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Wu M, Song G, Li J, Song Z, Zhao B, Liang L, Li W, Hu H, Tu H, Li S, Li P, Zhang B, Wang W, Zhang Y, Zhang W, Zheng W, Wang J, Wen Y, Wang K, Li A, Zhou T, Zhang Y, Li H. Innervation of nociceptor neurons in the spleen promotes germinal center responses and humoral immunity. Cell 2024; 187:2935-2951.e19. [PMID: 38772371 DOI: 10.1016/j.cell.2024.04.027] [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: 09/01/2023] [Revised: 03/18/2024] [Accepted: 04/20/2024] [Indexed: 05/23/2024]
Abstract
Peripheral sensory neurons widely innervate various tissues to continuously monitor and respond to environmental stimuli. Whether peripheral sensory neurons innervate the spleen and modulate splenic immune response remains poorly defined. Here, we demonstrate that nociceptive sensory nerve fibers extensively innervate the spleen along blood vessels and reach B cell zones. The spleen-innervating nociceptors predominantly originate from left T8-T13 dorsal root ganglia (DRGs), promoting the splenic germinal center (GC) response and humoral immunity. Nociceptors can be activated by antigen-induced accumulation of splenic prostaglandin E2 (PGE2) and then release calcitonin gene-related peptide (CGRP), which further promotes the splenic GC response at the early stage. Mechanistically, CGRP directly acts on B cells through its receptor CALCRL-RAMP1 via the cyclic AMP (cAMP) signaling pathway. Activating nociceptors by ingesting capsaicin enhances the splenic GC response and anti-influenza immunity. Collectively, our study establishes a specific DRG-spleen sensory neural connection that promotes humoral immunity, suggesting a promising approach for improving host defense by targeting the nociceptive nervous system.
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Affiliation(s)
- Min Wu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Guangping Song
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China; School of Medicine, Tsinghua University, Beijing, China
| | - Jianing Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Zengqing Song
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Bing Zhao
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Liyun Liang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China; School of Medicine, Tsinghua University, Beijing, China
| | - Wenlong Li
- Chinese Institute for Brain Research, Beijing, China
| | - Huaibin Hu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Haiqing Tu
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Sen Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Peiyao Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China; School of Medicine, Tsinghua University, Beijing, China
| | - Biyu Zhang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Wen Wang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Yu Zhang
- School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Wanpeng Zhang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Weifan Zheng
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Jiarong Wang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Yuqi Wen
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Kai Wang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Ailing Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China
| | - Tao Zhou
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China.
| | - Yucheng Zhang
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China.
| | - Huiyan Li
- Nanhu Laboratory, National Center of Biomedical Analysis, Beijing, China.
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Jo YH. Differential transcriptional profiles of vagal sensory neurons in female and male mice. Front Neurosci 2024; 18:1393196. [PMID: 38808032 PMCID: PMC11131592 DOI: 10.3389/fnins.2024.1393196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/24/2024] [Indexed: 05/30/2024] Open
Abstract
Introduction Differences in metabolic homeostasis, diabetes, and obesity between males and females are evident in rodents and humans. Vagal sensory neurons in the vagus nerve ganglia innervate a variety of visceral organs and use specialized nerve endings to sense interoceptive signals. This visceral organ-brain axis plays a role in relaying interoceptive signals to higher brain centers, as well as in regulating the vago-vagal reflex. I hypothesized that molecularly distinct populations of vagal sensory neurons would play a role in causing differences in metabolic homeostasis between the sexes. Methods SnRNA-Seq was conducted on dissociated cells from the vagus nerve ganglia using the 10X Genomics Chromium platform. Results Single-nucleus RNA sequencing analysis of vagal sensory neurons from female and male mice revealed differences in the transcriptional profiles of cells in the vagus nerve ganglia. These differences are linked to the expression of sex-specific genes such as Xist, Tsix, and Ddx3y. Among the 13 neuronal clusters, one-fourth of the neurons in male mice were located in the Ddx3y-enriched VN1 and VN8 clusters, which displayed higher enrichment of Trpv1, Piezo2, Htr3a, and Vip genes. In contrast, 70% of the neurons in females were found in Xist-enriched clusters VN4, 6, 7, 10, 11, and 13, which showed enriched genes such as Fgfr1, Lpar1, Cpe, Esr1, Nrg1, Egfr, and Oprm1. Two clusters of satellite cells were identified, one of which contained oligodendrocyte precursor cells in male mice. A small population of cells expressed Ucp1 and Plin1, indicating that they are epineural adipocytes. Discussion Understanding the physiological implications of distinct transcriptomic profiles in vagal sensory neurons on energy balance and metabolic homeostasis would help develop sex-specific treatments for obesity and metabolic dysregulation.
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Affiliation(s)
- Young-Hwan Jo
- The Fleischer Institute for Diabetes and Metabolism, Albert Einstein College of Medicine, New York, NY, United States
- Division of Endocrinology, Department of Medicine, Albert Einstein College of Medicine, New York, NY, United States
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, NY, United States
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Wang K, Fu Y, Li L, Zhang L, Huang M, Yan W, Shan X, Yan Z, Lu Y. Gut Microbiota Moderates Multimodal Brain Structure-Function Integration and Behavioral Cognition in Growth Hormone Deficient Children. Neuroendocrinology 2024:1-10. [PMID: 38679006 DOI: 10.1159/000539097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
INTRODUCTION Previous brain studies of growth hormone deficiency (GHD) often used single-modal neuroimaging, missing the complexity captured by multimodal data. Growth hormone affects gut microbiota and metabolism in GHD. However, from a gut-brain axis (GBA) perspective, the relationship between abnormal GHD brain development and microbiota alterations remains unclear. The ultimate goal is to uncover the manifestations underlying GBA abnormalities in GHD and idiopathic short stature (ISS). METHODS Participants included 23 GHD and 25 ISS children. The fusion independent component analysis was applied to integrate multimodal brain data (high-resolution structural, diffusion tensor, and resting-state functional MRI) covering regional homogeneity (ReHo), amplitude of low frequency fluctuations (ALFF), and white matter fractional anisotropy (FA). Gut microbiome diversity and metabolites were analyzed using 16S sequencing and proton nuclear magnetic resonance (1H-NMR). Associations between multimodal neuroimaging and cognition were assessed using moderation analysis. RESULTS Six independent components (IC) of ReHo, ALFF, and FA differed significantly between GHD and ISS patients, with three functional components linked to the processing speed index. GHD individuals showed higher levels of acetate, nicotinate, and lysine in microbiota metabolism. Higher alpha diversity in GHD strengthened connections between ReHo-IC1, ReHo-IC5, ALFF-IC1, and the processing speed index, while increasing agathobacter levels in ISS weakened the link between ALFF-IC1 and the speech comprehension index. CONCLUSIONS Our findings uncover differing brain structure and functional fusion in GHD, alongside microbiota metabolism of short-chain fatty acids. Additionally, microbiome influences connections between neuroimaging and cognition, offering insight into diverse GBA patterns in GHD and ISS, enhancing our understanding of the disease's pathophysiology and interventions.
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Affiliation(s)
- Keren Wang
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yuchuan Fu
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Lan Li
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Lingfeng Zhang
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Mei Huang
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Weihao Yan
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaoou Shan
- Department of Pediatric Endocrinology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Zhihan Yan
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
- Key Laboratory of Structural Malformations in Children of Zhejiang Province, Wenzhou, China
- Wenzhou Key Laboratory of Structural and Functional Imaging, Wenzhou, China
| | - Yi Lu
- Department of Radiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
- Key Laboratory of Structural Malformations in Children of Zhejiang Province, Wenzhou, China
- Wenzhou Key Laboratory of Structural and Functional Imaging, Wenzhou, China
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Hwang J, Okada J, Pessin JE, Chua SC, Schwartz GJ, Jo YH. Liver-innervating vagal sensory neurons play an indispensable role in the development of hepatic steatosis and anxiety-like behavior in mice fed a high-fat diet. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.20.581228. [PMID: 38659949 PMCID: PMC11042226 DOI: 10.1101/2024.02.20.581228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Background and Aims The visceral organ-brain axis, mediated by vagal sensory neurons in the vagal nerve ganglion, is essential for maintaining various physiological functions. In this study, we investigated the impact of liver-projecting vagal sensory neurons on energy balance, hepatic steatosis, and anxiety-like behavior in mice under obesogenic conditions. Methods We performed single-nucleus RNA sequencing of vagal sensory neurons innervating the liver. Based on our snRNA-Seq results, we used the Avil CreERT2 strain to identify vagal sensory neurons that innervate the liver. Results A small subset of polymodal sensory neurons innervating the liver was located in the left and right ganglia, projecting centrally to the nucleus of the tractus solitarius, area postrema, and dorsal motor nucleus of the vagus, and peripherally to the periportal areas in the liver. Male and female control mice developed diet-induced obesity (DIO) during high-fat diet feeding. Deleting liver-projecting advillin-positive vagal sensory neurons prevented DIO in male and female mice, and these outcomes are associated with increased energy expenditure. Although males and females exhibited improved glucose homeostasis following disruption of liver-projecting vagal sensory neurons, only male mice displayed increased insulin sensitivity. The loss of liver-projecting vagal sensory neurons limited the progression of hepatic steatosis in male and female mice fed a steatogenic diet. Finally, mice lacking liver-innervating vagal sensory neurons exhibited less anxiety-like behavior compared to the control mice. Conclusions The liver-brain axis contributes to the regulation of energy balance, glucose tolerance, hepatic steatosis, and anxiety-like behavior depending on the nutrient status in healthy and obesogenic conditions.
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Yang D, Xu J, Xu K, Xu P. Skeletal interoception in osteoarthritis. Bone Res 2024; 12:22. [PMID: 38561376 PMCID: PMC10985098 DOI: 10.1038/s41413-024-00328-6] [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: 09/14/2023] [Revised: 03/02/2024] [Accepted: 03/16/2024] [Indexed: 04/04/2024] Open
Abstract
The interoception maintains proper physiological conditions and metabolic homeostasis by releasing regulatory signals after perceving changes in the internal state of the organism. Among its various forms, skeletal interoception specifically regulates the metabolic homeostasis of bones. Osteoarthritis (OA) is a complex joint disorder involving cartilage, subchondral bone, and synovium. The subchondral bone undergoes continuous remodeling to adapt to dynamic joint loads. Recent findings highlight that skeletal interoception mediated by aberrant mechanical loads contributes to pathological remodeling of the subchondral bone, resulting in subchondral bone sclerosis in OA. The skeletal interoception is also a potential mechanism for chronic synovial inflammation in OA. In this review, we offer a general overview of interoception, specifically skeletal interoception, subchondral bone microenviroment and the aberrant subchondral remedeling. We also discuss the role of skeletal interoception in abnormal subchondral bone remodeling and synovial inflammation in OA, as well as the potential prospects and challenges in exploring novel OA therapies that target skeletal interoception.
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Affiliation(s)
- Dinglong Yang
- Department of Joint Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, 710054, China
| | - Jiawen Xu
- Department of Orthopedic Surgery and Orthopedic Research Institute, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Ke Xu
- Department of Joint Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, 710054, China
| | - Peng Xu
- Department of Joint Surgery, Honghui Hospital, Xi'an Jiaotong University, Xi'an, 710054, China.
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Pan Y, Bu T, Deng X, Jia J, Yuan G. Gut microbiota and type 2 diabetes mellitus: a focus on the gut-brain axis. Endocrine 2024; 84:1-15. [PMID: 38227168 DOI: 10.1007/s12020-023-03640-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 11/30/2023] [Indexed: 01/17/2024]
Abstract
Type 2 diabetes mellitus (T2DM) has become one of the most serious public healthcare challenges, contributing to increased mortality and disability. In the past decades, significant progress has been made in understanding the pathogenesis of T2DM. Mounting evidence suggested that gut microbiota (GM) plays a significant role in the development of T2DM. Communication between the GM and the brain is a complex bidirectional connection, known as the "gut-brain axis," via the nervous, neuroendocrine, and immune systems. Gut-brain axis has an essential impact on various physiological processes, including glucose metabolism, food intake, gut motility, etc. In this review, we provide an outline of the gut-brain axis. We also highlight how the dysbiosis of the gut-brain axis affects glucose homeostasis and even results in T2DM.
