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Li P, Xiao Y, Zhou L, Zhang X, Xu Y, Wang X, Zou M, Guo X. A bibliometric analysis of interstitial cells of Cajal research. Front Med (Lausanne) 2024; 11:1391545. [PMID: 38831987 PMCID: PMC11145981 DOI: 10.3389/fmed.2024.1391545] [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: 02/26/2024] [Accepted: 03/25/2024] [Indexed: 06/05/2024] Open
Abstract
Objective The significance of interstitial cells of Cajal (ICC) in the gastrointestinal tract has garnered increasing attention. In recent years, approximately 80 articles on ICC have been published annually in various journals. However, no bibliometric study has specifically focused on the literature related to ICC. Therefore, we conducted a comprehensive bibliometric analysis of ICC to reveal dynamic scientific developments, assisting researchers in exploring hotspots and emerging trends while gaining a global perspective. Methods We conducted a literature search in the Web of Science Core Collection (WoSCC) from January 1, 2013, to December 31, 2023, to identify relevant literature on ICC. We employed bibliometric software, namely VOSviewer and CiteSpace, to analyze various aspects including annual publication output, collaborations, research hotspots, current status, and development trends in this domain. Results A total of 891 English papers were published in 359 journals by 928 institutions from 57 countries/regions. According to the keyword analysis of the literature, researchers mainly focused on "c-Kit," "expression," "smooth muscle," and "nitric oxide" related to ICC over the past 11 years. However, with "SIP syncytium," "ANO1," "enteric neurons," "gastrointestinal stromal tumors (GIST)," and "functional dyspepsia (FD)," there has been a growing interest in the relationship between ANO1, SIP syncytium, and ICC, as well as the role of ICC in the treatment of GIST and FD. Conclusion Bibliometric analysis has revealed the current status of ICC research. The association between ANO1, SIP syncytium, enteric neurons and ICC, as well as the role of ICC in the treatment of GIST versus FD has become the focus of current research. However, further research and collaboration on a global scale are still needed. Our analysis is particularly valuable to researchers in gastroenterology, oncology, and cell biology, providing insights that can guide future research directions.
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Affiliation(s)
- Pengyu Li
- School of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha, China
| | - Yadan Xiao
- School of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha, China
| | - Lan Zhou
- Integrated Traditional Chinese and Western Medicine Department, The Third Hospital of Changsha, Changsha, China
| | - Xuyuan Zhang
- School of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha, China
| | - Yin Xu
- Department of Gastroenterology, The First Hospital of Hunan University of Chinese Medicine, Changsha, China
| | - Xiaojuan Wang
- Department of Gastroenterology, The First Hospital of Hunan University of Chinese Medicine, Changsha, China
| | - Menglong Zou
- Department of Gastroenterology, The First Hospital of Hunan University of Chinese Medicine, Changsha, China
| | - Xuan Guo
- Science & Technology Innovation Center (National Key Laboratory Cultivation Base of Chinese Medicinal Powder & Innovative Medicinal Jointly Established by Province and Ministry), Hunan University of Chinese Medicine, Changsha, China
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2
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Zhang YX, Zhang YJ, Li M, Tian JX, Tong XL. Common Pathophysiological Mechanisms and Treatment of Diabetic Gastroparesis. J Neurogastroenterol Motil 2024; 30:143-155. [PMID: 38576367 PMCID: PMC10999838 DOI: 10.5056/jnm23100] [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: 07/06/2023] [Revised: 10/29/2023] [Accepted: 11/06/2023] [Indexed: 04/06/2024] Open
Abstract
Diabetic gastroparesis (DGP) is a common complication of diabetes mellitus, marked by gastrointestinal motility disorder, a delayed gastric emptying present in the absence of mechanical obstruction. Clinical manifestations include postprandial fullness and epigastric discomfort, bloating, nausea, and vomiting. DGP may significantly affect the quality of life and productivity of patients. Research on the relationship between gastrointestinal dynamics and DGP has received much attention because of the increasing prevalence of DGP. Gastrointestinal motility disorders are closely related to a variety of factors including the absence and destruction of interstitial cells of Cajal, abnormalities in the neuro-endocrine system and hormone levels. Therefore, this study will review recent literature on the mechanisms of DGP and gastrointestinal motility disorders as well as the development of prokinetic treatment of gastrointestinal motility disorders in order to give future research directions and identify treatment strategies for DGP.
