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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 2024:10.1007/s00441-024-03890-x. [PMID: 38587529 DOI: 10.1007/s00441-024-03890-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [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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Davis MJ, Zawieja SD. Pacemaking in the lymphatic system. J Physiol 2024. [PMID: 38520402 DOI: 10.1113/jp284752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/08/2024] [Indexed: 03/25/2024] Open
Abstract
Lymphatic collecting vessels exhibit spontaneous phasic contractions that are critical for lymph propulsion and tissue fluid homeostasis. This rhythmic activity is driven by action potentials conducted across the lymphatic muscle cell (LMC) layer to produce entrained contractions. The contraction frequency of a lymphatic collecting vessel displays exquisite mechanosensitivity, with a dynamic range from <1 to >20 contractions per minute. A myogenic pacemaker mechanism intrinsic to the LMCs was initially postulated to account for pressure-dependent chronotropy. Further interrogation into the cellular constituents of the lymphatic vessel wall identified non-muscle cell populations that shared some characteristics with interstitial cells of Cajal, which have pacemaker functions in the gastrointestinal and lower urinary tracts, thus raising the possibility of a non-muscle cell pacemaker. However, recent genetic knockout studies in mice support LMCs and a myogenic origin of the pacemaker activity. LMCs exhibit stochastic, but pressure-sensitive, sarcoplasmic reticulum calcium release (puffs and waves) from IP3R1 receptors, which couple to the calcium-activated chloride channel Anoctamin 1, causing depolarisation. The resulting electrical activity integrates across the highly coupled lymphatic muscle electrical syncytia through connexin 45 to modulate diastolic depolarisation. However, multiple other cation channels may also contribute to the ionic pacemaking cycle. Upon reaching threshold, a voltage-gated calcium channel-dependent action potential fires, resulting in a nearly synchronous calcium global calcium flash within the LMC layer to drive an entrained contraction. This review summarizes the key ion channels potentially responsible for the pressure-dependent chronotropy of lymphatic collecting vessels and various mechanisms of IP3R1 regulation that could contribute to frequency tuning.
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Affiliation(s)
- Michael J Davis
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, USA
| | - Scott D Zawieja
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, USA
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Lu C, Luo H, Wang Y, Jing S, Zhao J, Zou K, Wu F, Ying H. Regulation of PDGFRα + cells and ICC in progesterone-mediated slow colon transit in pregnant mice. Heliyon 2024; 10:e25227. [PMID: 38333873 PMCID: PMC10850515 DOI: 10.1016/j.heliyon.2024.e25227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 12/22/2023] [Accepted: 01/23/2024] [Indexed: 02/10/2024] Open
Abstract
Background Progesterone can inhibit intestinal smooth muscle contraction; however, the specific mechanism remains unclear. Besides smooth muscle cells, smooth muscle has two important mesenchymal cells, namely interstitial cells of Cajal (ICC) and PDGFRα+ cells, which induce the contraction and relaxation of smooth muscles. We aimed to explore the regulation of PDGFRα+ cells and ICC in progesterone-mediated colon slow transit in pregnant mice. Methods Colon transit experiments were performed in vivo and in vitro to observe slow colon transit. The expression of PDGFRα and c-KIT was detected by Western blot, RT-PCR, and immunofluorescence. An isometric tension experiment was performed to investigate smooth muscle contractions. Results The colon transit time in pregnant mice was longer than that in non-pregnant mice. Progesterone significantly blocks colonic smooth muscle contractions. However, when the relaxation and contraction of PDGFRα+ cells and ICC are blocked, progesterone cannot inhibit smooth muscle contraction. When the function of only PDGFRα+ cells are blocked, progesterone has a more obvious inhibitory effect on smooth muscle in the non-pregnant group than that in the pregnant group. However, when ICC alone was blocked, progesterone inhibited smooth muscle contractions more clearly in pregnant mice. The protein and mRNA expression of PDGFRα was higher and c-KIT was lower in pregnant mice. PDGFRα+ cells and ICC from smooth muscle all co-localize progesterone receptors. Conclusions Under the regulation of progesterone, the relaxation function of PDGFRα+ cells is enhanced and the contraction function of ICC is weakened, leading to the slow colon transit of pregnant mice.
