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Haddad M, Khazali H, Janahmadi M, Ghanbarian H. The differential effects of blocking retinal orexin receptors on the expression of retinal c-fos and hypothalamic Vip, PACAP, Bmal1, and c-fos in Male Wistar Rats. Exp Eye Res 2024; 244:109943. [PMID: 38797259 DOI: 10.1016/j.exer.2024.109943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 05/18/2024] [Accepted: 05/23/2024] [Indexed: 05/29/2024]
Abstract
Orexin A and B (OXA and OXB) and their receptors are expressed in the majority of retinal neurons in humans, rats, and mice. Orexins modulate signal transmission between the different layers of the retina. The suprachiasmatic nucleus (SCN) and the retina are central and peripheral components of the body's biological clocks; respectively. The SCN receives photic information from the retina through the retinohypothalamic tract (RHT) to synchronize bodily functions with environmental changes. In present study, we aimed to investigate the impact of inhibiting retinal orexin receptors on the expression of retinal Bmal1 and c-fos, as well as hypothalamic c-fos, Bmal1, Vip, and PACAP at four different time-points (Zeitgeber time; ZT 3, 6, 11, and ZT-0). The intravitreal injection (IVI) of OX1R antagonist (SB-334867) and OX2R antagonist (JNJ-10397049) significantly up-regulated c-fos expression in the retina. Additionally, compared to the control group, the combined injection of SB-334867 and JNJ-10397049 showed a greater increase in retinal expression of this gene. Moreover, the expression of hypothalamic Vip and PACAP was significantly up-regulated in both the SB-334867 and JNJ-10397049 groups. In contrast, the expression of Bmal1 was down-regulated. Furthermore, the expression of hypothalamic c-fos was down-regulated in all groups treated with SB-334867 and JNJ-10397049. Additionally, the study demonstrated that blocking these receptors in the retina resulted in alterations in circadian rhythm parameters such as mesor, amplitude, and acrophase. Finally, it affected the phase of gene expression rhythms in both the retina and hypothalamus, as identified through cosinor analysis and the zero-amplitude test. This study represents the initial exploration of how retinal orexin receptors influence expression of rhythmic genes in the retina and hypothalamus. These findings could provide new insights into how the retina regulates the circadian rhythm in both regions and illuminate the role of the orexinergic system expression within the retina.
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Affiliation(s)
- Muhammad Haddad
- Department of Zoology, Faculty of Sciences, Aleppo University, Aleppo, Syria; Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
| | - Homayoun Khazali
- Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
| | - Mahyar Janahmadi
- Department of Physiology and Neuroscience, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Ghanbarian
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Haddad M, Khazali H, Janahmadi M, Ghanbarian H. Inhibition of the retinal orexin receptors affects the hypothalamic-pituitary-gonadal axis through retinal pituitary adenylate cyclase activating polypeptide (PACAP) in male Wistar rats. Gen Comp Endocrinol 2023; 337:114242. [PMID: 36801394 DOI: 10.1016/j.ygcen.2023.114242] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/08/2023] [Accepted: 02/15/2023] [Indexed: 02/19/2023]
Abstract
Orexins A and B (OXA and OXB) and their receptors are expressed in the retina of both human and rodents and play a vital role in regulating signal transmission circuits in the retina. There is an anatomical-physiological relationship between the retinal ganglion cells and suprachiasmatic nucleus (SCN) through glutamate as a neurotransmitter and retinal pituitary adenylate cyclase-activating polypeptide (PACAP) as a co-transmitter. SCN is the main brain center for regulating the circadian rhythm, which governs the reproductive axis. The impact of retinal orexin receptors on the hypothalamic-pituitary-gonadal axis has not been investigated. Retinal OX1R or/and OX2R in adult male rats by 3 µl of SB-334867 (1 µg) or/and 3 µl of JNJ-10397049 (2 µg) were antagonized via intravitreal injection (IVI). Four time-periods were considered (3, 6, 12, and 24 h) for the controls without any treatment, SB-334867, JNJ-10397049, and SB-334867 + JNJ-10397049 groups. Antagonizing retinal OX1R or/and OX2R resulted in a significant elevation of retinal PACAP expression compared to control animals. In addition, expression of GnRH increased non-significantly in the hypothalamus over the 6 h of the study, and the serum concentration of LH decreased significantly in the SB-334867 group after 3 h of injection. Furthermore, testosterone serum levels declined significantly, especially within 3 h of injection; serum levels of progesterone were also exposed to a significant rise at least within 3 h of injection. However, the retinal PACAP expression changes were mediated by OX1R more effectively than by OX2R. In this study, we report the retinal orexins and their receptors as light-independent factors by which the retina affects the hypothalamic-pituitary-gonadal axis.
