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Halverson HE, Kim J, Khilkevich A, Mauk MD, Augustine GJ. Feedback inhibition underlies new computational functions of cerebellar interneurons. eLife 2022; 11:77603. [PMID: 36480240 PMCID: PMC9771357 DOI: 10.7554/elife.77603] [Citation(s) in RCA: 3] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
The function of a feedback inhibitory circuit between cerebellar Purkinje cells and molecular layer interneurons (MLIs) was defined by combining optogenetics, neuronal activity recordings both in cerebellar slices and in vivo, and computational modeling. Purkinje cells inhibit a subset of MLIs in the inner third of the molecular layer. This inhibition is non-reciprocal, short-range (less than 200 μm) and is based on convergence of one to two Purkinje cells onto MLIs. During learning-related eyelid movements in vivo, the activity of a subset of MLIs progressively increases as Purkinje cell activity decreases, with Purkinje cells usually leading the MLIs. Computer simulations indicate that these relationships are best explained by the feedback circuit from Purkinje cells to MLIs and that this feedback circuit plays a central role in making cerebellar learning efficient.
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Affiliation(s)
- Hunter E Halverson
- Center for Learning and Memory, The University of TexasAustinUnited States
| | - Jinsook Kim
- Program in Neuroscience & Mental Health, Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore,Institute of Molecular and Cell BiologySingaporeSingapore
| | - Andrei Khilkevich
- Center for Learning and Memory, The University of TexasAustinUnited States
| | - Michael D Mauk
- Center for Learning and Memory, The University of TexasAustinUnited States,Department of Neuroscience, The University of TexasAustinUnited States
| | - George J Augustine
- Program in Neuroscience & Mental Health, Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore,Institute of Molecular and Cell BiologySingaporeSingapore
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Fang Y, Wang S, Lv J, Zhao Z, Guo N, Wu G, Tong J, Wang Z. Slc39a2-Mediated Zinc Homeostasis Modulates Innate Immune Signaling in Phenylephrine-Induced Cardiomyocyte Hypertrophy. Front Cardiovasc Med 2021; 8:736911. [PMID: 34790705 PMCID: PMC8592093 DOI: 10.3389/fcvm.2021.736911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 07/06/2021] [Accepted: 10/12/2021] [Indexed: 01/05/2023] Open
Abstract
Zinc dyshomeostasis has been involved in the pathogenesis of cardiac hypertrophy; however, the dynamic regulation of intracellular zinc and its downstream signaling in cardiac hypertrophy remain largely unknown. Using Zincpyr1 staining, we found a significant decrease of intracellular Zinc concentration in phenylephrine (PE)-induced hypertrophy of neonatal rat ventricular myocytes (NRVMs). We then screened SLC39 family members responsible for zinc uptake and identified Slc39a2 as the only one altered by PE treatment. Slc39a2 knockdown in NRVMs reduced the intracellular Zinc level, and exacerbated the hypertrophic responses to PE treatment. In contrast, adenovirus-mediated Slc39a2 overexpression enhanced zinc uptake and suppressed PE-induced Nppb expression. RNA sequencing analysis showed a pro-hypertrophic transcriptome reprogramming after Slc39a2 knockdown. Interestingly, the innate immune signaling pathways, including NOD signaling, TOLL-like receptor, NFκB, and IRFs, were remarkably enriched in the Slc39a2-regulated genes. Slc39a2 deficiency enhanced the phosphorylation of P65 NFκB and STAT3, and reduced the expression of IκBα. Finally, the expression of IRF7 was significantly increased by Slc39a2 knockdown, which was in turn suppressed by IRF7 knockdown. Our data demonstrate that zinc homeostasis mediated by a Slc39a2/IRF7 regulatory circuit contributes to the alteration of innate immune signaling in cardiomyocyte hypertrophy.