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Affiliation(s)
- Chen Lu
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
- Hospital and Institute of Obstetrics and Gynecology, Shanghai Medical College, Fudan University, Shanghai, 200032, China
| | - Hui Luo
- Department of Obstetrics and Gynecology, International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200030, China
| | - Ye Wang
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Shuang Jing
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Jun Zhao
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Kexin Zou
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Fan Wu
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
| | - Hao Ying
- Department of Obstetrics and Gynecology, Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, 200092, China
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Guo SC, Yu B, Jia Q, Yan HY, Wang LQ, Sun FF, Ma TH, Yang H. Loureirin C extracted from Dracaena cochinchinensis S.C. Chen prevents rotaviral diarrhea in mice by inhibiting the intestinal Ca 2+-activated Cl - channels. J Ethnopharmacol 2024; 318:117077. [PMID: 37625605 DOI: 10.1016/j.jep.2023.117077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Resina Draconis (RD) is the red resin of Dracaena cochinchinensis (Lour.) S.C. Chen and most used as a hemostatic drug in traditional Chinese medicine. Recent studies have reported that RD has a therapeutic effect on gastrointestinal diseases. Loureirin A, B, and C (LA, LB, and LC) are dihydrochalcone compounds isolated from RD. AIM OF THE STUDY Dehydration is the primary cause of death in rotaviral diarrhea. Inhibition of Ca2+-activated Cl- channels (CaCCs)-mediated Cl- secretion significantly reduced fluid secretion in rotaviral diarrhea. RD was used to treat digestive diseases such as diarrhea and abdominal pain; however, the pharmacological mechanism remains unclear. This study investigated the effects of RD and loureirin on intestinal Cl- channels and their therapeutic effects on rotavirus-induced diarrhea, aiming to reveal RD's molecular basis, targets, and mechanisms for treating rotaviral diarrhea. MATERIALS AND METHODS Cell-based fluorescence quenching assays were used to examine the effect of RD and loureirin on Cl- channels activity. Electrophysiological properties were tested using short-circuit current experiments in epithelial cells or freshly isolated mouse intestinal tissue. Fecal water content, intestinal peristalsis rate, and smooth muscle contraction were measured in neonatal mice infected with SA-11 rotavirus before and after LC treatment or adult mice. RESULTS RD, LA, LB, and LC inhibited CaCCs-mediated Cl- current in HT-29 cells and colonic epithelium. The inhibitory effect of LC on CaCCs was primarily on the apical side in epithelial cells, which may be partially produced by affecting cytoplasmic Ca2+ levels. LC significantly inhibited TMEM16A-mediated Cl- current. Characterization studies revealed that LC inhibited basolateral K+ channel activity without affecting Na+/K+-ATPase activity in the colonic epithelium. Although LC activated the cystic fibrosis transmembrane regulator in epithelial cells, its effect was not apparent in colonic epithelium. In vivo, LC significantly reduced the fecal water content, intestinal peristalsis rate, and smooth muscle contraction of mice infected with rotavirus. CONCLUSION RD and its active compound LC inhibit intestinal CaCCs activity, which might mediate the anti-rotaviral diarrheal effect of RD.
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Affiliation(s)
- Si-Cheng Guo
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Bo Yu
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Qian Jia
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Han-Yu Yan
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Li-Qin Wang
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Fang-Fang Sun
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China; Nuclear Medicine Department, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, PR China.
| | - Tong-Hui Ma
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Hong Yang
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
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Arreola J, Pérez-Cornejo P, Segura-Covarrubias G, Corral-Fernández N, León-Aparicio D, Guzmán-Hernández ML. Function and Regulation of the Calcium-Activated Chloride Channel Anoctamin 1 (TMEM16A). Handb Exp Pharmacol 2024; 283:101-151. [PMID: 35768554 DOI: 10.1007/164_2022_592] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Various human tissues express the calcium-activated chloride channel Anoctamin 1 (ANO1), also known as TMEM16A. ANO1 allows the passive chloride flux that controls different physiological functions ranging from muscle contraction, fluid and hormone secretion, gastrointestinal motility, and electrical excitability. Overexpression of ANO1 is associated with pathological conditions such as hypertension and cancer. The molecular cloning of ANO1 has led to a surge in structural, functional, and physiological studies of the channel in several tissues. ANO1 is a homodimer channel harboring two pores - one in each monomer - that work independently. Each pore is activated by voltage-dependent binding of two intracellular calcium ions to a high-affinity-binding site. In addition, the binding of phosphatidylinositol 4,5-bisphosphate to sites scattered throughout the cytosolic side of the protein aids the calcium activation process. Furthermore, many pharmacological studies have established ANO1 as a target of promising compounds that could treat several illnesses. This chapter describes our current understanding of the physiological roles of ANO1 and its regulation under physiological conditions as well as new pharmacological compounds with potential therapeutic applications.
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Affiliation(s)
- Jorge Arreola
- Physics Institute, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.
| | - Patricia Pérez-Cornejo
- Department of Physiology and Biophysics, School of Medicine of Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - Guadalupe Segura-Covarrubias
- Physics Institute, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | - Nancy Corral-Fernández
- Department of Physiology and Biophysics, School of Medicine of Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - Daniel León-Aparicio
- Physics Institute, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
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Sanders KM, Drumm BT, Cobine CA, Baker SA. Ca 2+ dynamics in interstitial cells: foundational mechanisms for the motor patterns in the gastrointestinal tract. Physiol Rev 2024; 104:329-398. [PMID: 37561138 DOI: 10.1152/physrev.00036.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 06/29/2023] [Accepted: 08/06/2023] [Indexed: 08/11/2023] Open
Abstract
The gastrointestinal (GI) tract displays multiple motor patterns that move nutrients and wastes through the body. Smooth muscle cells (SMCs) provide the forces necessary for GI motility, but interstitial cells, electrically coupled to SMCs, tune SMC excitability, transduce inputs from enteric motor neurons, and generate pacemaker activity that underlies major motor patterns, such as peristalsis and segmentation. The interstitial cells regulating SMCs are interstitial cells of Cajal (ICC) and PDGF receptor (PDGFR)α+ cells. Together these cells form the SIP syncytium. ICC and PDGFRα+ cells express signature Ca2+-dependent conductances: ICC express Ca2+-activated Cl- channels, encoded by Ano1, that generate inward current, and PDGFRα+ cells express Ca2+-activated K+ channels, encoded by Kcnn3, that generate outward current. The open probabilities of interstitial cell conductances are controlled by Ca2+ release from the endoplasmic reticulum. The resulting Ca2+ transients occur spontaneously in a stochastic manner. Ca2+ transients in ICC induce spontaneous transient inward currents and spontaneous transient depolarizations (STDs). Neurotransmission increases or decreases Ca2+ transients, and the resulting depolarizing or hyperpolarizing responses conduct to other cells in the SIP syncytium. In pacemaker ICC, STDs activate voltage-dependent Ca2+ influx, which initiates a cluster of Ca2+ transients and sustains activation of ANO1 channels and depolarization during slow waves. Regulation of GI motility has traditionally been described as neurogenic and myogenic. Recent advances in understanding Ca2+ handling mechanisms in interstitial cells and how these mechanisms influence motor patterns of the GI tract suggest that the term "myogenic" should be replaced by the term "SIPgenic," as this review discusses.
