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Bachor TP, Hwang E, Yulyaningsih E, Attal K, Mifsud F, Pham V, Vagena E, Huarcaya R, Valdearcos M, Vaisse C, Williams KW, Emmerson PJ, Xu AW. Identification of AgRP cells in the murine hindbrain that drive feeding. Mol Metab 2024; 80:101886. [PMID: 38246589 PMCID: PMC10844855 DOI: 10.1016/j.molmet.2024.101886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/10/2024] [Accepted: 01/16/2024] [Indexed: 01/23/2024] Open
Abstract
OBJECTIVE The central melanocortin system is essential for the regulation of food intake and body weight. Agouti-related protein (AgRP) is the sole orexigenic component of the central melanocortin system and is conserved across mammalian species. AgRP is currently known to be expressed exclusively in the mediobasal hypothalamus, and hypothalamic AgRP-expressing neurons are essential for feeding. Here we characterized a previously unknown population of AgRP cells in the mouse hindbrain. METHODS Expression of AgRP in the hindbrain was investigated using gene expression analysis, single-cell RNA sequencing, immunofluorescent analysis and multiple transgenic mice with reporter expressions. Activation of AgRP neurons was achieved by Designer Receptors Exclusively Activated by Designer Drugs (DREADD) and by transcranial focal photo-stimulation using a step-function opsin with ultra-high light sensitivity (SOUL). RESULTS AgRP expressing cells were present in the area postrema (AP) and the adjacent subpostrema area (SubP) and commissural nucleus of the solitary tract (cNTS) of the mouse hindbrain (termed AgRPHind herein). AgRPHind cells consisted of locally projecting neurons as well as tanycyte-like cells. Food deprivation stimulated hindbrain Agrp expression as well as neuronal activity of subsets of AgRPHind cells. In adult mice that lacked hypothalamic AgRP neurons, chemogenetic activation of AgRP neurons resulted in hyperphagia and weight gain. In addition, transcranial focal photo-stimulation of hindbrain AgRP cells increased food intake in adult mice with or without hypothalamic AgRP neurons. CONCLUSIONS Our study indicates that the central melanocortin system in the hindbrain possesses an orexigenic component, and that AgRPHind neurons stimulate feeding independently of hypothalamic AgRP neurons.
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Affiliation(s)
- Tomas P Bachor
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Eunsang Hwang
- Center for Hypothalamic Research, Department of Internal Medicine, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Ernie Yulyaningsih
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Kush Attal
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Francois Mifsud
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Viana Pham
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Eirini Vagena
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Renzo Huarcaya
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Martin Valdearcos
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Christian Vaisse
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA
| | - Kevin W Williams
- Center for Hypothalamic Research, Department of Internal Medicine, the University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Paul J Emmerson
- Lilly Research Laboratories, Lilly Corporate Center, Eli Lilly & Company, Indianapolis, IN, USA
| | - Allison W Xu
- Diabetes Center and Department of Anatomy, University of California, San Francisco, California, USA.
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Li J, Che Z, Wan X, Manshaii F, Xu J, Chen J. Biomaterials and bioelectronics for self-powered neurostimulation. Biomaterials 2024; 304:122421. [PMID: 38065037 DOI: 10.1016/j.biomaterials.2023.122421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 12/30/2023]
Abstract
Self-powered neurostimulation via biomaterials and bioelectronics innovation has emerged as a compelling approach to explore, repair, and modulate neural systems. This review examines the application of self-powered bioelectronics for electrical stimulation of both the central and peripheral nervous systems, as well as isolated neurons. Contemporary research has adeptly harnessed biomechanical and biochemical energy from the human body, through various mechanisms such as triboelectricity, piezoelectricity, magnetoelasticity, and biofuel cells, to power these advanced bioelectronics. Notably, these self-powered bioelectronics hold substantial potential for delivering neural stimulations that are customized for the treatment of neurological diseases, facilitation of neural regeneration, and the development of neuroprosthetics. Looking ahead, we expect that the ongoing advancements in biomaterials and bioelectronics will drive the field of self-powered neurostimulation toward the realization of more advanced, closed-loop therapeutic solutions, paving the way for personalized and adaptable neurostimulators in the coming decades.
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Affiliation(s)
- Jinlong Li
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Ziyuan Che
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Xiao Wan
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Farid Manshaii
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Jing Xu
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Jun Chen
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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Che Z, O'Donovan S, Xiao X, Wan X, Chen G, Zhao X, Zhou Y, Yin J, Chen J. Implantable Triboelectric Nanogenerators for Self-Powered Cardiovascular Healthcare. Small 2023; 19:e2207600. [PMID: 36759957 DOI: 10.1002/smll.202207600] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/23/2023] [Indexed: 06/18/2023]
Abstract
Triboelectric nanogenerators (TENGs) have gained significant traction in recent years in the bioengineering community. With the potential for expansive applications for biomedical use, many individuals and research groups have furthered their studies on the topic, in order to gain an understanding of how TENGs can contribute to healthcare. More specifically, there have been a number of recent studies focusing on implantable triboelectric nanogenerators (I-TENGs) toward self-powered cardiac systems healthcare. In this review, the progression of implantable TENGs for self-powered cardiovascular healthcare, including self-powered cardiac monitoring devices, self-powered therapeutic devices, and power sources for cardiac pacemakers, will be systematically reviewed. Long-term expectations of these implantable TENG devices through their biocompatibility and other utilization strategies will also be discussed.