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Affiliation(s)
- Muhammad Haddad
- Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran
| | - Homayoun Khazali
- Department of Animal Sciences and Marine Biology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran.
| | - Mahyar Janahmadi
- Neuroscience Research Center and Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Hossein Ghanbarian
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Li Y, Yang XY, Jin N, Zhen C, Zhu SY, Chu WY, Zhang HH, Xu AP, Wu J, Wang MY, Zheng C. Activation of M 3-AChR and IP 3/Ca 2+/PKC signaling pathways by pilocarpine increases glycine-induced currents in ventral horn neurons of the spinal cord. Neurosci Lett 2022; 782:136690. [PMID: 35598692 DOI: 10.1016/j.neulet.2022.136690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/14/2022] [Accepted: 05/16/2022] [Indexed: 02/05/2023]
Abstract
Our study aimed to determine the effects of pilocarpine and the mechanisms involving muscarinic acetylcholine receptors (mAChRs) on glycine receptors (GlyRs) in neurons of the spinal cord ventral horn. An enzymatic digestion combined with acute mechanical separation was applied to isolate neurons from the spinal cord ventral horn. Patch-clamp recording was then used to investigate the outcomes of pilocarpine. Our results indicate that pilocarpine increased the glycine currents in a concentration-dependent manner, which was blocked by the M3-AChR selective antagonists 4-DAMP and J104129. Pilocarpine also enhanced the glycine currents in nominally Ca2+-free extracellular solution. Conversely, the enhancement of glycine currents by pilocarpine disappeared when intracellular Ca2+ was chelated by BAPTA. Heparin and Xe-C, which are IP3 receptor antagonists, also totally abolished the pilocarpine effect. Furthermore, Bis-IV, a PKC inhibitor, eliminated the pilocarpine effect. Additionally, PMA, a PKC activator, mimicked the pilocarpine effect. These results indicate that pilocarpine may increase the glycine currents by activating the M3-AChRs and IP3/Ca2+/PKC pathways.
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Affiliation(s)
- Yan Li
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Xin-Yu Yang
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Na Jin
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Cheng Zhen
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Su-Yue Zhu
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Wan-Yu Chu
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Huan-Huan Zhang
- Psychophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Ai-Ping Xu
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Jie Wu
- Laboratory of Brain Function and Diseases, Shantou University Medical College, Shantou, Guangdong 515041, China
| | - Meng-Ya Wang
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
| | - Chao Zheng
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui 241002, China
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Zhang T, Ruan HZ, Wang YC, Shao YQ, Zhou W, Weng SJ, Zhong YM. Signaling Mechanism for Modulation by GLP-1 and Exendin-4 of GABA Receptors on Rat Retinal Ganglion Cells. Neurosci Bull 2022; 38:622-636. [PMID: 35278196 PMCID: PMC9206055 DOI: 10.1007/s12264-022-00826-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/10/2021] [Indexed: 11/29/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) is expressed in retinal neurons, but its role in the retina is largely unknown. Here, we demonstrated that GLP-1 or the GLP-1 receptor (GLP-1R; a G protein-coupled receptor) agonist exendin-4 suppressed γ-aminobutyric acid receptor (GABAR)-mediated currents through GLP-1Rs in isolated rat retinal ganglion cells (GCs). Pre-incubation with the stimulatory G protein (Gs) inhibitor NF 449 abolished the exendin-4 effect. The exendin-4-induced suppression was mimicked by perfusion with 8-Br-cAMP (a cAMP analog), but was eliminated by the protein kinase A (PKA) inhibitor Rp-cAMP/KT-5720. The exendin-4 effect was accompanied by an increase in [Ca2+]i of GCs through the IP3-sensitive pathway and was blocked in Ca2+-free solution. Furthermore, when the activity of calmodulin (CaM) and CaM-dependent protein kinase II (CaMKII) was inhibited, the exendin-4 effect was eliminated. Consistent with this, exendin-4 suppressed GABAR-mediated light-evoked inhibitory postsynaptic currents in GCs in rat retinal slices. These results suggest that exendin-4-induced suppression may be mediated by a distinct Gs/cAMP-PKA/IP3/Ca2+/CaM/CaMKII signaling pathway, following the activation of GLP-1Rs.