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Affiliation(s)
- Yu-Xin Zhang
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yan-Jiao Zhang
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Min Li
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jia-Xing Tian
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xiao-Lin Tong
- Institute of Metabolic Diseases, Guang'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
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3
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Di Natale MR, Hunne B, Stebbing MJ, Wang X, Liu Z, Furness JB. Characterization of neuromuscular transmission and projections of muscle motor neurons in the rat stomach. Am J Physiol Gastrointest Liver Physiol 2024; 326:G78-G93. [PMID: 37987773 DOI: 10.1152/ajpgi.00194.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 11/22/2023]
Abstract
The stomach is the primary reservoir of the gastrointestinal tract, where ingested content is broken down into small particles. Coordinated relaxation and contraction is essential for rhythmic motility and digestion, but how the muscle motor innervation is organized to provide appropriate graded regional control is not established. In this study, we recorded neuromuscular transmission to the circular muscle using intracellular microelectrodes to investigate the spread of the influence of intrinsic motor neurons. In addition, microanatomical investigations of neuronal projections and pharmacological analysis were conducted to investigate neuromuscular relationships. We found that inhibitory neurotransmission to the circular muscle is graded with stimulus strength and circumferential distance from the stimulation site. The influence of inhibitory neurons declined between 1 and 11 mm from the stimulation site. In the antrum, corpus, and fundus, the declines at 11 mm were about 20%, 30%, and 50%, respectively. Stimulation of inhibitory neurons elicited biphasic hyperpolarizing potentials often followed by prolonged depolarizing events in the distal stomach, but only hyperpolarizing events in the proximal stomach. Excitatory neurotransmission influence varied greatly between proximal stomach, where depolarizing events occurred, and distal stomach, where no direct electrical effects in the muscle were observed. Structural studies using microlesion surgeries confirmed a dominant circumferential projection. We conclude that motor neuron influences extend around the gastric circumference, that the effectiveness can be graded by the recruitment of different numbers of motor neuron nerve terminals to finely control gastric motility, and that the ways in which the neurons influence the muscle differ between anatomical regions.NEW & NOTEWORTHY This study provides a detailed mapping of nerve transmission to the circular muscle of the different anatomical regions of rat stomach. It shows that excitatory and inhibitory influences extend around the gastric circumference and that there is a summation of neural influence that allows for finely graded control of muscle tension and length. Nerve-mediated electrical events are qualitatively and quantitatively different between regions, for example, excitatory neurons have direct effects on fundus but not antral muscle.
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Affiliation(s)
- Madeleine R Di Natale
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Billie Hunne
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Victoria, Australia
| | - Martin J Stebbing
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Xiaokai Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, United States
| | - Zhongming Liu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, United States
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan, United States
| | - John B Furness
- Department of Anatomy and Physiology, University of Melbourne, Parkville, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
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4
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Sanders KM, Drumm BT, Cobine CA, Baker SA. Ca 2+ dynamics in interstitial cells: foundational mechanisms for the motor patterns in the gastrointestinal tract. Physiol Rev 2024; 104:329-398. [PMID: 37561138 DOI: 10.1152/physrev.00036.2022] [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: 11/16/2022] [Revised: 06/29/2023] [Accepted: 08/06/2023] [Indexed: 08/11/2023] Open
Abstract