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Affiliation(s)
- Ziyuan Che
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Sarah O'Donovan
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Xiao Xiao
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Xiao Wan
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Guorui Chen
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Xun Zhao
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yihao Zhou
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Junyi Yin
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Jun Chen
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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Korgan AC, Oliveira-Abreu K, Wei W, Martin SLA, Bridges ZJD, Leal-Cardoso JH, Kaczorowski CC, O'Connell KMS. High sucrose consumption decouples intrinsic and synaptic excitability of AgRP neurons without altering body weight. Int J Obes (Lond) 2023; 47:224-235. [PMID: 36725979 PMCID: PMC10023568 DOI: 10.1038/s41366-023-01265-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/17/2023] [Accepted: 01/19/2023] [Indexed: 02/03/2023]
Abstract
BACKGROUND/OBJECTIVE As the obesity epidemic continues, the understanding of macronutrient influence on central nervous system function is critical for understanding diet-induced obesity and potential therapeutics, particularly in light of the increased sugar content in processed foods. Previous research showed mixed effects of sucrose feeding on body weight gain but has yet to reveal insight into the impact of sucrose on hypothalamic functioning. Here, we explore the impact of liquid sucrose feeding for 12 weeks on body weight, body composition, caloric intake, and hypothalamic AgRP neuronal function and synaptic plasticity. METHODS Patch-clamp electrophysiology of hypothalamic AgRP neurons, metabolic phenotyping and food intake were performed on C57BL/6J mice. RESULTS While mice given sugar-sweetened water do not gain significant weight, they do show subtle differences in body composition and caloric intake. When given sugar-sweetened water, mice show similar alterations to AgRP neuronal excitability as in high-fat diet obese models. Increased sugar consumption also primes mice for increased caloric intake and weight gain when given access to a HFD. CONCLUSIONS Our results show that elevated sucrose consumption increased activity of AgRP neurons and altered synaptic excitability. This may contribute to obesity in mice and humans with access to more palatable (HFD) diets.
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Affiliation(s)
- Austin C Korgan
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | - Klausen Oliveira-Abreu
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
- Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil
| | - Wei Wei
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
- Georgia State University, Atlanta, GA, USA
| | | | - Zoey J D Bridges
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
| | | | - Catherine C Kaczorowski
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA
- Neuroscience Program, Graduate School of Biomedical Science, Tufts University School of Medicine, Boston, MA, USA
| | - Kristen M S O'Connell
- The Jackson Laboratory for Mammalian Genetics, Bar Harbor, ME, USA.
- Graduate School of Biomedical Science and Engineering, University of Maine, Orono, ME, USA.
- Neuroscience Program, Graduate School of Biomedical Science, Tufts University School of Medicine, Boston, MA, USA.
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Huang A, Maier MT, Vagena E, Xu AW. Modulation of foraging-like behaviors by cholesterol-FGF19 axis. Cell Biosci 2023; 13:20. [PMID: 36732847 PMCID: PMC9893607 DOI: 10.1186/s13578-023-00955-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/03/2023] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Foraging for food precedes food consumption and is an important component of the overall metabolic programming that regulates feeding. Foraging is governed by central nervous system neuronal circuits but how it is influenced by diet and hormonal signals is still not well understood. RESULTS In this study, we show that dietary cholesterol exerted suppressive effects on locomotor activity and that these effects were partially mediated by the neuropeptide Agouti-related protein (AgRP). High dietary cholesterol stimulated intestinal expression of fibroblast growth factor 15 (Fgf15), an ortholog of the human fibroblast growth factor 19 (FGF19). Intracerebroventricular infusion of FGF19 peptide reduced exploratory activity in the open field test paradigm. On the other hand, the lack of dietary cholesterol enhanced exploratory activity in the open field test, but this effect was abolished by central administration of FGF19. CONCLUSIONS Experiments in this study show that dietary cholesterol suppresses locomotor activity and foraging-like behaviors, and this regulation is in part mediated by AgRP neurons. Dietary cholesterol or the central action of FGF19 suppresses exploratory behaviors, and the anxiogenic effects of dietary cholesterol may be mediated by the effect of FGF19 in the mouse brain. This study suggests that dietary cholesterol and intestinal hormone FGF15/19 signal a satiating state to the brain, thereby suppressing foraging-like behaviors.
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Affiliation(s)
- Alyssa Huang
- Diabetes Center, University of California, San Francisco, CA, 94143, USA
| | - Matthew T Maier
- Diabetes Center, University of California, San Francisco, CA, 94143, USA
| | - Eirini Vagena
- Diabetes Center, University of California, San Francisco, CA, 94143, USA
| | - Allison W Xu
- Diabetes Center, University of California, San Francisco, CA, 94143, USA. .,Department of Anatomy, University of California, San Francisco, CA, 94143, USA.
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