 3 s) and (2) low-frequency spike-timing stimulation (1 Hz, 200 pulses). In addition, GLU(K6) subunit plays an important role in the expression of kainate-induced Ca2+ transients in the substantia gelatinosa. On the other hand, genetic deletion of GLU(K5) or GLU(K6) subunit does not prevent the induction of long-term depression. These results indicate that unique expression of kainate receptors subunits is important in regulating spinal synaptic plasticity and thereby processing of sensory information, including pain.
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Affiliation(s)
- Dong-Ho Youn
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
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27
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Abstract
It is well-known that pH changes can influence a lot of cellular processes. In this work, we have specifically studied the influence of alkalinization, which can be developed in spinal cord neurons during hyperventilation (respiratory alkalosis) and chronic renal failure (metabolic alkalosis) on calcium homeostasis. Application of Tyrode solution with increased pH (pH = 8.8) to secondary sensory neurons isolated from rat spinal dorsal horn induced elevation of intracellular free calcium concentration in the cytosol ([Ca2+]i) if applied after membrane depolarization. Repetitive application of alkaline solution led to disappearance of such elevations. Depletion of endoplasmic reticulum (ER) calcium stores by 30 mM caffeine almost completely blocked the effect of elevated extracellular pH. If caffeine-induced [Ca2+]i transients were evoked during alkalinization, their amplitudes were decreased by 41%. Preapplication of 500 nM ionomycin resulted in disappearance of alkalinization-induced [Ca2+]i transients, whereas prolonged applications (for 20 min) of 200 nM thapsigargin, a blocker of Ca2+ ATPase of the endoplasmic reticulum, resulted in disappearance of the rapid phase of the [Ca2+]i transients induced by alkalinization. Preapplication of the mitochondrial protonophore CCCP (10 microM) also induced changes in the alkalinization-induced calcium response--it lost its peak and was transformed into an irregular wave terminating in several seconds. The data obtained indicate that alkalinization induces an increase of [Ca2+]i level in the investigated neurons via a combined action of both intracellular Ca2+-accumulating structures--the endoplasmic reticulum and mitochondria. This suggestion was supported by morphological data that both structures in these neurons are tightly connected and may interact during release of accumulated calcium ions.
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Affiliation(s)
- E Potapenko
- Bogomoletz Institute of Physiology, Kiev 01024, Ukraine
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Voitenko N, Gerber G, Youn D, Randic M. Peripheral inflammation-induced increase of AMPA-mediated currents and Ca2+ transients in the presence of cyclothiazide in the rat substantia gelatinosa neurons. Cell Calcium 2004; 35:461-9. [PMID: 15003855 DOI: 10.1016/j.ceca.2003.11.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2003] [Revised: 09/19/2003] [Accepted: 11/01/2003] [Indexed: 11/23/2022]
Abstract
This study employing a rodent model of acute pain investigated the influence of carrageenan-induced inflammation on the ability of S-alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor activation to induce membrane currents and rises in cytosolic free calcium concentration ([Ca2+]i) in the rat substantia gelatinosa (SG) neurons using simultaneous whole-cell patch-clamp recording and fura-2 calcium imaging in spinal cord slices of L4-L5 segments. The novel finding of this study is that carrageenan-induced inflammation, in the presence of cyclothiazide, an inhibitor of AMPA receptor desensitization, produces a sustained facilitation of the AMPA-mediated membrane current and rises in [Ca2+]i in both the soma and proximal dendrites of SG neurons recorded on the injected side 3 h after the induction of inflammation. These results suggest that in carrageenan-inflamed rats AMPA receptors undergo some alterations that influence AMPA receptors desensitization and/or sensitivity to cyclothiazide.
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Affiliation(s)
- N Voitenko
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA.
