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Hwang SJ, Kim M, Jones A, Basma N, Baker SA, Sanders KM, Ward SM. Interstitial cells of the sip syncytium regulate basal membrane potential in murine gastric corpus. FASEB J 2024; 38:e23863. [PMID: 39143726 DOI: 10.1096/fj.202400982r] [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: 04/30/2024] [Revised: 07/11/2024] [Accepted: 07/23/2024] [Indexed: 08/16/2024]
Abstract
Smooth muscle cells (SMCs), Interstitial cells of Cajal (ICC) and Platelet-derived growth factor receptor α positive (PDGFRα+) cells form an integrated, electrical syncytium within the gastrointestinal (GI) muscular tissues known as the SIP syncytium. Immunohistochemical analysis of gastric corpus muscles showed that c-KIT+/ANO1+ ICC-IM and PDGFRα+ cells were closely apposed to one another in the same anatomical niches. We used intracellular microelectrode recording from corpus muscle bundles to characterize the roles of intramuscular ICC and PDGFRα+ cells in conditioning membrane potentials of gastric muscles. In muscle bundles, that have a relatively higher input impedance than larger muscle strips or sheets, we recorded an ongoing discharge of stochastic fluctuations in membrane potential, previously called unitary potentials or spontaneous transient depolarizations (STDs) and spontaneous transient hyperpolarizations (STHs). We reasoned that STDs should be blocked by antagonists of ANO1, the signature conductance of ICC. Activation of ANO1 has been shown to generate spontaneous transient inward currents (STICs), which are the basis for STDs. Ani9 reduced membrane noise and caused hyperpolarization, but this agent did not block the fluctuations in membrane potential quantitatively. Apamin, an antagonist of small conductance Ca2+-activated K+ channels (SK3), the signature conductance in PDGFRα+ cells, further reduced membrane noise and caused depolarization. Reversing the order of channel antagonists reversed the sequence of depolarization and hyperpolarization. These experiments show that the ongoing discharge of STDs and STHs by ICC and PDGFRα+ cells, respectively, exerts conditioning effects on membrane potentials in the SIP syncytium that would effectively regulate the excitability of SMCs.
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Affiliation(s)
- Sung Jin Hwang
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, USA
| | - MinKyung Kim
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, USA
| | - Amanda Jones
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, USA
| | - Naseer Basma
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, USA
| | - Salah A Baker
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, USA
| | - Kenton M Sanders
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, USA
| | - Sean M Ward
- Department of Physiology & Cell Biology, Reno School of Medicine, University of Nevada, Reno, Nevada, USA
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2
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Inaba M. Optogenetic techniques for understanding the gut peristalsis during chicken embryonic development. Biochem Soc Trans 2024; 52:1727-1735. [PMID: 39051133 DOI: 10.1042/bst20231337] [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: 03/19/2024] [Revised: 06/25/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024]
Abstract
Gut peristaltic movements transport ingested materials along the gut axis, which is critical for food digestion and nutrient absorption. While a large amount of studies have been devoted to analyzing the physiological functions of peristalsis in adults, little is known about how the peristaltic system is established during embryogenesis. In recent years, the chicken developing gut has emerged as an excellent model, in which specific sites along the gut axis can be genetically labeled enabling live imaging and optogenetic analyses. This review provides an overview of recent progress in optogenetic studies of gut peristalsis. Analyses with an improved channelrhodopsin-2 variant demonstrated that the peristalsis can artificially be generated in the developing gut. These studies unveiled novel functional coordination between different regions along the gut axis. In addition, imaging with GCaMP6s, a genetically encoded calcium indicator, enabled a fine mapping of developmental changes in the peristaltic patterns as Ca2+ signals. These advanced techniques will broaden our knowledge of how embryonic peristalsis is established at the cellular and molecular level, leading to the understanding of physiological and pathological processes in adult peristalsis.
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Affiliation(s)
- Masafumi Inaba
- Department of Zoology, Graduate School of Science, Kyoto University, Kitashirakawa, Sakyo-ku, Kyoto, Japan
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3
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Kudo W, Mitsui R, Hashitani H. Involvement of ANO1 currents in pacemaking of PDGFRα-positive specialised smooth muscle cells in rat caudal epididymis. Cell Tissue Res 2024; 397:1-12. [PMID: 38587529 DOI: 10.1007/s00441-024-03890-x] [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: 11/19/2023] [Accepted: 03/14/2024] [Indexed: 04/09/2024]
Abstract
The epididymal duct exhibits spontaneous phasic contractions (SPCs) to store and transport sperm. Here, we explored molecular identification of pacemaker cells driving SPCs in the caudal epididymal duct and also investigated properties of pacemaker currents underlying SPCs focusing on ANO1 Ca2+-activated Cl- channels (CaCCs). Immunohistochemistry was performed to visualise the distribution of platelet-derived growth factor receptor α (PDGFRα)- or ANO1-positive cells in the rat caudal epididymal duct. Perforated whole-cell patch clamp technique was applied to enzymatically isolated epididymal cells, while SPCs were recorded with video edge-tracking technique. Immunohistochemistry revealed the distribution of α-smooth muscle actin (α-SMA)-positive cells co-expressing both PDGFRα and ANO1 in the innermost smooth muscle layer. Approximately one-third of isolated epididymis cells exhibited spontaneous transient inward currents (STICs) at the holding potential -60 mV. The reversal potential for STICs was close to the calculated chloride equivalent potential depending on intracellular Cl- concentrations. Ani9 (3 µM), the ANO1 specific inhibitor, decreased both amplitude and frequency of STICs, while cyclopiazonic acid (CPA, 30 µM), a sarco-/endoplasmic reticulum Ca2+-ATPase (SERCA) inhibitor, abolished STICs. Ani9 (3 or 10 µM) reduced the frequency of SPCs without changing their amplitude. Thus, PDGFRα+, ANO1+ specialised smooth muscle cells (SMCs) appear to function as pacemaker cells to electrically drive epididymal SPCs by generating ANO1-dependnet STICs. STICs arising from spontaneous Ca2+ release from intracellular Ca2+ store and subsequent opening of ANO1 result in depolarisations that spread into adjacent SMCs where L-type voltage-dependent Ca2+ channels are activated to develop SPCs.
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Affiliation(s)
- Wataru Kudo
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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4
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Gupta A, Manchanda R. Computational modeling of inhibitory signal transduction in urinary bladder PDGFRα+ cells. Comput Methods Biomech Biomed Engin 2024; 27:1161-1170. [PMID: 37424292 DOI: 10.1080/10255842.2023.2234063] [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: 02/24/2023] [Accepted: 06/30/2023] [Indexed: 07/11/2023]
Abstract
A crucial aspect of bladder function is the maintenance of a normo-active detrusor during bladder filling. The physiological mechanisms and pathways underlying this function are yet to be fully elucidated. Premature detrusor contractions are a key phenotype in detrusor overactivity, a common pathophysiological condition of the urinary bladder. Recent literature has identified PDFGRα+ cells as mediators in transducing inhibitory signals to detrusor smooth muscle cells via gap junctions. We employ computational modeling to study transduction pathways via which inhibitory signals are generated in PDFGRα+ cells in response to purinergic, nitrergic and mechanical stimuli. The key focus of our study here is to explore the effect of ATP, stretch and NO on the membrane potential of PDFGRα+ cells, which is driven to hyperpolarized potentials via the activation of SK3 channels. Our results indicate that purinergic, mechanical and nitrergic inputs can induce significant membrane hyperpolarizations of 20-35 mV relative to the resting membrane potential. Given the interconnections between PDFGRα+ cells and detrusor SMCs through gap junctions, these hyperpolarizations can have significant functional implications in the maintenance of a normo-active detrusor as also in departures from this state as seen in detrusor overactivity.
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Affiliation(s)
- Amritanshu Gupta
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Rohit Manchanda
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
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5
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Ni Bhraonain E, Turner J, Hannigan K, Sanders K, Cobine C. Immunohistochemical characterization of interstitial cells and their relationship to motor neurons within the mouse esophagus. RESEARCH SQUARE 2024:rs.3.rs-4474290. [PMID: 38947055 PMCID: PMC11213231 DOI: 10.21203/rs.3.rs-4474290/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Interstitial cells of Cajal (ICC) and PDGFRα+ cells regulate smooth muscle motility in the gastrointestinal (GI) tract. However, their role(s) in esophageal motility are still unclear. The mouse esophagus has traditionally been described as almost entirely skeletal muscle in nature though ICC have been identified along its entire length. The current study evaluated the distribution of skeletal and smooth muscle within the esophagus using a mouse selectively expressing eGFP in smooth muscle cells (SMCs). The relationship of SMCs to ICC and PDGFRα+ cells was also examined. SMCs declined in density in the oral direction however SMCs represented ~ 25% of the area in the distal esophagus suggesting a likeness to the transition zone observed in humans. ANO1+ intramuscular ICC (ICC-IM) were distributed along the length of the esophagus though like SMCs, declined proximally. ICC-IM were closely associated with SMCs but were also found in regions devoid of SMCs. Intramuscular and submucosal PDGFRα+ cells were densely distributed throughout the esophagus though only intramuscular PDGFRα+ cells within the LES and distal esophagus highly expressed SK3. ICC-IM and PDGFRα+ cells were closely associated with nNOS+, VIP+, VAChT+ and TH+ neurons throughout the LES and distal esophagus. GFAP+ cells resembling intramuscular enteric glia were observed within the muscle and were closely associated with ICC-IM and PDGFRα+ cells, occupying a similar location to c. These data suggest that the mouse esophagus is more similar to the human than thought previously and thus set the foundation for future functional and molecular studies using transgenic mice.
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Llorente C. The Imperative for Innovative Enteric Nervous System-Intestinal Organoid Co-Culture Models: Transforming GI Disease Modeling and Treatment. Cells 2024; 13:820. [PMID: 38786042 PMCID: PMC11119846 DOI: 10.3390/cells13100820] [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: 03/15/2024] [Revised: 04/29/2024] [Accepted: 05/08/2024] [Indexed: 05/25/2024] Open
Abstract
This review addresses the need for innovative co-culture systems integrating the enteric nervous system (ENS) with intestinal organoids. The breakthroughs achieved through these techniques will pave the way for a transformative era in gastrointestinal (GI) disease modeling and treatment strategies. This review serves as an introduction to the companion protocol paper featured in this journal. The protocol outlines the isolation and co-culture of myenteric and submucosal neurons with small intestinal organoids. This review provides an overview of the intestinal organoid culture field to establish a solid foundation for effective protocol application. Remarkably, the ENS surpasses the number of neurons in the spinal cord. Referred to as the "second brain", the ENS orchestrates pivotal roles in GI functions, including motility, blood flow, and secretion. The ENS is organized into myenteric and submucosal plexuses. These plexuses house diverse subtypes of neurons. Due to its proximity to the gut musculature and its cell type complexity, there are methodological intricacies in studying the ENS. Diverse approaches such as primary cell cultures, three-dimensional (3D) neurospheres, and induced ENS cells offer diverse insights into the multifaceted functionality of the ENS. The ENS exhibits dynamic interactions with the intestinal epithelium, the muscle layer, and the immune system, influencing epithelial physiology, motility, immune responses, and the microbiome. Neurotransmitters, including acetylcholine (ACh), serotonin (5-HT), and vasoactive intestinal peptide (VIP), play pivotal roles in these intricate interactions. Understanding these dynamics is imperative, as the ENS is implicated in various diseases, ranging from neuropathies to GI disorders and neurodegenerative diseases. The emergence of organoid technology presents an unprecedented opportunity to study ENS interactions within the complex milieu of the small and large intestines. This manuscript underscores the urgent need for standardized protocols and advanced techniques to unravel the complexities of the ENS and its dynamic relationship with the gut ecosystem. The insights gleaned from such endeavors hold the potential to revolutionize GI disease modeling and treatment paradigms.
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Affiliation(s)
- Cristina Llorente
- Department of Medicine, University of California San Diego, MC0063, 9500 Gilman Drive, La Jolla, CA 92093, USA
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Grainger N. Identifying peristaltic pacemaker cells in the upper urinary tract. J Physiol 2024. [PMID: 38180778 DOI: 10.1113/jp284754] [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: 10/01/2023] [Accepted: 12/18/2023] [Indexed: 01/06/2024] Open
Abstract
Urine expulsion from the upper urinary tract is a necessary process that eliminates waste, promotes renal filtration and prevents nephron damage. To facilitate the movement of urine boluses throughout the upper urinary tract, smooth muscle cells that line the renal pelvis contract in a coordinated effort to form peristaltic waves. Resident pacemaker cells in the renal pelvis are critical to this process and spontaneously evoke transient depolarizations that initiate each peristaltic wave and establish rhythmic contractions. Renal pacemakers have been termed atypical smooth muscle cells due to their low expression of smooth muscle myosin and poor organization of myofilaments compared to typical (or contractile) smooth muscle cells that perform peristalsis. Recent findings discovered that pacemaker cells also express the tyrosine kinase receptor PDGFRα, enabling their identification and purification amongst other renal pelvis cell types. Improved identification methods have determined that the calcium-activated chloride channel, ANO1, is expressed by pacemaker cells and may contribute to spontaneous depolarization. A greater understanding of pacemaker and peristaltic mechanisms is warranted since aberrant contractile function may underlie diseases such as hydronephrosis, a deleterious condition that can cause significant and irreversible nephron injury.