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Affiliation(s)
- Tao Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Hang-Ze Ruan
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yong-Chen Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yu-Qi Shao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Wei Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Shi-Jun Weng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yong-Mei Zhong
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
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Yang X, Zhu S, Jin N, Li Y, Zhen C, Zhang H, Xu A, Wang M, Zheng C. [Orexin-A inhibits γ-aminobutyric acid current of neonatal rat spinal cord ventral horn neurons by activating OX 1R, OX 2R and Ca 2+-independent PKC]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2021; 41:694-701. [PMID: 34134956 DOI: 10.12122/j.issn.1673-4254.2021.05.09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To investigate the effect of orexin-A on the functionality of ionotropic γ-aminobutyric acid (GABA) receptors in spinal cord ventral horn neurons and its mechanisms. OBJECTIVE The spinal cord containing the lumbosacral enlargement was isolated from neonatal SD rats (7-12 days old) and sliced. The slices were digested with papain (in 0.18 g/30 mL artificial cerebrospinal fluid) for 40-60 min, and the ventral horn neurons were separated acutely using fire-polished Pasteur pipettes. After the cells adhered to the bottom of Petri dishes, patch-clamp experiments combined with pharmacological methods were performed to test the effects of orexin-A on GABA currents of the neurons treated with SB334867 (a selective OX1R antagonist), TCSOX229 (a selective OX2R antagonist), Bis-Ⅳ (a PKC inhibitor), PMA (a PKC agonist), Rp-cAMP (a PKA inhibitor), or BAPTA (Ca2+ chelator). OBJECTIVE The isolated neurons maintained good morphologies with diverse shapes of cell body and long protrusions. Treatment with orexin-A significantly inhibited the amplitude of GABA-induced current (P < 0.001, n=49) with an inhibition rate of (67.48±12.50)%. SB334867 and TCSOX229, when applied simultaneously, completely abolished the suppressive effect of orexin-A on the GABA currents (P=0.93, n=6), and their separate use partially relieved the suppressive effect of orexin-A (P=0.001, n=8; P=0.02, n=8). The application of Bis-Ⅳ also abolished the suppressive effect of orexin-A on GABA currents (P=0.31, n=5). PMA mimicked the effect of orexin-A in these neurons and significantly inhibited GABA currents with an inhibition rate of (60.79±10.94)%, and the application of orexin-A did not cause further suppression of GABA currents in PMA-treated neurons (P=0.15, n=6). Orexin-A was still capable of suppressing GABA currents in Rp-cAMP-treated neurons (P=0.001, n=5). The extracellular Ca2+-free solution (P=0.004, n=8) or the presence of BAPTA (P=0.04, n=7) did not significantly affect the inhibitory effect of orexin-A on GABA currents. OBJECTIVE Orexin-A inhibits GABA currents in the ventral horn neurons of rat spinal cord probably by activating OX1R, OX2R and Ca2+-independent PKC.