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Affiliation(s)
- Yi Pan
- Department of Endocrinology and Metabolism, The Affiliated Hospital of Jiangsu University, Institute of Endocrine and Metabolic Diseases, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Tong Bu
- Department of Endocrinology and Metabolism, The Affiliated Hospital of Jiangsu University, Institute of Endocrine and Metabolic Diseases, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Xia Deng
- Department of Endocrinology and Metabolism, The Affiliated Hospital of Jiangsu University, Institute of Endocrine and Metabolic Diseases, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Jue Jia
- Department of Endocrinology and Metabolism, The Affiliated Hospital of Jiangsu University, Institute of Endocrine and Metabolic Diseases, Jiangsu University, Zhenjiang, Jiangsu, China
| | - Guoyue Yuan
- Department of Endocrinology and Metabolism, The Affiliated Hospital of Jiangsu University, Institute of Endocrine and Metabolic Diseases, Jiangsu University, Zhenjiang, Jiangsu, China.
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Borgmann D, Fenselau H. Vagal pathways for systemic regulation of glucose metabolism. Semin Cell Dev Biol 2024; 156:244-252. [PMID: 37500301 DOI: 10.1016/j.semcdb.2023.07.010] [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: 10/05/2022] [Revised: 06/20/2023] [Accepted: 07/20/2023] [Indexed: 07/29/2023]
Abstract
Maintaining blood glucose at an appropriate physiological level requires precise coordination of multiple organs and tissues. The vagus nerve bidirectionally connects the central nervous system with peripheral organs crucial to glucose mobilization, nutrient storage, and food absorption, thereby presenting a key pathway for the central control of blood glucose levels. However, the precise mechanisms by which vagal populations that target discrete tissues participate in glucoregulation are much less clear. Here we review recent advances unraveling the cellular identity, neuroanatomical organization, and functional contributions of both vagal efferents and vagal afferents in the control of systemic glucose metabolism. We focus on their involvement in relaying glucoregulatory cues from the brain to peripheral tissues, particularly the pancreatic islet, and by sensing and transmitting incoming signals from ingested food to the brain. These recent findings - largely driven by advances in viral approaches, RNA sequencing, and cell-type selective manipulations and tracings - have begun to clarify the precise vagal neuron populations involved in the central coordination of glucose levels, and raise interesting new possibilities for the treatment of glucose metabolism disorders such as diabetes.
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Affiliation(s)
- Diba Borgmann
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Physical Activity Research (CFAS), Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark
| | - Henning Fenselau
- Synaptic Transmission in Energy Homeostasis Group, Max Planck Institute for Metabolism Research, Gleueler Strasse 50, 50931 Cologne, Germany; Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Kerpener Strasse 26, 50937 Cologne, Germany; Excellence Cluster on Cellular Stress Responses in Aging Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Straße 26, Cologne 50931, Germany.
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Lai TT, Tsai YH, Liou CW, Fan CH, Hou YT, Yao TH, Chuang HL, Wu WL. The gut microbiota modulate locomotion via vagus-dependent glucagon-like peptide-1 signaling. NPJ Biofilms Microbiomes 2024; 10:2. [PMID: 38228675 DOI: 10.1038/s41522-024-00477-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 01/04/2024] [Indexed: 01/18/2024] Open
Abstract
Locomotor activity is an innate behavior that can be triggered by gut-motivated conditions, such as appetite and metabolic condition. Various nutrient-sensing receptors distributed in the vagal terminal in the gut are crucial for signal transduction from the gut to the brain. The levels of gut hormones are closely associated with the colonization status of the gut microbiota, suggesting a complicated interaction among gut bacteria, gut hormones, and the brain. However, the detailed mechanism underlying gut microbiota-mediated endocrine signaling in the modulation of locomotion is still unclear. Herein, we show that broad-spectrum antibiotic cocktail (ABX)-treated mice displayed hypolocomotion and elevated levels of the gut hormone glucagon-like peptide-1 (GLP-1). Blockade of the GLP-1 receptor and subdiaphragmatic vagal transmission rescued the deficient locomotor phenotype in ABX-treated mice. Activation of the GLP-1 receptor and vagal projecting brain regions led to hypolocomotion. Finally, selective antibiotic treatment dramatically increased serum GLP-1 levels and decreased locomotion. Colonizing Lactobacillus reuteri and Bacteroides thetaiotaomicron in microbiota-deficient mice suppressed GLP-1 levels and restored the hypolocomotor phenotype. Our findings identify a mechanism by which specific gut microbes mediate host motor behavior via the enteroendocrine and vagal-dependent neural pathways.
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Affiliation(s)
- Tzu-Ting Lai
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yu-Hsuan Tsai
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Chia-Wei Liou
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Ching-Hsiang Fan
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yu-Tian Hou
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Tzu-Hsuan Yao
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Hsiao-Li Chuang
- National Laboratory Animal Center, National Applied Research Laboratories, Taipei, 115202, Taiwan
| | - Wei-Li Wu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
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Akagi Y, Takayama Y, Nihashi Y, Yamashita A, Yoshida R, Miyamoto Y, Kida YS. Functional engineering of human iPSC-derived parasympathetic neurons enhances responsiveness to gastrointestinal hormones. FEBS Open Bio 2024; 14:63-78. [PMID: 38013211 PMCID: PMC10761937 DOI: 10.1002/2211-5463.13741] [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: 10/24/2023] [Revised: 11/15/2023] [Accepted: 11/23/2023] [Indexed: 11/29/2023] Open
Abstract
Food-derived biological signals are transmitted to the brain via peripheral nerves through the paracrine activity of gastrointestinal (GI) hormones. The signal transduction circuit of the brain-gut axis has been analyzed in animals; however, species-related differences and animal welfare concerns necessitate investigation using in vitro human experimental models. Here, we focused on the receptors of five GI hormones (CCK, GLP1, GLP2, PYY, and serotonin (5-HT)), and established human induced pluripotent stem cell (iPSC) lines that functionally expressed each receptor. Compared to the original iPSCs, iPSCs expressing one of the receptors did not show any differences in global mRNA expression, genomic stability, or differentiation capacities of the three germ layers. We induced parasympathetic neurons from these established iPSC lines to assess vagus nerve activity. We generated GI hormone receptor-expressing neurons (CCKAR, GLP1R, and NPY2R-neuron) and tested their responsiveness to each ligand using Ca2+ imaging and microelectrode array recording. GI hormone receptor-expressing neurons (GLP2R and HTR3A) were generated directly by gene induction into iPSC-derived peripheral nerve progenitors. These receptor-expressing neurons promise to contribute to a better understanding of how the body responds to GI hormones via the brain-gut axis, aid in drug development, and offer an alternative to animal studies.
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Affiliation(s)
- Yuka Akagi
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
- Tsukuba Life Science Innovation Program (T‐LSI), School of Comprehensive Human SciencesUniversity of TsukubaTsukubaJapan
| | - Yuzo Takayama
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
| | - Yuma Nihashi
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
| | - Azusa Yamashita
- Analytical Science Laboratories, Asahi Quality & Innovations, Ltd.MoriyaJapan
| | - Risa Yoshida
- Analytical Science Laboratories, Asahi Quality & Innovations, Ltd.MoriyaJapan
| | - Yasuhisa Miyamoto
- Analytical Science Laboratories, Asahi Quality & Innovations, Ltd.MoriyaJapan
| | - Yasuyuki S. Kida
- Cellular and Molecular Biotechnology Research InstituteNational Institute of Advanced Industrial Science and Technology (AIST)TsukubaJapan
- School of Integrative & Global Majors (SIGMA)University of TsukubaTsukubaJapan
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Guo W, Xiong W. From gut microbiota to brain: implications on binge eating disorders. Gut Microbes 2024; 16:2357177. [PMID: 38781112 PMCID: PMC11123470 DOI: 10.1080/19490976.2024.2357177] [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: 12/30/2023] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
The prevalence of eating disorders has been increasing over the last 50 years. Binge eating disorder (BED) and bulimia nervosa (BN) are two typical disabling, costly and life-threatening eating disorders that substantially compromise the physical well-being of individuals while undermining their psychological functioning. The distressing and recurrent episodes of binge eating are commonly observed in both BED and BN; however, they diverge as BN often involves the adoption of inappropriate compensatory behaviors aimed at averting weight gain. Normal eating behavior is coordinated by a well-regulated trade-off between intestinal and central ingestive mechanism. Conversely, despite the fact that the etiology of BED and BN remains incompletely resolved, emerging evidence corroborates the notion that dysbiosis of gastrointestinal microbiome and its metabolites, alteration of gut-brain axis, as well as malfunctioning central circuitry regulating motivation, execution and reward all contribute to the pathology of binge eating. In this review, we aim to outline the current state of knowledge pertaining to the potential mechanisms through which each component of the gut-brain axis participates in binge eating behaviors, and provide insight for the development of microbiome-based therapeutic interventions that hold promise in ameliorating patients afflicted with binge eating disorders.
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Affiliation(s)
- Weiwei Guo
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
| | - Wei Xiong
- Department of Neurology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
- Anhui Province Key Laboratory of Biomedical Imaging and Intelligent Processing, Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
- CAS Key Laboratory of Brain Function and Disease, Hefei, China
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11
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Tang Y, Du J, Wu H, Wang M, Liu S, Tao F. Potential Therapeutic Effects of Short-Chain Fatty Acids on Chronic Pain. Curr Neuropharmacol 2024; 22:191-203. [PMID: 36173071 PMCID: PMC10788890 DOI: 10.2174/1570159x20666220927092016] [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: 05/31/2022] [Revised: 07/03/2022] [Accepted: 09/13/2022] [Indexed: 11/22/2022] Open
Abstract
The intestinal homeostasis maintained by the gut microbiome and relevant metabolites is essential for health, and its disturbance leads to various intestinal or extraintestinal diseases. Recent studies suggest that gut microbiome-derived metabolites short-chain fatty acids (SCFAs) are involved in different neurological disorders (such as chronic pain). SCFAs are produced by bacterial fermentation of dietary fibers in the gut and contribute to multiple host processes, including gastrointestinal regulation, cardiovascular modulation, and neuroendocrine-immune homeostasis. Although SCFAs have been implicated in the modulation of chronic pain, the detailed mechanisms that underlie such roles of SCFAs remain to be further investigated. In this review, we summarize currently available research data regarding SCFAs as a potential therapeutic target for chronic pain treatment and discuss several possible mechanisms by which SCFAs modulate chronic pain.
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Affiliation(s)
- Yuanyuan Tang
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan, China
- Key Laboratory for Molecular Neurology of Xinxiang, Xinxiang, Henan, China
| | - Juan Du
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan, China
| | - Hongfeng Wu
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan, China
| | - Mengyao Wang
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, Henan, China
| | - Sufang Liu
- Department of Biomedical Sciences, College of Dentistry, Texas A&M University Dallas, Texas, USA
| | - Feng Tao
- Department of Biomedical Sciences, College of Dentistry, Texas A&M University Dallas, Texas, USA
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Arnold RA, Fowler DK, Peters JH. TRPV1 enhances cholecystokinin signaling in primary vagal afferent neurons and mediates the central effects on spontaneous glutamate release in the NTS. Am J Physiol Cell Physiol 2024; 326:C112-C124. [PMID: 38047304 PMCID: PMC11192538 DOI: 10.1152/ajpcell.00409.2023] [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: 08/25/2023] [Revised: 11/02/2023] [Accepted: 11/21/2023] [Indexed: 12/05/2023]
Abstract
The gut peptide cholecystokinin (CCK) is released during feeding and promotes satiation by increasing excitation of vagal afferent neurons that innervate the upper gastrointestinal tract. Vagal afferent neurons express CCK1 receptors (CCK1Rs) in the periphery and at central terminals in the nucleus of the solitary tract (NTS). While the effects of CCK have been studied for decades, CCK receptor signaling and coupling to membrane ion channels are not entirely understood. Previous findings have implicated L-type voltage-gated calcium channels as well as transient receptor potential (TRP) channels in mediating the effects of CCK, but the lack of selective pharmacology has made determining the contributions of these putative mediators difficult. The nonselective ion channel transient receptor potential vanilloid subtype 1 (TRPV1) is expressed throughout vagal afferent neurons and controls many forms of signaling, including spontaneous glutamate release onto NTS neurons. Here we tested the hypothesis that CCK1Rs couple directly to TRPV1 to mediate vagal signaling using fluorescent calcium imaging and brainstem electrophysiology. We found that CCK signaling at high concentrations (low-affinity binding) was potentiated in TRPV1-containing afferents and that TRPV1 itself mediated the enhanced CCK1R signaling. While competitive antagonism of TRPV1 failed to alter CCK1R signaling, TRPV1 pore blockade or genetic deletion (TRPV1 KO) significantly reduced the CCK response in cultured vagal afferents and eliminated its ability to increase spontaneous glutamate release in the NTS. Together, these results establish that TRPV1 mediates the low-affinity effects of CCK on vagal afferent activation and control of synaptic transmission in the brainstem.NEW & NOTEWORTHY Cholecystokinin (CCK) signaling via the vagus nerve reduces food intake and produces satiation, yet the signaling cascades mediating these effects remain unknown. Here we report that the capsaicin receptor transient receptor potential vanilloid subtype 1 (TRPV1) potentiates CCK signaling in the vagus and mediates the ability of CCK to control excitatory synaptic transmission in the nucleus of the solitary tract. These results may prove useful in the future development of CCK/TRPV1-based therapeutic interventions.