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Affiliation(s)
- Yu Fang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China.,State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shun Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jian Lv
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China.,State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhenyi Zhao
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,School of Pharmacy, Health Science Center, Shenzhen University, Shenzhen, China
| | - Ningning Guo
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China.,State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Gang Wu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China
| | - Jingjing Tong
- School of Life Sciences, Central China Normal University, Wuhan, China
| | - Zhihua Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Shenzhen Key Laboratory of Cardiovascular Disease, Fuwai Hospital Chinese Academy of Medical Sciences, Shenzhen, China.,State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Yamashita M. Electrical Circuits That Supply Constant Electric Fields In Vitro. Bioelectricity 2020; 2:293-297. [PMID: 34471851 PMCID: PMC8370331 DOI: 10.1089/bioe.2019.0036] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Background: To study the molecular mechanism of galvanotropism in vitro, the strength of an electric field (EF) must be controlled precisely. In this study, I present a culture system that supplies an EF of constant strength by regulating the amount of current supplied to the culture medium. Materials and Methods: Voltage of the medium was recorded at two fixed points along the current flow throughout the culture period. The voltage drop between the two points was maintained at the desired value by a negative feedback circuit and an operational amplifier. Results: The field strength was defined by the voltage drop and the distance between the two points, and in this system, the EF can range from 0.0005 to 15 mV/mm. Conclusions: This culture system may be a useful tool to determine the nature of galvanotropism.
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Affiliation(s)
- Masayuki Yamashita
- Center for Basic Medical Research, International University of Health and Welfare, Ohtawara, Japan
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Liang X, Zeng J, Wang L, Shen L, Ma X, Li S, Wu Y, Ma L, Ci X, Guo Q, Jia M, Shen H, Sun Y, Liu Z, Liu S, Li W, Yu H, Chen C, Jia J. Histone demethylase RBP2 promotes malignant progression of gastric cancer through TGF-β1-(p-Smad3)-RBP2-E-cadherin-Smad3 feedback circuit. Oncotarget 2015; 6:17661-74. [PMID: 25974964 DOI: 10.18632/oncotarget.3756] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 04/25/2015] [Indexed: 12/24/2022] Open
Abstract
Some feedback pathways are critical in the process of tumor development or malignant progression. However the mechanisms through which these pathways are epigenetically regulated have not been fully elucidated. Here, we demonstrated that the histone demethylase RBP2 was crucial for TGF-β1-(p-Smad3)-RBP2-E-cadherin-Smad3 feedback circuit that was implicated in malignant progression of tumors and its knockdown significantly inhibited gastric cancer (GC) metastasis both in vitro and in vivo. Mechanistically, RBP2 can directly bind to E-cadherin promoter and suppress its expression, facilitating EMT and distant metastasis of GC. RBP2 can also be induced by TGF-β1, a key inducer of EMT, through phosphorylated Smad3 (p-Smad3) pathway in GC. The upregulated RBP2 can be recruited by p-smad3 to E-cadherin promoter and enhance its suppression, contributing to the promotion of metastasis of GC. In addition, the suppression of E-cadherin by RBP2 attenuated inhibition of Smad3 phosphorylation (exerted by E-cadherin), resulting further induction of RBP2 expression, and thus constituting positive feedback regulation during GC malignant progression. This TGF-β1-(p-Smad3)-RBP2- E-cadherin-Smad3 feedback circuit may be a novel mechanism for GC malignant progression and suppression of RBP2 expression may serve as a new strategy for the prevention of tumor distant metastasis.