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Affiliation(s)
- X Yang
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - S Zhu
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - N Jin
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - Y Li
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - C Zhen
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China.,Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - H Zhang
- Psychophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - A Xu
- Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - M Wang
- Cell Electrophysiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
| | - C Zheng
- Neurobiology Laboratory, Institute of Physiological Sciences, Wannan Medical College, Wuhu 241002, China
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Orexin-A differentially modulates inhibitory and excitatory synaptic transmission in rat inner retina. Neuropharmacology 2021; 187:108492. [PMID: 33582153 DOI: 10.1016/j.neuropharm.2021.108492] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/08/2021] [Accepted: 02/06/2021] [Indexed: 11/21/2022]
Abstract
In this work, modulation by orexin-A of the release of glutamate and GABA from bipolar and amacrine cells respectively was studied by examining the effects of the neuropeptide on miniature excitatory postsynaptic currents (mEPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) of rat retinal ganglion cells (GCs). Using RNAscope in situ hybridization in combination with immunohistochemistry, we showed positive signals for orexin receptor-1 (OX1R) mRNA in the bipolar cell terminals and those for orexin receptor-2 (OX2R) mRNA in the amacrine cell terminals. With whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that application of orexin-A reduced the interevent interval of mEPSCs of GCs through OX1R. However, it increased the interevent interval of mIPSCs, mediated by GABAA receptors, through OX2R. Furthermore, orexin-A-induced reduction of mEPSC interevent interval was abolished by the application of PI-PLC inhibitors or PKC inhibitors. In contrast, orexin-A-induced increase of GABAergic mIPSC interevent interval was mimicked by 8-Br-cAMP or an adenylyl cyclase activator, but was eliminated by PKA antagonists. Finally, application of nimodipine, an L-type Ca2+ channel blocker, increased both mEPSC and mIPSC interevent interval, and co-application of orexin-A no longer changed the mEPSCs and mIPSCs. We conclude that orexin-A increases presynaptic glutamate release onto GCs by activating L-type Ca2+ channels in bipolar cells, a process that is mediated by an OX1R/PI-PLC/PKC signaling pathway. However, orexin-A decreases presynaptic GABA release onto GCs by inhibiting L-type Ca2+ channels in amacrine cells, a process that is mediated by an OX2R/cAMP-PKA signaling pathway.
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Orexin-A Intensifies Mouse Pupillary Light Response by Modulating Intrinsically Photosensitive Retinal Ganglion Cells. J Neurosci 2021; 41:2566-2580. [PMID: 33536197 DOI: 10.1523/jneurosci.0217-20.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 01/16/2021] [Accepted: 01/22/2021] [Indexed: 12/24/2022] Open
Abstract
We show for the first time that the neuropeptide orexin modulates pupillary light response, a non-image-forming visual function, in mice of either sex. Intravitreal injection of the orexin receptor (OXR) antagonist TCS1102 and orexin-A reduced and enhanced pupillary constriction in response to light, respectively. Orexin-A activated OX1Rs on M2-type intrinsically photosensitive retinal ganglion cells (M2 cells), and caused membrane depolarization of these cells by modulating inward rectifier potassium channels and nonselective cation channels, thus resulting in an increase in intrinsic excitability. The increased intrinsic excitability could account for the orexin-A-evoked increase in spontaneous discharges and light-induced spiking rates of M2 cells, leading to an intensification of pupillary constriction. Orexin-A did not alter the light response of M1 cells, which could be because of no or weak expression of OX1Rs on them, as revealed by RNAscope in situ hybridization. In sum, orexin-A is likely to decrease the pupil size of mice by influencing M2 cells, thereby improving visual performance in awake mice via enhancing the focal depth of the eye's refractive system.SIGNIFICANCE STATEMENT This study reveals the role of the neuropeptide orexin in mouse pupillary light response, a non-image-forming visual function. Intravitreal orexin-A administration intensifies light-induced pupillary constriction via increasing the excitability of M2 intrinsically photosensitive retinal ganglion cells by activating the orexin receptor subtype OX1R. Modulation of inward rectifier potassium channels and nonselective cation channels were both involved in the ionic mechanisms underlying such intensification. Orexin could improve visual performance in awake mice by reducing the pupil size and thereby enhancing the focal depth of the eye's refractive system.
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Jin N, Zhu SY, Yang XY, Zhen C, Li Y, Zhang HH, Xu AP, Wang MY, Zheng C. Orexin-A potentiates glycine currents by activating OX 1R and IP 3/Ca 2+/PKC signaling pathways in spinal cord ventral horn neurons. Brain Res Bull 2021; 169:196-204. [PMID: 33515654 DOI: 10.1016/j.brainresbull.2021.01.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/25/2020] [Accepted: 01/22/2021] [Indexed: 11/30/2022]
Abstract
Orexin-A/B modulates multiple physical functions by activating their receptors (OX1R and OX2R), but its effects in the spinal cord motor control remain unknown. Using acute separation (by digestive enzyme) of cells and patch-clamp recordings, we aimed to investigate the effect and mechanisms of orexin-A on the glycine receptors in the spinal cord ventral horn neurons. Orexin-A potentiated the glycine currents by activating OX1R. In Ca2+-free extracellular solution, orexin-A still increased the glycine currents. While, the orexin-A-induced potentiation was blocked when Ca2+ was chelated by internal infusion of BAPTA, and the orexin-A effect was abolished by the IP3 receptor antagonists heparin and Xe-C. The PKC inhibitor Bis-IV nullified the orexin-A effect. In addition, orexin-A did not cause a further enhancement of the glycine currents after bath application of the PKC activator PMA. In conclusion, after OX1R is activated, a distinct IP3/Ca2+-dependent PKC signaling pathway, is likely responsible for the orexin-A potentiation on glycine currents in the spinal cord ventral horn neurons.