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Affiliation(s)
- Rachel A Arnold
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States
| | - Daniel K Fowler
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States
| | - James H Peters
- Department of Integrative Physiology and Neuroscience, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States
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13
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Lai TT, Liou CW, Tsai YH, Lin YY, Wu WL. Butterflies in the gut: the interplay between intestinal microbiota and stress. J Biomed Sci 2023; 30:92. [PMID: 38012609 PMCID: PMC10683179 DOI: 10.1186/s12929-023-00984-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 11/06/2023] [Indexed: 11/29/2023] Open
Abstract
Psychological stress is a global issue that affects at least one-third of the population worldwide and increases the risk of numerous psychiatric disorders. Accumulating evidence suggests that the gut and its inhabiting microbes may regulate stress and stress-associated behavioral abnormalities. Hence, the objective of this review is to explore the causal relationships between the gut microbiota, stress, and behavior. Dysbiosis of the microbiome after stress exposure indicated microbial adaption to stressors. Strikingly, the hyperactivated stress signaling found in microbiota-deficient rodents can be normalized by microbiota-based treatments, suggesting that gut microbiota can actively modify the stress response. Microbiota can regulate stress response via intestinal glucocorticoids or autonomic nervous system. Several studies suggest that gut bacteria are involved in the direct modulation of steroid synthesis and metabolism. This review provides recent discoveries on the pathways by which gut microbes affect stress signaling and brain circuits and ultimately impact the host's complex behavior.
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Affiliation(s)
- Tzu-Ting Lai
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Chia-Wei Liou
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yu-Hsuan Tsai
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yuan-Yuan Lin
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Wei-Li Wu
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
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14
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Kim H, Park KT, Jo H, Shin Y, Chung G, Ko SG, Jin YH, Kim W. The effect of ginger extract on cisplatin-induced acute anorexia in rats. Front Pharmacol 2023; 14:1267254. [PMID: 38026983 PMCID: PMC10665510 DOI: 10.3389/fphar.2023.1267254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023] Open
Abstract
Cisplatin is a platinum-based chemotherapeutic agent widely used to treat various cancers. However, several side effects have been reported in treated patients. Among these, acute anorexia is one of the most severe secondary effects. In this study, a single oral administration of 100 or 500 mg/kg ginger extract (GE) significantly alleviated the cisplatin-induced decrease in food intake in rats. However, these body weight and water intake decreases were reversed in the 100 mg/kg group rats. To elucidate the underlying mechanism of action, serotonin (5-HT) and 5-HT2C, 3A, and 4 receptors in the nodose ganglion of the vagus nerve were investigated. The results showed that cisplatin-induced increases in serotonin levels in both the blood and nodose ganglion tissues were significantly decreased by100 and 500 mg/kg of GE administration. On 5-HT receptors, 5-HT3A and 4, but not 2C receptors, were affected by cisplatin, and GE 100 and 500 mg/kg succeeded in downregulating the evoked upregulated gene of these receptors. Protein expression of 5-HT3A and 4 receptors were also reduced in the 100 mg/kg group. Furthermore, the injection of 5-HT3A, and 4 receptors antagonists (palonostron, 0.1 mg/kg, i.p.; piboserod, 1 mg/kg, i.p., respectively) in cisplatin treated rats prevented the decrease in food intake. Using high-performance liquid chromatography (HPLC) analysis, [6]-gingerol and [6]-shogaol were identified and quantified as the major components of GE, comprising 4.12% and 2.15% of the GE, respectively. Although [6]-gingerol or [6]-shogaol alone failed to alleviate the evoked anorexia, when treated together, the effect was significant on the cisplatin-induced decrease in food intake. These results show that GE can be considered a treatment option to alleviate cisplatin-induced anorexia.
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Affiliation(s)
- Hyeonah Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Keun-Tae Park
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Heejoon Jo
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Yuchan Shin
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Geehoon Chung
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Seong-Gyu Ko
- Korean Medicine-Based Drug Repositioning Cancer Research Center, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Young-Ho Jin
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Woojin Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
- Korean Medicine-Based Drug Repositioning Cancer Research Center, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
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15
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Wang L, Gao F, Wang Z, Liang F, Dai Y, Wang M, Wu J, Chen Y, Yan Q, Wang L. Transcutaneous auricular vagus nerve stimulation in the treatment of disorders of consciousness: mechanisms and applications. Front Neurosci 2023; 17:1286267. [PMID: 37920298 PMCID: PMC10618368 DOI: 10.3389/fnins.2023.1286267] [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: 08/31/2023] [Accepted: 10/05/2023] [Indexed: 11/04/2023] Open
Abstract
This review provides an in-depth exploration of the mechanisms and applications of transcutaneous auricular vagus nerve stimulation (taVNS) in treating disorders of consciousness (DOC). Beginning with an exploration of the vagus nerve's role in modulating brain function and consciousness, we then delve into the neuroprotective potential of taVNS demonstrated in animal models. The subsequent sections assess the therapeutic impact of taVNS on human DOC, discussing the safety, tolerability, and various factors influencing the treatment response. Finally, the review identifies the current challenges in taVNS research and outlines future directions, emphasizing the need for large-scale trials, optimization of treatment parameters, and comprehensive investigation of taVNS's long-term effects and underlying mechanisms. This comprehensive overview positions taVNS as a promising and safe modality for DOC treatment, with a focus on understanding its intricate neurophysiological influence and optimizing its application in clinical settings.
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Affiliation(s)
- Likai Wang
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Fei Gao
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Zhan Wang
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Feng Liang
- First Clinical Medical College, Shanxi Medical University, Taiyuan, China
| | - Yongli Dai
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Mengchun Wang
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Jingyi Wu
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Yaning Chen
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Qinjie Yan
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
| | - Litong Wang
- Department of Rehabilitation Medicine, The Second Hospital of Dalian Medical University, Dalian, China
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16
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Ullah H, Arbab S, Tian Y, Liu CQ, Chen Y, Qijie L, Khan MIU, Hassan IU, Li K. The gut microbiota-brain axis in neurological disorder. Front Neurosci 2023; 17:1225875. [PMID: 37600019 PMCID: PMC10436500 DOI: 10.3389/fnins.2023.1225875] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 07/07/2023] [Indexed: 08/22/2023] Open
Abstract
The gut microbiota (GM) plays an important role in the physiology and pathology of the host. Microbiota communicate with different organs of the organism by synthesizing hormones and regulating body activity. The interaction of the central nervous system (CNS) and gut signaling pathways includes chemical, neural immune and endocrine routes. Alteration or dysbiosis in the gut microbiota leads to different gastrointestinal tract disorders that ultimately impact host physiology because of the abnormal microbial metabolites that stimulate and trigger different physiologic reactions in the host body. Intestinal dysbiosis leads to a change in the bidirectional relationship between the CNS and GM, which is linked to the pathogenesis of neurodevelopmental and neurological disorders. Increasing preclinical and clinical studies/evidence indicate that gut microbes are a possible susceptibility factor for the progression of neurological disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) and autism spectrum disorder (ASD). In this review, we discuss the crucial connection between the gut microbiota and the central nervous system, the signaling pathways of multiple biological systems and the contribution of gut microbiota-related neurological disorders.
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Affiliation(s)
- Hanif Ullah
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Safia Arbab
- Key Laboratory of Veterinary Pharmaceutical Development, Ministry of Agriculture, Lanzhou, China
- Key Laboratory of New Animal Drug Project of Gansu Province, Lanzhou, China
- Lanzhou Institute of Husbandry and Pharmaceutical Sciences, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Yali Tian
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Chang-qing Liu
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Yuwen Chen
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Li Qijie
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
| | - Muhammad Inayat Ullah Khan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, China
| | - Inam Ul Hassan
- Department of Microbiology, Hazara University Mansehra, Mansehra, Pakistan
| | - Ka Li
- Department of Nursing, West China Hospital, West China School of Nursing, Sichuan University, Chengdu, China
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17
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Brown SSG, Westwater ML, Seidlitz J, Ziauddeen H, Fletcher PC. Hypothalamic volume is associated with body mass index. Neuroimage Clin 2023; 39:103478. [PMID: 37558541 PMCID: PMC10509524 DOI: 10.1016/j.nicl.2023.103478] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/19/2023] [Accepted: 07/18/2023] [Indexed: 08/11/2023]
Abstract
The hypothalamus is an important neuroendocrine hub for the control of appetite and satiety. In animal studies it has been established that hypothalamic lesioning or stimulation causes alteration to feeding behaviour and consequently body mass, and exposure to high calorie diets induces hypothalamic inflammation. These findings suggest that alterations in hypothalamic structure and function are both a cause and a consequence of changes to food intake. However, there is limited in vivo human data relating the hypothalamus to obesity or eating disorders, in part due to technical problems relating to its small size. Here, we used a novel automated segmentation algorithm to exploratorily investigate the relationship between hypothalamic volume, normalised to intracranial volume, and body mass index (BMI). The analysis was applied across four independent datasets comprising of young adults (total n = 1,351 participants) spanning a range of BMIs (13.3 - 47.8 kg/m2). We compared underweight (including individuals with anorexia nervosa), healthy weight, overweight and obese individuals in a series of complementary analyses. We report that overall hypothalamic volume is significantly larger in overweight and obese groups of young adults. This was also observed for a number of hypothalamic sub-regions. In the largest dataset (the HCP-Young Adult dataset (n = 1111)) there was a significant relationship between hypothalamic volume and BMI. We suggest that our findings of a positive relationship between hypothalamic volume and BMI is potentially consistent with hypothalamic inflammation as seen in animal models in response to high fat diet, although more research is needed to establish a causal relationship. Overall, we present novel, in vivo findings that link elevated BMI to altered hypothalamic structure. This has important implications for study of the neural mechanisms of obesity in humans.
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Affiliation(s)
- Stephanie S G Brown
- Department of Psychiatry, University of Cambridge, Addenbrookes Hospital, Cambridge CB2 0QQ, United Kingdom.
| | - Margaret L Westwater
- Department of Psychiatry, University of Cambridge, Addenbrookes Hospital, Cambridge CB2 0QQ, United Kingdom; Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, United Kingdom
| | - Jakob Seidlitz
- Department of Child and Adolescent Psychiatry and Behavioral Science, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA; Lifespan Brain Institute of Children's Hospital of Philadelphia and University of Pennsylvania, Philadelphia, PA, USA
| | - Hisham Ziauddeen
- Department of Psychiatry, University of Cambridge, Addenbrookes Hospital, Cambridge CB2 0QQ, United Kingdom
| | - Paul C Fletcher
- Department of Psychiatry, University of Cambridge, Addenbrookes Hospital, Cambridge CB2 0QQ, United Kingdom; Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0QQ, United Kingdom; Cambridgeshire and Peterborough NHS Trust, United Kingdom
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18
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Villalobos J, Payne SC, Ward GM, Andrikopoulos S, Hyakumura T, MacIsaac RJ, Fallon JB. Stimulation parameters for directional vagus nerve stimulation. Bioelectron Med 2023; 9:16. [PMID: 37464423 DOI: 10.1186/s42234-023-00117-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 06/09/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Autonomic nerve stimulation is used as a treatment for a growing number of diseases. We have previously demonstrated that application of efferent vagus nerve stimulation (eVNS) has promising glucose lowering effects in a rat model of type 2 diabetes. This paradigm combines high frequency pulsatile stimulation to block nerve activation in the afferent direction with low frequency stimulation to activate the efferent nerve section. In this study we explored the effects of the parameters for nerve blocking on the ability to inhibit nerve activation in the afferent direction. The overarching aim is to establish a blocking stimulation strategy that could be applied using commercially available implantable pulse generators used in the clinic. METHODS Male rats (n = 20) had the anterior abdominal vagus nerve implanted with a multi-electrode cuff. Evoked compound action potentials (ECAP) were recorded at the proximal end of the electrode cuff. The efficacy of high frequency stimulation to block the afferent ECAP was assessed by changes in the threshold and saturation level of the response. Blocking frequency and duty cycle of the blocking pulses were varied while maintaining a constant 4 mA current amplitude. RESULTS During application of blocking at lower frequencies (≤ 4 kHz), the ECAP threshold increased (ANOVA, p < 0.001) and saturation level decreased (p < 0.001). Application of higher duty cycles (> 70%) led to an increase in evoked neural response threshold (p < 0.001) and a decrease in saturation level (p < 0.001). During the application of a constant pulse width and frequency (1 or 1.6 kHz, > 70% duty cycle), the charge delivered per pulse had a significant influence on the magnitude of the block (ANOVA, p = 0.003), and was focal (< 2 mm range). CONCLUSIONS This study has determined the range of frequencies, duty cycles and currents of high frequency stimulation that generate an efficacious, focal axonal block of a predominantly C-fiber tract. These findings could have potential application for the treatment of type 2 diabetes.