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Affiliation(s)
- Kenton M Sanders
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada-Reno, Reno, Nevada, United States
| | - Bernard T Drumm
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Caroline A Cobine
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Salah A Baker
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada-Reno, Reno, Nevada, United States
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Zawieja SD, Pea GA, Broyhill SE, 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 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Du P, Joshi V, Beyder A. Tracking Gut Motility in Organ and Cultures. Methods Mol Biol 2023; 2644:449-466. [PMID: 37142940 DOI: 10.1007/978-1-0716-3052-5_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Gastrointestinal (GI) motility is a key component of digestive health, and it is complex, involving a multitude of cell types and mechanisms to drive both rhythmic and arrhythmic activity. Tracking GI motility in organ and tissue cultures across multiple temporal (seconds, minutes, hours, days) scales can provide valuable information regarding dysmotility and to evaluate treatment options. Here, the chapter describes a simple method to monitor GI motility in organotypic cultures, using a single video camera is placed perpendicularly to the surface of the tissue. A cross-correlational analysis is used to track the relative movements of tissues between subsequent frames and subsequent fitting procedures to fit finite element functions to the deformed tissue to calculate the strain fields. Additional motility index measures from the displacement information are used to further quantify the behaviors of the tissues that are maintained in organotypic culture over days. The protocols presented in this chapter can be adapted to study organotypic cultures from other organs.
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Affiliation(s)
- Peng Du
- Auckland Bioengineering Institute, Department of Engineering Science and Biomedical Engineering, University of Auckland, Auckland, New Zealand.
| | - Vikram Joshi
- Department of Physiology and Biomedical Engineering, Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Arthur Beyder
- Department of Physiology and Biomedical Engineering, Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
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Ko E, Woo MS, Kang D. Testosterone secretion is affected by receptor tyrosine kinase c-Kit and anoctamin 1 activation in mouse Leydig cells. J Anim Reprod Biotechnol 2022; 37:87-95. [DOI: 10.12750/jarb.37.2.87] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Choi S, Seo H, Lee K, Shin DH, Wu MJ, Wu W, Huang X, Zhang J, Hong C, Jun JY. Hyperpolarization-activated cyclic nucleotide-gated channels working as pacemaker channels in colonic interstitial cells of Cajal. J Cell Mol Med 2021; 26:364-374. [PMID: 34845842 PMCID: PMC8743669 DOI: 10.1111/jcmm.17087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/28/2021] [Accepted: 11/17/2021] [Indexed: 11/29/2022] Open
Abstract
Hyperpolarization‐activated cyclic nucleotide‐gated (HCN) channels function as pacemaker channels in spontaneously active cells. We studied the existence of HCN channels and their functional roles in the interstitial cells of Cajal (ICC) from the mouse colon using electrophysiological, immunohistochemical and molecular techniques. HCN1 and HCN3 channels were detected in anoctamin‐1 (Ca2+‐activated Cl− channel; ANO1)‐positive cells within the muscular and myenteric layers in colonic tissues. The mRNA transcripts of HCN1 and HCN3 channels were expressed in ANO1‐positive ICC. In the deletion of HCN1 and HCN3 channels in colonic ICC, the pacemaking potential frequency was reduced. Basal cellular adenylate cyclase activity was decreased by adenylate cyclase inhibitor in colonic ICC, whereas cAMP‐specific phosphodiesterase inhibitors increased it. 8‐Bromo‐cyclic AMP and rolipram increased spontaneous intracellular Ca2+ oscillations. In addition, Ca2+‐dependent adenylate cyclase 1 (AC1) mRNA was detected in colonic ICC. Sulprostone, a PGE2‐EP3 agonist, increased the pacemaking potential frequency, maximum rate of rise of resting membrane in pacemaker potentials and basal cellular adenylate cyclase activity in colonic ICC. These results indicate that HCN channels exist in colonic ICC and participate in generating pacemaking potentials. Thus, HCN channels may be therapeutic targets in disturbed colonic motility disorders.