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Fedirko N, Vats Y, Kruglikov I, Voitenko N. Role of Ca2+,Mg2+-ATPases in Diabetes-Induced Alterations in Calcium Homeostasis in Input Neurons of the Nociceptive System. NEUROPHYSIOLOGY+ 2004. [DOI: 10.1023/b:neph.0000048339.09774.09] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Kruglikov I, Gryshchenko O, Shutov L, Kostyuk E, Kostyuk P, Voitenko N. Diabetes-induced abnormalities in ER calcium mobilization in primary and secondary nociceptive neurons. Pflugers Arch 2004; 448:395-401. [PMID: 15048576 DOI: 10.1007/s00424-004-1263-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Accepted: 02/23/2004] [Indexed: 10/26/2022]
Abstract
Development of diabetic sensory polyneuropathy is associated with alterations in intracellular calcium homeostasis in primary and secondary nociceptive neurons. We have shown previously that in a model of streptozotocin (STZ)-induced diabetes, the calcium signal is prolonged and calcium release from ryanodine-sensitive calcium stores down-regulated in neurons of the nociceptive system. The aim of the present study was a more detailed characterization of calcium homeostasis in primary (dorsal root ganglia, DRG) and secondary (dorsal horn, DH) nociceptive neurons in STZ-induced diabetes. Fluorescence video-imaging was used to measure free cytosolic [Ca2+] ([Ca2+]i) in lumbar nociceptive neurons of control and streptozotocin-diabetic rats. Resting [Ca2+]i rose progressively in these neurons with the duration of diabetes and calcium mobilization from the endoplasmic reticulum (ER) decreased during diabetes. The amplitude of calcium release from both ryanodine- and IP3-sensitive calcium stores induced by caffeine, ionomycin, ATP or glutamate was significantly (P<0.01) lower in DRG and DH neurons from 6-week STZ-diabetic rats. Diabetes-induced changes in the calcium homeostasis were similar in DRG and DH neurons indicating that they might be general for many types of neurons from the central and peripheral nervous systems.
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Affiliation(s)
- I Kruglikov
- Bogomoletz Institute of Physiology, 4 Bogomoletz St., 01024, Kiev, Ukraine
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Kostyuk P, Potapenko E, Siryk I, Voitenko N, Kostyuk E. Intracellular calcium homeostasis changes induced in rat spinal cord neurons by extracellular acidification. Neurochem Res 2003; 28:1543-7. [PMID: 14570399 DOI: 10.1023/a:1025626526410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Changes in intracellular Ca2+ induced by extracellular acidification to pH = 6 were studied in isolated rat spinal dorsal horn neurons using indo-1 fluorescent technique. In all neurons such treatment induced a decrease of basal [Ca2+]i level by 20.8%, preceded in some of them by temporary increase. The changes were completely reversible. The depolarization-induced [Ca2+]i transients became strongly and also reversibly depressed. If tested after termination of acidification, they demonstrated substantial prolongation of their decay phase, reaching 310% at 120 sec after the application of depolarization. To analyze the mechanisms of such changes, mitochondrial protonophore CCCP has been applied between the end of acidification and the depolarizing pulse. This completely eliminated the described slowing of the transients' decay. To the contrary, application of caffeine to induce Ca2+ release from the endoplasmic reticulum did not show significant changes in the corresponding [Ca2+]i transients. A conclusion is made that in mammalian neurons extracellular acidification, apart from inhibiting voltage-operated Ca2+ channels, also substantially alters the Ca2+ exchange function of mitochondria responsible for rapid accumulation of ions and their delayed release back into the cytosol.
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Affiliation(s)
- P Kostyuk
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine.