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Christianson CA, Goplen NP, Zafar I, Irvin C, Good JT, Rollins DR, Gorentla B, Liu W, Gorska MM, Chu H, Martin RJ, Alam R. Persistence of asthma requires multiple feedback circuits involving type 2 innate lymphoid cells and IL-33. J Allergy Clin Immunol 2015; 136:59-68.e14. [PMID: 25617223 DOI: 10.1016/j.jaci.2014.11.037] [Citation(s) in RCA: 211] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 11/17/2014] [Accepted: 11/19/2014] [Indexed: 01/18/2023]
Abstract
BACKGROUND Asthma in a mouse model spontaneously resolves after cessation of allergen exposure. We developed a mouse model in which asthma features persisted for 6 months after cessation of allergen exposure. OBJECTIVE We sought to elucidate factors contributing to the persistence of asthma. METHODS We used a combination of immunologic, genetic, microarray, and pharmacologic approaches to dissect the mechanism of asthma persistence. RESULTS Elimination of T cells though antibody-mediated depletion or lethal irradiation and transplantation of recombination-activating gene (Rag1)(-/-) bone marrow in mice with chronic asthma resulted in resolution of airway inflammation but not airway hyperreactivity or remodeling. Elimination of T cells and type 2 innate lymphoid cells (ILC2s) through lethal irradiation and transplantation of Rag2(-/-)γc(-/-) bone marrow or blockade of IL-33 resulted in resolution of airway inflammation and hyperreactivity. Persistence of asthma required multiple interconnected feedback and feed-forward circuits between ILC2s and epithelial cells. Epithelial IL-33 induced ILC2s, a rich source of IL-13. The latter directly induced epithelial IL-33, establishing a positive feedback circuit. IL-33 autoinduced, generating another feedback circuit. IL-13 upregulated IL-33 receptors and facilitated IL-33 autoinduction, thus establishing a feed-forward circuit. Elimination of any component of these circuits resulted in resolution of chronic asthma. In agreement with the foregoing, IL-33 and ILC2 levels were increased in the airways of asthmatic patients. IL-33 levels correlated with disease severity. CONCLUSIONS We present a critical network of feedback and feed-forward interactions between epithelial cells and ILC2s involved in maintaining chronic asthma. Although T cells contributed to the severity of chronic asthma, they were redundant in maintaining airway hyperreactivity and remodeling.
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Affiliation(s)
| | - Nicholas P Goplen
- Division of Allergy and Immunology, National Jewish Health, Denver, Colo
| | - Iram Zafar
- Division of Allergy and Immunology, National Jewish Health, Denver, Colo
| | - Chaoyu Irvin
- Division of Allergy and Immunology, National Jewish Health, Denver, Colo
| | - James T Good
- Division of Pulmonary Medicine, Department of Medicine, National Jewish Health, Denver, Colo
| | - Donald R Rollins
- Division of Pulmonary Medicine, Department of Medicine, National Jewish Health, Denver, Colo
| | | | - Weimin Liu
- Division of Allergy and Immunology, National Jewish Health, Denver, Colo
| | - Magdalena M Gorska
- Division of Allergy and Immunology, National Jewish Health, Denver, Colo; University of Colorado Denver, Denver, Colo
| | - HongWei Chu
- Division of Pulmonary Medicine, Department of Medicine, National Jewish Health, Denver, Colo; University of Colorado Denver, Denver, Colo
| | - Richard J Martin
- Division of Pulmonary Medicine, Department of Medicine, National Jewish Health, Denver, Colo; University of Colorado Denver, Denver, Colo
| | - Rafeul Alam
- Division of Allergy and Immunology, National Jewish Health, Denver, Colo; University of Colorado Denver, Denver, Colo.
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Shao Z, Burkhalter A. Different balance of excitation and inhibition in forward and feedback circuits of rat visual cortex. J Neurosci 1996; 16:7353-65. [PMID: 8929442 PMCID: PMC6578929] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Different cortical areas are linked reciprocally via forward and feedback connections. Forward connections are involved in the representation of retinal images, whereas feedback pathways may play a role in the selection and interpretation of visual information. To examine the synaptic mechanisms of forward and feedback connections between primary and secondary visual cortical areas directly, we have performed intracellular recordings in slices of rat visual cortex. Irrespective of stimulus intensity and membrane potential, 78% (45/58) of the cells in striate cortex activated by feedback input showed monosynaptic responses that were depolarizing only, and inhibitory inputs were evident merely as a slight acceleration in the decay of EPSPs. In contrast, in 89% (17/19) of the cells, stimulation of forward input evoked monosynaptic excitatory postsynaptic potentials (EPSPs), followed by disynaptic, hyperpolarizing inhibitory postsynaptic potentials (IPSPs). EPSPs followed by IPSPs also were recorded after stimulation of local connections within primary visual cortex (92%, 12/13) and after activation of thalamocortical input (91%, 10/11). These results suggest that the synaptic organization of feedback connections are distinct from forward, local, and thalamocortical circuits. The findings further indicate that intracortical back projections exert modulatory influences via synaptic mechanisms in which weak inhibitory input is strongly dominated by excitation.
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Affiliation(s)
- Z Shao
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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