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Zhai X, Zhang H, Xia Z, Liu M, Du G, Jiang Z, Zhou H, Luo D, Dou D, Li J, Wang W, Li X, Jin B. Oxytocin alleviates liver fibrosis via hepatic macrophages. JHEP Rep 2024; 6:101032. [PMID: 38882603 PMCID: PMC11177191 DOI: 10.1016/j.jhepr.2024.101032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 01/22/2024] [Accepted: 01/26/2024] [Indexed: 06/18/2024] Open
Abstract
Background & Aims Previous studies demonstrated oxytocin treatment effectiveness in reducing mortality and reversing liver fibrosis in mice. However, the underlying mechanism remains obscure, given the absence of oxytocin receptor expression in hepatic stellate cells, the primary liver fibrosis effector cells. Methods A comprehensive map of cell populations in fibrotic liver was generated using single-cell sequencing. The map enabled our study of the target cells of oxytocin action in the liver in more dimensions. Furthermore, we elucidated the mechanism of the oxytocin signaling system in hepatic macrophages using oxytocin receptor-specific knockout mice and liver fibrosis animal models. Results The carbon tetrachloride-induced hepatic fibrosis and bile duct ligation hepatic fibrosis mouse models demonstrated that oxytocin reversed hepatic fibrosis in mice. The mapped liver cell populations demonstrated that oxytocin promoted the phenotypic switch from Ly6high to Ly6Clow in myeloid-derived macrophages. The phenotypic control of oxytocin signaling system activation on this phenotypic switch was validated using myeloid-specific oxytocin receptor knockout mice. Subsequent studies demonstrated that the calcium inward flow induced by oxytocin receptor activation activated the key orphan nuclear receptor NR4A1, which controls macrophage phenotypic switching. Specifically, calcium ions activated CREB, a key target regulator of NR4A1 expression. Conclusions The findings established hepatic macrophages as a hub responsible for the oxytocin-mediated alleviation of liver fibrosis. This study revealed a novel pathway where oxytocin regulates macrophage phenotype. Impact and implications Previous studies revealed for the first time the expression of oxytocin receptors in the liver. The present study shows that oxytocin reverses hepatic fibrosis and that hepatic macrophages are the central hub of oxytocin-mediated alleviation of hepatic fibrosis by promoting a phenotypic switch in hepatic macrophages, transitioning from Ly6high to Ly6Clow expression. The present study reveals a novel pathway by which oxytocin regulates macrophage phenotype. In addition, the potential applications of oxytocin and its analogues, as traditional drugs for clinical application, in the treatment of liver fibrosis deserve to be further explored.
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Affiliation(s)
- Xiangyu Zhai
- Department of Hepatobiliary Surgery, The Second Hospital of Shangdong University, Jinan, China
- Hepatobiliary Surgery Research Center of Shandong University, Jinan, China
| | - Hao Zhang
- Department of Hepatobiliary Surgery, The Second Hospital of Shangdong University, Jinan, China
- Hepatobiliary Surgery Research Center of Shandong University, Jinan, China
| | - Zhijia Xia
- Department of General, Visceral and Transplantation Surgery, University of Heidelberg, Heidelberg, Germany
| | - Mingkun Liu
- Organ Transplant Department, Qilu Hospital of Shangdong University, Jinan, China
| | - Gang Du
- Hepatobiliary Surgery Research Center of Shandong University, Jinan, China
- Organ Transplant Department, Qilu Hospital of Shangdong University, Jinan, China
| | - Zhengchen Jiang
- Hepatobiliary Surgery Research Center of Shandong University, Jinan, China
- Department of General Surgery, Shandong Provincial Qianfoshan Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Huaxin Zhou
- Department of Hepatobiliary Surgery, The Second Hospital of Shangdong University, Jinan, China