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Affiliation(s)
- Na Jin
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China
| | - Su-Yue Zhu
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China
| | - Xin-Yu Yang
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China
| | - Cheng Zhen
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China
| | - Yan Li
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China; Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China
| | - Huan-Huan Zhang
- Psychophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China
| | - Ai-Ping Xu
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China
| | - Meng-Ya Wang
- Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China.
| | - Chao Zheng
- Neurobiology Laboratory, Wannan Medical College, Wuhu, Anhui, 241002, China.
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Kong T, Qiu K, Liu M, Cheng B, Pan Y, Yang C, Chen J, Wang C. Orexin-A protects against oxygen-glucose deprivation/reoxygenation-induced cell damage by inhibiting endoplasmic reticulum stress-mediated apoptosis via the Gi and PI3K signaling pathways. Cell Signal 2019; 62:109348. [DOI: 10.1016/j.cellsig.2019.109348] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 10/26/2022]
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Choi B, Lee HW, Mo S, Kim JY, Kim HW, Rhyu IJ, Hong E, Lee YK, Choi JS, Kim CH, Kim H. Inositol 1,4,5-trisphosphate 3-kinase A overexpressed in mouse forebrain modulates synaptic transmission and mGluR-LTD of CA1 pyramidal neurons. PLoS One 2018; 13:e0193859. [PMID: 29617377 PMCID: PMC5884490 DOI: 10.1371/journal.pone.0193859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/20/2018] [Indexed: 11/18/2022] Open
Abstract
Inositol 1,4,5-trisphosphate 3-kinase A (IP3K-A) regulates the level of the inositol polyphosphates, inositol trisphosphate (IP3) and inositol tetrakisphosphate to modulate cellular signaling and intracellular calcium homeostasis in the central nervous system. IP3K-A binds to F-actin in an activity-dependent manner and accumulates in dendritic spines, where it is involved in the regulation of synaptic plasticity. IP3K-A knockout mice exhibit deficits in some forms of hippocampus-dependent learning and synaptic plasticity, such as long-term potentiation in the dentate gyrus synapses of the hippocampus. In the present study, to further elucidate the role of IP3K-A in the brain, we developed a transgenic (Tg) mouse line in which IP3K-A is conditionally overexpressed approximately 3-fold in the excitatory neurons of forebrain regions, including the hippocampus. The Tg mice showed an increase in both presynaptic release probability of evoked responses, along with bigger synaptic vesicle pools, and miniature excitatory postsynaptic current amplitude, although the spine density or the expression levels of the postsynaptic density-related proteins NR2B, synaptotagmin 1, and PSD-95 were not affected. Hippocampal-dependent learning and memory tasks, including novel object recognition and radial arm maze tasks, were partially impaired in Tg mice. Furthermore, (R,S)-3,5-dihydroxyphenylglycine-induced metabotropic glutamate receptor long-term depression was inhibited in Tg mice and this inhibition was dependent on protein kinase C but not on the IP3 receptor. Long-term potentiation and depression dependent on N-methyl-d-aspartate receptor were marginally affected in Tg mice. In summary, this study shows that overexpressed IP3K-A plays a role in some forms of hippocampus-dependent learning and memory tasks as well as in synaptic transmission and plasticity by regulating both presynaptic and postsynaptic functions.