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Affiliation(s)
- Nathan Grainger
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA
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8
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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 PMCID: PMC11281822 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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Wu Z, Wang Q, Yang F, Wang J, Zhao Y, Perrino BA, Chen J. Functional and Transcriptomic Characterization of Postnatal Maturation of ENS and SIP Syncytium in Mice Colon. Biomolecules 2023; 13:1688. [PMID: 38136560 PMCID: PMC10741935 DOI: 10.3390/biom13121688] [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: 08/22/2023] [Revised: 10/16/2023] [Accepted: 11/14/2023] [Indexed: 12/24/2023] Open
Abstract
The interplay of the enteric nervous system (ENS) and SIP syncytium (smooth muscle cells-interstitial cells of Cajal-PDGFRα+ cells) plays an important role in the regulation of gastrointestinal (GI) motility. This study aimed to investigate the dynamic regulatory mechanisms of the ENS-SIP system on colon motility during postnatal development. Colonic samples of postnatal 1-week-old (PW1), 3-week-old (PW3), and 5-week-old (PW5) mice were characterized by RNA sequencing, qPCR, Western blotting, isometric force recordings (IFR), and colonic motor complex (CMC) force measurements. Our study showed that the transcriptional expression of Pdgfrα, c-Kit, P2ry1, Nos1, and Slc18a3, and the protein expression of nNOS, c-Kit, and ANO1 significantly increased with age from PW1 to PW5. In PW1 and PW3 mice, colonic migrating movement was not fully developed. In PW5 mice, rhythmic CMCs were recorded, similar to the CMC pattern described previously in adult mice. The inhibition of nNOS revealed excitatory and non-propulsive responses which are normally suppressed due to ongoing nitrergic inhibition. During postnatal development, molecular data demonstrated the establishment and expansion of ICC and PDGFRα+ cells, along with nitrergic and cholinergic nerves and purinergic receptors. Our findings are important for understanding the role of the SIP syncytium in generating and establishing CMCs in postnatal, developing murine colons.
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Affiliation(s)
- Zhihao Wu
- Department of General Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong School of Medicine, Shanghai 200127, China
| | - Qianqian Wang
- Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200001, China
| | - Fan Yang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Jiaxuan Wang
- Department of General Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong School of Medicine, Shanghai 200127, China
| | - Yuying Zhao
- Department of General Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong School of Medicine, Shanghai 200127, China
| | - Brian A. Perrino
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Jie Chen
- Department of General Surgery, Shanghai Children’s Medical Center, Shanghai Jiao Tong School of Medicine, Shanghai 200127, China
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10
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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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11
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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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12
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Mawe GM, Sanders KM, Camilleri M. Overview of the Enteric Nervous System. Semin Neurol 2023; 43:495-505. [PMID: 37562453 DOI: 10.1055/s-0043-1771466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Propulsion of contents in the gastrointestinal tract requires coordinated functions of the extrinsic nerves to the gut from the brain and spinal cord, as well as the neuromuscular apparatus within the gut. The latter includes excitatory and inhibitory neurons, pacemaker cells such as the interstitial cells of Cajal and fibroblast-like cells, and smooth muscle cells. Coordination between these extrinsic and enteric neurons results in propulsive functions which include peristaltic reflexes, migrating motor complexes in the small intestine which serve as the housekeeper propelling to the colon the residual content after digestion, and mass movements in the colon which lead to defecation.
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Affiliation(s)
- Gary M Mawe
- Department of Neurological Sciences, The University of Vermont, Burlington, Vermont
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada
| | - Michael Camilleri
- Division of Gastroenterology and Hepatology, Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.), Mayo Clinic, Rochester, Minnesota
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13
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Chaen T, Kurosawa T, Kishi K, Kaji N, Ikemoto-Uezumi M, Uezumi A, Hori M. Transcriptome analysis of mesenchymal stromal cells of the large and small intestinal smooth muscle layers reveals a unique gastrontestinal stromal signature. Biochem Biophys Rep 2023; 34:101478. [PMID: 37153863 PMCID: PMC10160341 DOI: 10.1016/j.bbrep.2023.101478] [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: 01/07/2023] [Revised: 03/31/2023] [Accepted: 04/23/2023] [Indexed: 05/10/2023] Open
Abstract
Mesenchymal stromal cells in the muscle layer of the large intestine are essential for the regulation of intestinal motility. They form electrogenic syncytia with the smooth muscle and interstitial cells of Cajal (ICCs) to regulate smooth muscle contraction. Mesenchymal stromal cells are present in the muscle layer throughout the gastrointestinal tract. However, their area-specific characteristics remain ambiguous. In this study, we compared mesenchymal stromal cells from the large and small intestinal muscle layers. Histological analysis using immunostaining showed that the cells in the large and small intestines were morphologically distinct. We established a method to isolate mesenchymal stromal cells from wild-type mice with platelet-derived growth factor receptor-alpha (PDGFRα) as a marker on the cell surface and performed RNAseq. Transcriptome analysis revealed that PDGFRα+ cells in the large intestine exhibited increased expression levels of collagen-related genes, whereas PDGFRα+ cells in the small intestine exhibited increased expression levels of channel/transporter genes, including Kcn genes. These results suggest that mesenchymal stromal cells differ morphologically and functionally depending on gastrointestinal tract. Further investigations of the cellular properties of mesenchymal stromal cells in the gastrointestinal tract will aid in optimizing methods for the prevention and treatment of gastrointestinal diseases.
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Affiliation(s)
- Takashi Chaen
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medical Sciences, Graduate School of Agriculture and Life Sciences, Tokyo University, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Tamaki Kurosawa
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medical Sciences, Graduate School of Agriculture and Life Sciences, Tokyo University, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
- Division of Cell Heterogeneity, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi, Fukuoka, 812-8582, Japan
| | - Kazuhisa Kishi
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medical Sciences, Graduate School of Agriculture and Life Sciences, Tokyo University, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Noriyuki Kaji
- Laboratory of Veterinary Pharmacology, School of Veterinary Medicine, Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5201, Japan
| | - Madoka Ikemoto-Uezumi
- Division of Cell Heterogeneity, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi, Fukuoka, 812-8582, Japan
| | - Akiyoshi Uezumi
- Division of Cell Heterogeneity, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi, Fukuoka, 812-8582, Japan
| | - Masatoshi Hori
- Laboratory of Veterinary Pharmacology, Department of Veterinary Medical Sciences, Graduate School of Agriculture and Life Sciences, Tokyo University, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
- Corresponding author.
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14
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Zheng H, Peri L, Ward GK, Sanders KM, Ward SM. Cardiac PDGFRα + interstitial cells generate spontaneous inward currents that contribute to excitability in the heart. FASEB J 2023; 37:e22929. [PMID: 37086093 PMCID: PMC10402933 DOI: 10.1096/fj.202201712r] [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: 10/20/2022] [Revised: 03/06/2023] [Accepted: 04/05/2023] [Indexed: 04/23/2023]
Abstract
The cell types and conductance that contribute to normal cardiac functions remain under investigation. We used mice that express an enhanced green fluorescent protein (eGFP)-histone 2B fusion protein driven off the cell-specific endogenous promoter for Pdgfra to investigate the distribution and functional role of PDGFRα+ cells in the heart. Cardiac PDGFRα+ cells were widely distributed within the endomysium of atria, ventricle, and sino-atrial node (SAN) tissues. PDGFRα+ cells formed a discrete network of cells, lying in close apposition to neighboring cardiac myocytes in mouse and Cynomolgus monkey (Macaca fascicularis) hearts. Expression of eGFP in nuclei allowed unequivocal identification of these cells following enzymatic dispersion of muscle tissues. FACS purification of PDGFRα+ cells from the SAN and analysis of gene transcripts by qPCR revealed that they were a distinct population of cells that expressed gap junction transcripts, Gja1 and Gjc1. Cardiac PDGFRα+ cells generated spontaneous transient inward currents (STICs) and spontaneous transient depolarizations (STDs) that reversed at 0 mV. Reversal potential was maintained when ECl = -40 mV. [Na+ ]o replacement and FTY720 abolished STICs, suggesting they were due to a non-selective cation conductance (NSCC) carried by TRPM7. PDGFRα+ cells also express β2 -adrenoceptor gene transcripts, Adrb2. Zinterol, a selective β2 -receptor agonist, increased the amplitude and frequency of STICs, suggesting these cells could contribute to adrenergic regulation of cardiac excitability. PDGFRα+ cells in cardiac muscles generate inward currents via an NSCC. STICs generated by these cells may contribute to the integrated membrane potentials of cardiac muscles, possibly affecting the frequency of pacemaker activity.
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Affiliation(s)
- Haifeng Zheng
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Lauren Peri
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Grace K. Ward
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Kenton M. Sanders
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Sean M. Ward
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
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15
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Perrino BA, Malogan J, Cobine CA, Sasse KC. Mfge8 is expressed by pericytes in gastric antrum submucosa from patients with obesity. Am J Physiol Cell Physiol 2023; 324:C992-C1006. [PMID: 36939201 PMCID: PMC10110711 DOI: 10.1152/ajpcell.00043.2023] [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: 02/02/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/21/2023]
Abstract
The main function of the stomach is to digest ingested food. Gastric antrum muscular contractions mix ingested food with digestive enzymes and stomach acid and propel the chyme through the pyloric sphincter at a rate in which the small intestine can process the chyme for optimal nutrient absorption. Mfge8 binding to α8β1 integrins helps regulate gastric emptying by reducing the force of antral smooth muscle contractions. The source of Mfge8 within gastric muscles is unclear. Since Mfge8 is a secreted protein, Mfge8 could be delivered via the circulation, or be locally secreted by cells within the muscle layers. In this study, we identify a source of Mfge8 within human gastric antrum muscles using spatial transcriptomic analysis. We show that Mfge8 is expressed in subpopulations of Mef2c+ perivascular cells within the submucosa layer of the gastric antrum. Mef2c is expressed in subpopulations of NG2+ and PDGFRB+ pericytes. Mfge8 is expressed in NG2+/Mef2c+ pericytes, but not in NG2+/Mef2c-, PDGFRB+/Mef2c-, or PDGFRB+/Mef2c+ pericytes. Mfge8 is absent from CD34+ endothelial cells but is expressed in a small population of perivascular ACTA2+ cells. We also show that α8 integrin is not expressed by interstitial cells of Cajal (ICC), supporting the findings that Mfge8 attenuates gastric antrum smooth muscle contractions by binding to α8β1 integrins on enteric smooth muscle cells. These findings suggest a novel, supplementary mechanism of regulation of gastric antrum motility by cellular regulators of capillary blood flow, in addition to the regulation of gastric antrum motility by the enteric nervous system and the SMC, ICC, and PDGFRα+ cell (SIP) syncytium.
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Affiliation(s)
- Brian A Perrino
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, United States
| | - Justin Malogan
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, United States
| | - Caroline A Cobine
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, United States
| | - Kent C Sasse
- Nevada Surgical Associates, Reno, Nevada, United States
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16
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Lee KY, Sung TS, Koh BH, Ryoo SB, Chun JN, Kim SH, Park KJ, So I. Distribution and Function of Platelet-derived Growth Factor Receptor Alpha-positive Cells and Purinergic Neurotransmission in the Human Colon: Is It Different Between the Right and Left Colon? J Neurogastroenterol Motil 2022; 28:678-692. [PMID: 36250374 PMCID: PMC9577575 DOI: 10.5056/jnm21117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 08/17/2022] [Indexed: 11/23/2022] Open
Abstract
Background/Aims Platelet-derived growth factor receptor alpha-positive (PDGFRα+) cells function in the purinergic regulation of gastrointestinal motility, and purines are reportedly inhibitory neurotransmitters in the enteric nervous system. We explore the distribution and function of PDGFRα+ cells related to purinergic inhibitory neurotransmission in human right and left colons. Methods Human colonic segments were prepared with mucosa and submucosa intact, and the circular muscle tension and longitudinal muscle tension were recorded. Purinergic neurotransmitters were administered after recording the regular contractions. Immunohistochemistry was performed on the circular muscle layers. Intracellular recording was performed on the colonic muscular layer. SK3, P2RY1, and PDGFR-α mRNA expression was tested by quantitative real-time polymerase chain reaction (qPCR). Results Adenosine triphosphate (ATP) treatment significantly decreased the frequency and area under the curve (AUC) of the segmental contraction in right and left colons. Beta-nicotinamide adenine dinucleotide (β-NAD) decreased the frequency in the right colon and the amplitude, frequency and AUC in the left colon. Apamin significantly increased frequency and AUC in the left colon, and after apamin pretreatment, ATP and β-NAD did not change segmental contractility. Through intracellular recordings, a resting membrane potential decrease occurred after ATP administration; however, the degree of decrease between the right and left colon was not different. PDGFRα+ cells were distributed evenly in the circular muscle layers of right and left colons. SK3, P2RY1, and PDGFRα expression was not different between the right and left colon. Conclusion Purines reduce right and left colon contractility similarly, and purinergic inhibitory neurotransmission can be regulated by PDGFRα+ cells in the human colon.