The gastrointestinal (GI) tract displays multiple motor patterns that move nutrients and wastes through the body. Smooth muscle cells (SMCs) provide the forces necessary for GI motility, but interstitial cells, electrically coupled to SMCs, tune SMC excitability, transduce inputs from enteric motor neurons, and generate pacemaker activity that underlies major motor patterns, such as peristalsis and segmentation. The interstitial cells regulating SMCs are interstitial cells of Cajal (ICC) and PDGF receptor (PDGFR)α+ cells. Together these cells form the SIP syncytium. ICC and PDGFRα+ cells express signature Ca2+-dependent conductances: ICC express Ca2+-activated Cl- channels, encoded by Ano1, that generate inward current, and PDGFRα+ cells express Ca2+-activated K+ channels, encoded by Kcnn3, that generate outward current. The open probabilities of interstitial cell conductances are controlled by Ca2+ release from the endoplasmic reticulum. The resulting Ca2+ transients occur spontaneously in a stochastic manner. Ca2+ transients in ICC induce spontaneous transient inward currents and spontaneous transient depolarizations (STDs). Neurotransmission increases or decreases Ca2+ transients, and the resulting depolarizing or hyperpolarizing responses conduct to other cells in the SIP syncytium. In pacemaker ICC, STDs activate voltage-dependent Ca2+ influx, which initiates a cluster of Ca2+ transients and sustains activation of ANO1 channels and depolarization during slow waves. Regulation of GI motility has traditionally been described as neurogenic and myogenic. Recent advances in understanding Ca2+ handling mechanisms in interstitial cells and how these mechanisms influence motor patterns of the GI tract suggest that the term "myogenic" should be replaced by the term "SIPgenic," as this review discusses.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada-Reno, Reno, Nevada, United States
| | - Bernard T Drumm
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Caroline A Cobine
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Salah A Baker
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada-Reno, Reno, Nevada, United States
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Zawieja SD, Pea GA, Broyhill SE, Patro A, Bromert KH, Li M, Norton CE, Castorena-Gonzalez JA, Hancock EJ, Bertram CD, Davis MJ. IP3R1 underlies diastolic ANO1 activation and pressure-dependent chronotropy in lymphatic collecting vessels. J Gen Physiol 2023; 155:e202313358. [PMID: 37851027 PMCID: PMC10585095 DOI: 10.1085/jgp.202313358] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 08/11/2023] [Accepted: 09/22/2023] [Indexed: 10/19/2023] Open
Abstract
Pressure-dependent chronotropy of murine lymphatic collecting vessels relies on the activation of the Ca2+-activated chloride channel encoded by Anoctamin 1 (Ano1) in lymphatic muscle cells. Genetic ablation or pharmacological inhibition of ANO1 results in a significant reduction in basal contraction frequency and essentially complete loss of pressure-dependent frequency modulation by decreasing the rate of the diastolic depolarization phase of the ionic pacemaker in lymphatic muscle cells (LMCs). Oscillating Ca2+ release from sarcoendoplasmic reticulum Ca2+ channels has been hypothesized to drive ANO1 activity during diastole, but the source of Ca2+ for ANO1 activation in smooth muscle remains unclear. Here, we investigated the role of the inositol triphosphate receptor 1 (Itpr1; Ip3r1) in this process using pressure myography, Ca2+ imaging, and membrane potential recordings in LMCs of ex vivo pressurized inguinal-axillary lymphatic vessels from control or Myh11CreERT2;Ip3r1fl/fl (Ip3r1ismKO) mice. Ip3r1ismKO vessels had significant reductions in contraction frequency and tone but an increased contraction amplitude. Membrane potential recordings from LMCs of Ip3r1ismKO vessels revealed a depressed diastolic depolarization rate and an elongation of the plateau phase of the action potential (AP). Ca2+ imaging of LMCs using the genetically encoded Ca2+ sensor GCaMP6f demonstrated an elongation of the Ca2+ flash associated with an AP-driven contraction. Critically, diastolic subcellular Ca2+ transients were absent in LMCs of Ip3r1ismKO mice, demonstrating the necessity of IP3R1 activity in controlling ANO1-mediated diastolic depolarization. These findings indicate a critical role for IP3R1 in lymphatic vessel pressure-dependent chronotropy and contractile regulation.