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Affiliation(s)
- Joel Villalobos
- Bionics Institute, East Melbourne, Vic, Australia
- Department of Medical Bionics, University of Melbourne, Parkville, Vic, Australia
| | - Sophie C Payne
- Bionics Institute, East Melbourne, Vic, Australia
- Department of Medical Bionics, University of Melbourne, Parkville, Vic, Australia
| | - Glenn M Ward
- Bionics Institute, East Melbourne, Vic, Australia
- Department of Endocrinology and Diabetes, St Vincent's Hospital Melbourne, Fitzroy, Vic, Australia
- Department of Medicine, St Vincent's Hospital Melbourne, University of Melbourne, Fitzroy, Vic, Australia
| | - Sofianos Andrikopoulos
- Australian Centre for Accelerating Diabetes Innovations, University of Melbourne, Parkville, Australia
- Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Vic, Australia
| | - Tomoko Hyakumura
- Bionics Institute, East Melbourne, Vic, Australia
- Department of Medical Bionics, University of Melbourne, Parkville, Vic, Australia
| | - Richard J MacIsaac
- Bionics Institute, East Melbourne, Vic, Australia
- Department of Endocrinology and Diabetes, St Vincent's Hospital Melbourne, Fitzroy, Vic, Australia
- Department of Medicine, St Vincent's Hospital Melbourne, University of Melbourne, Fitzroy, Vic, Australia
- Australian Centre for Accelerating Diabetes Innovations, University of Melbourne, Parkville, Australia
| | - James B Fallon
- Bionics Institute, East Melbourne, Vic, Australia.
- Department of Medical Bionics, University of Melbourne, Parkville, Vic, Australia.
- Australian Diabetes Society, Sydney, NSW, Australia.
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19
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Isola JVV, Ko S, Ocañas SR, Stout MB. Role of Estrogen Receptor α in Aging and Chronic Disease. ADVANCES IN GERIATRIC MEDICINE AND RESEARCH 2023; 5:e230005. [PMID: 37425648 PMCID: PMC10327608 DOI: 10.20900/agmr20230005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Estrogen receptor alpha (ERα) plays a crucial role in reproductive function in both sexes. It also mediates cellular responses to estrogens in multiple nonreproductive organ systems, many of which regulate systemic metabolic homeostasis and inflammatory processes in mammals. The loss of estrogens and/or ERα agonism during aging is associated with the emergence of several comorbid conditions, particularly in females undergoing the menopausal transition. Emerging data also suggests that male mammals likely benefit from ERα agonism if done in a way that circumvents feminizing characteristics. This has led us, and others, to speculate that tissue-specific ERα agonism may hold therapeutic potential for curtailing aging and chronic disease burden in males and females that are at high-risk of cancer and/or cardiovascular events with traditional estrogen replacement therapies. In this mini-review, we emphasize the role of ERα in the brain and liver, summarizing recent evidence that indicates these two organs systems mediate the beneficial effects of estrogens on metabolism and inflammation during aging. We also discuss how 17α-estradiol administration elicits health benefits in an ERα-dependent manner, which provides proof-of-concept that ERα may be a druggable target for attenuating aging and age-related disease burden.
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Affiliation(s)
- José V. V. Isola
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Sunghwan Ko
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
| | - Sarah R. Ocañas
- Genes & Human Disease Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
| | - Michael B. Stout
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, USA
- Oklahoma City Veterans Affairs Medical Center, Oklahoma City, OK 73104, USA
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20
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Kupari J, Ernfors P. Molecular taxonomy of nociceptors and pruriceptors. Pain 2023; 164:1245-1257. [PMID: 36718807 PMCID: PMC10184562 DOI: 10.1097/j.pain.0000000000002831] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/10/2022] [Accepted: 11/21/2022] [Indexed: 02/01/2023]
Affiliation(s)
- Jussi Kupari
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Patrik Ernfors
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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21
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Girardi G, Zumpano D, Goshi N, Raybould H, Seker E. Cultured Vagal Afferent Neurons as Sensors for Intestinal Effector Molecules. BIOSENSORS 2023; 13:601. [PMID: 37366967 DOI: 10.3390/bios13060601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/28/2023]
Abstract
The gut-brain axis embodies the bi-directional communication between the gastrointestinal tract and the central nervous system (CNS), where vagal afferent neurons (VANs) serve as sensors for a variety of gut-derived signals. The gut is colonized by a large and diverse population of microorganisms that communicate via small (effector) molecules, which also act on the VAN terminals situated in the gut viscera and consequently influence many CNS processes. However, the convoluted in vivo environment makes it difficult to study the causative impact of the effector molecules on VAN activation or desensitization. Here, we report on a VAN culture and its proof-of-principle demonstration as a cell-based sensor to monitor the influence of gastrointestinal effector molecules on neuronal behavior. We initially compared the effect of surface coatings (poly-L-lysine vs. Matrigel) and culture media composition (serum vs. growth factor supplement) on neurite growth as a surrogate of VAN regeneration following tissue harvesting, where the Matrigel coating, but not the media composition, played a significant role in the increased neurite growth. We then used both live-cell calcium imaging and extracellular electrophysiological recordings to show that the VANs responded to classical effector molecules of endogenous and exogenous origin (cholecystokinin serotonin and capsaicin) in a complex fashion. We expect this study to enable platforms for screening various effector molecules and their influence on VAN activity, assessed by their information-rich electrophysiological fingerprints.
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Affiliation(s)
- Gregory Girardi
- Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616, USA
| | - Danielle Zumpano
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA
| | - Noah Goshi
- Department of Biomedical Engineering, University of California-Davis, Davis, CA 95616, USA
| | - Helen Raybould
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA
| | - Erkin Seker
- Department of Electrical and Computer Engineering, University of California-Davis, Davis, CA 95616, USA
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22
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Zhang S, He H, Wang Y, Wang X, Liu X. Transcutaneous auricular vagus nerve stimulation as a potential novel treatment for polycystic ovary syndrome. Sci Rep 2023; 13:7721. [PMID: 37173458 PMCID: PMC10182028 DOI: 10.1038/s41598-023-34746-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 05/06/2023] [Indexed: 05/15/2023] Open
Abstract
Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of childbearing age. The etiology of PCOS is multifactorial, and current treatments for PCOS are far from satisfactory. Recently, an imbalanced autonomic nervous system (ANS) with sympathetic hyperactivity and reduced parasympathetic nerve activity (vagal tone) has aroused increasing attention in the pathogenesis of PCOS. In this paper, we review an innovative therapy for the treatment of PCOS and related co-morbidities by targeting parasympathetic modulation based on non-invasive transcutaneous auricular vagal nerve stimulation (ta-VNS). In this work, we present the role of the ANS in the development of PCOS and describe a large number of experimental and clinical reports that support the favorable effects of VNS/ta-VNS in treating a variety of symptoms, including obesity, insulin resistance, type 2 diabetes mellitus, inflammation, microbiome dysregulation, cardiovascular disease, and depression, all of which are also commonly present in PCOS patients. We propose a model focusing on ta-VNS that may treat PCOS by (1) regulating energy metabolism via bidirectional vagal signaling; (2) reversing insulin resistance via its antidiabetic effect; (3) activating anti-inflammatory pathways; (4) restoring homeostasis of the microbiota-gut-brain axis; (5) restoring the sympatho-vagal balance to improve CVD outcomes; (6) and modulating mental disorders. ta-VNS is a safe clinical procedure and it might be a promising new treatment approach for PCOS, or at least a supplementary treatment for current therapeutics.
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Affiliation(s)
- Shike Zhang
- Southern University of Science and Technology Yantian Hospital, Shenzhen, 518081, China
- Shenzhen Yantian District People's Hospital, Shenzhen, 518081, China
| | - Hui He
- First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China.
| | - Yu Wang
- First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin, 150040, China
| | - Xiao Wang
- First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China
| | - Xiaofang Liu
- Chinese People's Liberation Army General Hospital, Beijing, 100853, China
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Prospective Multicenter Study of the Primary Obesity Surgery Endoluminal (POSE 2.0) Procedure for Treatment of Obesity. Clin Gastroenterol Hepatol 2023; 21:81-89.e4. [PMID: 35533995 DOI: 10.1016/j.cgh.2022.04.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/18/2022] [Accepted: 04/20/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS The Primary Obesity Surgery Endoluminal (POSE) 2.0 procedure involves a novel pattern of full-thickness gastric body plications to shorten and narrow the stomach using durable suture anchor pairs. Our prospective, multicenter trial examined the safety, efficacy, durability, and physiologic effects of POSE 2.0 in adults with obesity. METHODS Adults with obesity underwent POSE 2.0 at 3 centers. Primary outcomes were percent total body weight loss (%TBWL) and proportion of patients achieving >5% TBWL at 12 months. Secondary outcomes included change in obesity comorbidities, satiety, quality of life at 6 months, and durability of plications at 12 and 24 months. Subjects were followed for adverse events throughout the study duration. RESULTS 44 patients (61% female; mean age, 45 ± 9.7 years; mean body mass index, 37 ± 2.1 kg/m2) were enrolled. This procedure used an average of 19 suture anchor pairs, with a mean duration of 37 ± 11 minutes, and was technically successful in all subjects. Mean %TBWL at 12 months was 15.7% ± 6.8%. At 12 months, %TBWL >5%, >10%, and >15% was achieved in 98%, 86%, and 58% of patients, respectively. Improvements in lipid profile, liver biochemistries, and hepatic steatosis were seen at 6 months. Improvements in hepatic steatosis persisted for 24 months in a subgroup of patients (P < .01). POSE 2.0 reduced maximum tolerated meal volume (P = .03) and was associated with increased fullness (P < .01) and improved eating behavior (P < .01) at 6 months. Impact of weight on quality-of-life questionnaire improved at 6 months (2.23 vs 1.23; P < .01). Repeat assessment at 24 months (n = 26) showed fully intact plications. No serious adverse events occurred. CONCLUSION POSE 2.0 is an effective and durable endoscopic bariatric therapy which may influence physiologic pathways impacting satiety. Larger comparative studies are needed to further elucidate these initial findings. CLINICALTRIALS gov Identifier: NCT03721731.
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24
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Central and peripheral regulations mediated by short-chain fatty acids on energy homeostasis. Transl Res 2022; 248:128-150. [PMID: 35688319 DOI: 10.1016/j.trsl.2022.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 05/16/2022] [Accepted: 06/01/2022] [Indexed: 11/24/2022]
Abstract
The human gut microbiota influences obesity, insulin resistance, and the subsequent development of type 2 diabetes (T2D). The gut microbiota digests and ferments nutrients resulting in the production of short-chain fatty acids (SCFAs), which generate various beneficial metabolic effects on energy and glucose homeostasis. However, their roles in the central nervous system (CNS)-mediated outputs on the metabolism have only been minimally studied. Here, we explore what is known and future directions that may be worth exploring in this emerging area. Specifically, we searched studies or data in English by using PubMed, Google Scholar, and the Human Metabolome Database. Studies were filtered by time from 1978 to March 2022. As a result, 195 studies, 53 reviews, 1 website, and 1 book were included. One hundred and sixty-five of 195 studies describe the production and metabolism of SCFAs or the effects of SCFAs on energy homeostasis, glucose balance, and mental diseases through the gut-brain axis or directly by a central pathway. Thirty of 195 studies show that inappropriate metabolism and excessive of SCFAs are metabolically detrimental. Most studies suggest that SCFAs exert beneficial metabolic effects by acting as the energy substrate in the TCA cycle, regulating the hormones related to satiety regulation and insulin secretion, and modulating immune cells and microglia. These functions have been linked with AMPK signaling, GPCRs-dependent pathways, and inhibition of histone deacetylases (HDACs). However, the studies focusing on the central effects of SCFAs are still limited. The mechanisms by which central SCFAs regulate appetite, energy expenditure, and blood glucose during different physiological conditions warrant further investigation.