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Affiliation(s)
- Kil-Yong Lee
- Department of Surgery, Uijeongbu St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Uijeongbu-si, Gyeonggi-do, Korea
| | - Tae Sik Sung
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea.,Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, USA
| | - Byoung H Koh
- Department of Physiology and Cell Biology, University of Nevada Reno School of Medicine, Reno, NV, USA
| | - Seung-Bum Ryoo
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Jung Nyeo Chun
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Shin-Hye Kim
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Kyu Joo Park
- Department of Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Insuk So
- Department of Physiology, Seoul National University College of Medicine, Seoul, Korea
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17
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Altered functional responses by PAR1 agonist in murine dextran sodium sulphate-treated colon. Sci Rep 2022; 12:16746. [PMID: 36202914 PMCID: PMC9537183 DOI: 10.1038/s41598-022-21285-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 09/26/2022] [Indexed: 11/08/2022] Open
Abstract
Protease-activated receptor-1 (PAR1) is highly expressed in murine colonic smooth muscles. Responses to PAR1 activation are complex and result from responses in multiple cell types. We investigated whether PAR1 responses are altered in inflamed colon induced by dextran sodium sulfate (DSS)-treatment. Colitis was induced in C57BL/6 mice by administration of 3% DSS in drinking water for 7 days. Measurements of isometric force, transmembrane potentials from impaled smooth muscle cells, quantitative PCR and Western blots were performed. Thrombin, an activator of PAR1, caused transient hyperpolarization and relaxation of untreated colons, but these responses decreased in DSS-treated colons. Apamin caused depolarization and increased contractions of muscles from untreated mice. This response was decreased in DSS-treated colons. Expression of Kcnn3 and Pdgfra also decreased in DSS-treated muscles. A second phase of thrombin responses is depolarization and increased contractions in untreated muscles. However, thrombin did cause depolarization in DSS-treated colon, yet it increased colonic contractions. The latter effect was associated with enhanced expression of MYPT1 and CPI-17. The propagation velocity and frequency of colonic migrating motor complexes in DSS-treated colon was significantly higher compared to control colons. In summary, DSS treatment causes loss of transient relaxations due to downregulation of SK3 channels in PDGFRα+ cells and may increase contractile responses due to increased Ca2+ sensitization of smooth muscle cells via PAR1 activation.
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18
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Clayton DR, Ruiz WG, Dalghi MG, Montalbetti N, Carattino MD, Apodaca G. Studies of ultrastructure, gene expression, and marker analysis reveal that mouse bladder PDGFRA + interstitial cells are fibroblasts. Am J Physiol Renal Physiol 2022; 323:F299-F321. [PMID: 35834272 PMCID: PMC9394772 DOI: 10.1152/ajprenal.00135.2022] [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: 05/10/2022] [Revised: 06/07/2022] [Accepted: 07/06/2022] [Indexed: 11/22/2022] Open
Abstract
Fibroblasts are crucial to normal and abnormal organ and tissue biology, yet we lack basic insights into the fibroblasts that populate the bladder wall. Candidates may include bladder interstitial cells (also referred to as myofibroblasts, telocytes, and interstitial cells of Cajal-like cells), which express the fibroblast-associated marker PDGFRA along with VIM and CD34 but whose form and function remain enigmatic. By applying the latest insights in fibroblast transcriptomics, coupled with studies of gene expression, ultrastructure, and marker analysis, we observe the following: 1) that mouse bladder PDGFRA+ cells exhibit all of the ultrastructural hallmarks of fibroblasts including spindle shape, lack of basement membrane, abundant endoplasmic reticulum and Golgi, and formation of homotypic cell-cell contacts (but not heterotypic ones); 2) that they express multiple canonical fibroblast markers (including Col1a2, CD34, LY6A, and PDGFRA) along with the universal fibroblast genes Col15a1 and Pi16 but they do not express Kit; and 3) that PDGFRA+ fibroblasts include suburothelial ones (which express ACTA2, CAR3, LY6A, MYH10, TNC, VIM, Col1a2, and Col15a1), outer lamina propria ones (which express CD34, LY6A, PI16, VIM, Col1a2, Col15a1, and Pi16), intermuscular ones (which express CD34, VIM, Col1a2, Col15a1, and Pi16), and serosal ones (which express CD34, PI16, VIM, Col1a2, Col15a1, and Pi16). Collectively, our study revealed that the ultrastructure of PDFRA+ interstitial cells combined with their expression of multiple canonical and universal fibroblast-associated gene products indicates that they are fibroblasts. We further propose that there are four regionally distinct populations of fibroblasts in the bladder wall, which likely contribute to bladder function and dysfunction.NEW & NOTEWORTHY We currently lack basic insights into the fibroblasts that populate the bladder wall. By exploring the ultrastructure of mouse bladder connective tissue cells, combined with analyses of their gene and protein expression, our study revealed that PDGRA+ interstitial cells (also referred to as myofibroblasts, telocytes, and interstitial cells of Cajal-like cells) are fibroblasts and that the bladder wall contains multiple, regionally distinct populations of these cells.
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Affiliation(s)
- Dennis R Clayton
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Wily G Ruiz
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Marianela G Dalghi
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | - Marcelo D Carattino
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Gerard Apodaca
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
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19
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Ding F, Guo R, Cui ZY, Hu H, Zhao G. Clinical application and research progress of extracellular slow wave recording in the gastrointestinal tract. World J Gastrointest Surg 2022; 14:544-555. [PMID: 35979419 PMCID: PMC9258241 DOI: 10.4240/wjgs.v14.i6.544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/21/2022] [Accepted: 05/17/2022] [Indexed: 02/06/2023] Open
Abstract
The physiological function of the gastrointestinal (GI) tract is based on the slow wave generated and transmitted by the interstitial cells of Cajal. Extracellular myoelectric recording techniques are often used to record the characteristics and propagation of slow wave and analyze the models of slow wave transmission under physiological and pathological conditions to further explore the mechanism of GI dysfunction. This article reviews the application and research progress of electromyography, bioelectromagnetic technology, and high-resolution mapping in animal and clinical experiments, summarizes the clinical application of GI electrical stimulation therapy, and reviews the electrophysiological research in the biliary system.
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Affiliation(s)
- Fan Ding
- Center of Gallbladder Disease, East Hospital of Tongji University, Shanghai 200120, China
- Institute of Gallstone Disease, Tongji University School of Medicine, Shanghai 200331, China
| | - Run Guo
- Department of Ultrasonography, East Hospital of Tongji University, Shanghai 200120, China
| | - Zheng-Yu Cui
- Department of Internal Medicine of Traditional Chinese Medicine, East Hospital of Tongji University, Shanghai 200120, China
| | - Hai Hu
- Center of Gallbladder Disease, East Hospital of Tongji University, Shanghai 200120, China
- Institute of Gallstone Disease, Tongji University School of Medicine, Shanghai 200331, China
| | - Gang Zhao
- Center of Gallbladder Disease, East Hospital of Tongji University, Shanghai 200120, China
- Institute of Gallstone Disease, Tongji University School of Medicine, Shanghai 200331, China
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20
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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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21
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Xie L, Fletcher RB, Bhatia D, Shah D, Phipps J, Deshmukh S, Zhang H, Ye J, Lee S, Le L, Newman M, Chen H, Sura A, Gupta S, Sanman LE, Yang F, Meng W, Baribault H, Vanhove GF, Yeh WC, Li Y, Lu C. Robust Colonic Epithelial Regeneration and Amelioration of Colitis via FZD-Specific Activation of Wnt Signaling. Cell Mol Gastroenterol Hepatol 2022; 14:435-464. [PMID: 35569814 PMCID: PMC9305022 DOI: 10.1016/j.jcmgh.2022.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/29/2022] [Accepted: 05/05/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND AND AIMS Current management of inflammatory bowel disease leaves a clear unmet need to treat the severe epithelial damage. Modulation of Wnt signaling might present an opportunity to achieve histological remission and mucosal healing when treating IBD. Exogenous R-spondin, which amplifies Wnt signals by maintaining cell surface expression of Frizzled (Fzd) and low-density lipoprotein receptor-related protein receptors, not only helps repair intestine epithelial damage, but also induces hyperplasia of normal epithelium. Wnt signaling may also be modulated with the recently developed Wnt mimetics, recombinant antibody-based molecules mimicking endogenous Wnts. METHODS We first compared the epithelial healing effects of RSPO2 and a Wnt mimetic with broad Fzd specificity in an acute dextran sulfate sodium mouse colitis model. Guided by Fzd expression patterns in the colon epithelium, we also examined the effects of Wnt mimetics with subfamily Fzd specificities. RESULTS In the DSS model, Wnt mimetics repaired damaged colon epithelium and reduced disease activity and inflammation and had no apparent effect on uninjured tissue. We further identified that the FZD5/8 and LRP6 receptor-specific Wnt mimetic, SZN-1326-p, was associated with the robust repair effect. Through a range of approaches including single-cell transcriptome analyses, we demonstrated that SZN-1326-p directly impacted epithelial cells, driving transient expansion of stem and progenitor cells, promoting differentiation of epithelial cells, histologically restoring the damaged epithelium, and secondarily to epithelial repair, reducing inflammation. CONCLUSIONS It is feasible to design Wnt mimetics such as SZN-1326-p that impact damaged intestine epithelium specifically and restore its physiological functions, an approach that holds promise for treating epithelial damage in inflammatory bowel disease.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Chenggang Lu
- Correspondence Address correspondence to: Chenggang Lu, PhD, Surrozen, Inc., 171 Oyster Point Boulevard, Suite 400, South San Francisco, CA 94080.
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22
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Kurahashi M, Baker SA, Kito Y, Bartlett A, Hara M, Takeyama H, Hashitani H, Sanders KM. PDGFRα + Interstitial Cells are Effector Cells of PACAP Signaling in Mouse and Human Colon. Cell Mol Gastroenterol Hepatol 2022; 14:357-373. [PMID: 35569815 PMCID: PMC9250024 DOI: 10.1016/j.jcmgh.2022.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 05/01/2022] [Accepted: 05/05/2022] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Platelet-derived growth factor receptor α (PDGFRα)-positive interstitial cells (PIC) are interposed between enteric nerve fibers and smooth muscle cells (SMCs) in the tunica muscularis of the gastrointestinal tract. PIC have robust expression of small conductance Ca2+ activated K+ channels 3 (SK3 channels) and transduce inhibitory inputs from purinergic and sympathetic nerves in mouse and human colon. We investigated whether PIC also express pituitary adenylate cyclase-activating polypeptide (PACAP) receptors, PAC1 (PAC1R), and are involved in mediating inhibitory regulation of colonic contractions by PACAP in mouse and human colons. METHODS Gene expression analysis, Ca2+ imaging, and contractile experiments were performed on mouse colonic muscles. Ca2+ imaging, intracellular electrical recordings, and contractile experiments were performed on human colonic muscles. RESULTS Adcyap1r1 (encoding PAC1R) is highly expressed in mouse PIC. Interstitial cells of Cajal (ICC) and SMCs expressed far lower levels of Adcyap1r. Vipr1 and Vipr2 were expressed at low levels in PIC, ICC, and SMCs. PACAP elicited Ca2+ transients in mouse PIC and inhibited spontaneous phasic contractions via SK channels. In human colonic muscles, PAC1R agonists elicited Ca2+ transients in PIC, hyperpolarized SMCs through SK channels and inhibited spontaneous phasic contractions. CONCLUSIONS PIC of mouse and human colon utilize PAC1R-SK channel signal pathway to inhibit colonic contractions in response to PACAP. Effects of PACAP are in addition to the previously described purinergic and sympathetic inputs to PIC. Thus, PIC integrate inhibitory inputs from at least 3 neurotransmitters and utilize several types of receptors to activate SK channels and regulate colonic contractile behaviors.