- Hepatobiliary Surgery Research Center of Shandong University, Jinan, China
| | - Dan Luo
- Pathology Tissue Bank, Qilu Hospital of Shandong University, Jinan, China
| | - Dandan Dou
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Jingxin Li
- Department of Physiology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Wei Wang
- Medical Integration and Practice Center, Shandong University, Jinan, China
| | - Xiaosong Li
- Clinical Molecular Medicine Testing Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Bin Jin
- Department of Hepatobiliary Surgery, The Second Hospital of Shangdong University, Jinan, China
- Hepatobiliary Surgery Research Center of Shandong University, Jinan, China
- Organ Transplant Department, Qilu Hospital of Shangdong University, Jinan, China
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Liu Y, Wang XR, Jiang YH, Li T, Ling S, Wang HY, Yu JW, Jia SW, Liu XY, Hou CM, Parpura V, Wang YF. Interactions between the Astrocytic Volume-Regulated Anion Channel and Aquaporin 4 in Hyposmotic Regulation of Vasopressin Neuronal Activity in the Supraoptic Nucleus. Cells 2023; 12:1723. [PMID: 37443757 PMCID: PMC10341125 DOI: 10.3390/cells12131723] [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: 05/02/2023] [Revised: 06/11/2023] [Accepted: 06/19/2023] [Indexed: 07/15/2023] Open
Abstract
We assessed interactions between the astrocytic volume-regulated anion channel (VRAC) and aquaporin 4 (AQP4) in the supraoptic nucleus (SON). Acute SON slices and cultures of hypothalamic astrocytes prepared from rats received hyposmotic challenge (HOC) with/without VRAC or AQP4 blockers. In acute slices, HOC caused an early decrease with a late rebound in the neuronal firing rate of vasopressin neurons, which required activity of astrocytic AQP4 and VRAC. HOC also caused a persistent decrease in the excitatory postsynaptic current frequency, supported by VRAC and AQP4 activity in early HOC; late HOC required only VRAC activity. These events were associated with the dynamics of glial fibrillary acidic protein (GFAP) filaments, the late retraction of which was mediated by VRAC activity; this activity also mediated an HOC-evoked early increase in AQP4 expression and late subside in GFAP-AQP4 colocalization. AQP4 activity supported an early HOC-evoked increase in VRAC levels and its colocalization with GFAP. In cultured astrocytes, late HOC augmented VRAC currents, the activation of which depended on AQP4 pre-HOC/HOC activity. HOC caused an early increase in VRAC expression followed by a late rebound, requiring AQP4 and VRAC, or only AQP4 activity, respectively. Astrocytic swelling in early HOC depended on AQP4 activity, and so did the early extension of GFAP filaments. VRAC and AQP4 activity supported late regulatory volume decrease, the retraction of GFAP filaments, and subside in GFAP-VRAC colocalization. Taken together, astrocytic morphological plasticity relies on the coordinated activities of VRAC and AQP4, which are mutually regulated in the astrocytic mediation of HOC-evoked modulation of vasopressin neuronal activity.
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Affiliation(s)
- Yang Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Xiao-Ran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Yun-Hao Jiang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
- Neuroscience Laboratory for Translational Medicine, School of Mental Health, Qiqihar Medical University, Qiqihar 161006, China
| | - Shuo Ling
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Hong-Yang Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Jia-Wei Yu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Shu-Wei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Xiao-Yu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Chun-Mei Hou
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
| | - Vladimir Parpura
- International Translational Neuroscience Research Institute, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin 150081, China (H.-Y.W.)