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Vagus nerve stimulation increases stomach-brain coupling via a vagal afferent pathway. Brain Stimul 2022; 15:1279-1289. [PMID: 36067977 DOI: 10.1016/j.brs.2022.08.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/27/2022] [Accepted: 08/24/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Maintaining energy homeostasis is vital and supported by vagal signaling between digestive organs and the brain. Previous research has established a gastric network in the brain that is phase synchronized with the rhythm of the stomach, but tools to perturb its function were lacking. OBJECTIVE To evaluate whether stomach-brain coupling can be acutely increased by non-invasively stimulating vagal afferent projections to the brain. METHODS Using a single-blind randomized crossover design, we investigated the effect of acute right-sided transcutaneous auricular vagus nerve stimulation (taVNS) versus sham stimulation on stomach-brain coupling. RESULTS In line with preclinical research, taVNS increased stomach-brain coupling in the nucleus of the solitary tract (NTS) and the midbrain while boosting coupling across the brain. Crucially, in the cortex, taVNS-induced changes in coupling occurred primarily in transmodal regions and were associated with changes in hunger ratings as indicators of the subjective metabolic state. CONCLUSIONS taVNS increases stomach-brain coupling via an NTS-midbrain pathway that signals gut-induced reward, indicating that communication between the brain and the body is effectively modulated by vago-vagal signaling. Such insights may help us better understand the role of vagal afferents in orchestrating the recruitment of the gastric network which could pave the way for novel neuromodulatory treatments.
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Parent MB. Using Postmeal Measures and Manipulations to Investigate Hippocampal Mnemonic Control of Eating Behavior. Neuroscience 2022; 497:228-238. [PMID: 34998891 PMCID: PMC9256844 DOI: 10.1016/j.neuroscience.2021.12.040] [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: 09/12/2021] [Revised: 12/27/2021] [Accepted: 12/30/2021] [Indexed: 10/19/2022]
Abstract
Episodic meal-related memories provide the brain with a powerful mechanism for tracking and controlling eating behavior because they contain a detailed record of recent energy intake that likely outlasts the physiological signals generated by feeding bouts. This review briefly summarizes evidence from human participants showing that episodic meal-related memory limits later eating behavior and then describes our research aimed at investigating whether hippocampal neurons mediate the inhibitory effects of meal-related memory on subsequent feeding. Our approach has been inspired by pioneering work conducted by Ivan Izquierdo and others who used posttraining manipulations to investigate memory consolidation. This review describes the rationale and value of posttraining manipulations, how Izquierdo used them to demonstrate that dorsal hippocampal (dHC) neurons are critical for memory consolidation, and how we have adapted this strategy to investigate whether dHC neurons are necessary for mnemonic control of energy intake. I describe our evidence showing that ingestion activates the molecular processes necessary for synaptic plasticity and memory during the early postprandial period, when the memory of the meal would be undergoing consolidation, and then summarize our findings showing that neural activity in dHC neurons is critical during the early postprandial period for limiting future intake. Collectively, our evidence supports the hypothesis that dHC neurons mediate the inhibitory effects of ingestion-related memory on future intake and demonstrates that post-experience memory modulation is not confined to artificial laboratory memory tasks.
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Affiliation(s)
- M B Parent
- Neuroscience Institute & Department of Psychology, Georgia State University, PO Box 5030, Atlanta, GA 30303, USA.
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27
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Mamedova E, Árting LB, Rekling JC. Bile acids induce Ca 2+ signaling and membrane permeabilizations in vagal nodose ganglion neurons. Biochem Biophys Rep 2022; 31:101288. [PMID: 35669985 PMCID: PMC9162955 DOI: 10.1016/j.bbrep.2022.101288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 11/20/2022] Open
Abstract
Bile acids (BAs) play an important role in the digestion of dietary fats and act as signaling molecules. However, due to their solubilizing properties, high concentrations in the gut may negatively affect gut epithelium and possibly afferent fibers innervating the gastrointestinal tract (GI). To determine the effect of BAs on intracellular Ca2+ and membrane permeabilization we tested a range of concentrations of two BAs on vagal nodose ganglion (NG) neurons, Chinese Hamster Ovary (CHO), and PC12 cell lines. NG explants from mice were drop-transduced with the genetically encoded Ca2+ indicator AAV9-Syn-jGCaMP7s and used to measure Ca2+ changes upon application of deoxycholic acid (DCA) and taurocholic acid (TCA). We found that both BAs induced a Ca2+ increase in NG neurons in a dose-dependent manner. The DCA-induced Ca2+ increase was dependent on intracellular Ca2+ stores. NG explants, with an intact peripheral part of the vagus nerve, showed excitation of NG neurons in nerve field recordings upon exposure to DCA. The viability of NG neurons at different BA concentrations was determined, and compared to CHO and PC12 cells lines using propidium iodide labeling, showing threshold concentrations of BA-induced cell death at 400–500 μM. These observations suggest that BAs act as Ca2+-inducing signaling molecules in vagal sensory neurons at low concentrations, but induce cell death at higher concentrations, which may occur during inflammatory bowel diseases. Intracellular Ca2+ is measured in hundreds of explant vagal sensory neurons using jGCaMP7s. Bile acids deoxycholic acid and taurocholic acid induce a Ca2+ increase in vagal sensory neurons. Deoxycholic acid -induced Ca2+ increase is dependent on intracellular Ca2+ stores. Bile acid concentrations above 400–500 μM permeabilize the membrane inducing cell death.
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28
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Payne SC, Ward G, Fallon JB, Hyakumura T, Prins JB, Andrikopoulos S, MacIsaac RJ, Villalobos J. Blood glucose modulation and safety of efferent vagus nerve stimulation in a type 2 diabetic rat model. Physiol Rep 2022; 10:e15257. [PMID: 35439355 PMCID: PMC9017977 DOI: 10.14814/phy2.15257] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 12/21/2022] Open
Abstract
Vagus nerve stimulation is emerging as a promising treatment for type 2 diabetes. Here, we evaluated the ability of stimulation of the vagus nerve to reduce glycemia in awake, freely moving metabolically compromised rats. A model of type 2 diabetes (n = 10) was induced using a high‐fat diet and low doses of streptozotocin. Stimulation of the abdominal vagus nerve was achieved by pairing 15 Hz pulses on a distal pair of electrodes with high‐frequency blocking stimulation (26 kHz, 4 mA) on a proximal pair of electrodes to preferentially produce efferent conducting activity (eVNS). Stimulation was well tolerated in awake, freely moving rats. During 1 h of eVNS, glycemia decreased in 90% of subjects (−1.25 ± 1.25 mM h, p = 0.017), and 2 dB above neural threshold was established as the most effective “dose” of eVNS (p = 0.009). Following 5 weeks of implantation, eVNS was still effective, resulting in significantly decreased glycemia (−1.7 ± 0.6 mM h, p = 0.003) during 1 h of eVNS. There were no overt changes in fascicle area or signs of histopathological damage observed in implanted vagal nerve tissue following chronic implantation and stimulation. Demonstration of the biocompatibility and safety of eVNS in awake, metabolically compromised animals is a critical first step to establishing this therapy for clinical use. With further development, eVNS could be a promising novel therapy for treating type 2 diabetes.
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Affiliation(s)
- Sophie C Payne
- Bionics Institute, East Melbourne, Victoria, Australia.,Department of Medical Bionics, University of Melbourne, Parkville, Victoria, Australia
| | - Glenn Ward
- Bionics Institute, East Melbourne, Victoria, Australia.,Department of Endocrinology and Diabetes, St Vincent's Hospital Melbourne, Fitzroy, Victoria, Australia.,Melbourne Medical School, University of Melbourne, Parkville, Victoria, Australia
| | - James B Fallon
- Bionics Institute, East Melbourne, Victoria, Australia.,Department of Medical Bionics, University of Melbourne, Parkville, Victoria, Australia
| | - Tomoko Hyakumura
- Bionics Institute, East Melbourne, Victoria, Australia.,Department of Medical Bionics, University of Melbourne, Parkville, Victoria, Australia
| | - Johannes B Prins
- Melbourne Medical School, University of Melbourne, Parkville, Victoria, Australia.,Department of Endocrinology, Royal Melbourne Hospital, Parkville, Victoria, Australia.,Australian Centre for Accelerating Diabetes Innovations, University of Melbourne, Melbourne, Australia
| | - Sofianos Andrikopoulos
- Australian Centre for Accelerating Diabetes Innovations, University of Melbourne, Melbourne, Australia.,Department of Medicine (Austin Health), University of Melbourne, Heidelberg, Victoria, Australia
| | - Richard J MacIsaac
- Bionics Institute, East Melbourne, Victoria, Australia.,Department of Endocrinology and Diabetes, St Vincent's Hospital Melbourne, Fitzroy, Victoria, Australia.,Melbourne Medical School, University of Melbourne, Parkville, Victoria, Australia.,Australian Centre for Accelerating Diabetes Innovations, University of Melbourne, Melbourne, Australia
| | - Joel Villalobos
- Bionics Institute, East Melbourne, Victoria, Australia.,Department of Medical Bionics, University of Melbourne, Parkville, Victoria, Australia
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Prescott SL, Liberles SD. Internal senses of the vagus nerve. Neuron 2022; 110:579-599. [PMID: 35051375 PMCID: PMC8857038 DOI: 10.1016/j.neuron.2021.12.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/30/2021] [Accepted: 12/11/2021] [Indexed: 12/16/2022]
Abstract
The vagus nerve is an indispensable body-brain connection that controls vital aspects of autonomic physiology like breathing, heart rate, blood pressure, and gut motility, reflexes like coughing and swallowing, and survival behaviors like feeding, drinking, and sickness responses. Classical physiological studies and recent molecular/genetic approaches have revealed a tremendous diversity of vagal sensory neuron types that innervate different internal organs, with many cell types remaining poorly understood. Here, we review the state of knowledge related to vagal sensory neurons that innervate the respiratory, cardiovascular, and digestive systems. We focus on cell types and their response properties, physiological/behavioral roles, engaged neural circuits and, when possible, sensory receptors. We are only beginning to understand the signal transduction mechanisms used by vagal sensory neurons and upstream sentinel cells, and future studies are needed to advance the field of interoception to the level of mechanistic understanding previously achieved for our external senses.
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30
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Silencing gut CCK cells alters gut reaction to sugar. Nat Neurosci 2022; 25:136-138. [PMID: 35027762 DOI: 10.1038/s41593-021-00998-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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31
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Singh R, Stogios N, Smith E, Lee J, Maksyutynsk K, Au E, Wright DC, De Palma G, Graff-Guerrero A, Gerretsen P, Müller DJ, Remington G, Hahn M, Agarwal SM. Gut microbiome in schizophrenia and antipsychotic-induced metabolic alterations: a scoping review. Ther Adv Psychopharmacol 2022; 12:20451253221096525. [PMID: 35600753 PMCID: PMC9118432 DOI: 10.1177/20451253221096525] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 04/07/2022] [Indexed: 12/11/2022] Open
Abstract
Schizophrenia (SCZ) is a severe mental disorder with high morbidity and lifetime disability rates. Patients with SCZ have a higher risk of developing metabolic comorbidities such as obesity and diabetes mellitus, leading to increased mortality. Antipsychotics (APs), which are the mainstay in the treatment of SCZ, increase the risk of these metabolic perturbations. Despite extensive research, the mechanism underlying SCZ pathophysiology and associated metabolic comorbidities remains unclear. In recent years, gut microbiota (GMB) has been regarded as a 'chamber of secrets', particularly in the context of severe mental illnesses such as SCZ, depression, and bipolar disorder. In this scoping review, we aimed to investigate the underlying role of GMB in the pathophysiology of SCZ and metabolic alterations associated with APs. Furthermore, we also explored the therapeutic benefits of prebiotic and probiotic formulations in managing SCZ and AP-induced metabolic alterations. A systematic literature search yielded 46 studies from both preclinical and clinical settings that met inclusion criteria for qualitative synthesis. Preliminary evidence from preclinical and clinical studies indicates that GMB composition changes are associated with SCZ pathogenesis and AP-induced metabolic perturbations. Fecal microbiota transplantation from SCZ patients to mice has been shown to induce SCZ-like behavioral phenotypes, further supporting the plausible role of GMB in SCZ pathogenesis. This scoping review recapitulates the preclinical and clinical evidence suggesting the role of GMB in SCZ symptomatology and metabolic adverse effects associated with APs. Moreover, this scoping review also discusses the therapeutic potentials of prebiotic/probiotic formulations in improving SCZ symptoms and attenuating metabolic alterations related to APs.