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Affiliation(s)
- Masaaki Kurahashi
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Iowa, Iowa City, Iowa, USA,Correspondence Address correspondence to: Masaaki Kurahashi, MD, PhD, 200 Hawkins Dr, University of Iowa, Department of Internal Medicine, Division of Gastroenterology and Hepatology, Iowa City, IA 52242. tel: (319) 467-8963.
| | - Salah A. Baker
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Yoshihiko Kito
- Department of Pharmacology, Faculty of Medicine, Saga University, Saga, Japan
| | - Allison Bartlett
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Masayasu Hara
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiromitsu Takeyama
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Kenton M. Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada, USA
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23
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Mercado-Perez A, Beyder A. Gut feelings: mechanosensing in the gastrointestinal tract. Nat Rev Gastroenterol Hepatol 2022; 19:283-296. [PMID: 35022607 PMCID: PMC9059832 DOI: 10.1038/s41575-021-00561-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/22/2021] [Indexed: 12/11/2022]
Abstract
The primary function of the gut is to procure nutrients. Synchronized mechanical activities underlie nearly all its endeavours. Coordination of mechanical activities depends on sensing of the mechanical forces, in a process called mechanosensation. The gut has a range of mechanosensory cells. They function either as specialized mechanoreceptors, which convert mechanical stimuli into coordinated physiological responses at the organ level, or as non-specialized mechanosensory cells that adjust their function based on the mechanical state of their environment. All major cell types in the gastrointestinal tract contain subpopulations that act as specialized mechanoreceptors: epithelia, smooth muscle, neurons, immune cells, and others. These cells are tuned to the physical properties of the surrounding tissue, so they can discriminate mechanical stimuli from the baseline mechanical state. The importance of gastrointestinal mechanosensation has long been recognized, but the latest discoveries of molecular identities of mechanosensors and technical advances that resolve the relevant circuitry have poised the field to make important intellectual leaps. This Review describes the mechanical factors relevant for normal function, as well as the molecules, cells and circuits involved in gastrointestinal mechanosensing. It concludes by outlining important unanswered questions in gastrointestinal mechanosensing.
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Affiliation(s)
- Arnaldo Mercado-Perez
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, MN, USA
- Medical Scientist Training Program (MSTP), Mayo Clinic, Rochester, MN, USA
| | - Arthur Beyder
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology & Hepatology, Mayo Clinic, Rochester, MN, USA.
- Department of Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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Mischopoulou M, D'Ambrosio M, Bigagli E, Luceri C, Farrugia G, Cipriani G. Role of Macrophages and Mast Cells as Key Players in the Maintenance of Gastrointestinal Smooth Muscle Homeostasis and Disease. Cell Mol Gastroenterol Hepatol 2022; 13:1849-1862. [PMID: 35245688 PMCID: PMC9123576 DOI: 10.1016/j.jcmgh.2022.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 12/18/2022]
Abstract
The gut contains the largest macrophage pool in the body, with populations of macrophages residing in the mucosa and muscularis propria of the gastrointestinal (GI) tract. Muscularis macrophages (MMs), which are located within the muscularis propria, interact with cells essential for GI function, such as interstitial cells of Cajal, enteric neurons, smooth muscle cells, enteric glia, and fibroblast-like cells, suggesting that these immune cells contribute to several aspects of GI function. This review focuses on the latest insights on the factors contributing to MM heterogeneity and the functional interaction of MMs with other cell types essential for GI function. This review integrates the latest findings on macrophages in other organs with increasing knowledge of MMs to better understand their role in a healthy and diseased gut. We describe the factors that contribute to (muscularis macrophage) MM heterogeneity, and the nature of MM interactions with cells regulating GI function. Finally, we also describe the increasing evidence suggesting a critical role of another immune cell type, the mast cell, in normal and diseased GI physiology.
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Affiliation(s)
| | - Mario D'Ambrosio
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Elisabetta Bigagli
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
| | - Cristina Luceri
- Section of Pharmacology and Toxicology, Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Florence, Italy
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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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Takeya M, Higashi R, Hashitani H, Nakamura KI, Hayashi T, Nakashima N, Takano M. PDGFRα (+) subepithelial interstitial cells act as a pacemaker to drive smooth muscle of the guinea pig seminal vesicle. J Physiol 2022; 600:1703-1730. [PMID: 35081665 DOI: 10.1113/jp281686] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/18/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS In many visceral smooth muscle organs, spontaneous contractions are electrically driven by non-muscular pacemaker cells. In guinea pig seminal vesicles (SVs), as yet unidentified mucosal cells appear to drive neighbouring smooth muscle cells (SMCs). Two populations of spontaneously active cells are distributed in the SV mucosa. Basal epithelial cells (BECs) generate asynchronous, irregular spontaneous Ca2+ transients and spontaneous transient depolarisations (STDs). In contrast, subepithelial interstitial cells (SICs) develop synchronous Ca2+ oscillations and electrical slow waves. Pancytokeratin-immunoreactive (IR) BECs are located on the apical side of the basement membrane (BM), while platelet-derived growth factor receptor α (PDGFRα)-IR SICs are located on the basal side of the BM. Spontaneous Ca2+ transients in SICs are synchronised with those in SV SMCs. Dye-coupling between SICs and SMCs suggests that SICs act as pacemaker cells to drive the spontaneous contractions of SV smooth muscle. ABSTRACT Smooth muscle cells (SMCs) of the guinea pig seminal vesicle (SV) develop spontaneous phasic contractions, Ca2+ flashes and electrical slow waves in a mucosa dependent manner, thus it was envisaged that pacemaker cells reside in the mucosa. Here, we aimed to identify the pacemaker cells in SV mucosa using intracellular microelectrode and fluorescent Ca2+ imaging techniques. Morphological characteristics of the mucosal pacemaker cells were also investigated using focused ion beam/scanning electron microscopy tomography and fluorescent immunohistochemistry. Two populations of mucosal cells developed spontaneous Ca2+ transients and electrical activity, namely basal epithelial cells (BECs) and subepithelial interstitial cells (SICs). Pancytokeratin-immunoreactive BECs were located on the apical side of the basement membrane (BM) and generated asynchronous, irregular spontaneous Ca2+ transients and spontaneous transient depolarisations (STDs). The spontaneous Ca2+ transients and STDs were not diminished by 10 μM nifedipine but abolished by 10 μM cyclopiazonic acid (CPA). Platelet-derived growth factor receptor α (PDGFRα)-immunoreactive SICs were distributed just beneath the basal side of the BM and developed synchronous Ca2+ oscillations (SCOs) and electrical slow waves, which were suppressed by 3 μM nifedipine and abolished by 10 μM CPA. In SV mucosal preparations in which some smooth muscle bundles remained attached, SICs and residual SMCs developed temporally-correlated spontaneous Ca2+ transients. Neurobiotin injected into SICs spread to not only neighbouring SICs but also to neighbouring SMCs or vice versa. These results suggest that PDGFRα (+) SICs electrotonically drive the spontaneous contractions of SV smooth muscle. Abstract figure legend The seminal vesicles (SVs) of guinea pig generate spontaneous phasic contractions (SPCs). SV smooth muscle cells (SMCs, pink) develop SPCs associated with spontaneous electrical slow waves and Ca2+ flashes, which require the attachment of mucosal layer. Histological examination demonstrated the layer of PDGFRα-immunoreactive subepithelial interstitial cells (SICs, green) underneath of the basement membrane. The SICs spontaneously develop synchronous Ca2+ oscillations and the electrical slow waves, at the frequency corresponding to those of SPCs. The dye-coupling between SICs and SMCs further suggested that the synchronous electrical slow waves in the SICs electrotonically conduct to the SV SMCs via gap junctions (orange). Thus, the SICs appear to act as electrical pacemaker cells driving SPCs of SV. The basal epithelial cells (BECs, brown) also generated asynchronous, irregular spontaneous Ca2+ transients and spontaneous transient depolarisations, although their roles in developing SPCs remains to be explored. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Mitsue Takeya
- Division of Integrated Autonomic Function, Department of Physiology, Kurume University School of Medicine, Kurume, Japan
| | - Ryuhei Higashi
- Electron Microscopic Laboratory, Central Research Unit of Kurume University School of Medicine, Kurume, Japan
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Kei-Ichiro Nakamura
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, Kurume, Japan
| | | | - Noriyuki Nakashima
- Division of Integrated Autonomic Function, Department of Physiology, Kurume University School of Medicine, Kurume, Japan
| | - Makoto Takano
- Division of Integrated Autonomic Function, Department of Physiology, Kurume University School of Medicine, Kurume, Japan
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Sanders KM, Baker SA, Drumm BT, Kurahashi M. Ca 2+ Signaling Is the Basis for Pacemaker Activity and Neurotransduction in Interstitial Cells of the GI Tract. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:229-241. [PMID: 36587162 DOI: 10.1007/978-3-031-05843-1_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Years ago gastrointestinal motility was thought to be due to interactions between enteric nerves and smooth muscle cells (SMCs) in the tunica muscularis. Thus, regulatory mechanisms controlling motility were either myogenic or neurogenic. Now we know that populations of interstitial cells, c-Kit+ (interstitial cells of Cajal or ICC), and PDGFRα+ cells (formerly "fibroblast-like" cells) are electrically coupled to SMCs, forming the SIP syncytium. Pacemaker and neurotransduction functions are provided by interstitial cells through Ca2+ release from the endoplasmic reticulum (ER) and activation of Ca2+-activated ion channels in the plasma membrane (PM). ICC express Ca2+-activated Cl- channels encoded by Ano1. When activated, Ano1 channels produce inward current and, therefore, depolarizing or excitatory effects in the SIP syncytium. PDGFRα+ cells express Ca2+-activated K+ channels encoded by Kcnn3. These channels generate outward current when activated and hyperpolarizing or membrane-stabilizing effects in the SIP syncytium. Inputs from enteric and sympathetic neurons regulate Ca2+ transients in ICC and PDGFRα+ cells, and currents activated in these cells conduct to SMCs and regulate contractile behaviors. ICC also serve as pacemakers, generating slow waves that are the electrophysiological basis for gastric peristalsis and intestinal segmentation. Pacemaker types of ICC express voltage-dependent Ca2+ conductances that organize Ca2+ transients, and therefore Ano1 channel openings, into clusters that define the amplitude and duration of slow waves. Ca2+ handling mechanisms are at the heart of interstitial cell function, yet little is known about what happens to Ca2+ dynamics in these cells in GI motility disorders.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA.
| | - Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA
| | - Bernard T Drumm
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA
| | - Masaaki Kurahashi
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, NV, USA.,Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of Iowa, Iowa, Iowa City, USA
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New Concepts of the Interplay Between the Gut Microbiota and the Enteric Nervous System in the Control of Motility. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1383:55-69. [PMID: 36587146 DOI: 10.1007/978-3-031-05843-1_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Propulsive gastrointestinal (GI) motility is critical for digestive physiology and host defense. GI motility is finely regulated by the intramural reflex pathways of the enteric nervous system (ENS). The ENS is in turn regulated by luminal factors: diet and the gut microbiota. The gut microbiota is a vast ecosystem of commensal bacteria, fungi, viruses, and other microbes. The gut microbiota not only regulates the motor programs of the ENS but also is critical for the normal structure and function of the ENS. In this chapter, we highlight recent research that has shed light on the microbial mechanisms of interaction with the ENS involved in the control of motility. Toll-like receptor signaling mechanisms have been shown to maintain the structural integrity of the ENS and the neurochemical phenotypes of enteric neurons, in part through the production of trophic factors including glia-derived neurotrophic factor. Microbiota-derived short-chain fatty acids and/or single-stranded RNA regulates the synthesis of serotonin in enterochromaffin cells, which are involved in the initiation of enteric reflexes, among other functions. Further evidence suggests a crucial role for microbial modulation of serotonin in maintaining the integrity of the ENS through enteric neurogenesis. Understanding the microbial pathways of enteric neural control sheds new light on digestive health and provides novel treatment strategies for GI motility disorders.
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Abstract
Gastroparesis is characterized by symptoms suggestive of, and objective evidence of, delayed gastric emptying in the absence of mechanical obstruction. This review addresses the normal emptying of solids and liquids from the stomach and details the myogenic and neuromuscular control mechanisms, including the specialized function of the pyloric sphincter, that result in normal emptying, based predominantly on animal research. A clear understanding of fundamental mechanisms is necessary to comprehend derangements leading to gastroparesis, and additional research on human gastric muscles is needed. The section on pathophysiology of gastroparesis considers neuromuscular diseases that affect nonsphincteric gastric muscle, disorders of the extrinsic neural control, and pyloric dysfunction that lead to gastroparesis. The potential cellular basis for gastroparesis is attributed to the effects of oxidative stress and inflammation, with increased pro-inflammatory and decreased resident macrophages, as observed in full-thickness biopsies from patients with gastroparesis. Predominant diagnostic tests involving measurements of gastric emptying, the use of a functional luminal imaging probe, and high-resolution antral duodenal manometry in characterizing the abnormal motor functions at the gastroduodenal junction are discussed. Management is based on supporting nutrition; dietary interventions, including the physical reduction in particle size of solid foods; pharmacological agents, including prokinetics and anti-emetics; and interventions such as gastric electrical stimulation and pyloromyotomy. These are discussed briefly, and comment is added on the potential for individualized treatments in the future, based on optimal gastric emptying measurement and objective documentation of the underlying pathophysiology causing the gastroparesis.