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Affiliation(s)
- Seok Choi
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Hyunhyo Seo
- Department of Anatomy, Brain Science & Engineering Institute, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Kyungmin Lee
- Department of Anatomy, Brain Science & Engineering Institute, School of Medicine, Kyungpook National University, Daegu, Korea
| | - Dong Hoon Shin
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Mei Jin Wu
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Wenhao Wu
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Xingyou Huang
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Jingwei Zhang
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Chansik Hong
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
| | - Jae Yeoul Jun
- Department of Physiology, College of Medicine, Chosun University, Gwangju, Korea
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Otsuka Y, Bai X, Tanaka Y, Ihara E, Chinen T, Ogino H, Ogawa Y. Involvement of interstitial cells of Cajal in nicotinic acetylcholine receptor-induced relaxation of the porcine lower esophageal sphincter. Eur J Pharmacol 2021; 910:174491. [PMID: 34506779 DOI: 10.1016/j.ejphar.2021.174491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 08/27/2021] [Accepted: 09/03/2021] [Indexed: 11/15/2022]
Abstract
The interstitial cells of Cajal (ICCs) play an important role in coordinated gastrointestinal motility. The present study aimed to elucidate whether or how ICCs are involved in the lower esophageal sphincter (LES) relaxation induced by stimulation of the nicotinic acetylcholine receptor. The application of 1,1-dimethyl-4-phenyl-piperazinium (DMPP; a nicotinic acetylcholine receptor agonist) induced a transient relaxation in the circular smooth muscle of the porcine LES. DMPP-induced relaxation was abolished by not only 1 μM tetrodotoxin but also the inhibition of ICC activity by pretreatment with 100 μM carbenoxolone (a gap junction inhibitor), pretreatment with 100 μM CaCCinh-A01 (an anoctamin-1 blocker acting as a calcium-activated chloride channel inhibitor), and pretreatment with Cl--free solution. However, pretreatment with 100 μM Nω-nitro-L-arginine methyl ester had little effect on DMPP-induced relaxation. Furthermore, DMPP-induced relaxation was inhibited by pretreatment with 1 mM suramin, a purinergic P2 receptor antagonist, but not by 1 μM VIP (6-28), a vasoactive intestinal peptide (VIP) receptor antagonist. Stimulation of the purinergic P2 receptor with adenosine triphosphate (ATP) induced relaxation, which was abolished by the inhibition of ICC activity by pretreatment with CaCCinh-A01. In conclusion, membrane hyperpolarization of the ICCs via the activation of anoctamin-1 plays a central role in DMPP-induced relaxation. ATP may be a neurotransmitter for inhibitory enteric neurons, which stimulate the ICCs. The ICCs act as the interface of neurotransmission of nicotinic acetylcholine receptor in order to induce LES relaxation.
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Affiliation(s)
- Yoshihiro Otsuka
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Xiaopeng Bai
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yoshimasa Tanaka
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Eikichi Ihara
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan; Department of Gastroenterology and Metabolism, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
| | - Takatoshi Chinen
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Haruei Ogino
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Yoshihiro Ogawa
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
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13
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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14
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Bai W, Liu M, Xiao Q. The diverse roles of TMEM16A Ca 2+-activated Cl - channels in inflammation. J Adv Res 2021; 33:53-68. [PMID: 34603778 PMCID: PMC8463915 DOI: 10.1016/j.jare.2021.01.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/17/2020] [Accepted: 01/24/2021] [Indexed: 12/14/2022] Open
Abstract
Background Transmembrane protein 16A (TMEM16A) Ca2+-activated Cl- channels have diverse physiological functions, such as epithelial secretion of Cl- and fluid and sensation of pain. Recent studies have demonstrated that TMEM16A contributes to the pathogenesis of infectious and non-infectious inflammatory diseases. However, the role of TMEM16A in inflammation has not been clearly elucidated. Aim of review In this review, we aimed to provide comprehensive information regarding the roles of TMEM16A in inflammation by summarizing the mechanisms underlying TMEM16A expression and activation under inflammatory conditions, in addition to exploring the diverse inflammatory signaling pathways activated by TMEM16A. This review attempts to develop the idea that TMEM16A plays a diverse role in inflammatory processes and contributes to inflammatory diseases in a cellular environment-dependent manner. Key scientific concepts of review Multiple inflammatory mediators, including cytokines (e.g., interleukin (IL)-4, IL-13, IL-6), histamine, bradykinin, and ATP/UTP, as well as bacterial and viral infections, promote TMEM16A expression and/or activity under inflammatory conditions. In addition, TMEM16A activates diverse inflammatory signaling pathways, including the IP3R-mediated Ca2+ signaling pathway, the NF-κB signaling pathway, and the ERK signaling pathway, and contributes to the pathogenesis of many inflammatory diseases. These diseases include airway inflammatory diseases, lipopolysaccharide-induced intestinal epithelial barrier dysfunction, acute pancreatitis, and steatohepatitis. TMEM16A also plays multiple roles in inflammatory processes by increasing vascular permeability and leukocyte adhesion, promoting inflammatory cytokine release, and sensing inflammation-induced pain. Furthermore, TMEM16A plays its diverse pathological roles in different inflammatory diseases depending on the disease severity, proliferating status of the cells, and its interacting partners. We herein propose cellular environment-dependent mechanisms that explain the diverse roles of TMEM16A in inflammation.