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Affiliation(s)
- Raghunath Singh
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Nicolette Stogios
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Emily Smith
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Jiwon Lee
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Kateryna Maksyutynsk
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Emily Au
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - David C Wright
- Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Giada De Palma
- Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, ON, Canada
| | - Ariel Graff-Guerrero
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Philip Gerretsen
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Daniel J Müller
- Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Gary Remington
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Margaret Hahn
- Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), Toronto, ON, Canada
| | - Sri Mahavir Agarwal
- Staff Psychiatrist and Clinician-Scientist, Medical Head, Clinical Research, Schizophrenia Division, Centre for Addiction and Mental Health (CAMH), 1051 Queen Street W, Toronto, ON M6J 1H3, Canada
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32
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Parent MB, Higgs S, Cheke LG, Kanoski SE. Memory and eating: A bidirectional relationship implicated in obesity. Neurosci Biobehav Rev 2022; 132:110-129. [PMID: 34813827 PMCID: PMC8816841 DOI: 10.1016/j.neubiorev.2021.10.051] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 10/17/2021] [Accepted: 10/28/2021] [Indexed: 01/03/2023]
Abstract
This paper reviews evidence demonstrating a bidirectional relationship between memory and eating in humans and rodents. In humans, amnesia is associated with impaired processing of hunger and satiety cues, disrupted memory of recent meals, and overconsumption. In healthy participants, meal-related memory limits subsequent ingestive behavior and obesity is associated with impaired memory and disturbances in the hippocampus. Evidence from rodents suggests that dorsal hippocampal neural activity contributes to the ability of meal-related memory to control future intake, that endocrine and neuropeptide systems act in the ventral hippocampus to provide cues regarding energy status and regulate learned aspects of eating, and that consumption of hypercaloric diets and obesity disrupt these processes. Collectively, this evidence indicates that diet-induced obesity may be caused and/or maintained, at least in part, by a vicious cycle wherein excess intake disrupts hippocampal functioning, which further increases intake. This perspective may advance our understanding of how the brain controls eating, the neural mechanisms that contribute to eating-related disorders, and identify how to treat diet-induced obesity.
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Affiliation(s)
- Marise B. Parent
- Neuroscience Institute & Department of Psychology, Georgia State University, Box 5030, Atlanta, GA 30303-5030, United States,Corresponding author: Marise B. Parent, , Georgia State University, PO Box 5030, Atlanta, GA 30303-5030, USA. Fax: 404-413-5446
| | - Suzanne Higgs
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, BI5 2TT, United Kingdom
| | - Lucy G. Cheke
- Department of Psychology, University of Cambridge, Downing Street, Cambridge, CB2 3EB United Kingdom
| | - Scott E Kanoski
- Department of Biological Sciences, Human and Evolutionary Biology Section, University of Southern California, Los Angeles, CA, 90089-0371, United States
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Matsubara Y, Kiyohara H, Teratani T, Mikami Y, Kanai T. Organ and brain crosstalk: The liver-brain axis in gastrointestinal, liver, and pancreatic diseases. Neuropharmacology 2021; 205:108915. [PMID: 34919906 DOI: 10.1016/j.neuropharm.2021.108915] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/01/2021] [Accepted: 12/06/2021] [Indexed: 12/15/2022]
Abstract
The liver is the largest organ in the human body and is responsible for the metabolism and storage of the three principal nutrients: carbohydrates, fats, and proteins. In addition, the liver contributes to the breakdown and excretion of alcohol, medicinal agents, and toxic substances and the production and secretion of bile. In addition to its role as a metabolic centre, the liver has recently attracted attention for its function in the liver-brain axis, which interacts closely with the central nervous system via the autonomic nervous system, including the vagus nerve. The liver-brain axis influences the control of eating behaviour in the central nervous system through stimuli from the liver. Conversely, neural signals from the central nervous system influence glucose, lipid, and protein metabolism in the liver. The liver also receives a constant influx of nutrients and hormones from the intestinal tract and compounds of bacterial origin via the portal system. As a result, the intestinal tract and liver are involved in various immunological interactions. A good example is the co-occurrence of primary sclerosing cholangitis and ulcerative colitis. These heterogeneous roles of the liver-brain axis are mediated via the vagus nerve in an asymmetrical manner. In this review, we provide an overview of these interactions, mainly with the liver but also with the brain and gut.
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Affiliation(s)
- Yuta Matsubara
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Hiroki Kiyohara
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Toshiaki Teratani
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yohei Mikami
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
| | - Takanori Kanai
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, 100-0004, Japan.
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Ito T, Yamamoto Y, Yamagishi N, Kanai Y. Stomach secretes estrogen in response to the blood triglyceride levels. Commun Biol 2021; 4:1364. [PMID: 34876651 PMCID: PMC8651635 DOI: 10.1038/s42003-021-02901-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 11/23/2021] [Indexed: 11/29/2022] Open
Abstract
Mammals receive body energy information to maintain energy homeostasis. Ghrelin, insulin, leptin and vagal afferents transmit the status of fasting, blood glucose, body fat, and food intake, respectively. Estrogen also inhibits feeding behavior and lipogenesis, but increases body fat mass. However, how blood triglyceride levels are monitored and the physiological roles of estrogen from the perspective of lipid homeostasis remain unsettled. Here, we show that stomach secretes estrogen in response to the blood triglyceride levels. Estrogen-secreting gastric parietal cells predominantly use fatty acids as an energy source. Blood estrogen levels increase as blood triglyceride levels rise in a stomach-dependent manner. Estrogen levels in stomach tissues increase as blood triglyceride levels rise, and isolated gastric gland epithelium produces estrogen in a fatty acid-dependent manner. We therefore propose that stomach monitors and controls blood triglyceride levels using estrogen, which inhibits feeding behavior and lipogenesis, and promotes triglyceride uptake by adipocytes.
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Affiliation(s)
- Takao Ito
- Cell Biology and Anatomy, Graduate School of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Yuta Yamamoto
- Cell Biology and Anatomy, Graduate School of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Naoko Yamagishi
- Cell Biology and Anatomy, Graduate School of Medicine, Wakayama Medical University, Wakayama, Japan
| | - Yoshimitsu Kanai
- Cell Biology and Anatomy, Graduate School of Medicine, Wakayama Medical University, Wakayama, Japan.
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35
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Ye L, Rawls JF. Microbial influences on gut development and gut-brain communication. Development 2021; 148:dev194936. [PMID: 34758081 PMCID: PMC8627602 DOI: 10.1242/dev.194936] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/07/2021] [Indexed: 12/15/2022]
Abstract
The developmental programs that build and sustain animal forms also encode the capacity to sense and adapt to the microbial world within which they evolved. This is abundantly apparent in the development of the digestive tract, which typically harbors the densest microbial communities of the body. Here, we review studies in human, mouse, zebrafish and Drosophila that are revealing how the microbiota impacts the development of the gut and its communication with the nervous system, highlighting important implications for human and animal health.
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Cook TM, Gavini CK, Jesse J, Aubert G, Gornick E, Bonomo R, Gautron L, Layden BT, Mansuy-Aubert V. Vagal neuron expression of the microbiota-derived metabolite receptor, free fatty acid receptor (FFAR3), is necessary for normal feeding behavior. Mol Metab 2021; 54:101350. [PMID: 34626852 PMCID: PMC8567301 DOI: 10.1016/j.molmet.2021.101350] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/15/2021] [Accepted: 09/30/2021] [Indexed: 12/12/2022] Open
Abstract
Objective The vagus nerve provides a direct line of communication between the gut and the brain for proper regulation of energy balance and glucose homeostasis. Short-chain fatty acids (SCFAs) produced via gut microbiota fermentation of dietary fiber have been proposed to regulate host metabolism and feeding behavior via the vagus nerve, but the molecular mechanisms have not yet been elucidated. We sought to identify the G-protein-coupled receptors within vagal neurons that mediate the physiological and therapeutic benefits of SCFAs. Methods SCFA, particularly propionate, signaling occurs via free fatty acid receptor 3 (FFAR3), that we found expressed in vagal sensory neurons innervating throughout the gut. The lack of cell-specific animal models has impeded our understanding of gut/brain communication; therefore, we generated a mouse model for cre-recombinase-driven deletion of Ffar3. We comprehensively characterized the feeding behavior of control and vagal-FFAR3 knockout (KO) mice in response to various conditions including fasting/refeeding, western diet (WD) feeding, and propionate supplementation. We also utilized ex vivo organotypic vagal cultures to investigate the signaling pathways downstream of propionate FFAR3 activation. Results Vagal-FFAR3KO led to increased meal size in males and females, and increased food intake during fasting/refeeding and WD challenges. In addition, the anorectic effect of propionate supplementation was lost in vagal-FFAR3KO mice. Sequencing approaches combining ex vivo and in vivo experiments revealed that the cross-talk of FFAR3 signaling with cholecystokinin (CCK) and leptin receptor pathways leads to alterations in food intake. Conclusion Altogether, our data demonstrate that FFAR3 expressed in vagal neurons regulates feeding behavior and mediates propionate-induced decrease in food intake. Lack of vagal FFAR3 increases food intake. Anorectic effect of propionate is lost when FFAR3 is absent from vagal neurons. FFAR3 signaling cross-talks with cholecystokinin (CCK) and leptin receptor pathways to alter food intake.
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Affiliation(s)
- Tyler M Cook
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood IL, 60153, USA
| | - Chaitanya K Gavini
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood IL, 60153, USA
| | - Jason Jesse
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood IL, 60153, USA
| | - Gregory Aubert
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood IL, 60153, USA; Department of Internal Medicine, Division of Cardiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Emily Gornick
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood IL, 60153, USA
| | - Raiza Bonomo
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood IL, 60153, USA
| | - Laurent Gautron
- Center for Hypothalamic Research, Department of Internal Medicine, The University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, 75390, TX, USA
| | - Brian T Layden
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Virginie Mansuy-Aubert
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood IL, 60153, USA.
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37
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Büki A, Kekesi G, Horvath G, Vécsei L. A Potential Interface between the Kynurenine Pathway and Autonomic Imbalance in Schizophrenia. Int J Mol Sci 2021; 22:10016. [PMID: 34576179 PMCID: PMC8467675 DOI: 10.3390/ijms221810016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 02/07/2023] Open
Abstract
Schizophrenia is a neuropsychiatric disorder characterized by various symptoms including autonomic imbalance. These disturbances involve almost all autonomic functions and might contribute to poor medication compliance, worsened quality of life and increased mortality. Therefore, it has a great importance to find a potential therapeutic solution to improve the autonomic disturbances. The altered level of kynurenines (e.g., kynurenic acid), as tryptophan metabolites, is almost the most consistently found biochemical abnormality in schizophrenia. Kynurenic acid influences different types of receptors, most of them involved in the pathophysiology of schizophrenia. Only few data suggest that kynurenines might have effects on multiple autonomic functions. Publications so far have discussed the implication of kynurenines and the alteration of the autonomic nervous system in schizophrenia independently from each other. Thus, the coupling between them has not yet been addressed in schizophrenia, although their direct common points, potential interfaces indicate the consideration of their interaction. The present review gathers autonomic disturbances, the impaired kynurenine pathway in schizophrenia, and the effects of kynurenine pathway on autonomic functions. In the last part of the review, the potential interaction between the two systems in schizophrenia, and the possible therapeutic options are discussed.