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Affiliation(s)
- Michael Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
| | - Kenton M. Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV
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30
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Baker SA, Hwang SJ, Blair PJ, Sireika C, Wei L, Ro S, Ward SM, Sanders KM. Ca 2+ transients in ICC-MY define the basis for the dominance of the corpus in gastric pacemaking. Cell Calcium 2021; 99:102472. [PMID: 34537580 PMCID: PMC8592010 DOI: 10.1016/j.ceca.2021.102472] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/03/2021] [Accepted: 09/05/2021] [Indexed: 12/13/2022]
Abstract
Myenteric interstitial cells of Cajal (ICC-MY) generate and actively propagate electrical slow waves in the stomach. Slow wave generation and propagation are altered in gastric motor disorders, such as gastroparesis, and the mechanism for the gradient in slow wave frequency that facilitates proximal to distal propagation of slow waves and normal gastric peristalsis is poorly understood. Slow waves depend upon Ca2+-activated Cl- channels (encoded by Ano1). We characterized Ca2+ signaling in ICC-MY in situ using mice engineered to have cell-specific expression of GCaMP6f in ICC. Ca2+ signaling differed in ICC-MY in corpus and antrum. Localized Ca2+ transients were generated from multiple firing sites and were organized into Ca2+ transient clusters (CTCs). Ca2+ transient refractory periods occurred upon cessation of CTCs, but a relatively higher frequency of Ca2+ transients persisted during the inter-CTC interval in corpus than in antrum ICC-MY. The onset of Ca2+ transients after the refractory period was associated with initiation of the next CTC. Thus, CTCs were initiated at higher frequencies in corpus than in antrum ICC-MY. Initiation and propagation of CTCs (and electrical slow waves) depends upon T-type Ca2+ channels, and durations of CTCs relied upon L-type Ca2+ channels. The durations of CTCs mirrored the durations of slow waves. CTCs and Ca2+ transients between CTCs resulted from release of Ca2+ from intracellular stores and were maintained, in part, by store-operated Ca2+ entry. Our data suggest that Ca2+ release and activation of Ano1 channels both initiate and contribute to the plateau phase of slow waves.
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Affiliation(s)
- Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA.
| | - Sung Jin Hwang
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA
| | - Peter J Blair
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA
| | - Carlee Sireika
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA
| | - Lai Wei
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA
| | - Seungil Ro
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA
| | - Sean M Ward
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno, School of Medicine, Reno, Nevada 89557, USA.
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Verkuijl SJ, Friedmacher F, Harter PN, Rolle U, Broens PMA. Persistent bowel dysfunction after surgery for Hirschsprung’s disease: A neuropathological perspective. World J Gastrointest Surg 2021; 13:822-833. [PMID: 34512906 PMCID: PMC8394380 DOI: 10.4240/wjgs.v13.i8.822] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/12/2021] [Accepted: 07/05/2021] [Indexed: 02/06/2023] Open
Abstract
Hirschsprung’s disease (HD) is a congenital disorder, characterized by aganglionosis in the distal part of the gastrointestinal tract. Despite complete surgical resection of the aganglionic segment, both constipation and fecal incontinence persist in a considerable number of patients with limited treatment options. There is growing evidence for structural abnormalities in the ganglionic bowel proximal to the aganglionosis in both humans and animals with HD, which may play a role in persistent bowel dysfunction. These abnormalities include: (1) Histopathological abnormalities of enteric neural cells; (2) Imbalanced expression of neurotransmitters and neuroproteins; (3) Abnormal expression of enteric pacemaker cells; (4) Abnormalities of smooth muscle cells; and (5) Abnormalities within the extracellular matrix. Hence, a better understanding of these previously unrecognized neuropathological abnormalities may improve follow-up and treatment in patients with HD suffering from persistent bowel dysfunction following surgical correction. In the long term, further combination of clinical and neuropathological data will hopefully enable a translational step towards more individual treatment for HD.
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Affiliation(s)
- Sanne J Verkuijl
- Department of Pediatric Surgery, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt 60590, Germany
- Neurological Institute (Edinger-Institute), University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt 60528, Germany
- Department of Surgery, Division of Pediatric Surgery, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, Netherlands
| | - Florian Friedmacher
- Department of Pediatric Surgery, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt 60590, Germany
| | - Patrick N Harter
- Neurological Institute (Edinger-Institute), University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt 60528, Germany
| | - Udo Rolle
- Department of Pediatric Surgery, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt 60590, Germany
| | - Paul MA Broens
- Department of Surgery, Division of Pediatric Surgery, University of Groningen, University Medical Center Groningen, Groningen 9700 RB, Netherlands
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Sanders KM, Mutafova-Yambolieva VN. Neurotransmitters responsible for purinergic motor neurotransmission and regulation of GI motility. Auton Neurosci 2021; 234:102829. [PMID: 34146957 DOI: 10.1016/j.autneu.2021.102829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 12/17/2022]
Abstract
Classical concepts of peripheral neurotransmission were insufficient to explain enteric inhibitory neurotransmission. Geoffrey Burnstock and colleagues developed the idea that ATP or a related purine satisfies the criteria for a neurotransmitter and serves as an enteric inhibitory neurotransmitter in GI muscles. Cloning of purinergic receptors and development of specific drugs and transgenic mice have shown that enteric inhibitory responses depend upon P2Y1 receptors in post-junctional cells. The post-junctional cells that transduce purinergic neurotransmitters in the GI tract are PDGFRα+ cells and not smooth muscle cells (SMCs). PDGFRα+ cells express P2Y1 receptors, are activated by enteric inhibitory nerve stimulation and generate Ca2+ oscillations, express small-conductance Ca2+-activated K+ channels (SK3), and generate outward currents when exposed to P2Y1 agonists. These properties are consistent with post-junctional purinergic responses, and similar responses and effectors are not functional in SMCs. Refinements in methodologies to measure purines in tissue superfusates, such as high-performance liquid chromatography (HPLC) coupled with etheno-derivatization of purines and fluorescence detection, revealed that multiple purines are released during stimulation of intrinsic nerves. β-NAD+ and other purines, better satisfy criteria for the purinergic neurotransmitter than ATP. HPLC has also allowed better detection of purine metabolites, and coupled with isolation of specific types of post-junctional cells, has provided new concepts about deactivation of purine neurotransmitters. In spite of steady progress, many unknowns about purinergic neurotransmission remain and require additional investigation to understand this important regulatory mechanism in GI motility.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, School of Medicine, 1664 North Virginia Street, Reno, NV 89557, USA.
| | - Violeta N Mutafova-Yambolieva
- Department of Physiology and Cell Biology, University of Nevada, School of Medicine, 1664 North Virginia Street, Reno, NV 89557, USA
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Identification of PDGFRα-positive interstitial cells in the distal segment of the murine vas deferens. Sci Rep 2021; 11:7553. [PMID: 33824385 PMCID: PMC8024294 DOI: 10.1038/s41598-021-87049-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 03/23/2021] [Indexed: 01/17/2023] Open
Abstract
Platelet-derived growth factor receptor-α (PDGFRα)-positive interstitial cells (ICs) are widely distributed in various organs and may be involved in the motility of various tubular organs. We, for the first time, aimed to investigate the distribution, immunohistochemical characteristics, and ultrastructure of PDGFRα-positive ICs in murine vas deferens, using confocal laser scanning microscopy, transmission electron microscopy (TEM), and immuno-electron microscopy (immuno-EM). For immunofluorescence, we used antibodies against PDGFRα and other markers of ICs. PDGFRα-positive ICs were distributed widely in the lamina propria, smooth muscles, and serosal layers. Although most PDGFRα-positive ICs labeled CD34, they did not label CD34 in the subepithelial layers. Additionally, PDGFRα-positive ICs were in close proximity to each other, as also to the surrounding cells. TEM and immuno-EM findings revealed that PDGFRα-positive ICs established close physical interactions with adjacent ICs. Extracellular vesicles were also detected around the PDGFRα-positive ICs. Our morphological findings suggest that PDGFRα-positive ICs may have several subpopulations, which can play an important role in intercellular signaling via direct contact with the IC network and the extracellular vesicles in the murine vas deferens. Further investigation on PDGFRα-positive ICs in the vas deferens may lead to understanding the vas deferens mortility.
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Mussa BM, Khan AA, Srivastava A, Abdallah SH. Differentiated PDGFRα-Positive Cells: A Novel In-Vitro Model for Functional Studies of Neuronal Nitric Oxide Synthase. Int J Mol Sci 2021; 22:ijms22073514. [PMID: 33805311 PMCID: PMC8037384 DOI: 10.3390/ijms22073514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 03/12/2021] [Accepted: 03/25/2021] [Indexed: 12/16/2022] Open
Abstract
It is evident that depletion of interstitial cells and dysfunction of nitric oxide (NO) pathways are key players in development of several gastrointestinal (GI) motility disorders such as diabetic gastroparesis (DGP). One of the main limitations of DGP research is the lack of isolation methods that are specific to interstitial cells, and therefore conducting functional studies is not feasible. The present study aims (i) to differentiate telomerase transformed mesenchymal stromal cells (iMSCs) into platelet-derived growth factor receptor-α-positive cells (PDGFRα-positive cells) using connective tissue growth factor (CTGF) and L-ascorbic acids; (ii) to investigate the effects of NO donor and inhibitor on the survival rate of differentiated PDGFRα-positive cells; and (iii) to evaluate the impact of increased glucose concentrations, mimicking diabetic hyperglycemia, on the gene expression of neuronal nitric oxide synthase (nNOS). A fibroblastic differentiation-induction medium supplemented with connective tissue growth factor was used to differentiate iMSCs into PDGFRα-positive cells. The medium was changed every day for 21 days to maintain the biological activity of the growth factors. Gene and protein expression, scanning electron and confocal microscopy, and flow cytometry analysis of several markers were conducted to confirm the differentiation process. Methyl tetrazolium cell viability, nitrite measurement assays, and immunostaining were used to investigate the effects of NO on PDGFRα-positive cells. The present study, for the first time, demonstrated the differentiation of iMSCs into PDGFRα-positive cells. The outcomes of the functional studies showed that SNAP (NO donor) increased the survival rate of differentiated PDGFRα-positive cells whereas LNNA (NO inhibitor) attenuated these effects. Further experimentations revealed that hyperglycemia produced a significant increase in expression of nNOS in PDGFRα-positive cells. Differentiation of iMSCs into PDGFRα-positive cells is a novel model to conduct functional studies and to investigate the involvement of NO pathways. This will help in identifying new therapeutic targets for treatment of DGP.
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Affiliation(s)
- Bashair M. Mussa
- Basic Medical Sciences Department, College of Medicine, University of Sharjah, Sharjah 27272, United Arab Emirates
- Correspondence: ; Tel.: +971-65057220
| | - Amir Ali Khan
- Department of Applied Biology, College of Science, University of Sharjah, Sharjah 27272, United Arab Emirates;
| | - Ankita Srivastava
- Sharjah Institute for Medical Research, University of Sharjah, Sharjah 27272, United Arab Emirates;
| | - Sallam Hasan Abdallah
- Research Institute of Sciences & Engineering, University of Sharjah, Sharjah 27272, United Arab Emirates;
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Ji S, Traini C, Mischopoulou M, Gibbons SJ, Ligresti G, Faussone-Pellegrini MS, Sha L, Farrugia G, Vannucchi MG, Cipriani G. Muscularis macrophages establish cell-to-cell contacts with telocytes/PDGFRα-positive cells and smooth muscle cells in the human and mouse gastrointestinal tract. Neurogastroenterol Motil 2021; 33:e13993. [PMID: 33020982 PMCID: PMC7902307 DOI: 10.1111/nmo.13993] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 07/22/2020] [Accepted: 08/25/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND AIM Muscularis macrophages (MMs) not only mediate the innate immunity, but also functionally interact with cells important for gastrointestinal motility. The aim of this study was to determine the spatial relationship and types of contacts between the MMs and neighboring cells in the muscularis propria of human and mouse stomach, small intestine, and large intestine. METHODS The distribution and morphology of MMs and their contacts with other cells were investigated by immunohistochemistry and transmission electron microscopy. KEY RESULTS Immunohistochemistry showed variable shape and number of MMs according to their location in different portions of the muscle coat. By double labeling, a close association between MMs and neighboring cells, that is, neurons, smooth muscle cells, interstitial cells of Cajal (ICCs), telocytes (TCs)/PDGFRα-positive cells, was seen. Electron microscopy demonstrated that in the muscle layers of both animal species, MMs have similar ultrastructural features and have specialized cell-to-cell contacts with smooth muscle cells and TCs/PDGFRα-positive cells but not with ICCs and enteric neurons. CONCLUSION & INFERENCES This study describes varying patterns of distribution of MMs between different regions of the gut, and reports the presence of distinct and extended cell-to-cell contacts between MMs and smooth muscle cells and between MMs and TCs/PDGFRα-positive cells. In contrast, MMs, although close to ICCs and nerve elements, did not make contact with them. These findings indicate specialized and variable roles for MMs in the modulation of gastrointestinal motility whose significance should be more closely investigated in normal and pathological conditions.