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Affiliation(s)
- Weiliang Bai
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang 110004, China
| | - Mei Liu
- Department of Ion Channel Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Qinghuan Xiao
- Department of Ion Channel Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
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15
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Zhao W, Zhang L, Ermilov LG, Colmenares Aguilar MG, Linden DR, Eisenman ST, Romero MF, Farrugia G, Sha L, Gibbons SJ. Bicarbonate ion transport by the electrogenic Na + /HCO 3- cotransporter, NBCe1, is required for normal electrical slow-wave activity in mouse small intestine. Neurogastroenterol Motil 2021; 33:e14149. [PMID: 33837991 PMCID: PMC8485339 DOI: 10.1111/nmo.14149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 02/26/2021] [Accepted: 03/21/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND Normal gastrointestinal motility depends on electrical slow-wave activity generated by interstitial cells of Cajal (ICC) in the tunica muscularis of the gastrointestinal tract. A requirement for HCO3- in extracellular solutions used to record slow waves indicates a role for HCO3- transport in ICC pacemaking. The Slc4a4 gene transcript encoding the electrogenic Na+ /HCO3- cotransporter, NBCe1, is enriched in mouse small intestinal myenteric region ICC (ICC-MY) that generate slow waves. This study aimed to determine how extracellular HCO3- concentrations affect electrical activity in mouse small intestine and to determine the contribution of NBCe1 activity to these effects. METHODS Immunohistochemistry and sharp electrode electrical recordings were used. KEY RESULTS The NBCe1 immunoreactivity was localized to ICC-MY of the tunica muscularis. In sharp electrode electrical recordings, removal of HCO3- from extracellular solutions caused significant, reversible, depolarization of the smooth muscle and a reduction in slow-wave amplitude and frequency. In 100 mM HCO3- , the muscle hyperpolarized and slow wave amplitude and frequency increased. The effects of replacing extracellular Na+ with Li+ , an ion that does not support NBCe1 activity, were similar to, but larger than, the effects of removing HCO3- . There were no additional changes to electrical activity when HCO3- was removed from Li+ containing solutions. The Na+ /HCO3- cotransport inhibitor, S-0859 (30µM) significantly reduced the effect of removing HCO3- on electrical activity. CONCLUSIONS & INFERENCES These studies demonstrate a major role for Na+ /HCO3- cotransport by NBCe1 in electrical activity of mouse small intestine and indicated that regulation of intracellular acid:base homeostasis contributes to generation of normal pacemaker activity in the gastrointestinal tract.
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Affiliation(s)
- Wenchang Zhao
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA.,Neuroendocrine Pharmacology, China Medical University, Shenyang, Liaoning Province, P. R. China
| | - Liwen Zhang
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA.,Neuroendocrine Pharmacology, China Medical University, Shenyang, Liaoning Province, P. R. China
| | - Leonid G. Ermilov
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA
| | - Maria Gabriela Colmenares Aguilar
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA
| | - David R. Linden
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA
| | - Seth T. Eisenman
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA
| | - Michael F. Romero
- Physiology and Biomedical Engineering, Rochester, Minnesota, USA.,Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA
| | - Gianrico Farrugia
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA
| | - Lei Sha
- Neuroendocrine Pharmacology, China Medical University, Shenyang, Liaoning Province, P. R. China.,Corresponding Authors: Simon J Gibbons, Ph.D., Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, 55905, USA. . Telephone: +1 507 284 9652, Lei Sha, M.D., China Medical University, 77 Pu He Road, Shenbei New District, Shenyang, Liaoning Province, P. R. China, 110122, , . Telephone: +86 18900911003
| | - Simon J. Gibbons
- Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Rochester, Minnesota, USA.,Physiology and Biomedical Engineering, Rochester, Minnesota, USA.,Corresponding Authors: Simon J Gibbons, Ph.D., Enteric Neuroscience Program, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, 55905, USA. . Telephone: +1 507 284 9652, Lei Sha, M.D., China Medical University, 77 Pu He Road, Shenbei New District, Shenyang, Liaoning Province, P. R. China, 110122, , . Telephone: +86 18900911003
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16
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Pinto MC, Silva IAL, Figueira MF, Amaral MD, Lopes-Pacheco M. Pharmacological Modulation of Ion Channels for the Treatment of Cystic Fibrosis. J Exp Pharmacol 2021; 13:693-723. [PMID: 34326672 PMCID: PMC8316759 DOI: 10.2147/jep.s255377] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/30/2021] [Indexed: 12/12/2022] Open
Abstract
Cystic fibrosis (CF) is a life-shortening monogenic disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein, an anion channel that transports chloride and bicarbonate across epithelia. Despite clinical progress in delaying disease progression with symptomatic therapies, these individuals still develop various chronic complications in lungs and other organs, which significantly restricts their life expectancy and quality of life. The development of high-throughput assays to screen drug-like compound libraries have enabled the discovery of highly effective CFTR modulator therapies. These novel therapies target the primary defect underlying CF and are now approved for clinical use for individuals with specific CF genotypes. However, the clinically approved modulators only partially reverse CFTR dysfunction and there is still a considerable number of individuals with CF carrying rare CFTR mutations who remain without any effective CFTR modulator therapy. Accordingly, additional efforts have been pursued to identify novel and more potent CFTR modulators that may benefit a larger CF population. The use of ex vivo individual-derived specimens has also become a powerful tool to evaluate novel drugs and predict their effectiveness in a personalized medicine approach. In addition to CFTR modulators, pro-drugs aiming at modulating alternative ion channels/transporters are under development to compensate for the lack of CFTR function. These therapies may restore normal mucociliary clearance through a mutation-agnostic approach (ie, independent of CFTR mutation) and include inhibitors of the epithelial sodium channel (ENaC), modulators of the calcium-activated channel transmembrane 16A (TMEM16, or anoctamin 1) or of the solute carrier family 26A member 9 (SLC26A9), and anionophores. The present review focuses on recent progress and challenges for the development of ion channel/transporter-modulating drugs for the treatment of CF.