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Affiliation(s)
- Scott D. Zawieja
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Grace A. Pea
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Sarah E. Broyhill
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Advaya Patro
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Karen H. Bromert
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Min Li
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | - Charles E. Norton
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
| | | | - Edward J. Hancock
- School of Mathematics and Statistics, University of Sydney, Sydney, Australia
| | | | - Michael J. Davis
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
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6
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Sanders KM, Santana LF, Baker SA. Interstitial cells of Cajal - pacemakers of the gastrointestinal tract. J Physiol 2023. [PMID: 37997170 DOI: 10.1113/jp284745] [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: 10/02/2023] [Accepted: 11/06/2023] [Indexed: 11/25/2023] Open
Abstract
Gastrointestinal (GI) organs display spontaneous, non-neurogenic electrical, and mechanical rhythmicity that underlies fundamental motility patterns, such as peristalsis and segmentation. Electrical rhythmicity (aka slow waves) results from pacemaker activity generated by interstitial cells of Cajal (ICC). ICC express a unique set of ionic conductances and Ca2+ handling mechanisms that generate and actively propagate slow waves. GI smooth muscle cells lack these conductances. Slow waves propagate actively within ICC networks and conduct electrotonically to smooth muscle cells via gap junctions. Slow waves depolarize smooth muscle cells and activate voltage-dependent Ca2+ channels (predominantly CaV1.2), causing Ca2+ influx and excitation-contraction coupling. The main conductances responsible for pacemaker activity in ICC are ANO1, a Ca2+ -activated Cl- conductance, and CaV3.2. The pacemaker cycle, as currently understood, begins with spontaneous, localized Ca2+ release events in ICC that activate spontaneous transient inward currents due to activation of ANO1 channels. Depolarization activates CaV 3.2 channels, causing the upstroke depolarization phase of slow waves. The upstroke is transient and followed by a long-duration plateau phase that can last for several seconds. The plateau phase results from Ca2+ -induced Ca2+ release and a temporal cluster of localized Ca2+ transients in ICC that sustains activation of ANO1 channels and clamps membrane potential near the equilibrium potential for Cl- ions. The plateau phase ends, and repolarization occurs, when Ca2+ stores are depleted, Ca2+ release ceases and ANO1 channels deactivate. This review summarizes key mechanisms responsible for electrical rhythmicity in gastrointestinal organs.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, USA
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California, Davis, CA, USA
| | - Salah A Baker
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, USA
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7
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Zawieja SD, Pea GA, Broyhill SE, Bromert KH, Norton CE, Kim HJ, Li M, Castorena-Gonzalez JA, Drumm BT, Davis MJ. Lymphatic muscle cells are the innate pacemaker cells regulating mouse lymphatic collecting vessel contractions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.24.554619. [PMID: 37662284 PMCID: PMC10473772 DOI: 10.1101/2023.08.24.554619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Collecting lymphatic vessels (cLVs) exhibit spontaneous contractions with a pressure-dependent frequency, but the identity of the lymphatic pacemaker cell is still debated. By analogy to pacemakers in the GI and lower urinary tracts, proposed cLV pacemaker cells include interstitial cells of Cajal like cells (ICLC), pericytes, as well as the lymphatic muscle (LMCs) cells themselves. Here we tested the extent to which these cell types are invested into the mouse cLV wall and if any cell type exhibited morphological and functional processes characteristic of pacemaker cells: a contiguous network; spontaneous Ca2+ transients; and depolarization-induced propagated contractions. We employed inducible Cre (iCre) mouse models routinely used to target these specific cell populations including: c-kitCreERT2 to target ICLC; PdgfrβCreERT2 to target pericytes; PdgfrαCreER™ to target CD34+ adventitial fibroblast-like cells or ICLC; and Myh11CreERT2 to target LMCs. These specific inducible Cre lines were crossed to the fluorescent reporter ROSA26mT/mG, the genetically encoded Ca2+ sensor GCaMP6f, and the light-activated cation channel rhodopsin2 (ChR2). c-KitCreERT2 labeled both a sparse population of LECs and round adventitial cells that responded to the mast cell activator compound 48-80. PdgfrβCreERT2 drove recombination in both adventitial cells and LMCs, limiting its power to discriminate a pericyte specific population. PdgfrαCreER™ labeled a large population of interconnected, oak leaf-shaped cells primarily along the adventitial surface of the vessel. Titrated induction of the smooth muscle-specific Myh11CreERT2 revealed a LMC population with heterogeneous morphology. Only LMCs consistently, but heterogeneously, displayed spontaneous Ca2+ events during the diastolic period of the contraction cycle, and whose frequency was modulated in a pressure-dependent manner. Optogenetic depolarization through the expression of ChR2 by Myh11CreERT2, but not PdgfrαCreER™ or c-KitCreERT2, resulted in a propagated contraction. These findings support the conclusion that LMCs, or a subset of LMCs, are responsible for mouse cLV pacemaking.