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Affiliation(s)
- Sihan Ji
- Enteric NeuroScience Program, Mayo Clinic, Rochester, Minnesota, USA,Department of Neuroendocrine Pharmacology, School of Pharmacy, China Medical University, Shenyang, Liaoning, China
| | - Chiara Traini
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Italy
| | | | - Simon J. Gibbons
- Enteric NeuroScience Program, Mayo Clinic, Rochester, Minnesota, USA
| | | | | | - Lei Sha
- Department of Neuroendocrine Pharmacology, School of Pharmacy, China Medical University, Shenyang, Liaoning, China,Corresponding authors: Gianluca Cipriani, PhD, Mayo Clinic, Enteric NeuroScience Program, 200 First Street SW, Rochester, MN 55905, 507-210-6402, ; Maria Giuliana Vannucchi MD, PhD, Research Unit of Histology and Embryology, Dept of Experimental and Clinical Medicine, Viale G. Pieraccini,6, 50139 Florence, Italy, ; Lei Sha, MD, China Medical University, Department of Neuroendocrine Pharmacology, School of Pharmacy, Shenyang, Liaoning, China, 77 Pu He Road, Shenbei New District, Shenyang, Liaoning province, P. R. China,110122, 18900911003,
| | - Gianrico Farrugia
- Enteric NeuroScience Program, Mayo Clinic, Rochester, Minnesota, USA
| | - Maria Giuliana Vannucchi
- Department of Experimental and Clinical Medicine, Research Unit of Histology and Embryology, University of Florence, Italy,Corresponding authors: Gianluca Cipriani, PhD, Mayo Clinic, Enteric NeuroScience Program, 200 First Street SW, Rochester, MN 55905, 507-210-6402, ; Maria Giuliana Vannucchi MD, PhD, Research Unit of Histology and Embryology, Dept of Experimental and Clinical Medicine, Viale G. Pieraccini,6, 50139 Florence, Italy, ; Lei Sha, MD, China Medical University, Department of Neuroendocrine Pharmacology, School of Pharmacy, Shenyang, Liaoning, China, 77 Pu He Road, Shenbei New District, Shenyang, Liaoning province, P. R. China,110122, 18900911003,
| | - Gianluca Cipriani
- Enteric NeuroScience Program, Mayo Clinic, Rochester, Minnesota, USA,Corresponding authors: Gianluca Cipriani, PhD, Mayo Clinic, Enteric NeuroScience Program, 200 First Street SW, Rochester, MN 55905, 507-210-6402, ; Maria Giuliana Vannucchi MD, PhD, Research Unit of Histology and Embryology, Dept of Experimental and Clinical Medicine, Viale G. Pieraccini,6, 50139 Florence, Italy, ; Lei Sha, MD, China Medical University, Department of Neuroendocrine Pharmacology, School of Pharmacy, Shenyang, Liaoning, China, 77 Pu He Road, Shenbei New District, Shenyang, Liaoning province, P. R. China,110122, 18900911003,
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Hannigan KI, Bossey AP, Foulkes HJL, Drumm BT, Baker SA, Ward SM, Sanders KM, Keef KD, Cobine CA. A novel intramuscular Interstitial Cell of Cajal is a candidate for generating pacemaker activity in the mouse internal anal sphincter. Sci Rep 2020; 10:10378. [PMID: 32587396 PMCID: PMC7316801 DOI: 10.1038/s41598-020-67142-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 06/03/2020] [Indexed: 12/14/2022] Open
Abstract
The internal anal sphincter (IAS) generates phasic contractions and tone. Slow waves (SWs) produced by interstitial cells of Cajal (ICC) underlie phasic contractions in other gastrointestinal regions. SWs are also present in the IAS where only intramuscular ICC (ICC-IM) are found, however the evidence linking ICC-IM to SWs is limited. This study examined the possible relationship between ICC-IM and SWs by recording Ca2+ transients in mice expressing a genetically-encoded Ca2+-indicator in ICC (Kit-Cre-GCaMP6f). A role for L-type Ca2+ channels (CavL) and anoctamin 1 (ANO1) was tested since each is essential for SW and tone generation. Two distinct ICC-IM populations were identified. Type I cells (36% of total) displayed localised asynchronous Ca2+ transients not dependent on CavL or ANO1; properties typical of ICC-IM mediating neural responses in other gastrointestinal regions. A second novel sub-type, i.e., Type II cells (64% of total) generated rhythmic, global Ca2+ transients at the SW frequency that were synchronised with neighbouring Type II cells and were abolished following blockade of either CavL or ANO1. Thus, the spatiotemporal characteristics of Type II cells and their dependence upon CavL and ANO1 all suggest that these cells are viable candidates for the generation of SWs and tone in the IAS.
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Affiliation(s)
- Karen I Hannigan
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Aaron P Bossey
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Holly J L Foulkes
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Bernard T Drumm
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Sean M Ward
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Kathleen D Keef
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA
| | - Caroline A Cobine
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, 89557, USA.
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Qian J, Olbrecht S, Boeckx B, Vos H, Laoui D, Etlioglu E, Wauters E, Pomella V, Verbandt S, Busschaert P, Bassez A, Franken A, Bempt MV, Xiong J, Weynand B, van Herck Y, Antoranz A, Bosisio FM, Thienpont B, Floris G, Vergote I, Smeets A, Tejpar S, Lambrechts D. A pan-cancer blueprint of the heterogeneous tumor microenvironment revealed by single-cell profiling. Cell Res 2020; 30:745-762. [PMID: 32561858 PMCID: PMC7608385 DOI: 10.1038/s41422-020-0355-0] [Citation(s) in RCA: 359] [Impact Index Per Article: 89.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 05/05/2020] [Indexed: 12/16/2022] Open
Abstract
The stromal compartment of the tumor microenvironment consists of a heterogeneous set of tissue-resident and tumor-infiltrating cells, which are profoundly moulded by cancer cells. An outstanding question is to what extent this heterogeneity is similar between cancers affecting different organs. Here, we profile 233,591 single cells from patients with lung, colorectal, ovary and breast cancer (n = 36) and construct a pan-cancer blueprint of stromal cell heterogeneity using different single-cell RNA and protein-based technologies. We identify 68 stromal cell populations, of which 46 are shared between cancer types and 22 are unique. We also characterise each population phenotypically by highlighting its marker genes, transcription factors, metabolic activities and tissue-specific expression differences. Resident cell types are characterised by substantial tissue specificity, while tumor-infiltrating cell types are largely shared across cancer types. Finally, by applying the blueprint to melanoma tumors treated with checkpoint immunotherapy and identifying a naïve CD4+ T-cell phenotype predictive of response to checkpoint immunotherapy, we illustrate how it can serve as a guide to interpret scRNA-seq data. In conclusion, by providing a comprehensive blueprint through an interactive web server, we generate the first panoramic view on the shared complexity of stromal cells in different cancers.
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Affiliation(s)
- Junbin Qian
- VIB Center for Cancer Biology, Leuven, Belgium.,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Siel Olbrecht
- VIB Center for Cancer Biology, Leuven, Belgium.,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium.,Department of Obstetrics and Gynaecology, University Hospitals Leuven, Leuven, Belgium
| | - Bram Boeckx
- VIB Center for Cancer Biology, Leuven, Belgium.,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Hanne Vos
- Department of Oncology, KU Leuven, Surgical Oncology, University Hospitals Leuven, Leuven, Belgium
| | - Damya Laoui
- Lab of Cellular and Molecular Immunology, Vrije Universiteit Brussel, Brussels, Belgium.,Myeloid Cell Immunology Lab, VIB Center for Inflammation Research, Brussels, Belgium
| | - Emre Etlioglu
- Laboratory of Molecular Digestive Oncology, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Els Wauters
- Respiratory Oncology Unit (Pneumology) and Leuven Lung Cancer Group, University Hospital KU Leuven, Leuven, Belgium.,Laboratory of Pneumology, Department of Chronic Diseases, Metabolism and Ageing, KU Leuven, Leuven, Belgium
| | - Valentina Pomella
- Laboratory of Molecular Digestive Oncology, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Sara Verbandt
- Laboratory of Molecular Digestive Oncology, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Pieter Busschaert
- Department of Obstetrics and Gynaecology, University Hospitals Leuven, Leuven, Belgium
| | - Ayse Bassez
- VIB Center for Cancer Biology, Leuven, Belgium.,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Amelie Franken
- VIB Center for Cancer Biology, Leuven, Belgium.,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Marlies Vanden Bempt
- VIB Center for Cancer Biology, Leuven, Belgium.,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Jieyi Xiong
- VIB Center for Cancer Biology, Leuven, Belgium.,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Birgit Weynand
- Department of Imaging and Pathology, Laboratory of Translational Cell & Tissue Research and University Hospitals Leuven, Department of Pathology, KU Leuven-University of Leuven, B-3000, Leuven, Belgium
| | | | - Asier Antoranz
- Department of Imaging and Pathology, Laboratory of Translational Cell & Tissue Research and University Hospitals Leuven, Department of Pathology, KU Leuven-University of Leuven, B-3000, Leuven, Belgium
| | - Francesca Maria Bosisio
- Department of Imaging and Pathology, Laboratory of Translational Cell & Tissue Research and University Hospitals Leuven, Department of Pathology, KU Leuven-University of Leuven, B-3000, Leuven, Belgium
| | - Bernard Thienpont
- Laboratory for Functional Epigenetics, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Giuseppe Floris
- Department of Imaging and Pathology, Laboratory of Translational Cell & Tissue Research and University Hospitals Leuven, Department of Pathology, KU Leuven-University of Leuven, B-3000, Leuven, Belgium
| | - Ignace Vergote
- Department of Obstetrics and Gynaecology, University Hospitals Leuven, Leuven, Belgium
| | - Ann Smeets
- Department of Oncology, KU Leuven, Surgical Oncology, University Hospitals Leuven, Leuven, Belgium
| | - Sabine Tejpar
- Laboratory of Molecular Digestive Oncology, Department of Oncology, KU Leuven, Leuven, Belgium
| | - Diether Lambrechts
- VIB Center for Cancer Biology, Leuven, Belgium. .,Laboratory for Translational Genetics, Department of Human Genetics, KU Leuven, Leuven, Belgium.
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Hashitani H, Mitsui R, Lang R. Functional heterogeneity of PDGFRα (+) cells in spontaneously active urogenital tissues. Neurourol Urodyn 2020; 39:1667-1678. [PMID: 32531084 DOI: 10.1002/nau.24431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/02/2020] [Indexed: 11/06/2022]
Abstract
AIMS As PDGFRα (+) cells appear not to suppress the excitability of detrusor smooth muscle by generating SK3-dependent hyperpolarising as proposed in the gastrointestinal tract, we further explored the functional roles of PDGFRα (+) cells in regulating the spontaneous activity of urogenital tissues. METHODS Using PDGFRα-eGFP mice, intracellular Ca2+ signaling in PDGFRα (+) cells of the bladder lamina propria, renal pelvis, and seminal vesicle were visualized using Cal-590 fluorescence. The distribution and SK3 expression of PDGFRα (+) cells were also examined by immunohistochemistry. RESULTS In the bladder lamina propria, SK3 (-) PDGFRα (+) cells exhibited spontaneous Ca2+ transients and responded to stimulation of P2Y1 purinoceptors with MRS2365 (100 nM) or adenosine diphosphate (ADP) (100 μM) by developing Ca2+ transients. In the proximal renal pelvis, PDGFRα (+) cells were distributed in the mucosal, muscular and serosal layers but did not express SK3 immunoreactivity. PDGFRα (+) cells in the musculature resembling atypical smooth muscle cells generated spontaneous Ca2+ transients that were partially suppressed upon P2Y1-stimulation, while vigorously responding to human angiotensin II (100 nM). In the seminal vesicle, PDGFRα (+) cells in the musculature but not mucosa expressed SK3 immunoreactivity. In the mucosa, the P2Y1 stimulation evoked Ca2+ transients in both PDGFRα (+) cells and PDGFRα (-) cells. CONCLUSION PDGFRα (+) cells in spontaneously active urogenital tissues display heterogeneity in terms of their SK3 expression and P2Y1-induced Ca2+ responses. Muscular PDGFRα (+) cells in the renal pelvis and mucosal PDGFRα (+) cells in the seminal vesicle may generate depolarizing signals to drive smooth muscle cells.