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Fedirko N, Kopach O, Kruglikov I, Kostyuk P, Voitenko N. Imaging of [Ca2+] in the Intracellular Calcium Stores of Permeabilized Cells. NEUROPHYSIOLOGY+ 2003. [DOI: 10.1023/b:neph.0000008800.23957.76] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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33
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Shishkin V, Potapenko E, Kostyuk E, Girnyk O, Voitenko N, Kostyuk P. Role of mitochondria in intracellular calcium signaling in primary and secondary sensory neurones of rats. Cell Calcium 2002; 32:121-30. [PMID: 12208232 DOI: 10.1016/s0143-4160(02)00095-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The participation of different calcium-regulated mechanisms in the generation of cytosolic Ca(2+) transients during neuronal excitation has been compared in isolated large and small primary (dorsal root ganglia (DRG)) and secondary (spinal dorsal horn (DH)) rat sensory neurones. As it was shown before in murine primary sensory neurones the application of mitochondrial protonophore CCCP by itself induced only small elevation of [Ca(2+)](i). However, its preceding application substantially increased the peak amplitude of depolarization-induced transients. Application of CCCP immediately after termination of the depolarizing pulse induced in both types of primary neurones a massive release of Ca(2+) from mitochondria into the cytosol. In secondary neurones application of CCCP by itself induced a substantial release of Ca(2+) from the mitochondria, but its preceding application resulted in only an insignificant increase in the peak amplitude of depolarization-triggered calcium transients. Application of CCCP immediately after termination of depolarization elicited a small release of Ca(2+), which became more pronounced when the application was delayed. Preceding application of CCCP increased the amplitude of the transients induced by caffeine-triggered Ca(2+) release from the endoplasmic reticulum in secondary neurones and did not affect those in large primary neurones. These findings may be explained by substantial differences in the density and distribution of mitochondria in the cytosol of primary and secondary sensory neurones. This suggestion was confirmed electronmicroscopically, showing a much lower density of mitochondria near plasmalemma in secondary sensory neurones and predominant clustered location of mitochondria beneath the plasmalemma in the primary cells. The possible functional importance of these differences is discussed.
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Affiliation(s)
- V Shishkin
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Bogomoletz Street 4, Kiev 01024, Ukraine
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34
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Kruglikov I, Shutov L, Potapenko E, Kostyuk P, Voitenko N. NEUROPHYSIOLOGY+ 2002; 34:165-167. [DOI: 10.1023/a:1020782712344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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35
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Shutov L, Kruglikov I, Shishkin V, Borisovskaya M, Kostyuk E, Voitenko N. NEUROPHYSIOLOGY+ 2002; 34:230-232. [DOI: 10.1023/a:1020736224156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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36
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Shishkin V, Potapenko E, Puchkov D, Kostyuk E, Voitenko N, Kostyuk P. NEUROPHYSIOLOGY+ 2002; 34:226-229. [DOI: 10.1023/a:1020784107318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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37
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Fedirko N, Vats J, Klevets M, Kruglikov I, Voitenko N. NEUROPHYSIOLOGY+ 2002; 34:127-129. [DOI: 10.1023/a:1020701921913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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38
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Abstract
Elevations of cytosolic free Ca2+ concentration ([Ca2+]i) induced by addition of ATP have been compared in rat dorsal horn neurones in slices and after their isolation. ATP application induced in neurones in situ a rise of [Ca2+]i by 201 +/- 12 nM. In Ca2+-free external solution the rise was 156 +/- 14 nM (n = 45 of 76), indicating the presence of active purinergic metabotropic receptors in about 59% of neurones. [Ca2+]i transients induced by 2MeSATP in Ca2+-free external solution were completely abolished by 10 microM PPADS, indicating that some of the corresponding receptors are of the P2Y1 type. In acutely isolated neurones which lost their dendrites, there were no metabotropic response. The results confirm the presence of metabotropic postsynaptic purinoreceptors located in the dendritic tree of dorsal horn neurones.