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Affiliation(s)
- Byungil Choi
- Department of Anatomy, College of Medicine, Korea University, Brain Korea, Seoul, Korea
| | - Hyun Woo Lee
- Department of Anatomy, College of Medicine, Korea University, Brain Korea, Seoul, Korea
| | - Seojung Mo
- Department of Anatomy, College of Medicine, Korea University, Brain Korea, Seoul, Korea
| | - Jin Yong Kim
- Department of Anatomy, College of Medicine, Korea University, Brain Korea, Seoul, Korea
| | - Hyun Wook Kim
- Department of Anatomy, College of Medicine, Korea University, Brain Korea, Seoul, Korea
| | - Im Joo Rhyu
- Department of Anatomy, College of Medicine, Korea University, Brain Korea, Seoul, Korea
| | - Eunhwa Hong
- Department of Psychology, Korea University, Seoul, Korea
| | - Yeon Kyung Lee
- Department of Psychology, Korea University, Seoul, Korea
| | - June-Seek Choi
- Department of Psychology, Korea University, Seoul, Korea
| | - Chong-Hyun Kim
- Center for Neuroscience, Brain Science Institute, Korea Institute of Science and Technology and Neuroscience Program, Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul, Korea
- * E-mail: (C-HK); (HK)
| | - Hyun Kim
- Department of Anatomy, College of Medicine, Korea University, Brain Korea, Seoul, Korea
- * E-mail: (C-HK); (HK)
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Orexin-B modulates synaptic transmission of rod bipolar cells in rat retina. Neuropharmacology 2018; 133:38-50. [PMID: 29325900 DOI: 10.1016/j.neuropharm.2018.01.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/31/2017] [Accepted: 01/04/2018] [Indexed: 12/16/2022]
Abstract
Orexin-A, -B play a crucial role in arousal and feeding by activating two G-protein-coupled receptors: orexin receptor 1 (OX1R) and orexin receptor 2 (OX2R). Orexins, along with orexin receptors, are expressed in retinal neurons, and they have been shown to differentially modulate excitatory AMPA receptors of amacrine and ganglion cells in the inner retina. In this work we report that orexin-B modulates the activity of rod bipolar cells (RBCs) located in the outer retina of rat. Intravitreal injection of orexin-B increased the amplitude of the scotopic electroretinographic b-wave, a reflection of RBC activity, recorded in vivo. Patch clamp recordings in rat retinal slices showed that orexin-B did not change glutamatergic excitatory component of the RBC response driven by photoreceptors. Effects of orexin-B on GABA receptor-mediated synaptic transmission of RBCs were then examined. In retinal slice preparations orexin-B suppressed GABA receptor-mediated inhibitory postsynaptic currents of RBCs in the inner plexiform layer. Furthermore, using whole-cell recordings in isolated RBCs it was shown that orexin-B suppressed GABAC receptor-, but not GABAA receptor-, mediated currents of the RBCs, an effect that was blocked by OX1R and OX2R antagonists. The orexin-B-induced inhibition of GABAC currents was likely mediated by a Gi/o/PC-PLC/Ca2+-independent PKC signaling pathway, as such inhibition was absent when each step of the above-pathway was blocked with GDP-β-S/pertussis toxin (for Gi/o), D609 (for PLC), bisindolylmaleimide IV (for PKC)/rottlerin (for PKCδ), respectively. The orexin-B-induced potentiation of RBC activity may improve visual acuity and contrast sensitivity of the animal during the dark period (wake phase).
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Qiao SN, Zhou W, Liu LL, Zhang DQ, Zhong YM. Orexin-A Suppresses Signal Transmission to Dopaminergic Amacrine Cells From Outer and Inner Retinal Photoreceptors. Invest Ophthalmol Vis Sci 2017; 58:4712-4721. [PMID: 28910447 PMCID: PMC5598320 DOI: 10.1167/iovs.17-21835] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Purpose The neuropeptides orexin-A and orexin-B are widely expressed in the vertebrate retina; however, their role in visual function is unclear. This study investigates whether and how orexins modulate signal transmission to dopaminergic amacrine cells (DACs) from both outer retinal photoreceptors (rods and cones) and inner retinal photoreceptors (melanopsin-expressing intrinsically photosensitive retinal ganglion cells [ipRGCs]). Methods A whole-cell voltage-clamp technique was used to record light-induced responses from genetically labeled DACs in flat-mount mouse retinas. Rod and cone signaling to DACs was confirmed pharmacologically (in wild-type retinas), whereas retrograde melanopsin signaling to DACs was isolated either pharmacologically (in wild-type retinas) or by genetic deletion of rod and cone function (in transgenic mice). Results Orexin-A attenuated rod/cone-mediated light responses in the majority of DACs and inhibited all DACs that exhibited melanopsin-based light responses, suggesting that exogenous orexin suppresses signal transmission from rods, cones, and ipRGCs to DACs. In addition, orexin receptor 1 antagonist SB334867 and orexin receptor 2 antagonist TCS OX229 enhanced melanopsin-based DAC responses, indicating that endogenous orexins inhibit signal transmission from ipRGCs to DACs. We further found that orexin-A inhibits melanopsin-based DAC responses via orexin receptors on DACs, whereas orexin-A may modulate signal transmission from rods and cones to DACs through activation of orexin receptors on DACs and their upstream neurons. Conclusions Our results suggest that orexins could influence visual function via the dopaminergic system in the mammalian retina.