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Affiliation(s)
- Madalena C Pinto
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Iris A L Silva
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miriam F Figueira
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Margarida D Amaral
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
| | - Miquéias Lopes-Pacheco
- Biosystems & Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisboa, Lisboa, Portugal
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17
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Wang H, Ma D, Zhu X, Liu P, Li S, Yu B, Yang H. Nimodipine inhibits intestinal and aortic smooth muscle contraction by regulating Ca 2+-activated Cl - channels. Toxicol Appl Pharmacol 2021; 421:115543. [PMID: 33872679 DOI: 10.1016/j.taap.2021.115543] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 04/07/2021] [Accepted: 04/13/2021] [Indexed: 12/18/2022]
Abstract
Nimodipine is a clinically used dihydropyridine L-type calcium channel antagonist that effectively inhibits transmembrane Ca2+ influx following the depolarization of smooth muscle cells, but the detailed effect on smooth muscle contraction is not fully understood. Ca2+-activated Cl- channels (CaCCs) in vascular smooth muscle cells (VSMCs) may regulate vascular contractility. We found that nimodipine can inhibit transmembrane protein 16A (TMEM16A) activity in a concentration-dependent manner by cell-based fluorescence-quenching assay and short-circuit current analysis, with an IC50 value of ~5 μM. Short-circuit current analysis also showed that nimodipine prevented Ca2+-activated Cl- current in both HT-29 cells and mouse colonic epithelia accompanied by significantly decreased cytoplasmic Ca2+ concentrations. In the absence of extracellular Ca2+, nimodipine still exhibited an inhibitory effect on TMEM16A/CaCCs. Additionally, the application of nimodipine to CFTR-expressing FRT cells and mouse colonic mucosa resulted in mild activation of CFTR-mediated Cl- currents. Nimodipine inhibited basolateral CCh-activated K+ channel activity with no effect on Na+/K+-ATPase activity. Evaluation of intestinal smooth muscle contraction showed that nimodipine inhibits intestinal smooth muscle contractility and frequency, with an activity pattern that was similar to that of non-specific inhibitors of CaCCs. In aortic smooth muscle, the expression of TMEM16A in thoracic aorta is higher than that in abdominal aorta, corresponding to stronger maximum contractility in thoracic aorta smooth muscle stimulated by phenylephrine (PE) and Eact. Nimodipine completely inhibited the contraction of aortic smooth muscle stimulated by Eact, and partially inhibited the contraction stimulated by PE. In summary, the results indicate that nimodipine effectively inhibits TMEM16A/CaCCs by reduction transmembrane Ca2+ influx and directly interacting with TMEM16A, explaining the mechanisms of nimodipine relaxation of intestinal and aortic smooth muscle contraction and providing new targets for pharmacological applications.
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MESH Headings
- Animals
- Anoctamin-1/antagonists & inhibitors
- Anoctamin-1/metabolism
- Aorta, Abdominal/drug effects
- Aorta, Abdominal/metabolism
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/metabolism
- Calcium Channel Blockers/toxicity
- Calcium Signaling/drug effects
- HT29 Cells
- Humans
- Ileum/drug effects
- Ileum/metabolism
- In Vitro Techniques
- Male
- Mice, Inbred C57BL
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/metabolism
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Nimodipine/toxicity
- Rats
- Rats, Sprague-Dawley
- Vasoconstriction/drug effects
- Mice
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Affiliation(s)
- Hao Wang
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, School of Life Sciences, Liaoning Normal University, Dalian 116000, PR China; Laboratory medical college, Jilin Medical University, Jilin 132013, PR China
| | - Di Ma
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, School of Life Sciences, Liaoning Normal University, Dalian 116000, PR China
| | - Xiaojuan Zhu
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, School of Life Sciences, Liaoning Normal University, Dalian 116000, PR China
| | - Panyue Liu
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, School of Life Sciences, Liaoning Normal University, Dalian 116000, PR China
| | - Shuai Li
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, School of Life Sciences, Liaoning Normal University, Dalian 116000, PR China
| | - Bo Yu
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, School of Life Sciences, Liaoning Normal University, Dalian 116000, PR China.
| | - Hong Yang
- Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, School of Life Sciences, Liaoning Normal University, Dalian 116000, PR China.