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Jiang YH, Li T, Liu Y, Liu X, Jia S, Hou C, Chen G, Wang H, Ling S, Gao Q, Wang XR, Wang YF. Contribution of inwardly rectifying K + channel 4.1 of supraoptic astrocytes to the regulation of vasopressin neuronal activity by hypotonicity. Glia 2023; 71:704-719. [PMID: 36408843 DOI: 10.1002/glia.24306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/06/2022] [Accepted: 11/12/2022] [Indexed: 11/22/2022]
Abstract
Astrocytic morphological plasticity and its modulation of adjacent neuronal activity are largely determined by astrocytic volume regulation, in which glial fibrillary acidic protein (GFAP), aquaporin 4 (AQP4), and potassium channels including inwardly rectifying K+ channel 4.1 (Kir4.1) are essential. However, associations of astrocyte-dominant Kir4.1 with other molecules in astrocytic volume regulation and the subsequent influence on neuronal activity remain unclear. Here, we report our study on these issues using primary cultures of rat pups' hypothalamic astrocytes and male adult rat brain slices. In astrocyte culture, hyposmotic challenge (HOC) significantly decreased GFAP monomer expression and astrocytic volume at 1.5 min and increased Kir4.1 expression and inwardly rectifying currents (IRCs) at 10 min. BaCl2 (100 μmol/l) suppressed the HOC-increased IRCs, which was simulated by VU0134992 (2 μmol/l), a Kir4.1 blocker. Preincubation of the astrocyte culture with TGN-020 (10 μmol/l, a specific AQP4 blocker) made the HOC-increased Kir4.1 currents insignificant. In hypothalamic brain slices, HOC initially decreased and then increased the firing rate of vasopressin (VP) neurons in the supraoptic nucleus. In the presence of BaCl2 or VU0134992, HOC-elicited rebound increase in VP neuronal activity was blocked. GFAP was molecularly associated with Kir4.1, which was increased by HOC at 20 min; this increase was blocked by BaCl2 . These results suggest that HOC-evoked astrocytic retraction or decrease in the volume and length of its processes is associated with increased Kir4.1 activity. Kir4.1 involvement in HOC-elicited astrocytic retraction is associated with AQP4 activity and GFAP plasticity, which together determines the rebound excitation of VP neurons.
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Affiliation(s)
- Yun-Hao Jiang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China.,Neuroelectrophysiology Laboratory, School of Mental Health, Qiqihar Medical University, Qiqihar, China
| | - Yang Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Chunmei Hou
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Guichuan Chen
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Hongyang Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuo Ling
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Qiang Gao
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiao-Ran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
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Ueta Y. Transgenic approaches to opening up new fields of vasopressin and oxytocin research. J Neuroendocrinol 2021; 33:e13055. [PMID: 34713515 DOI: 10.1111/jne.13055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 10/07/2021] [Accepted: 10/07/2021] [Indexed: 11/29/2022]
Abstract
Transgenic approaches have been applied to generate transgenic rats that express exogenous genes in arginine vasopressin (AVP)- and oxytocin (OXT)-producing magnocellular neurosecretory cells (MNCs) of the hypothalamic-neurohypophyseal system (HNS). First, the fusion gene that expresses AVP-enhanced green fluorescent protein (eGFP) and OXT-monomeric red fluorescent protein 1 (mRFP1) was used to visualize AVP- and OXT-producing MNCs and their axon terminals in the HNS under fluorescence microscopy. Second, the fusion gene that expresses c-fos-eGFP and c-fos-mRFP1 was used to identify activated neurons physiologically in the central nervous system, including MNCs, circumventricular organs and spinal cord. In addition, AVP-eGFP x c-fos-mRFP1 and OXT-mRFP1 × c-fos-eGFP double transgenic rats were generated to identify activated AVP- and OXT-producing MNCs using appropriate physiological stimuli. Third, the fusion gene that expresses AVP-chanelrhodopsin 2 (ChR2)-eGFP and AVP-hM3Dq-mCherry was used to activate AVP- and OXT-producing MNCs by optogenetic and chemogenetic approaches. In each step, these transgenic approaches in rats have provided new insights on the physiological roles of AVP and OXT not only in the HNS, but also in the whole body. In this review, we summarize the transgenic rats that we generated, as well as related physiological findings.