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Affiliation(s)
- Sheng-Nan Qiao
- Institutes of Brain Science, Fudan University, Shanghai, China.,Eye Research Institute, Oakland University, Rochester, Michigan, United States
| | - Wei Zhou
- Institutes of Brain Science, Fudan University, Shanghai, China
| | - Lei-Lei Liu
- Eye Research Institute, Oakland University, Rochester, Michigan, United States
| | - Dao-Qi Zhang
- Eye Research Institute, Oakland University, Rochester, Michigan, United States
| | - Yong-Mei Zhong
- Institutes of Brain Science, Fudan University, Shanghai, China.,State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China.,Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
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Orexin-A promotes Glu uptake by OX1R/PKCα/ERK1/2/GLT-1 pathway in astrocytes and protects co-cultured astrocytes and neurons against apoptosis in anoxia/hypoglycemic injury in vitro. Mol Cell Biochem 2016; 425:103-112. [DOI: 10.1007/s11010-016-2866-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 11/02/2016] [Indexed: 12/31/2022]
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14
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Deng QQ, Sheng WL, Zhang G, Weng SJ, Yang XL, Zhong YM. Signalling mechanism for somatostatin receptor 5-mediated suppression of AMPA responses in rat retinal ganglion cells. Neuropharmacology 2016; 107:215-226. [DOI: 10.1016/j.neuropharm.2016.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 01/25/2016] [Accepted: 03/02/2016] [Indexed: 01/21/2023]
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Activation of the sigma receptor 1 modulates AMPA receptor-mediated light-evoked excitatory postsynaptic currents in rat retinal ganglion cells. Neuroscience 2016; 332:53-60. [PMID: 27373906 DOI: 10.1016/j.neuroscience.2016.06.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 06/15/2016] [Accepted: 06/24/2016] [Indexed: 11/20/2022]
Abstract
Sigma receptor (σR), a unique receptor family, is classified into three subtypes: σR1, σR2 and σR3. It was previously shown that σR1 activation induced by 1μM SKF10047 (SKF) suppressed N-methyl-d-aspartate (NMDA) receptor-mediated responses of rat retinal ganglion cells (GCs) and the suppression was mediated by a distinct Ca(2+)-dependent phospholipase C (PLC)-protein kinase C (PKC) pathway. In the present work, using whole-cell patch-clamp techniques in rat retinal slice preparations, we further demonstrate that SKF of higher dosage (50μM) significantly suppressed AMPA receptor (AMPAR)-mediated light-evoked excitatory postsynaptic currents (L-EPSCs) of retinal ON-type GCs (ON GCs), and the effect was reversed by the σR1 antagonist BD1047, suggesting the involvement of σR1. The SKF (50μM) effect was unlikely due to a change in glutamate release from bipolar cells, as suggested by the unaltered paired-pulse ratio (PPR) of AMPAR-mediated EPSCs of ON GCs. SKF (50μM) did not change L-EPSCs of ON GCs when the G protein inhibitor GDP-β-S or the protein kinase G (PKG) inhibitor KT5823 was intracellularly infused. Calcium imaging further revealed that SKF (50μM) did not change intracellular calcium concentration in GCs and persisted to suppress L-EPSCs when intracellular calcium was chelated by BAPTA. The SKF (50μM) effect was intact when protein kinase A (PKA) and phosphatidylinostiol (PI)-PLC signaling pathways were both blocked. We conclude that the SKF (50μM) effect is Ca(2+)-independent, PKG-dependent, but not involving PKA, PI-PLC pathways.