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Guo P, Liu Y, Xu X, Ma G, Hou X, Fan Y, Zhang M. Coronary hypercontractility to acidosis owes to the greater activity of TMEM16A/ANO1 in the arterial smooth muscle cells. Biomed Pharmacother 2021; 139:111615. [PMID: 34243598 DOI: 10.1016/j.biopha.2021.111615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/05/2021] [Accepted: 04/12/2021] [Indexed: 10/21/2022] Open
Abstract
BACKGROUND Severe acidosis deteriorates cardiac injury. Rat coronary arteries (RCAs) are unusually hypercontractive to extracellular (o) acidosis (EA). TMEM16A-encoded anoctamin 1 (ANO1), a Ca2+-activated chloride channel (CaCC), plays an important role in regulating coronary arterial tension. PURPOSE We tested the possibility that the activation of CaCCs in the arterial smooth muscle cell (ASMC) contributes to EA-induced RCA constriction. METHODS ANO1 expression was detected with immunofluorescence staining and Western blot. TMEM16A mRNA was assessed with quantitative Real-Time PCR. Cl- currents and membrane potentials were quantified with a patch clamp. The vascular tension was recorded with a myograph. Intracellular (i) level of Cl- and Ca2+ was measured with fluorescent molecular probes. RESULTS ANO1 was expressed in all tested arterial myocytes, but was much more abundant in RCA ASMCs as compared with ASMCs isolated from rat cerebral basilar, intrarenal and mesenteric arteries. EA reduced [Cl-]i levels, augmented CaCC currents exclusively in RCA ASMCs and depolarized RCA ASMCs to a greater extent. Cl- deprivation, which depleted [Cl-]i by incubating the arteries or their ASMCs in Cl--free bath solution, decreased EA-induced [Cl-]i reduction, diminished EA-induced CaCC augmentation and time-dependently depressed EA-induced RCA constriction. Inhibitor studies showed that these EA-induced effects including RCA constriction, CaCC current augmentation, [Cl-]i reduction and/or [Ca2+]i elevation were depressed by various Cl- channel blockers, [Ca2+]i release inhibitors and L-type voltage-gated Ca2+ channel inhibitor nifedipine. ANO1 antibody attenuated all observed changes induced by EA in RCA ASMCs. CONCLUSION The greater activity of RCA ASMC CaCCs complicated with an enhanced Ca2+ mobilization from both [Ca2+]i release and [Ca2+]o influx plays a pivotal role in the distinctive hypercontractility of RCAs to acidosis. Translation of these findings to human beings may lead to a new conception in our understanding and treating cardiac complications in severe acidosis.
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Affiliation(s)
- Pengmei Guo
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Taiyuan 030001, Shanxi Province, China
| | - Yu Liu
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Taiyuan 030001, Shanxi Province, China
| | - Xiaojia Xu
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Taiyuan 030001, Shanxi Province, China
| | - Guijin Ma
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Taiyuan 030001, Shanxi Province, China
| | - Xiaomin Hou
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Taiyuan 030001, Shanxi Province, China
| | - Yanying Fan
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Taiyuan 030001, Shanxi Province, China.
| | - Mingsheng Zhang
- Department of Pharmacology, Shanxi Medical University, Xinjiannanlu 56, Taiyuan 030001, Shanxi Province, China.
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19
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Abstract
Urinary continence is maintained in the lower urinary tract by the contracture of urethral sphincters, including smooth muscle of the internal urethral sphincter. These contractions occlude the urethral lumen, preventing urine leakage from the bladder to the exterior. Over the past 20 years, research on the ionic conductances that contribute to urethral smooth muscle contractility has greatly accelerated. A debate has emerged over the role of interstitial cell of Cajal (ICC)-like cells in the urethra and their expression of Ca2+-activated Cl- channels encoded by anoctamin-1 [Ano1; transmembrane member 16 A (Tmem16a) gene]. It has been proposed that Ano1 channels expressed in urethral ICC serve as a source of depolarization for smooth muscle cells, increasing their excitability and contributing to tone. Although a clear role for Ano1 channels expressed in ICC is evident in other smooth muscle organs, such as the gastrointestinal tract, the role of these channels in the urethra is unclear, owing to differences in the species (rabbit, rat, guinea pig, sheep, and mouse) examined and experimental approaches by different groups. The importance of clarifying this situation is evident as effective targeting of Ano1 channels may lead to new treatments for urinary incontinence. In this review, we summarize the key findings from different species on the role of ICC and Ano1 channels in urethral contractility. Finally, we outline proposals for clarifying this controversial and important topic by addressing how cell-specific optogenetic and inducible cell-specific genetic deletion strategies coupled with advances in Ano1 channel pharmacology may clarify this area in future studies.NEW & NOTEWORTHY Studies from the rabbit have shown that anoctamin-1 (Ano1) channels expressed in urethral interstitial cells of Cajal (ICC) serve as a source of depolarization for smooth muscle cells, increasing excitability and tone. However, the role of urethral Ano1 channels is unclear, owing to differences in the species examined and experimental approaches. We summarize findings from different species on the role of urethral ICC and Ano1 channels in urethral contractility and outline proposals for clarifying this topic using cell-specific optogenetic approaches.