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Affiliation(s)
- S D Zawieja
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
| | - G A Pea
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
| | - S E Broyhill
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
| | - K H Bromert
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
| | - C E Norton
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
| | - H J Kim
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
| | - M Li
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
| | | | - B T Drumm
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, A91 K584, Ireland
| | - M J Davis
- Dept. of Medical Pharmacology & Physiology, University of Missouri, Columbia, Missouri
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8
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Choi EL, Taheri N, Tan E, Matsumoto K, Hayashi Y. The Crucial Role of the Interstitial Cells of Cajal in Neurointestinal Diseases. Biomolecules 2023; 13:1358. [PMID: 37759758 PMCID: PMC10526372 DOI: 10.3390/biom13091358] [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: 08/11/2023] [Revised: 09/03/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Neurointestinal diseases result from dysregulated interactions between the nervous system and the gastrointestinal (GI) tract, leading to conditions such as Hirschsprung's disease and irritable bowel syndrome. These disorders affect many people, significantly diminishing their quality of life and overall health. Central to GI motility are the interstitial cells of Cajal (ICC), which play a key role in muscle contractions and neuromuscular transmission. This review highlights the role of ICC in neurointestinal diseases, revealing their association with various GI ailments. Understanding the functions of the ICC could lead to innovative perspectives on the modulation of GI motility and introduce new therapeutic paradigms. These insights have the potential to enhance efforts to combat neurointestinal diseases and may lead to interventions that could alleviate or even reverse these conditions.
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Affiliation(s)
- Egan L. Choi
- Enteric Neuroscience Program and Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Guggenheim 10, 200 1st Street SW, Rochester, MN 55905, USA; (E.L.C.); (N.T.)
- Gastroenterology Research Unit, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
| | - Negar Taheri
- Enteric Neuroscience Program and Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Guggenheim 10, 200 1st Street SW, Rochester, MN 55905, USA; (E.L.C.); (N.T.)
- Gastroenterology Research Unit, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
| | - Elijah Tan
- Enteric Neuroscience Program and Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Guggenheim 10, 200 1st Street SW, Rochester, MN 55905, USA; (E.L.C.); (N.T.)
- Gastroenterology Research Unit, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
| | - Kenjiro Matsumoto
- Laboratory of Pathophysiology, Faculty of Pharmaceutical Sciences, Doshisha Women’s College of Liberal Arts, Kyoto 610-0395, Japan;
| | - Yujiro Hayashi
- Enteric Neuroscience Program and Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine and Science, Guggenheim 10, 200 1st Street SW, Rochester, MN 55905, USA; (E.L.C.); (N.T.)
- Gastroenterology Research Unit, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, USA
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9
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Hwang SJ, Drumm BT, Kim MK, Lyu JH, Baker S, Sanders KM, Ward SM. Calcium transients in intramuscular interstitial cells of Cajal of the murine gastric fundus and their regulation by neuroeffector transmission. J Physiol 2022; 600:4439-4463. [PMID: 36057845 DOI: 10.1113/jp282876] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/15/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The cells responsible for mediating enteric neuroeffector transmission remain controversial. In the stomach intramuscular interstitial cells of Cajal (ICC-IM) were the first ICC reported to receive cholinergic and nitrergic neural inputs. Utilization of a cell specific calcium biosensor, GCaMP6f, the activity and neuroeffector responses of ICC-IM were examined. ICC-IM were highly active, generating stochastic intracellular Ca2+ -transients. Stimulation of enteric motor nerves abolished Ca2+ -transients in ICC-IM. This inhibitory response was preceded by a global rise in intracellular Ca2+ . Individual ICC-IM responded to nerve stimulation with a rise in Ca2+ followed by inhibition of Ca2+ -transients. Inhibition of Ca2+ -transients was blocked by the nitric oxide synthase antagonist, L-NNA. The global rise in Ca2+ was inhibited by the muscarinic antagonist, atropine. Simultaneous intracellular recordings with video imaging revealed that the global rise in intracellular Ca2+ and inhibition of Ca2+ -transients was temporally associated with rapid excitatory junction potentials followed by more sustained inhibitory junction potentials. The data presented support the premise of serial innervation of ICC-IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach. ABSTRACT Enteric neurotransmission is critical for coordinating motility throughout the gastrointestinal (GI) tract. However, there is considerable controversy regarding the cells that are responsible for the transduction of these neural