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Affiliation(s)
- Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
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Wang X, Li T, Liu Y, Jia S, Liu X, Jiang Y, Wang P, Parpura V, Wang Y. Aquaporin 4 differentially modulates osmotic effects on vasopressin neurons in rat supraoptic nucleus. Acta Physiol (Oxf) 2021; 232:e13672. [PMID: 33978309 DOI: 10.1111/apha.13672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/28/2021] [Accepted: 05/06/2021] [Indexed: 12/24/2022]
Abstract
AIM Glial fibrillary acidic protein (GFAP) molecularly associates with aquaporin 4 (AQP4) in astrocytic plasticity. Here, we further examined how AQP4 modulates osmotic effects on vasopressin (VP) neurons in rat supraoptic nucleus (SON) through interactions with GFAP in astrocytes. METHODS Brain slices from adult male rats were kept under osmotic stimulation. Western blot, co-immunoprecipitation, immunohistochemistry and patch-clamp recordings were used for analysis of expressions and interactions between GFAP and AQP4, astrocyte-specific proteins in the SON, as well as their influence on VP neuronal activity. Data were analysed using SPSS software. RESULTS Hyposmotic challenge (HOC) of acute SON slices caused an early (within 5 minutes) and transient increase in the colocalization of AQP4 with GFAP filaments. This effect was prominent at astrocytic processes surrounding VP neuron somata and was accompanied by inhibition of VP neuronal activity. Similar HOC effect was seen in the SON isolated from rats subjected to in vivo HOC, wherein a transiently increased molecular association between GFAP and AQP4 was detected using co-immunoprecipitation. The late stage rebound excitation (10 minutes) of VP neurons in brain slices subjected to HOC and the associated astrocytic GFAP's 'return to normal' were both hampered by 2-(nicotinamide)-1,3,4-thiadiazole, a specific AQP4 channel blocker that itself did not influence VP neuronal activity. Moreover, this agent prevented hyperosmotic stress-evoked excitation of VP neurons and associated reduction in GFAP filaments. CONCLUSION These findings indicate that osmotically driven increase in VP neuronal activity requires the activation of AQP4, which determines a retraction of GFAP filaments.
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Affiliation(s)
- Xiaoran Wang
- Department of Physiology Harbin Medical University Harbin China
| | - Tong Li
- Department of Physiology Harbin Medical University Harbin China
| | - Yang Liu
- Department of Physiology Harbin Medical University Harbin China
| | - Shuwei Jia
- Department of Physiology Harbin Medical University Harbin China
| | - Xiaoyu Liu
- Department of Physiology Harbin Medical University Harbin China
| | - Yunhao Jiang
- Department of Physiology Harbin Medical University Harbin China
| | - Ping Wang
- Department of Genetics Harbin Medical University Harbin China
| | - Vladimir Parpura
- Department of Neurobiology The University of Alabama at Birmingham Birmingham AL USA
| | - Yu‐Feng Wang
- Department of Physiology Harbin Medical University Harbin China
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Wei HH, Yuan XS, Chen ZK, Chen PP, Xiang Z, Qu WM, Li RX, Zhou GM, Huang ZL. Presynaptic inputs to vasopressin neurons in the hypothalamic supraoptic nucleus and paraventricular nucleus in mice. Exp Neurol 2021; 343:113784. [PMID: 34139240 DOI: 10.1016/j.expneurol.2021.113784] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 05/29/2021] [Accepted: 06/13/2021] [Indexed: 11/29/2022]
Abstract
Arginine vasopressin (AVP) neurons in the hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN) are involved in important physiological behaviors, such as controling osmotic stability and thermoregulation. However, the presynaptic input patterns governing AVP neurons have remained poorly understood due to their heterogeneity, as well as intermingling of AVP neurons with other neurons both in the SON and PVN. In the present study, we employed a retrograde modified rabies-virus system to reveal the brain areas that provide specific inputs to AVP neurons in the SON and PVN. We found that AVP neurons of the SON and PVN received similar input patterns from multiple areas of the brain, particularly massive afferent inputs from the diencephalon and other brain regions of the limbic system; however, PVNAVP neurons received relatively broader and denser inputs compared to SONAVP neurons. Additionally, SONAVP neurons received more projections from the median preoptic nucleus and organum vasculosum of the lamina terminalis (a circumventricular organ), compared to PVNAVP neurons, while PVNAVP neurons received more afferent inputs from the bed nucleus of stria terminalis and dorsomedial nucleus of the hypothalamus, both of which are thermoregulatory nuclei, compared to those of SONAVP neurons. In addition, both SONAVP and PVNAVP neurons received direct afferent projections from the bilateral suprachiasmatic nucleus, which is the master regulator of circadian rhythms and is concomitantly responsible for fluctuations in AVP levels. Taken together, our present results provide a comprehensive understanding of the specific afferent framework of AVP neurons both in the SON and PVN, and lay the foundation for further dissecting the diverse roles of SONAVP and PVNAVP neurons.