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Affiliation(s)
- Alexandra Büki
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary; (A.B.); (G.K.); (G.H.)
| | - Gabriella Kekesi
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary; (A.B.); (G.K.); (G.H.)
| | - Gyongyi Horvath
- Department of Physiology, Albert Szent-Györgyi Medical School, University of Szeged, Dóm tér 10., H-6720 Szeged, Hungary; (A.B.); (G.K.); (G.H.)
| | - László Vécsei
- Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6., H-6725 Szeged, Hungary
- MTA-SZTE Neuroscience Research Group, H-6725 Szeged, Hungary
- Interdisciplinary Excellence Center, Department of Neurology, Albert Szent-Györgyi Medical School, University of Szeged, Semmelweis u. 6., H-6725 Szeged, Hungary
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38
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Berland C, Small DM, Luquet S, Gangarossa G. Dietary lipids as regulators of reward processes: multimodal integration matters. Trends Endocrinol Metab 2021; 32:693-705. [PMID: 34148784 DOI: 10.1016/j.tem.2021.05.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2021] [Revised: 05/08/2021] [Accepted: 05/24/2021] [Indexed: 02/03/2023]
Abstract
The abundance of energy-dense and palatable diets in the modern food environment tightly contributes to the obesity pandemic. The reward circuit participates to the regulation of body homeostasis by integrating energy-related signals with neural substrates encoding cognitive and motivational components of feeding behaviors. Obesity and lipid-rich diets alter dopamine (DA) transmission leading to reward dysfunctions and food overconsumption. Recent reports indicate that dietary lipids can act, directly and indirectly, as functional modulators of the DA circuit. This raises the possibility that nutritional or genetic conditions affecting 'lipid sensing' mechanisms might lead to maladaptations of the DA system. Here, we discuss the most recent findings connecting dietary lipid sensing with DA signaling and its multimodal influence on circuits regulating food-reward processes.
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Affiliation(s)
- Chloé Berland
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France; Department of Medicine, The Naomi Berrie Diabetes Center, Columbia University, New York, NY 10032, USA
| | - Dana M Small
- Department of Psychiatry, and the Modern Diet and Physiology Research Center, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Serge Luquet
- Université de Paris, BFA, UMR 8251, CNRS, F-75013 Paris, France.
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39
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Raybould HE, Zumpano DL. Microbial metabolites and the vagal afferent pathway in the control of food intake. Physiol Behav 2021; 240:113555. [PMID: 34375620 DOI: 10.1016/j.physbeh.2021.113555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 07/06/2021] [Accepted: 08/06/2021] [Indexed: 02/06/2023]
Abstract
The gut microbiota is able to influence overall energy balance via effects on both energy intake and expenditure, and is a peripheral target for potential obesity therapies. However, the precise mechanism by which the gut microbiota influences energy intake and body weight regulation is not clear. Microbes use small molecules to communicate with each other; some of these molecules are ligands at mammalian receptors and this may be a mechanism by which microbes communicate with the host. Here we briefly review the literature showing beneficial effects of microbial metabolites on food intake regulation and examine the potential role for vagal afferent neurons, the gut-brain axis.
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Affiliation(s)
- Helen E Raybould
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, UC Davis, Davis, CA 95616, USA.
| | - Danielle L Zumpano
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, UC Davis, Davis, CA 95616, USA
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40
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The Interplay between Nutrition, Innate Immunity, and the Commensal Microbiota in Adaptive Intestinal Morphogenesis. Nutrients 2021; 13:nu13072198. [PMID: 34206809 PMCID: PMC8308283 DOI: 10.3390/nu13072198] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/20/2021] [Accepted: 06/23/2021] [Indexed: 12/15/2022] Open
Abstract
The gastrointestinal tract is a functionally and anatomically segmented organ that is colonized by microbial communities from birth. While the genetics of mouse gut development is increasingly understood, how nutritional factors and the commensal gut microbiota act in concert to shape tissue organization and morphology of this rapidly renewing organ remains enigmatic. Here, we provide an overview of embryonic mouse gut development, with a focus on the intestinal vasculature and the enteric nervous system. We review how nutrition and the gut microbiota affect the adaptation of cellular and morphologic properties of the intestine, and how these processes are interconnected with innate immunity. Furthermore, we discuss how nutritional and microbial factors impact the renewal and differentiation of the epithelial lineage, influence the adaptation of capillary networks organized in villus structures, and shape the enteric nervous system and the intestinal smooth muscle layers. Intriguingly, the anatomy of the gut shows remarkable flexibility to nutritional and microbial challenges in the adult organism.
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41
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Abstract
The gut microbiota has the capacity to affect host appetite via intestinal satiety pathways, as well as complex feeding behaviors. In this Review, we highlight recent evidence that the gut microbiota can modulate food preference across model organisms. We discuss effects of the gut microbiota on the vagus nerve and brain regions including the hypothalamus, mesolimbic system, and prefrontal cortex, which play key roles in regulating feeding behavior. Crosstalk between commensal bacteria and the central and peripheral nervous systems is associated with alterations in signaling of neurotransmitters and neuropeptides such as dopamine, brain-derived neurotrophic factor (BDNF), and glucagon-like peptide-1 (GLP-1). We further consider areas for future research on mechanisms by which gut microbes may influence feeding behavior involving these neural pathways. Understanding roles for the gut microbiota in feeding regulation will be important for informing therapeutic strategies to treat metabolic and eating disorders.
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42
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Imai J, Katagiri H. Regulation of systemic metabolism by the autonomic nervous system consisting of afferent and efferent innervation. Int Immunol 2021; 34:67-79. [PMID: 33982088 DOI: 10.1093/intimm/dxab023] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/10/2021] [Indexed: 12/18/2022] Open
Abstract
Autonomic nerves, sympathetic and parasympathetic, innervate organs and modulate their functions. It has become evident that afferent and efferent signals of the autonomic nervous system play important roles in regulating systemic metabolism, thereby maintaining homeostasis at the whole-body level. Vagal afferent nerves receive signals, such as nutrients and hormones, from the peripheral organs/tissues including the gastrointestinal tract and adipose tissue then transmit these signals to the hypothalamus, thereby regulating feeding behavior. In addition to roles in controlling appetite, areas in the hypothalamus serves as regulatory centers of both sympathetic and parasympathetic efferent fibers. These efferent innervations regulate the functions of peripheral organs/tissues, such as pancreatic islets, adipose tissues and the liver, which play roles in metabolic regulation. Furthermore, recent evidence has unraveled the metabolic regulatory systems governed by autonomic nerve circuits. In these systems, afferent nerves transmit metabolic information from peripheral organs to the central nervous system (CNS) and the CNS thereby regulates the organ functions through the efferent fibers of autonomic nerves. Thus, the autonomic nervous system regulates the homeostasis of systemic metabolism, and both afferent and efferent fibers play critical roles in its regulation. In addition, several lines of evidence demonstrate the roles of the autonomic nervous system in regulating and dysregulating the immune system. This review introduces variety of neuron-mediated inter-organ cross-talk systems and organizes the current knowledge of autonomic control/coordination of systemic metabolism, focusing especially on a liver-brain-pancreatic β-cell autonomic nerve circuit, as well as highlighting the potential importance of connections with the neuronal and immune systems.
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Affiliation(s)
- Junta Imai
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, Japan
| | - Hideki Katagiri
- Department of Metabolism and Diabetes, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, Japan
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43
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Plassmann H, Schelski DS, Simon MC, Koban L. How we decide what to eat: Toward an interdisciplinary model of gut-brain interactions. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2021; 13:e1562. [PMID: 33977675 PMCID: PMC9286667 DOI: 10.1002/wcs.1562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 11/12/2022]
Abstract
Everyday dietary decisions have important short‐term and long‐term consequences for health and well‐being. How do we decide what to eat, and what physiological and neurobiological systems are involved in those decisions? Here, we integrate findings from thus‐far separate literatures: (a) the cognitive neuroscience of dietary decision‐making, and (b) growing evidence of gut–brain interactions and especially influences of the gut microbiome on diet and health outcomes. We review findings that suggest that dietary decisions and food consumption influence nutrient sensing, homeostatic signaling in the gut, and the composition of the gut microbiome. In turn, the microbiome can influence host health and behavior. Through reward signaling pathways, the microbiome could potentially affect food and drink decisions. Such bidirectional links between gut microbiome and the brain systems underlying dietary decision‐making may lead to self‐reinforcing feedback loops that determine long‐term dietary patterns, body mass, and health outcomes. This article is categorized under:Economics > Individual Decision‐Making Psychology > Brain Function and Dysfunction Psychology > Reasoning and Decision Making
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Affiliation(s)
- Hilke Plassmann
- Marketing Area, INSEAD, Fontainebleau, France.,Paris Brain Institute (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| | - Daniela Stephanie Schelski
- Center for Economics and Neuroscience, University of Bonn, Bonn, Germany.,Institute of Experimental Epileptology and Cognition Research, University of Bonn Medical Center, Bonn, Germany
| | - Marie-Christine Simon
- Institute of Nutrition and Food Science (IEL), Nutrition and Microbiota, University of Bonn, Bonn, Germany
| | - Leonie Koban
- Marketing Area, INSEAD, Fontainebleau, France.,Paris Brain Institute (ICM), INSERM U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
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44
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Stogios N, Gdanski A, Gerretsen P, Chintoh AF, Graff-Guerrero A, Rajji TK, Remington G, Hahn MK, Agarwal SM. Autonomic nervous system dysfunction in schizophrenia: impact on cognitive and metabolic health. NPJ SCHIZOPHRENIA 2021; 7:22. [PMID: 33903594 PMCID: PMC8076312 DOI: 10.1038/s41537-021-00151-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 03/18/2021] [Indexed: 12/17/2022]
Abstract
Schizophrenia (SCZ) is a psychiatric disorder characterized by a wide range of positive, negative and cognitive symptoms, along with an increased risk of metabolic syndrome and cardiovascular disease that contribute to a 15-20-year reduced life expectancy. Autonomic dysfunction, in the form of increased sympathetic activity and decreased parasympathetic activity, is postulated to be implicated in SCZ and its treatment. The aim of this narrative review is to view SCZ through an autonomic lens and synthesize the evidence relating autonomic dysfunction to different domains of SCZ. Using various methods of assessing autonomic activity, autonomic dysfunction was found to be associated with multiple aspects of SCZ pathophysiology, including symptom severity, cognitive impairment, and the development of cardiometabolic comorbidities, such as metabolic syndrome and high BMI. The strongest association of low heart rate variability was noted among patients on antipsychotic treatment with high-affinity muscarinic antagonism (i.e., clozapine, olanzapine and quetiapine). The review will also suggest ways in which studying autonomic dysfunction can help reduce morbidity and mortality associated with SCZ and its treatment.
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Affiliation(s)
- Nicolette Stogios
- Institute of Medical Science, University of Toronto, Toronto, Canada.,Center for Addiction and Mental Health (CAMH), Toronto, Canada
| | | | - Philip Gerretsen
- Institute of Medical Science, University of Toronto, Toronto, Canada.,Center for Addiction and Mental Health (CAMH), Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Araba F Chintoh
- Center for Addiction and Mental Health (CAMH), Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Ariel Graff-Guerrero
- Institute of Medical Science, University of Toronto, Toronto, Canada.,Center for Addiction and Mental Health (CAMH), Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Tarek K Rajji
- Institute of Medical Science, University of Toronto, Toronto, Canada.,Center for Addiction and Mental Health (CAMH), Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Gary Remington
- Institute of Medical Science, University of Toronto, Toronto, Canada.,Center for Addiction and Mental Health (CAMH), Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Margaret K Hahn
- Institute of Medical Science, University of Toronto, Toronto, Canada.,Center for Addiction and Mental Health (CAMH), Toronto, Canada.,Department of Psychiatry, University of Toronto, Toronto, Canada
| | - Sri Mahavir Agarwal
- Institute of Medical Science, University of Toronto, Toronto, Canada. .,Center for Addiction and Mental Health (CAMH), Toronto, Canada. .,Department of Psychiatry, University of Toronto, Toronto, Canada.