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Zhang PP, Zhang G, Zhou W, Weng SJ, Yang XL, Zhong YM. Signaling mechanism for modulation by ATP of glycine receptors on rat retinal ganglion cells. Sci Rep 2016; 6:28938. [PMID: 27357477 PMCID: PMC4928062 DOI: 10.1038/srep28938] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 06/13/2016] [Indexed: 12/30/2022] Open
Abstract
ATP modulates voltage- and ligand-gated channels in the CNS via the activation of ionotropic P2X and metabotropic P2Y receptors. While P2Y receptors are expressed in retinal neurons, the function of these receptors in the retina is largely unknown. Using whole-cell patch-clamp techniques in rat retinal slice preparations, we demonstrated that ATP suppressed glycine receptor-mediated currents of OFF type ganglion cells (OFF-GCs) dose-dependently, and the effect was in part mediated by P2Y1 and P2Y11, but not by P2X. The ATP effect was abolished by intracellular dialysis of a Gq/11 protein inhibitor and phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor, but not phosphatidylcholine (PC)-PLC inhibitor. The ATP effect was accompanied by an increase in [Ca(2+)]i through the IP3-sensitive pathway and was blocked by intracellular Ca(2+)-free solution. Furthermore, the ATP effect was eliminated in the presence of PKC inhibitors. Neither PKA nor PKG system was involved. These results suggest that the ATP-induced suppression may be mediated by a distinct Gq/11/PI-PLC/IP3/Ca(2+)/PKC signaling pathway, following the activation of P2Y1,11 and other P2Y subtypes. Consistently, ATP suppressed glycine receptor-mediated light-evoked inhibitory postsynaptic currents of OFF-GCs. These results suggest that ATP may modify the ON-to-OFF crossover inhibition, thus changing action potential patterns of OFF-GCs.
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Affiliation(s)
- Ping-Ping Zhang
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Gong Zhang
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Wei Zhou
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Shi-Jun Weng
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Xiong-Li Yang
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Yong-Mei Zhong
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
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Liu F, Weng SJ, Yang XL, Zhong YM. Orexin-A potentiates L-type calcium/barium currents in rat retinal ganglion cells. Neuroscience 2015; 305:225-37. [PMID: 26259903 DOI: 10.1016/j.neuroscience.2015.08.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/27/2015] [Accepted: 08/04/2015] [Indexed: 01/07/2023]
Abstract
Two neuropeptides, orexin-A and orexin-B (also called hypocretin-1 and -2), have been implicated in sleep/wake regulation, feeding behaviors via the activation of two subtypes of G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). While the expression of orexins and orexin receptors is immunohistochemically revealed in retinal neurons, the function of these peptides in the retina is largely unknown. Using whole-cell patch-clamp recordings in rat retinal slices, we demonstrated that orexin-A increased L-type-like barium currents (IBa,L) in ganglion cells (GCs), and the effect was blocked by the selective OX1R antagonist SB334867, but not by the OX2R antagonist TCS OX2 29. The orexin-A effect was abolished by intracellular dialysis of GDP-β-S/GPAnt-2A, a Gq protein inhibitor, suggesting the mediation of Gq. Additionally, during internal dialysis of the phosphatidylinositol (PI)-phospholipase C (PLC) inhibitor U73122, orexin-A did not change the IBa,L of GCs, whereas the orexin-A effect persisted in the presence of the phosphatidylcholine (PC)-PLC inhibitor D609. The orexin-A-induced potentiation was not seen with internal infusion of Ca(2+)-free solution or when inositol 1,4,5-trisphosphate (IP3)-sensitive Ca(2+) release from intracellular stores was blocked by heparin/xestospongins-C. Moreover, the orexin-A effect was mimicked by the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate, but was eliminated when PKC was inhibited by bisindolylmaleimide IV (Bis-IV)/Gö6976. Neither adenosine 3',5'-cyclic monophosphate (cAMP)-protein kinase A (PKA) nor guanosine 3',5'-cyclic monophosphate (cGMP)-protein kinase G (PKG) signaling pathway was likely involved, as orexin-A persisted to potentiate the IBa,L of GCs no matter these two pathways were activated or inhibited. These results suggest that, by activating OX1R, orexin-A potentiates the IBa,L of rat GCs through a distinct Gq/PI-PLC/IP3/Ca(2+)/PKC signaling pathway.
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Affiliation(s)
- F Liu
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - S-J Weng
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - X-L Yang
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China
| | - Y-M Zhong
- Institute of Neurobiology, State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, 138 Yixueyuan Road, Shanghai 200032, China.
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