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Affiliation(s)
- Hao-Hua Wei
- Department of Anatomy and Histoembryology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China; Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Xiang-Shan Yuan
- Department of Anatomy and Histoembryology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China; Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
| | - Ze-Ka Chen
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Pei-Pei Chen
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Zhe Xiang
- Department of Anatomy and Histoembryology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Wei-Min Qu
- Department of Pharmacology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Rui-Xi Li
- Department of Anatomy and Histoembryology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Guo-Min Zhou
- Department of Anatomy and Histoembryology, School of Basic Medical Sciences, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
| | - Zhi-Li Huang
- Department of Pharmacology, School of Basic Medical Sciences, 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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MacGregor DJ, Leng G. Network and Population Function in Neuroendocrine Systems. SYSTEMS MEDICINE 2021. [DOI: 10.1016/b978-0-12-801238-3.11371-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Li D, Liu X, Liu H, Li T, Jia S, Wang X, Wang P, Qin D, Wang YF. Key Roles of Cyclooxygenase 2-Protein Kinase A-Hyperpolarization-activated Cyclic Nucleotide-gated Channel 3 Pathway in the Regulation of Oxytocin Neuronal Activity in Lactating Rats with Intermittent Pup-Deprivation. Neuroscience 2020; 452:13-25. [PMID: 33137408 DOI: 10.1016/j.neuroscience.2020.10.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/09/2020] [Indexed: 12/14/2022]
Abstract
Suckling-evoked pulsatile release of oxytocin (OT) from the posterior pituitary plays a key role in breastfeeding, which relies on burst-like discharges of OT neurons. To explore cellular mechanisms regulating OT neuronal activity, using lactating rats with pup-deprivation (PD) during postpartum day 1-5, we observed the involvement of prostaglandin, cyclic AMP/protein kinase A (PKA) and hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3) signaling pathway in OT neuronal activity. PD gradually reduced lactation efficiency. Intermittent PD (IPD) was largely reversed by intranasally-applied OT (IAO) but not by hypodermically-applied OT. IPD caused involution-like histological changes in the mammary glands, increased hypothalamic OT release but did not influence plasma OT concentrations. In the supraoptic nucleus, IPD increased OT receptor (OTR) expressions in OT neurons as well as Gαq subunit, Gβ subunit and cyclooxygenase 2 (Cox-2). These effects except that on Gβ subunit were reversed by IAO. Notably, IPD increased the expression of catalytic subunit of PKA in the SON, specifically in vasopressin neurons but not in OT neurons. In addition, IPD increased the expression of HCN3. IAO partially reversed these changes in the SON. Lastly, blocking HCN3 blocked excitation and burst firing in OT neurons-evoked by prostaglandin E2, a key mediator of OT-evoked burst firing; blocking Cox-2 or PKA reduced the molecular association between OTR and HCN3. Thus, there is a prostaglandin-cAMP/PKA-HCN3 pathway in the regulation of OT neuronal activity. PD disrupts lactation performance through uncoupling OTR and PKA-HCN3 signaling. The reversal effect of IAO highlights its therapeutic potential in PD-evoked hypogalactia.
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Affiliation(s)
- Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Haitao Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Ping Wang
- Department of Genetics, School of Basic Medical Sciences, Harbin Medical University, Harbin, China
| | - Danian Qin
- Department of Physiology, Shantou University of Medical College, Shantou, China
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, Harbin, China.