inputs. In the present study, utilization of a cell-specific calcium biosensor GCaMP6f, the spontaneous activity and neuroeffector responses of intramuscular ICC (ICC-IM) to motor neural inputs was examined. Simultaneous intracellular microelectrode recordings and high-speed video-imaging during nerve stimulation was used to reveal the temporal relationship between changes in intracellular Ca2+ and post-junctional electrical responses to neural stimulation. ICC-IM were highly active, generating intracellular Ca2+ -transients that occurred stochastically, from multiple independent sites in single ICC-IM. Ca2+ -transients were not entrained in single ICC-IM or between neighboring ICC-IM. Activation of enteric motor neurons produced a dominant inhibitory response that abolished Ca2+ -transients in ICC-IM. This inhibitory response was often preceded by a summation of Ca2+ -transients that led to a global rise in Ca2+ . Individual ICC-IM responded to nerve stimulation by a global rise in Ca2+ followed by inhibition of Ca2+ -transients. The inhibition of Ca2+ -transients was blocked by the nitric oxide synthase antagonist, L-NNA. The global rise in intracellular Ca2+ was inhibited by the muscarinic antagonist, atropine. Simultaneous intracellular microelectrode recordings with video-imaging revealed that the rise in Ca2+ was temporally associated with rapid excitatory junction potentials and the inhibition of Ca2+ -transients with inhibitory junction potentials. These data support the premise of serial innervation of ICC-IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach. Abstract figure legend Intramuscular interstitial cells of Cajal (ICC-IM) of the gastric fundus receive nitrergic inhibitory and cholinergic excitatory neuroeffector motor inputs. Using a genetically encoded calcium sensor we demonstrate that ICC-IM are highly active cells generating stochastic intracellular Ca2 -transients. Stimulation of enteric motor nerves abolished Ca2 -transients in ICC-IM, produced an inhibitory junction potential (IJP) and muscle relaxation that was mediated by nitric oxide (left hand side of figure). This inhibitory response was often preceded by a global rise in intracellular Ca2 in ICC-IM, a rapid excitatory junction potential (EJP) and muscle contraction, that was mediated by acetylcholine (right hand side of figure). Individual ICC-IM could respond to both excitatory and inhibitory neural inputs. These data support the premise of serial innervation of ICC-IM in excitatory and inhibitory neuroeffector transmission in the proximal stomach. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Sung Jin Hwang
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Bernard T Drumm
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Min Kyung Kim
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Ju Hyeong Lyu
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Sal Baker
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Kenton M Sanders
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
| | - Sean M Ward
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, NV, 89557, USA
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10
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Moon SB, Hwang SJ, Baker S, Kim M, Sasse K, Koh SD, Sanders KM, Ward SM. Changes in interstitial cells and gastric excitability in a mouse model of sleeve gastrectomy. PLoS One 2022; 17:e0269909. [PMID: 35737727 PMCID: PMC9223402 DOI: 10.1371/journal.pone.0269909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/31/2022] [Indexed: 11/18/2022] Open
Abstract
Obesity is a critical risk factor of several life-threatening diseases and the prevalence in adults has dramatically increased over the past ten years. In the USA the age-adjusted prevalence of obesity in adults was 42.4%, i.e., with a body mass index (BMI, weight (kg)/height (m)2) that exceeds 30 kg/m2. Obese individuals are at the higher risk of obesity-related diseases, co-morbid conditions, lower quality of life, and increased mortality more than those in the normal BMI range i.e., 18.5–24.9 kg/m2. Surgical treatment continues to be the most efficient and scientifically successful treatment for obese patients. Sleeve gastrectomy or vertical sleeve gastrectomy (VSG) is a relatively new gastric procedure to reduce body weight but is now the most popular bariatric operation. To date there have been few studies examining the changes in the cellular components and pacemaker activity that occur in the gastric wall following VSG and whether normal gastric activity recovers following VSG. In the present study we used a murine model to investigate the chronological changes of gastric excitability including electrophysiological, molecular and morphological changes in the gastric musculature following VSG. There is a significant disruption in specialized interstitial cells of Cajal in the gastric antrum following sleeve gastrectomy. This is associated with a loss of gastric pacemaker activity and post-junctional neuroeffector responses. Over a 4-month recovery period there was a gradual return in interstitial cells of Cajal networks, pacemaker activity and neural responses. These data describe for the first time the changes in gastric interstitial cells of Cajal networks, pacemaker activity and neuroeffector responses and the time-dependent recovery of ICC networks and normalization of motor activity and neural responses following VSG.