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Affiliation(s)
- I Kruglikov
- Department of General Physiology of Nervous System, Bogomoletz Institute of Physiology, 4, Bogomoletz St., Kiev 01024, Ukraine
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Kostyuk E, Voitenko N, Kruglikov I, Shmigol A, Shishkin V, Efimov A, Kostyuk P. Diabetes-induced changes in calcium homeostasis and the effects of calcium channel blockers in rat and mice nociceptive neurons. Diabetologia 2001; 44:1302-9. [PMID: 11692179 DOI: 10.1007/s001250100642] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS Distal neuropathy is the most common complication of diabetes mellitus, making it important to reveal the cellular mechanisms leading to its development, one of which might be the alteration in intracellular calcium homeostasis in primary and secondary nociceptive neurons. We aimed to investigate these possible changes. METHODS Control and streptozotocin-treated diabetic rats and mice were used. Changes in intracellular free calcium concentrations ([Ca(2+)]i) were measured fluorometrically in primary nociceptive neurons from dorsal root ganglia and in secondary nociceptive neurons from substantia gelatinosa of spinal dorsal horn slices. RESULTS Measurements of [Ca(2+)]i increases induced in dorsal root ganglion and dorsal horn neurons by membrane depolarization did not show any substantial difference in their peak amplitudes in control and diabetic animals. However, a definite prolongation of the decay phase of the transients was observed under diabetic conditions. Caffeine application to dorsal root ganglion and dorsal horn neurons induced a transient elevation of [Ca(2+)]i which was less prominent in cells from diabetic animals. Short-term application of a calcium channel blocker nifedipine showed a substantial amplification of its action in diabetic neurons. However, chronic administration of nimodipine induced a clear increase in the peak values of transients in dorsal root ganglion neurons of diabetic animals compared with those of untreated animals. CONCLUSION/INTERPRETATION The described changes of calcium signalling in nociceptive neurons could be the reason for the development of distal polyneuropathy and its symptoms in the early stages of diabetes mellitus.
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Affiliation(s)
- E Kostyuk
- Institute of Endocrinology, Kiev, Ukraine
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40
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Abstract
ATP receptor-mediated Ca2+ concentration changes were recorded from neocortical neurones in brain slices from 2 week-old rats. To measure the cytoplasmic concentration of Ca2+ ([Ca2+]i) slices were incubated with fura-2/AM, and the microfluorimetry system was focused on an individual cell. During transients the intracellular level of [Ca2+]i in the majority of neocortical neurones (98 of 102) varied in the concentration range of ATP 5-2000 microM between 41. 3+/-5 and 163+/-7 nM. The rank order of efficacy for purinoreceptor agonists in concentration 100 microM was: ATPgammaS>ATP>ADP>>AMP approximately Adenosine approximately alpha,beta-methylene ATP>UTP. 10 microM PPADS, a P2-purinoreceptor antagonist, reduced the ATP-induced [Ca2+]i response by 26%+/-4%. After elimination of calcium from extracellular solution the first ATP-induced [Ca2+]i transient decreased to 65+/-8%, suggesting the participation of metabotropic P2y triggered Ca-release in the generation of the transient. Elevation of cytosolic Ca2+ by activation of plasmalemmal Ca2+ channels failed to potentiate such release indicating the absence of effective reloading of the corresponding stores. No Ca2+-induced Ca2+-release has been observed in the investigated neurons.
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Affiliation(s)
- U Lalo
- Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Bogomoletz St., 4, 252024 Kyiv-24, Ukraine
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Abstract
Changes in neuronal Ca2+ homeostasis were studied on freshly isolated dorsal root ganglion neurons of adult control mice and mice with streptozotocin (STZ)-induced diabetes. The cytoplasmic free Ca2+ concentration ([Ca2+]in) was measured using indo-1 based microfluorimetry. The participation of mitochondria in [Ca2+]in homeostasis was determined by investigation of changes which occurred after addition of mitochondrial protonophore (CCCP) to the extracellular solution. In control cells 10 microM CCCP applied before membrane depolarization induced an increase of the amplitude of depolarization-induced [Ca2+]in transients and disappearance of their delayed recovery, indicating the participation of mitochondria in fast uptake of Ca2+ ions from the cytosol during the peak of the transient and subsequent slow release them back during its decay. In diabetic animals the increase of the peak transient amplitude under the action of CCCP became diminished in small (nociceptive) neurons and the delayed elevation of [Ca2+]in disappeared in both large and small neurons. It is concluded that in diabetic conditions substantial changes occur in the Ca2+ homeostatic functions of mitochondria, manifested by decreased Ca2+ uptake in small neurons and depressed Ca2+ release into the cytosol in all types of neurons.