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Sato-Numata K, Numata T, Ueta Y, Okada Y. Expression and functions of N-type Cav2.2 and T-type Cav3.1 channels in rat vasopressin neurons under normotonic conditions. J Physiol Sci 2020; 70:49. [PMID: 33059597 PMCID: PMC10717235 DOI: 10.1186/s12576-020-00775-w] [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: 08/10/2020] [Accepted: 09/28/2020] [Indexed: 11/10/2022]
Abstract
Arginine vasopressin (AVP) neurons play essential roles in sensing the change in systemic osmolarity and regulating AVP release from their neuronal terminals to maintain the plasma osmolarity. AVP exocytosis depends on the Ca2+ entry via voltage-gated Ca2+ channels (VGCCs) in AVP neurons. In this study, suppression by siRNA-mediated knockdown and pharmacological sensitivity of VGCC currents evidenced molecular and functional expression of N-type Cav2.2 and T-type Cav3.1 in AVP neurons under normotonic conditions. Also, both the Cav2.2 and Cav3.1 currents were found to be sensitive to flufenamic acid (FFA). TTX-insensitive spontaneous action potentials were suppressed by FFA and T-type VGCC blocker Ni2+. However, Cav2.2-selective ω-conotoxin GVIA failed to suppress the firing activity. Taken together, it is concluded that Cav2.2 and Cav3.1 are molecularly and functionally expressed and both are sensitive to FFA in unstimulated rat AVP neurons. Also, it is suggested that Cav3.1 is primarily involved in their action potential generation.
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Affiliation(s)
- Kaori Sato-Numata
- Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan
- Department of Physiology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Tomohiro Numata
- Department of Physiology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku, Kitakyushu-shi, Fukuoka, 807-8555, Japan
| | - Yasunobu Okada
- National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
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Li D, Liu H, Liu X, Wang H, Li T, Wang X, Jia S, Wang P, Wang YF. Involvement of Hyperpolarization-Activated Cyclic Nucleotide-Gated Channel 3 in Oxytocin Neuronal Activity in Lactating Rats With Pup Deprivation. ASN Neuro 2020; 12:1759091420944658. [PMID: 32962418 PMCID: PMC7517985 DOI: 10.1177/1759091420944658] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Oxytocin, a hypothalamic neuropeptide essential for breastfeeding, is mainly produced in oxytocin neurons in the supraoptic nucleus (SON) and paraventricular nucleus. However, mechanisms underlying oxytocin secretion, specifically the involvement of hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3) in oxytocin neuronal activity, remain unclear. Using a rat model of intermittent and continuous pup deprivation (PD) at the middle stage of lactation, we analyzed the contribution of HCN3 in oxytocin receptor (OTR)-associated signaling cascade to oxytocin neuronal activity in the SON. PD caused maternal depression, anxiety, milk shortage, involution of the mammary glands, and delays in uterine recovery, particularly in continuous PD. PD increased hypothalamic but not plasma oxytocin levels in enzyme-linked immunosorbent assay. In the SON, PD increased c-Fos expression but reduced expressions of cyclooxygenase-2 and HCN3 in Western blots and/or immunohistochemistry. Moreover, PD significantly increased the molecular association of OTR with HCN3 in coimmunoprecipitation. In brain slices, inhibition of HCN3 activity with DK-AH269 blocked prostaglandin E2-evoked increase in the firing activity and burst discharge in oxytocin neurons in patch-clamp recordings. In addition, oxytocin-evoked increase in the molecular association between OTR and HCN3 in brain slices of the SON was blocked by pretreatment with indomethacin, an inhibitor of cyclooxygenase-2. These results indicate that normal activity of oxytocin neurons is under the regulation of an oxytocin receptor-cyclooxygenase-2-HCN3 pathway and that PD disrupts maternal behavior through increasing intranuclear oxytocin secretion in the SON but likely reducing bolus oxytocin release into the blood through inhibition of HCN3 activity.
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Affiliation(s)
- Dongyang Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
| | - Haitao Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
| | - Xiaoyu Liu
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
| | - Hongyang Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
| | - Tong Li
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
| | - Xiaoran Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
| | - Shuwei Jia
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
| | - Ping Wang
- Department of Genetics, School of Basic Medical Sciences, Harbin Medical University
| | - Yu-Feng Wang
- Department of Physiology, School of Basic Medical Sciences, Harbin Medical University
- Yu-Feng Wang, Department of Physiology, School of Basic Medical Sciences, Harbin Medical University, 157 Baojian Road, Nangang, Harbin 150081, China.