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Affiliation(s)
- Suk Bae Moon
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, United States of America
| | - Sung Jin Hwang
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, United States of America
| | - Sal Baker
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, United States of America
| | - Minkyung Kim
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, United States of America
| | - Kent Sasse
- Sasse Surgical Associates, Reno, Nevada, United States of America
| | - Sang Don Koh
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, United States of America
| | - Kenton M. Sanders
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, United States of America
| | - Sean M. Ward
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, United States of America
- * E-mail:
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Drumm BT, Cobine CA, Baker SA. Insights on gastrointestinal motility through the use of optogenetic sensors and actuators. J Physiol 2022; 600:3031-3052. [PMID: 35596741 DOI: 10.1113/jp281930] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/13/2022] [Indexed: 11/08/2022] Open
Abstract
The muscularis of the gastrointestinal (GI) tract consists of smooth muscle cells (SMCs) and various populations of interstitial cells of Cajal (ICC), platelet-derived growth factor receptor α+ (PDGFRα+ ) cells, as well as excitatory and inhibitory enteric motor nerves. SMCs, ICC and PDGFRα+ cells form an electrically coupled syncytium, which together with inputs from the enteric nervous system (ENS) regulate GI motility. Early studies evaluating Ca2+ signalling behaviours in the GI tract relied upon indiscriminate loading of tissues with Ca2+ dyes. These methods lacked the means to study activity in specific cells of interest without encountering contamination from other cells within the preparation. Development of mice expressing optogenetic sensors (GCaMP, RCaMP) has allowed visualization of Ca2+ signalling behaviours in a cell specific manner. Additionally, availability of mice expressing optogenetic modulators (channelrhodopsins or halorhodospins) has allowed manipulation of specific signalling pathways using light. GCaMP expressing animals have been used to characterize Ca2+ signalling behaviours of distinct classes of ICC and SMCs throughout the GI musculature. These findings illustrate how Ca2+ signalling in ICC is fundamental in GI muscles, contributing to tone in sphincters, pacemaker activity in rhythmic muscles and relaying enteric signals to SMCs. Animals that express channelrhodopsin in specific neuronal populations have been used to map neural circuitry and to examine post junctional neural effects on GI motility. Thus, optogenetic approaches provide a novel means to examine the contribution of specific cell types to the regulation of motility patterns within complex multi-cellular systems. Abstract Figure Legends Optogenetic activators and sensors can be used to investigate the complex multi-cellular nature of the gastrointestinal (GI tract). Optogenetic activators that are activated by light such as channelrhodopsins (ChR2), OptoXR and halorhodopsinss (HR) proteins can be genetically encoded into specific cell types. This can be used to directly activate or silence specific GI cells such as various classes of enteric neurons, smooth muscle cells (SMC) or interstitial cells, such as interstitial cells of Cajal (ICC). Optogenetic sensors that are activated by different wavelengths of light such as green calmodulin fusion protein (GCaMP) and red CaMP (RCaMP) make high resolution of sub-cellular Ca2+ signalling possible within intact tissues of specific cell types. These tools can provide unparalleled insight into mechanisms underlying GI motility and innervation. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Bernard T Drumm
- Smooth Muscle Research Centre, Department of Life & Health Science, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland.,Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Caroline A Cobine
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Salah A Baker
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
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New open-source software for subcellular segmentation and analysis of spatiotemporal fluorescence signals using deep learning. iScience 2022; 25:104277. [PMID: 35573197 PMCID: PMC9095751 DOI: 10.1016/j.isci.2022.104277] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 04/04/2022] [Accepted: 04/18/2022] [Indexed: 11/20/2022] Open
Abstract
Cellular imaging instrumentation advancements as well as readily available optogenetic and fluorescence sensors have yielded a profound need for fast, accurate, and standardized analysis. Deep-learning architectures have revolutionized the field of biomedical image analysis and have achieved state-of-the-art accuracy. Despite these advancements, deep learning architectures for the segmentation of subcellular fluorescence signals is lacking. Cellular dynamic fluorescence signals can be plotted and visualized using spatiotemporal maps (STMaps), and currently their segmentation and quantification are hindered by slow workflow speed and lack of accuracy, especially for large datasets. In this study, we provide a software tool that utilizes a deep-learning methodology to fundamentally overcome signal segmentation challenges. The software framework demonstrates highly optimized and accurate calcium signal segmentation and provides a fast analysis pipeline that can accommodate different patterns of signals across multiple cell types. The software allows seamless data accessibility, quantification, and graphical visualization and enables large dataset analysis throughput. 4SM: an automated software solution for cellular dynamic fluorescence signal analysis 4SM relies on a novel machine-learning pipeline for fluorescence signal segmentation 4SM is fast and provides a consistent method for high-throughput analysis of datasets 4SM provides instant signal quantification and graphical representation of the results