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Affiliation(s)
- N Svichar
- Bogomoletz Institute of Physiology, Kiev, Ukraine
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42
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Kirischuk S, Matiash V, Kulik A, Voitenko N, Kostyuk P, Verkhratsky A. Activation of P2-purino-, alpha 1-adreno and H1-histamine receptors triggers cytoplasmic calcium signalling in cerebellar Purkinje neurons. Neuroscience 1996; 73:643-7. [PMID: 8809785 DOI: 10.1016/0306-4522(96)00205-9] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The cytoplasmic calcium concentration ([Ca2+]i) was measured from Purkinje neurons in acutely prepared cerebellar slices. Neurons were loaded with calcium indicator Fura-2 by 40-min slice incubation in Tyrode solution containing 5 microM Fura-2/AM and 0.02% pluronic-F127. Bath applications of ATP (100 microM), epinephrine (10 microM) and histamine (100 microM) triggered a transient increase of [Ca2+]i in Purkinje neurons. ATP-induced [Ca2+]i elevation in Purkinje neurons was mimicked by ADP, but not AMP or adenosine pointing to the involvement of P2Y metabotropic purinoreceptors. Epinephrine-triggered [Ca2+]i responses were blocked by the selective alpha 1-antagonist prazosin and were mimicked by the alpha 1-adrenoreceptor agonist phenylephrine, and were not affected by beta- and alpha 2-adrenoreceptor agonists (isoproterenol and clonidine) and antagonists (propranolol and yohimbine). Histamine-induced [Ca2+]i responses demonstrated specific sensitivity to selective H1 antagonist chlorpheniramine, and were not sensitive to H2 and H3 histamine receptors modulators. The [Ca2+]i responses to all three agonists persisted in Ca(2+)-free extracellular media and were blocked by slice preincubation with thapsigargin (500 nM). We conclude that cerebellar Purkinje neurons are endowed with metabotropic P2 gamma purinoreceptors, alpha 1-adrenoreceptors and H1 histamine receptors which mediate the generation of intracellular [Ca2+]i signals via activation of Ca2+ release from inositol-1,4,5-trisphosphate-sensitive intracellular stores.
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Affiliation(s)
- S Kirischuk
- Bogomoletz Institute of Physiology, Kiev, Ukraine
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Kirischuk S, Voitenko N, Kostyuk P, Verkhratsky A. Age-associated changes of cytoplasmic calcium homeostasis in cerebellar granule neurons in situ: investigation on thin cerebellar slices. Exp Gerontol 1996; 31:475-87. [PMID: 9415105 DOI: 10.1016/0531-5565(95)02070-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mechanisms of cytoplasmic calcium homeostasis were investigated in adult and old CBA mice. The cytoplasmic calcium concentration ([Ca2+]i) was measured on fura-2/AM loaded granule neurons in acutely isolated cerebellar slices. The resting [Ca2+]i was significantly higher in senile cerebellar granule neurons, being on average 60 +/- 15 nM (n = 163) in adult and 107 +/- 12 nM (n = 129) in old neurons. The depolarization-induced [Ca2+]i transients were markedly altered in old neurons as compared with adult ones: their amplitude was smaller by about five times, the rate of rise was prolonged about two times, and the complete recovery to the resting level after the end of depolarization was about five times longer. The amplitude of calcium release from caffeine/Ca(2+)-sensitive endoplasmic reticulum calcium stores also become significantly smaller in old neurons (the amplitudes of [Ca2+]i transients evoked by 30 mM caffeine were 75 +/- 27 nM (n = 29) in adult and 25 +/- 10 nM (n = 23) in old neurons). We conclude that neuronal aging is associated with prominent changes in the mechanisms responsible for [Ca2+]i regulation. These changes presumably include lowering of voltage-gated plasmalemmal Ca2+ influx and slowing down of Ca2+ extrusion from the cytoplasm.