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Kania A, Sambak P, Gugula A, Szlaga A, Soltys Z, Blasiak T, Hess G, Rajfur Z, Blasiak A. Electrophysiology and distribution of oxytocin and vasopressin neurons in the hypothalamic paraventricular nucleus: a study in male and female rats. Brain Struct Funct 2019; 225:285-304. [DOI: 10.1007/s00429-019-01989-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/15/2019] [Indexed: 12/30/2022]
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Maícas Royo J, Leng G, MacGregor DJ. The spiking and secretory activity of oxytocin neurones in response to osmotic stimulation: a computational model. J Physiol 2019; 597:3657-3671. [PMID: 31111496 DOI: 10.1113/jp278045] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS A quantitative model of oxytocin neurones that combines a spiking model, a model of stimulus-secretion coupling and a model of plasma clearance of oxytocin was tested. To test the model, a variety of sources of published data were used that relate either the electrical activity of oxytocin cells or the secretion of oxytocin to experimentally induced changes in plasma osmotic pressure. To use these data to test the model, the experimental challenges involved were computationally simulated. The model predictions closely matched the reported outcomes of the different experiments. ABSTRACT Magnocellular vasopressin and oxytocin neurones in the rat hypothalamus project to the posterior pituitary, where they secrete their products into the bloodstream. In rodents, both vasopressin and oxytocin magnocellular neurones are osmoresponsive, and their increased spiking activity is mainly a consequence of an increased synaptic input from osmoresponsive neurons in regions adjacent to the anterior wall of the third ventricle. Osmotically stimulated vasopressin secretion promotes antidiuresis while oxytocin secretion promotes natriuresis. In this work we tested a previously published computational model of the spiking and secretion activity of oxytocin cells against published evidence of changes in spiking activity and plasma oxytocin concentration in response to different osmotic challenges. We show that integrating this oxytocin model with a simple model of the osmoresponsive inputs to oxytocin cells achieves a strikingly close match to diverse sources of data. Comparing model predictions with published data using bicuculline to block inhibitory GABA inputs supports the conclusion that inhibitory inputs and excitatory inputs are co-activated by osmotic stimuli. Finally, we studied how the gain of osmotically stimulated oxytocin release changes in the presence of a hypovolaemic stimulus, showing that this is best explained by an inhibition of an osmotically regulated inhibitory drive to the magnocellular neurones.
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Affiliation(s)
- Jorge Maícas Royo
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Gareth Leng
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Duncan J MacGregor
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
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Leng G, Russell JA. The osmoresponsiveness of oxytocin and vasopressin neurones: Mechanisms, allostasis and evolution. J Neuroendocrinol 2019; 31:e12662. [PMID: 30451331 DOI: 10.1111/jne.12662] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 10/29/2018] [Accepted: 11/15/2018] [Indexed: 12/27/2022]
Abstract
In the rat supraoptic nucleus, every oxytocin cell projects to the posterior pituitary, and is involved both in reflex milk ejection during lactation and in regulating uterine contractions during parturition. All are also osmosensitive, regulating natriuresis. All are also regulated by signals that control appetite, including the neural and hormonal signals that arise from the gut after food intake and from the sites of energy storage. All are also involved in sexual behaviour, anxiety-related behaviours and social behaviours. The challenge is to understand how a single population of neurones can coherently regulate such a diverse set of functions and adapt to changing physiological states. Their multiple functions arise from complex intrinsic properties that confer sensitivity to a wide range of internal and environmental signals. Many of these properties have a distant evolutionary origin in multifunctional, multisensory neurones of Urbilateria, the hypothesised common ancestor of vertebrates, insects and worms. Their properties allow different patterns of oxytocin release into the circulation from their axon terminals in the posterior pituitary into other brain areas from axonal projections, as well as independent release from their dendrites.
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Affiliation(s)
- Gareth Leng
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - John A Russell
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
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