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Affiliation(s)
- Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Richard Lang
- Department of Physiology, Monash University, Clayton, Victoria, Australia
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Grainger N, Freeman RS, Shonnard CC, Drumm BT, Koh SD, Ward SM, Sanders KM. Identification and classification of interstitial cells in the mouse renal pelvis. J Physiol 2020; 598:3283-3307. [PMID: 32415739 DOI: 10.1113/jp278888] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Accepted: 04/29/2020] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Platelet-derived growth factor receptor-α (PDGFRα) is a novel biomarker along with smooth myosin heavy chain for the pacemaker cells (previously termed 'atypical' smooth muscle cells) in the murine and cynomolgus monkey pelvis-kidney junction. PDGFRα+ cells present in adventitial and urothelial layers of murine renal pelvis do not express smooth muscle myosin heavy chain (smMHC) but are in close apposition to nerve fibres. Most c-Kit+ cells in the renal pelvis are mast cells. Mast cells (CD117+ /CD45+ ) are more abundant in the proximal renal pelvis and pelvis-kidney junction regions whereas c-Kit+ interstitial cells (CD117+ /CD45- ) are found predominantly in the distal renal pelvis and ureteropelvic junction. PDGFRα+ cells are distinct from c-Kit+ interstitial cells. A subset of PDGFRα+ cells express the Ca2+ -activated Cl- channel, anoctamin-1, across the entire renal pelvis. Spontaneous Ca2+ transients were observed in c-Kit+ interstitial cells, smMHC+ PDGFRα cells and smMHC- PDGFRα cells using mice expressing genetically encoded Ca2+ sensors. ABSTRACT Rhythmic contractions of the renal pelvis transport urine from the kidneys into the ureter. Specialized pacemaker cells, termed atypical smooth muscle cells (ASMCs), are thought to drive the peristaltic contractions of typical smooth muscle cells (TSMCs) in the renal pelvis. Interstitial cells (ICs) in close proximity to ASMCs and TSMCs have been described, but the role of these cells is poorly understood. The presence and distributions of platelet-derived growth factor receptor-α+ (PDGFRα+ ) ICs in the pelvis-kidney junction (PKJ) and distal renal pelvis were evaluated. We found PDGFRα+ ICs in the adventitial layers of the pelvis, the muscle layer of the PKJ and the adventitia of the distal pelvis. PDGFRα+ ICs were distinct from c-Kit+ ICs in the renal pelvis. c-Kit+ ICs are a minor population of ICs in murine renal pelvis. The majority of c-Kit+ cells were mast cells. PDGFRα+ cells in the PKJ co-expressed smooth muscle myosin heavy chain (smMHC) and several other smooth muscle gene transcripts, indicating these cells are ASMCs, and PDGFRα is a novel biomarker for ASMCs. PDGFRα+ cells also express Ano1, which encodes a Ca2+ -activated Cl- conductance that serves as a primary pacemaker conductance in ICs of the GI tract. Spontaneous Ca2+ transients were observed in c-Kit+ ICs, smMHC+ PDGFRα cells and smMHC- PDGFRα cells using genetically encoded Ca2+ sensors. A reporter strain of mice with enhanced green fluorescent protein driven by the endogenous promotor for Pdgfra was shown to be a powerful new tool for isolating and characterizing the phenotype and functions of these cells in the renal pelvis.
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Affiliation(s)
- Nathan Grainger
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Ryan S Freeman
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Cameron C Shonnard
- Department of Physiology & Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Bernard T Drumm
- 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
| | - Sean M Ward
- 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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Gastreich-Seelig M, Jimenez M, Pouokam E. Mechanisms Associated to Nitroxyl (HNO)-Induced Relaxation in the Intestinal Smooth Muscle. Front Physiol 2020; 11:438. [PMID: 32581821 PMCID: PMC7283591 DOI: 10.3389/fphys.2020.00438] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/08/2020] [Indexed: 12/23/2022] Open
Abstract
The pharmacological properties of nitroxyl (HNO) donors in the gastrointestinal tract are unknown. We investigated the properties of this molecule in the regulation of gastrointestinal contractility focusing on its possible interaction with other gaseous signaling molecules such as NO and H2S. Organ bath, Ca2+ imaging, and microelectrode recordings were performed on rat intestinal samples, using Angeli’s salt as HNO donor. Angeli’s salt caused a concentration-dependent relaxation of longitudinal or circular muscle strips of the ileum and the proximal colon. This relaxation was strongly inhibited by the Rho-kinase inhibitor Y-27632 (10 μM), by the reducing agent DTT or by the inhibitor of soluble guanylate cyclase (sGC) ODQ (10 μM) alone or in combination with the inhibitors of the endogenous synthesis of H2S β-cyano-L-alanine (5 mM) and amino-oxyacetate (5 mM). Preventing endogenous synthesis of NO by the NO synthase inhibitor L-NAME (200 μM) did not affect the relaxation induced by HNO. HNO induced an increase in cytosolic Ca2+ concentration in colonic myocytes. It also elicited myocyte membrane hyperpolarization that amounted to −10.6 ± 1.1 mV. ODQ (10 μM) and Apamin (1 μM), a selective inhibitor of small conductance Ca2+-activated K+ channels (SKca), strongly antagonized this effect. We conclude that HNO relaxes the gastrointestinal tract musculature by hyperpolarizing myocytes via activation of the sGC/cGMP pathway similarly to NO, not only inhibiting the RhoK and activating MLCP as do both NO and H2S but also increasing cytosolic Ca2+ for activation of SKCa contributing to hyperpolarization.
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Affiliation(s)
- Mirko Gastreich-Seelig
- Institute for Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Giessen, Germany
| | - Marcel Jimenez
- Department of Cell Biology, Physiology and Immunology and Neurosciences Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ervice Pouokam
- Institute for Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Giessen, Germany
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Kurahashi M, Kito Y, Hara M, Takeyama H, Sanders KM, Hashitani H. Norepinephrine Has Dual Effects on Human Colonic Contractions Through Distinct Subtypes of Alpha 1 Adrenoceptors. Cell Mol Gastroenterol Hepatol 2020; 10:658-671.e1. [PMID: 32376421 PMCID: PMC7474159 DOI: 10.1016/j.jcmgh.2020.04.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Colonic musculature contain smooth muscle cells (SMC), interstitial cells of Cajal (ICC), and platelet-derived growth factor receptor α+ cells (PDGFRα+ cells), which are electrically coupled and operate together as the SIP syncytium. PDGFRα+ cells have enriched expression of small conductance Ca2+-activated K+ (SK) channels. Purinergic enteric neural input activates SK channels in PDGFRα+ cells, hyperpolarizes SMC, and inhibits colonic contractions. Recently we discovered that PDGFRα+ cells in mouse colon have enriched expression of α1A adrenoceptors (ARs), which coupled to activation of SK channels and inhibited colonic motility, and α1A ARs were principal targets for sympathetic regulation of colonic motility. Here we investigated whether PDGFRα+ cells in human colon express α1A ARs and share the roles as targets for sympathetic regulation of colonic motility. METHODS Isometric tension recording, intracellular recording, and Ca2+ imaging were performed on muscles of the human colon. Responses to α1 ARs agonists or electric field stimulation with AR antagonists and neuroleptic reagents were studied. RESULTS Exogenous or endogenous norepinephrine released from nerve fibers inhibited colonic contractions through binding to α1A ARs or enhanced colonic contractions by acting on α1D ARs. Inhibitory responses were blocked by apamin, an antagonist of SK channels. Phenylephrine, α1 AR agonists, or norepinephrine increased intracellular [Ca2+] in PDGFRα+ cells, but not in ICC, and hyperpolarized SMCs by binding to α1 ARs expressed by PDGFRα+ cells. CONCLUSIONS Human colonic contractions are inhibited by α1A ARs expressed in PDGFRα+ cells and activated by α1D ARs expressed in SMC.
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Affiliation(s)
- Masaaki Kurahashi
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada.
| | - Yoshihiko Kito
- Department of Pharmacology, Saga University, Saga, Japan
| | - Masayasu Hara
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Hiromitsu Takeyama
- Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
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42
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Kurahashi M, Kito Y, Baker SA, Jennings LK, Dowers JGR, Koh SD, Sanders KM. A novel postsynaptic signal pathway of sympathetic neural regulation of murine colonic motility. FASEB J 2020; 34:5563-5577. [PMID: 32086857 DOI: 10.1096/fj.201903134r] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/04/2020] [Accepted: 02/13/2020] [Indexed: 01/14/2023]
Abstract
Transcriptome data revealed α1 adrenoceptors (ARs) expression in platelet-derived growth factor receptor α+ cells (PDGFRα+ cells) in murine colonic musculature. The role of PDGFRα+ cells in sympathetic neural regulation of murine colonic motility was investigated. Norepinephrine (NE), via α1A ARs, activated a small conductance Ca2+ -activated K+ (SK) conductance, evoked outward currents and hyperpolarized PDGFRα+ cells (the α1A AR-SK channel signal pathway). α1 AR agonists increased intracellular Ca2+ transients in PDGFRα+ cells and inhibited spontaneous phasic contractions (SPCs) of colonic muscle through activation of a SK conductance. Sympathetic nerve stimulation inhibited both contractions of distal colon and propulsive contractions represented by the colonic migrating motor complexes (CMMCs) via the α1A AR-SK channel signal pathway. Postsynaptic signaling through α1A ARs in PDGFRα+ cells is a novel mechanism that conveys part of stress responses in the colon. PDGFRα+ cells appear to be a primary effector of sympathetic neural regulation of murine colonic motility.
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Affiliation(s)
- Masaaki Kurahashi
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, USA
| | - Yoshihiko Kito
- Department of Pharmacology, Saga University, Saga, Japan
| | - Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, USA
| | - Libby K Jennings
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, USA
| | - James G R Dowers
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, USA
| | - Sang Don Koh
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, USA
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Drumm BT, Rembetski BE, Messersmith K, Manierka MS, Baker SA, Sanders KM. Pacemaker function and neural responsiveness of subserosal interstitial cells of Cajal in the mouse colon. J Physiol 2020; 598:651-681. [PMID: 31811726 DOI: 10.1113/jp279102] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 11/22/2019] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Rhythmic action potentials and intercellular Ca2+ waves are generated in smooth muscle cells of colonic longitudinal muscles (LSMC). Longitudinal muscle excitability is tuned by input from subserosal ICC (ICC-SS), a population of ICC with previously unknown function. ICC-SS express Ano1 channels and generate spontaneous Ca2+ transients in a stochastic manner. Release of Ca2+ and activation of Ano1 channels causes depolarization of ICC-SS and LSMC, leading to activation of L-type Ca2+ channels, action potentials, intercellular Ca2+ waves and contractions in LSMC. Nitrergic neural inputs regulate the Ca2+ events in ICC-SS. Pacemaker activity in longitudinal muscle is an emergent property as a result of integrated processes in ICC-SS and LSMC. ABSTRACT Much is known about myogenic mechanisms in circular muscle (CM) in the gastrointestinal tract, although less is known about longitudinal muscle (LM). Two Ca2+ signalling behaviours occur in LM: localized intracellular waves not causing contractions and intercellular waves leading to excitation-contraction coupling. An Ano1 channel antagonist inhibited intercellular Ca2+ waves and LM contractions. Ano1 channels are expressed by interstitial cells of Cajal (ICC) but not by smooth muscle cells (SMCs). We investigated Ca2+ signalling in a novel population of ICC that lies along the subserosal surface of LM (ICC-SS) in mice expressing GCaMP6f in ICC. ICC-SS fired stochastic localized Ca2+ transients. Such events have been linked to activation of Ano1 channels in ICC. Ca2+ transients in ICC-SS occurred by release from stores most probably via inositol trisphosphate receptors. This activity relied on influx via store-operated Ca2+ entry and Orai channels. No voltage-dependent mechanism that synchronized Ca2+ transients in a single cell or between cells was found. Nitrergic agonists inhibited Ca2+ transients in ICC-SS, and stimulation of intrinsic nerves activated nitrergic responses in ICC-SS. Cessation of stimulation resulted in significant enhancement of Ca2+ transients compared to the pre-stimulus activity. No evidence of innervation by excitatory, cholinergic motor neurons was found. Our data suggest that ICC-SS contribute to regulation of LM motor activity. Spontaneous Ca2+ transients activate Ano1 channels in ICC-SS. Resulting depolarization conducts to SMCs, depolarizing membrane potential, activating L-type Ca2+ channels and initiating contraction. Rhythmic electrical and mechanical behaviours of LM are an emergent property of SMCs and ICC-SS.
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Affiliation(s)
- Bernard T Drumm
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Benjamin E Rembetski
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Katelyn Messersmith
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Marena S Manierka
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
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Abstract
BACKGROUND Recently, pathogenic alleles within ubiquitin N-recognin domain-containing E3 ligase 4 (UBR4) gene have been shown to be associated with Hirschsprung disease (HSCR). We determined the UBR4 expressions in Indonesian HSCR patients. METHODS We analyzed the UBR4 expressions in the colons of HSCR patient and anorectal malformation (ARM) patient as control by real-time polymerase chain reaction (qPCR). RESULTS Thirty-seven patients with non-syndromic HSCR and eighteen controls were involved in this study. qPCR revealed that the UBR4 expression was strongly decreased (0.77-fold) in the ganglionic group of patients with HSCR compared to the control group with ARM (ΔCT 2.43 ± 0.36 vs. 2.05 ± 0.69; p = 0.009), whereas the UBR4 expression was also significantly reduced (0.79-fold) in the aganglionic group of patients with HSCR compared to the control group with ARM (ΔCT 2.39 ± 0.46 vs. 2.05 ± 0.69; p = 0.044). However, the UBR4 expression change was not associated with gender (p = 0.35 and 0.80), nor with degree of aganglionosis both in ganglionic and aganglionic colons (p = 0.72 and 0.73), respectively. CONCLUSION Our study demonstrates that expression of UBR4 is decreased in both aganglionic and ganglionic colon of HSCR patients.