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45
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Li RJW, Batchuluun B, Zhang SY, Abraham MA, Wang B, Lim YM, Yue JTY, Lam TKT. Nutrient infusion in the dorsal vagal complex controls hepatic lipid and glucose metabolism in rats. iScience 2021; 24:102366. [PMID: 33870148 PMCID: PMC8044434 DOI: 10.1016/j.isci.2021.102366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 02/08/2021] [Accepted: 03/24/2021] [Indexed: 11/22/2022] Open
Abstract
Hypothalamic regulation of lipid and glucose homeostasis is emerging, but whether the dorsal vagal complex (DVC) senses nutrients and regulates hepatic nutrient metabolism remains unclear. Here, we found in rats DVC oleic acid infusion suppressed hepatic secretion of triglyceride-rich very-low-density lipoprotein (VLDL-TG), which was disrupted by inhibiting DVC long-chain fatty acyl-CoA synthetase that in parallel disturbed lipid homeostasis during intravenous lipid infusion. DVC glucose infusion elevated local glucose levels similarly as intravenous glucose infusion and suppressed hepatic glucose production. This was independent of lactate metabolism as inhibiting lactate dehydrogenase failed to disrupt glucose sensing and neither could DVC lactate infusion recapitulate glucose effect. DVC oleic acid and glucose infusion failed to lower VLDL-TG secretion and glucose production in high-fat fed rats, while inhibiting DVC farnesoid X receptor enhanced oleic acid but not glucose sensing. Thus, an impairment of DVC nutrient sensing may lead to the disruption of lipid and glucose homeostasis in metabolic syndrome. DVC oleic acid infusion lowers hepatic secretion of VLDL-TG in chow but not HF rats Inhibition of ACSL in the DVC negates lipid sensing DVC glucose infusion lowers hepatic glucose production in chow but not HF rats Inhibition of FXR in the DVC enhances oleic acid but not glucose sensing in HF rats
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Affiliation(s)
- Rosa J W Li
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.,Toronto General Hospital Research Institute, UHN, MaRS Center, TMDT 101 College Street, 10-705, Toronto, ON M5G 1L7, Canada
| | - Battsetseg Batchuluun
- Toronto General Hospital Research Institute, UHN, MaRS Center, TMDT 101 College Street, 10-705, Toronto, ON M5G 1L7, Canada
| | - Song-Yang Zhang
- Toronto General Hospital Research Institute, UHN, MaRS Center, TMDT 101 College Street, 10-705, Toronto, ON M5G 1L7, Canada
| | - Mona A Abraham
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.,Toronto General Hospital Research Institute, UHN, MaRS Center, TMDT 101 College Street, 10-705, Toronto, ON M5G 1L7, Canada
| | - Beini Wang
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.,Toronto General Hospital Research Institute, UHN, MaRS Center, TMDT 101 College Street, 10-705, Toronto, ON M5G 1L7, Canada
| | - Yu-Mi Lim
- Toronto General Hospital Research Institute, UHN, MaRS Center, TMDT 101 College Street, 10-705, Toronto, ON M5G 1L7, Canada.,Medical Research Institute, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul 03181, Republic of Korea
| | - Jessica T Y Yue
- Department of Physiology, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Tony K T Lam
- Department of Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.,Toronto General Hospital Research Institute, UHN, MaRS Center, TMDT 101 College Street, 10-705, Toronto, ON M5G 1L7, Canada.,Department of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.,Banting and Best Diabetes Centre, University of Toronto, Toronto, ON M5G 2C4, Canada
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46
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Richards P, Thornberry NA, Pinto S. The gut-brain axis: Identifying new therapeutic approaches for type 2 diabetes, obesity, and related disorders. Mol Metab 2021; 46:101175. [PMID: 33548501 PMCID: PMC8085592 DOI: 10.1016/j.molmet.2021.101175] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 01/21/2021] [Accepted: 01/27/2021] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The gut-brain axis, which mediates bidirectional communication between the gastrointestinal system and central nervous system (CNS), plays a fundamental role in multiple areas of physiology including regulating appetite, metabolism, and gastrointestinal function. The biology of the gut-brain axis is central to the efficacy of glucagon-like peptide-1 (GLP-1)-based therapies, which are now leading treatments for type 2 diabetes (T2DM) and obesity. This success and research to suggest a much broader role of gut-brain circuits in physiology and disease has led to increasing interest in targeting such circuits to discover new therapeutics. However, our current knowledge of this biology is limited, largely because the scientific tools have not been available to enable a detailed mechanistic understanding of gut-brain communication. SCOPE OF REVIEW In this review, we provide an overview of the current understanding of how sensory information from the gastrointestinal system is communicated to the central nervous system, with an emphasis on circuits involved in regulating feeding and metabolism. We then describe how recent technologies are enabling a better understanding of this system at a molecular level and how this information is leading to novel insights into gut-brain communication. We also discuss current therapeutic approaches that leverage the gut-brain axis to treat diabetes, obesity, and related disorders and describe potential novel approaches that have been enabled by recent advances in the field. MAJOR CONCLUSIONS The gut-brain axis is intimately involved in regulating glucose homeostasis and appetite, and this system plays a key role in mediating the efficacy of therapeutics that have had a major impact on treating T2DM and obesity. Research into the gut-brain axis has historically largely focused on studying individual components in this system, but new technologies are now enabling a better understanding of how signals from these components are orchestrated to regulate metabolism. While this work reveals a complexity of signaling even greater than previously appreciated, new insights are already being leveraged to explore fundamentally new approaches to treating metabolic diseases.
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Affiliation(s)
- Paul Richards
- Kallyope, Inc., 430 East 29th, Street, New York, NY, 10016, USA.
| | | | - Shirly Pinto
- Kallyope, Inc., 430 East 29th, Street, New York, NY, 10016, USA.
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47
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Duca FA, Waise TMZ, Peppler WT, Lam TKT. The metabolic impact of small intestinal nutrient sensing. Nat Commun 2021; 12:903. [PMID: 33568676 PMCID: PMC7876101 DOI: 10.1038/s41467-021-21235-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 01/19/2021] [Indexed: 12/12/2022] Open
Abstract
The gastrointestinal tract maintains energy and glucose homeostasis, in part through nutrient-sensing and subsequent signaling to the brain and other tissues. In this review, we highlight the role of small intestinal nutrient-sensing in metabolic homeostasis, and link high-fat feeding, obesity, and diabetes with perturbations in these gut-brain signaling pathways. We identify how lipids, carbohydrates, and proteins, initiate gut peptide release from the enteroendocrine cells through small intestinal sensing pathways, and how these peptides regulate food intake, glucose tolerance, and hepatic glucose production. Lastly, we highlight how the gut microbiota impact small intestinal nutrient-sensing in normal physiology, and in disease, pharmacological and surgical settings. Emerging evidence indicates that the molecular mechanisms of small intestinal nutrient sensing in metabolic homeostasis have physiological and pathological impact as well as therapeutic potential in obesity and diabetes. The gastrointestinal tract participates in maintaining metabolic homeostasis in part through nutrient-sensing and subsequent gut-brain signalling. Here the authors review the role of small intestinal nutrient-sensing in regulation of energy intake and systemic glucose metabolism, and link high-fat diet, obesity and diabetes with perturbations in these pathways.
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Affiliation(s)
- Frank A Duca
- BIO5 Institute, University of Arizona, Tucson, AZ, USA. .,School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ, USA.
| | - T M Zaved Waise
- Toronto General Hospital Research Institute, UHN, Toronto, Canada
| | - Willem T Peppler
- Toronto General Hospital Research Institute, UHN, Toronto, Canada
| | - Tony K T Lam
- Toronto General Hospital Research Institute, UHN, Toronto, Canada. .,Department of Physiology, University of Toronto, Toronto, Canada. .,Department of Medicine, University of Toronto, Toronto, Canada. .,Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada.
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48
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Abstract
Interoceptive signals from gut and adipose tissue and sensory cues from the environment are integrated by hubs in the brain to regulate feeding behavior and maintain homeostatic control of body weight. In vivo neural recordings have revealed that these signals control the activity of multiple layers of hunger neurons and eating is not only the result of feedback correction to a set point, but can also be under the influence of anticipatory regulations. A series of recent technical developments have revealed how peripheral and sensory signals, in particular, from the gut are conveyed to the brain to integrate neural circuits. Here, we describe the mechanisms involved in gastrointestinal stimulation by nutrients and how these signals act on the hindbrain to generate motivated behaviors. We also consider the organization of multidirectional intra- and extrahypothalamic circuits and how this has created a framework for understanding neural control of feeding.
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Affiliation(s)
- Alexandre Moura-Assis
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas, Campinas, Brazil
- Laboratory of Molecular Genetics, The Rockefeller University, New York, New York
| | - Jeffrey M Friedman
- Laboratory of Molecular Genetics, The Rockefeller University, New York, New York
- Howard Hughes Medical Institute, New York, New York
| | - Licio A Velloso
- Laboratory of Cell Signaling, Obesity and Comorbidities Research Center, State University of Campinas, Campinas, Brazil
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49
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Cawthon CR, Kirkland RA, Pandya S, Brinson NA, de La Serre CB. Non-neuronal crosstalk promotes an inflammatory response in nodose ganglia cultures after exposure to byproducts from gram positive, high-fat-diet-associated gut bacteria. Physiol Behav 2020; 226:113124. [PMID: 32763334 PMCID: PMC7530053 DOI: 10.1016/j.physbeh.2020.113124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 07/31/2020] [Accepted: 08/03/2020] [Indexed: 02/06/2023]
Abstract
Vagal afferent neurons (VAN) projecting to the lamina propria of the digestive tract are the primary source of gut-originating signals to the central nervous system (CNS). VAN cell bodies are found in the nodose ganglia (NG). Responsiveness of VAN to gut-originating signals is altered by feeding status with sensitivity to satiety signals such as cholecystokinin (CCK) increasing in the fed state. Chronic high-fat (HF) feeding results in inflammation at the level of the NG associated with a loss of VAN ability to switch phenotype from the fasted to the fed state. HF feeding also leads to compositional changes in the gut microbiota. HF diet consumption notably drives increased Firmicutes to Bacteroidetes phyla ratio and increased members of the Actinobacteria phylum. Firmicutes and Actinobacteria are largely gram positive (GP). In this study, we aimed to determine if byproducts from GP bacteria can induce an inflammatory response in cultured NG and to characterize the mechanism and cell types involved in the response. NG were collected from male Wistar rats and cultured for a total of 72 hours. At 48-68 hours after plating, cultures were treated with neuronal culture media in which Serinicoccus chungangensis had been grown and removed (SUP), lipoteichoic acid (LTA), or meso-diaminopimelic acid (meso-DAP). Some treatments included the glial inhibitors minocycline (MINO) and/or fluorocitrate (FC). The responses were evaluated using immunocytochemistry, qPCR, and electrochemiluminescence. We found that SUP induced an inflammatory response characterized by increased interleukin (IL)-6 staining and increased expression of genes for IL-6, interferon (IFN)γ, and tumor necrosis factor (TNF)α along with genes associated with cell-to-cell communication such as C-C motif chemokine ligand-2 (CCL2). Inclusion of inhibitors attenuated some responses but failed to completely normalize all indications of response, highlighting the role of immunocompetent cellular crosstalk in regulating the inflammatory response. LTA and meso-DAP produced responses that shared characteristics with SUP but were not identical. Our results support a role for HF associated GP bacterial byproducts' ability to contribute to vagal inflammation and to engage signaling from nonneuronal cells.
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Affiliation(s)
- Carolina R Cawthon
- Department of Foods and Nutrition, The University of Georgia, Athens, Georgia30602, United States
| | - Rebecca A Kirkland
- Department of Foods and Nutrition, The University of Georgia, Athens, Georgia30602, United States
| | - Shreya Pandya
- Department of Foods and Nutrition, The University of Georgia, Athens, Georgia30602, United States
| | - Nigel A Brinson
- Department of Foods and Nutrition, The University of Georgia, Athens, Georgia30602, United States
| | - Claire B de La Serre
- Department of Foods and Nutrition, The University of Georgia, Athens, Georgia30602, United States.
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Huang KP, Raybould HE. Estrogen and gut satiety hormones in vagus-hindbrain axis. Peptides 2020; 133:170389. [PMID: 32860834 PMCID: PMC8461656 DOI: 10.1016/j.peptides.2020.170389] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 07/27/2020] [Accepted: 08/22/2020] [Indexed: 10/23/2022]
Abstract
Estrogens modulate different physiological functions, including reproduction, inflammation, bone formation, energy expenditure, and food intake. In this review, we highlight the effect of estrogens on food intake regulation and the latest literature on intracellular estrogen signaling. In addition, gut satiety hormones, such as cholecystokinin, glucagon-like peptide 1 and leptin are essential to regulate ingestive behaviors in the postprandial period. These peripheral signals are sensed by vagal afferent terminals in the gut wall and transmitted to the hindbrain axis. Here we 1. review the role of the vagus-hindbrain axis in response to gut satiety signals and 2. consider the potential synergistic effects of estrogens on gut satiety signals at the level of vagal afferent neurons and nuclei located in the hindbrain. Understanding the action of estrogens in gut-brain axis provides a potential strategy to develop estrogen-based therapies for metabolic diseases and emphasizes the importance of sex difference in the treatment of obesity.
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Affiliation(s)
- Kuei-Pin Huang
- School of Veterinary Medicine, University of California Davis, CA, United States
| | - Helen E Raybould
- School of Veterinary Medicine, University of California Davis, CA, United States.
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