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Drumm BT, Hannigan KI, Lee JY, Rembetski BE, Baker SA, Koh SD, Cobine CA, Sanders KM. Ca 2+ signalling in interstitial cells of Cajal contributes to generation and maintenance of tone in mouse and monkey lower esophageal sphincters. J Physiol 2022; 600:2613-2636. [PMID: 35229888 DOI: 10.1113/jp282570] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/15/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The lower esophageal sphincter (LES) generates contractile tone preventing reflux of gastric contents into the esophagus. LES smooth muscle cells (SMCs) display depolarized membrane potentials facilitating activation of L-type Ca2+ channels. Interstitial cells of Cajal (ICC) express Ca2+ -activated Cl- channels encoded by Ano1 in mouse and monkey LES. Ca2+ signaling in ICC activates ANO1 currents in ICC. ICC displayed spontaneous Ca2+ transients in mice from multiple firing sites in each cell and no entrainment of Ca2+ firing between sites or between cells. Inhibition of ANO1 channels with a specific antagonist caused hyperpolarization of mouse LES and inhibition of tone in monkey and mouse LES muscles. Our data suggest a novel mechanism for LES tone in which Ca2+ transient activation of ANO1 channels in ICC generates depolarizing inward currents that conduct to SMCs to activate L-type Ca2+ currents, Ca2+ entry and contractile tone. ABSTRACT The lower esophageal sphincter (LES) generates tone and prevents reflux of gastric contents. LES smooth muscle cells (SMCs) are relatively depolarized, facilitating activation of Cav 1.2 channels to sustain contractile tone. We hypothesised that intramuscular interstitial cells of Cajal (ICC-IM), through activation of Ca2+ -activated-Cl- channels (ANO1), set membrane potentials of SMCs favorable for activation of Cav 1.2 channels. In some gastrointestinal muscles, ANO1 channels in ICC-IM are activated by Ca2+ transients, but no studies have examined Ca2+ dynamics in ICC-IM within the LES. Immunohistochemistry and qPCR were used to determine expression of key proteins and genes in ICC-IM and SMCs. These studies revealed that Ano1 and its gene product, ANO1 are expressed in c-Kit+ cells (ICC-IM) in mouse and monkey LES clasp muscles. Ca2+ signaling was imaged in situ, using mice expressing GCaMP6f specifically in ICC (Kit-KI-GCaMP6f). ICC-IM exhibited spontaneous Ca2+ transients from multiple firing sites. Ca2+ transients were abolished by CPA or caffeine but were unaffected by tetracaine or nifedipine. Maintenance of Ca2+ transients depended on Ca2+ influx and store reloading, as Ca2+ transient frequency was reduced in Ca2+ free solution or by Orai antagonist. Spontaneous tone of LES muscles from mouse and monkey was reduced ∼80% either by Ani9, an ANO1 antagonist or by the Cav 1.2 channel antagonist nifedipine. Membrane hyperpolarisation occurred in the presence of Ani9. These data suggest that intracellular Ca2+ activates ANO1 channels in ICC-IM in the LES. Coupling of ICC-IM to SMCs drives depolarization, activation of Cav 1.2 channels, Ca2+ entry and contractile tone. Abstract figure legend Proposed mechanism for generation of contractile tone in the lower esophageal sphincter (LES). Interstitial cells of Cajal (ICC) in the LES generate spontaneous, stochastic Ca2+ transients via Ca2+ release from the endoplasmic reticulum (ER). The Ca2+ transients activate ANO1 Cl- channels causing Cl- efflux (inward current). ANO1 currents have a depolarizing effect on ICC (+++s inside membrane) and this conducts through gap junctions (GJ) to smooth muscle cells (SMCs). Input from thousands of ICC results in depolarized membrane potentials (-40 to -50 mV) which is within the window current range for L-type Ca2+ channels. Activation of these channels causes Ca2+ influx, activation of contractile elements (CE) and development of tonic contraction. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Bernard T Drumm
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA.,Smooth Muscle Research Centre, Dundalk Institute of Technology, Ireland
| | - Karen I Hannigan
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Ji Yeon Lee
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Benjamin E Rembetski
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Salah A Baker
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Sang Don Koh
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Caroline A Cobine
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Kenton M Sanders
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
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