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Abstract
The cytoplasmic free calcium concentration ([Ca2+]i) was studied in Fura-2/AM loaded granule neurones in acutely prepared cerebellar slices isolated from neonatal (6 days old) and adult (30 days old) mice. Bath application of elevated (10-50 mM) KCl-containing extracellular solutions evoked [Ca2+]i rise which was dependent on extracellular Ca2+. The K(+)-induced [Ca2+]i elevation was inhibited to different extends by verapamil, nickel and omega-conotoxin suggesting the coexpression of different subtypes of plasmalemmal voltage-gated Ca2+ channels. Bath application of caffeine (10-40 mM) elevated [Ca2+]i by release of Ca2+ from intracellular stores. Caffeine-induced [Ca2+]i elevation was inhibited by 100 microM ryanodine and 500 nM thapsigargin. Depletion of internal Ca2+ stores by caffeine, or blockade of Ca2+ release channels by ryanodine, did not affect depolarization-induced [Ca2+]i transients, suggesting negligible involvement of Ca(2+)-induced Ca2+ release in [Ca2+]i signal generation following cell depolarization. External application of 100 microM glutamate, but not acetylcholine (1-100 microM), carbachol (10-100 microM) or (1S,3R)-ACPD (100-500 microM) evoked [Ca2+]i elevation. Part of glutamate-triggered [Ca2+]i transients in neurones from neonatal mice was due to Ca2+ release (presumably via inositol-(1,4,5)-trisphosphate-sensitive mechanisms) from internal Ca2+ stores. In adult animals, glutamate-triggered [Ca2+]i elevation was exclusively associated with plasmalemmal Ca2+ influx via both voltage-gated and glutamate-gated channels.
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Affiliation(s)
- S Kirischuk
- Bogomoletz Institute of Physiology and International Centre of Molecular Physiology, Kiev, Ukraine
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45
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Kirischuk S, Möller T, Voitenko N, Kettenmann H, Verkhratsky A. ATP-induced cytoplasmic calcium mobilization in Bergmann glial cells. J Neurosci 1995; 15:7861-71. [PMID: 8613725 PMCID: PMC6577954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
ATP receptor mediated Ca2+ signaling was recorded from Bergmann glial cells in cerebellar slices obtained from mice of different ages (postnatal days 6 to 45). To measure the cytoplasmic concentration of Ca2+ ([Ca2+]in), either individual cells were loaded with the Ca(2+)-sensitive probes using the whole cell patch clamp technique or slices were incubated with the dye and the microfluorimetric system was focused on individual cells. Signals were recorded either with single-detector microfluorimetry of the dye fura-2 or by confocal laser scanning microfluorimetry (fluo-3-based recordings). Extracellular application of 100 microns ATP caused a transient elevation of [Ca2+]in, which amplitude was significantly higher in Bergmann glial cell processes as compared with their soma. The rank order of potency for the purinoreceptor agonists was: ADP > or = ATP > UTP >> AMP = adenosine = alpha, beta-methylene-ATP. ATP-triggered Ca2+ transients were reversibly inhibited by the P2 purinoreceptor agonist suramin (100 microM). The involvement of P2 metabotropic receptors is inferred by the observation that ATP mediated cytoplasmic Ca2+ transients were not associated with a measurable change in membrane conductance. The [Ca2+]in increase was due to release from inositol-1,4,5-trisphosphate (InsP3)-sensitive intracellular stores since responses were still observed in Ca(2+)-free extracellular solutions and were irreversibly blocked by the inhibitor of the sarco(endo)plasmic reticulum Ca2+ ATPase, thapsigargin, and by the competitive inhibitor of the InsP3-gated intracellular Ca2+ channels heparin. Intracellular dialysis altered the refilling process of the InsP3-sensitive stores, suggesting that cytoplasmic factors control ATP mediated Ca2+ signalling.
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Affiliation(s)
- S Kirischuk
- Bogomoletz Institute of Physiology, Kiev-24, Ukraine
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