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Wang Q, Zang J, Huang X, Lu H, Xu W, Chen J. Colonic Dysmotility in Murine Partial Colonic Obstruction Due to Functional Changes in Interstitial Cells. J Neurogastroenterol Motil 2019; 25:589-601. [PMID: 31587550 PMCID: PMC6786438 DOI: 10.5056/jnm19136] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 08/07/2019] [Accepted: 08/27/2019] [Indexed: 12/11/2022] Open
Abstract
Background/Aims Interstitial cells play important roles in gastrointestinal (GI) neuro-smooth muscle transmission. The underlying mechanisms of colonic dysmotility have not been well illustrated. We established a partial colon obstruction (PCO) mouse model to investigate the changes of interstitial cells and the correlation with colonic motility. Methods Western blot technique was employed to observe the protein expressions of Kit, platelet-derived growth factor receptor-α (Pdgfra), Ca2+-activated Cl− (Ano1) channels, and small conductance Ca2+- activated K+ (SK) channels. Colonic migrating motor complexes (CMMCs) and isometric force measurements were employed in control mice and PCO mice. Results PCO mice showed distended abdomen and feces excretion was significantly reduced. Anatomically, the colon above the obstructive silicone ring was obviously dilated. Kit and Ano1 proteins in the colonic smooth muscle layer of the PCO colons were significantly decreased, while the expression of Pdgfra and SK3 proteins were significantly increased. The effects of a nitric oxide synthase inhibitor (L-NAME) and an Ano1 channel inhibitor (NPPB) on CMMC and colonic spontaneous contractions were decreased in the proximal and distal colons of PCO mice. The SK agonist, CyPPA and antagonist, apamin in PCO mice showed more effect to the CMMCs and colonic smooth muscle contractions. Conclusions Colonic transit disorder may be due to the downregulation of the Kit and Ano1 channels and the upregulation of SK3 channels in platelet-derived growth factor receptor-α positive (PDGFRα+) cells. The imbalance between interstitial cells of Cajal-Ano1 and PDGFRα-SK3 distribution might be a potential reason for the colonic dysmotility.
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Affiliation(s)
- Qianqian Wang
- Department of Pediatric Surgery, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Pediatric Surgery, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, China
| | - Jingyu Zang
- Department of Pediatric Surgery, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Pediatric Surgery, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, China
| | - Xu Huang
- Department of Anatomy and Physiology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hongli Lu
- Department of Anatomy and Physiology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Wenxie Xu
- Department of Pediatric Surgery, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Anatomy and Physiology, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Jie Chen
- Department of Pediatric Surgery, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.,Department of Pediatric Surgery, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, China
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Hayashi T, Hashitani H, Takeya M, Uemura KI, Nakamura KI, Igawa T. Properties of SK3 channel-expressing PDGFRα (+) cells in the rodent urinary bladder. Eur J Pharmacol 2019; 860:172552. [DOI: 10.1016/j.ejphar.2019.172552] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/05/2019] [Accepted: 07/15/2019] [Indexed: 11/27/2022]
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Grubišić V, Perez-Medina AL, Fried DE, Sévigny J, Robson SC, Galligan JJ, Gulbransen BD. NTPDase1 and -2 are expressed by distinct cellular compartments in the mouse colon and differentially impact colonic physiology and function after DSS colitis. Am J Physiol Gastrointest Liver Physiol 2019; 317:G314-G332. [PMID: 31188623 PMCID: PMC6774087 DOI: 10.1152/ajpgi.00104.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
ATP is both an important mediator of physiological gut functions such as motility and epithelial function, and a key danger signal that mediates cell death and tissue damage. The actions of extracellular ATP are regulated through the catalytic functions extracellular nucleoside triphosphate diphosphohydrolase-1 (NTPDase1), -2, -3, and -8, which ultimately generate nucleosides. Ectonucleotidases have distinct cellular associations, but the specific locations and functional roles of individual NTPDases in the intestine are still poorly understood. Here, we tested the hypothesis that differential and cell-selective regulation of purine hydrolysis by NTPDase1 and -2 plays important roles in gut physiology and disease. We studied Entpd1 and Entpd2 null mice in health and following colitis driven by 2% dextran sulfate sodium (DSS) administration using functional readouts of gut motility, epithelial barrier function, and neuromuscular communication. NTPDase1 is expressed by immune cells, and the ablation of Entpd1 altered glial numbers in the myenteric plexus. NTPDase2 is expressed by enteric glia, and the ablation of Entpd2 altered myenteric neuron numbers. Mice lacking either NTPDase1 or -2 exhibited decreased inhibitory neuromuscular transmission and altered components of inhibitory junction potentials. Ablation of Entpd2 increased gut permeability following inflammation. In conclusion, the location- and context-dependent extracellular nucleotide phosphohydrolysis by NTPDase1 and -2 substantially impacts gut function in health and disease.NEW & NOTEWORTHY Purines are important mediators of gastrointestinal physiology and pathophysiology. Nucleoside triphosphate diphosphohydrolases (NTPDases) regulate extracellular purines, but the roles of specific NTPDases in gut functions are poorly understood. Here, we used Entpd1- and Entpd2-deficient mice to show that the differential and cell-selective regulation of purine hydrolysis by NTPDase1 and -2 plays important roles in barrier function, gut motility, and neuromuscular communication in health and disease.
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Affiliation(s)
- Vladimir Grubišić
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Alberto L. Perez-Medina
- 2Department of Pharmacology and Toxicology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - David E. Fried
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Jean Sévigny
- 3Centre de recherche du CHU de Québec–Université Laval, Québec City, Quebec, Canada,4Département de Microbiologie-Infectiologie et d'Immunologie, Faculté de Médecine, Université Laval, Québec City, Quebec, Canada
| | - Simon C. Robson
- 5Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - James J. Galligan
- 2Department of Pharmacology and Toxicology and Neuroscience Program, Michigan State University, East Lansing, Michigan
| | - Brian D. Gulbransen
- 1Department of Physiology and Neuroscience Program, Michigan State University, East Lansing, Michigan
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Youm JB, Zheng H, Koh SD, Sanders KM. Na-K-2Cl Cotransporter and Store-Operated Ca 2+ Entry in Pacemaking by Interstitial Cells of Cajal. Biophys J 2019; 117:767-779. [PMID: 31400920 DOI: 10.1016/j.bpj.2019.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 06/26/2019] [Accepted: 07/11/2019] [Indexed: 01/13/2023] Open
Abstract
Pacemaker depolarization in interstitial cells of Cajal (ICCs) is believed to be induced by Ca2+ transients and activation of anoctamin-1 (Ano1) channels in the plasma membrane. However, block of store-operated calcium entry (SOCE) or the Na-K-2Cl cotransporter (NKCC1) terminates pacemaker activity in ICC, indicating these transporters are involved in the initiation or maintenance of pacemaker activity. We hypothesized that SOCE contributes to pacemaker depolarization by maintaining [Ca2+] in the endoplasmic reticulum, which is the underlying source of Ca2+ transients for activation of Ano1. NKCC1 maintains the Cl- gradient supporting the driving force for inward current mediated by Ano1. Currently mechanisms sustaining release of Ca2+ and activation of Ano1 channels during the plateau phase of slow waves are unknown, but the reverse mode of the Na+/Ca2+ exchange may contribute. We generated a mathematical model of pacemaker activity based on current empirical observations from ICC of mouse small intestine that incorporates functions of SOCE and NKCC1. This model reproduces experimental findings, suggesting roles for SOCE and Ano1 channels: blocking of either NKCC1 or SOCE in our model terminates pacemaker activity. Direct contribution of NKCC1 to pacemaker activity in a beat-to-beat manner is not predicted by our model. Instead, NKCC1 plays a maintenance role supporting the driving force for Cl- efflux. Incorporation of SOCE allows the model to drive pacemaker activity without a diastolic depolarization, as observed in cardiac pacemaking. Further biological experiments are necessary to validate and further refine the roles of NKCC1, Na+/Ca2+ exchange, and Ano1 in the pacemaker mechanism of ICC.
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Affiliation(s)
- Jae Boum Youm
- Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Korea
| | - Haifeng Zheng
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Sang Don Koh
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada.
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Lin Q, Qin M, Zhao SG, Liu ZX, Dou WJ, Zhang R, Li YL, Xi XH, Xu JQ, Ma LT, Wang JJ. The roles of PDGFRα signaling in the postnatal development and functional maintenance of the SMC-ICC-PDGFRα+ cell (SIP) syncytium in the colon. Neurogastroenterol Motil 2019; 31:e13568. [PMID: 30848008 DOI: 10.1111/nmo.13568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/15/2019] [Accepted: 01/15/2019] [Indexed: 01/02/2023]
Abstract
BACKGROUND The SIP syncytium in the gut consists of smooth muscle cells, interstitial cells of Cajal, and PDGFRα+ cells. We studied the fate of SIP cells after blocking PDGFRα receptor to explore the roles of PDGFRα signaling in the postnatal development and functional maintenance of the SIP syncytium. METHODS Crenolanib was administered to mice from P0, P10, or P50. The morphological changes in SIP cells were examined by immunofluorescence. Protein expression in SIP cells was detected by Western blotting. Moreover, colonic transit was analyzed by testing the colonic bead expulsion time. KEY RESULTS A dose of 5 mg(kg•day)-1 crenolanib administered for 10 days beginning on P0 apparently hindered the development of PDGFRα+ cells in the colonic longitudinal muscularis and myenteric plexus without influencing their proliferative activity and apoptosis, but this result was not seen in the colonic circular muscularis. SMCs were also inhibited by crenolanib. A dose of 7.5 mg(kg•day)-1 crenolanib administered for 15 days beginning on P0 caused reductions in both PDGFRα+ cells and ICC in the longitudinal muscularis, myenteric plexus, and circular muscularis. However, when crenolanib was administered at a dose of 5 mg(kg•day)-1 beginning on P10 or P50, it only noticeably decreased the number of PDGFRα+ cells in the colonic longitudinal muscularis. Crenolanib also caused PDGFRα+ cells to transdifferentiate into SMC in adult mice. Colonic transit was delayed after administration of crenolanib. CONCLUSIONS & INFERENCES Therefore, PDGFRα signaling is essential for the development and functional maintenance of the SIP cells, especially PDGFRα+ cells.
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Affiliation(s)
- Qiang Lin
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Ming Qin
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Shu-Guang Zhao
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Zhen-Xiong Liu
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Wei-Jia Dou
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Rong Zhang
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Yu-Long Li
- Department of Gastroenterology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Xiao-Hou Xi
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Jia-Qiao Xu
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Li-Tian Ma
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Jing-Jie Wang
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
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50
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Lu C, Lu H, Huang X, Liu S, Zang J, Li Y, Chen J, Xu W. Colonic Transit Disorder Mediated by Downregulation of Interstitial Cells of Cajal/Anoctamin-1 in Dextran Sodium Sulfate-induced Colitis Mice. J Neurogastroenterol Motil 2019; 25:316-331. [PMID: 30982243 PMCID: PMC6474700 DOI: 10.5056/jnm18173] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/15/2019] [Accepted: 02/26/2019] [Indexed: 01/08/2023] Open
Abstract
Background/Aims Interstitial cells of Cajal (ICC) and their special calcium-activated chloride channel, anoctamin-1 (ANO1) play pivotal roles in regulating colonic transit. This study is designed to investigate the role of ICC and the ANO1 channel in colonic transit disorder in dextran sodium sulfate (DSS)-treated colitis mice. Methods Colonic transit experiment, colonic migrating motor complexes (CMMCs), smooth muscle spontaneous contractile experiments, intracellular electrical recordings, western blotting analysis, and quantitative polymerase chain reaction were applied in this study. Results The mRNA and protein expressions of c-KIT and ANO1 channels were significantly decreased in the colons of DSS-colitis mice. The colonic artificial fecal-pellet transit experiment in vitro was significantly delayed in DSS-colitis mice. The CMMCs and smooth muscle spontaneous contractions were significantly decreased by 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), an ANO1 channel blocker, and NG-Nitro-L-arginine methyl ester hydrochloride (L-NAME), an inhibitor of nitric oxide synthase activity, in DSS-colitis mice compared with that of control mice. Intracellular electrical recordings showed that the amplitude of NPPB-induced hyperpolarization was more positive in DSS-colitis mice. The electric field stimulation-elicited nitric-dependent slow inhibitory junctional potentials were also more positive in DSS-colitis mice than those of control mice. Conclusion The results suggest that colonic transit disorder is mediated via downregulation of the nitric oxide/ICC/ANO1 signalling pathway in DSS-colitis mice.
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Affiliation(s)
- Chen Lu
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Department of Pediatric Surgery, Xin Hua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Hongli Lu
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xu Huang
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shaohua Liu
- Department of Anesthesiology, South Renji Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jingyu Zang
- Department of Pediatric Surgery, Xin Hua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yujia Li
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jie Chen
- Department of Pediatric Surgery, Xin Hua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wenxie Xu
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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