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Affiliation(s)
- Bernard T Drumm
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Keith D Thornbury
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Mark A Hollywood
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Gerard P Sergeant
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
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20
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Penfold JA, Wells CI, Du P, Qian A, Vather R, Bissett IP, O'Grady G. Relationships between serum electrolyte concentrations and ileus: A joint clinical and mathematical modeling study. Physiol Rep 2021; 9:e14735. [PMID: 33527737 PMCID: PMC7851429 DOI: 10.14814/phy2.14735] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/30/2020] [Accepted: 01/03/2021] [Indexed: 12/15/2022] Open
Abstract
Aim Prolonged postoperative ileus (PPOI) occurs in around 15% of patients after major abdominal surgery, posing a significant clinical and economic burden. Significant fluid and electrolyte changes may occur peri‐operatively, potentially contributing to PPOI; however, this association has not been clearly elucidated. A joint clinical‐theoretical study was undertaken to evaluate peri‐operative electrolyte concentration trends, their association with ileus, and predicted impact on bioelectrical slow waves in interstitial cells of Cajal (ICC) and smooth muscle cells (SMC). Methods Data were prospectively collected from 327 patients undergoing elective colorectal surgery. Analyses were performed to determine associations between peri‐operative electrolyte concentrations and prolonged ileus. Biophysically based ICC and SMC mathematical models were adapted to evaluate the theoretical impacts of extracellular electrolyte concentrations on cellular function. Results Postoperative day (POD) 1 calcium and POD 3 chloride, sodium were lower in the PPOI group (p < 0.05), and POD3 potassium was higher in the PPOI group (p < 0.05). Deficits beyond the reference range in PPOI patients were most notable for sodium (Day 3: 29.5% ileus vs. 18.5% no ileus, p = 0.04). Models demonstrated an 8.6% reduction in slow‐wave frequency following the measured reduction in extracellular NaCl on POD5, with associated changes in cellular slow‐wave morphology and amplitude. Conclusion Low serum sodium and chloride concentrations are associated with PPOI. Electrolyte abnormalities are unlikely to be a primary mechanism of ileus, but their pronounced effects on cellular electrophysiology predicted by modeling suggest these abnormalities may adversely impact motility recovery. Resolution and correction of electrolyte abnormalities in ileus may be clinically relevant.
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Affiliation(s)
- James A Penfold
- Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Cameron I Wells
- Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Anna Qian
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
| | - Ryash Vather
- Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand
| | - Ian P Bissett
- Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.,Department of Surgery, Auckland District Health Board, Auckland, New Zealand
| | - Gregory O'Grady
- Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.,Department of Surgery, Auckland District Health Board, Auckland, New Zealand.,Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
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21
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Colmenares Aguilar MG, Mazzone A, Eisenman ST, Strege PR, Bernard CE, Holmes HL, Romero MF, Farrugia G, Gibbons SJ. Expression of the regulated isoform of the electrogenic Na +/HCO 3- cotransporter, NBCe1, is enriched in pacemaker interstitial cells of Cajal. Am J Physiol Gastrointest Liver Physiol 2021; 320:G93-G107. [PMID: 33112159 PMCID: PMC8112189 DOI: 10.1152/ajpgi.00255.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Interstitial cells of Cajal (ICCs) generate electrical slow waves, which are required for normal gastrointestinal motility. The mechanisms for generation of normal pacemaking are not fully understood. Normal gastrointestinal contractility- and electrical slow-wave activity depend on the presence of extracellular HCO3-. Previous transcriptional analysis identified enrichment of mRNA encoding the electrogenic Na+/HCO3- cotransporter (NBCe1) gene (Slc4a4) in pacemaker myenteric ICCs in mouse small intestine. We aimed to determine the distribution of NBCe1 protein in ICCs of the mouse gastrointestinal tract and to identify the transcripts of the Slc4a4 gene in mouse and human small intestinal tunica muscularis. We determined the distribution of NBCe1 immunoreactivity (NBCe1-IR) by immunofluorescent labeling in mouse and human tissues. In mice, NBCe1-IR was restricted to Kit-positive myenteric ICCs of the stomach and small intestine and submuscular ICCs of the large intestine, that is, the slow wave generating subset of ICCs. Other subtypes of ICCs were NBCe1-negative. Quantitative real-time PCR identified >500-fold enrichment of Slc4a4-207 and Slc4a4-208 transcripts ["IP3-receptor-binding protein released by IP3" (IRBIT)-regulated isoforms] in Kit-expressing cells isolated from KitcreERT2/+, Rpl22tm1.1Psam/Sj mice and from single GFP-positive ICCs from Kittm1Rosay mice. Human jejunal tunica muscularis ICCs were also NBCe1-positive, and SLC4A4-201 and SLC4A4-204 RNAs were >300-fold enriched relative to SLC4A4-202. In summary, NBCe1 protein expressed in ICCs with electrical pacemaker function is encoded by Slc4a4 gene transcripts that generate IRBIT-regulated isoforms of NBCe1. In conclusion, Na+/HCO3- cotransport through NBCe1 contributes to the generation of pacemaker activity in subsets of ICCs.NEW & NOTEWORTHY In this study, we show that the electrogenic Na+/HCO3- cotransporter, NBCe1/Slc4a4, is expressed in subtypes of interstitial cells of Cajal (ICCs) responsible for electrical slow wave generation throughout the mouse gastrointestinal tract and is absent in other types of ICCs. The transcripts of Slc4a4 expressed in mouse ICCs and human gastrointestinal smooth muscle are the regulated isoforms. This indicates a key role for HCO3- transport in generation of gastrointestinal motility patterns.
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Affiliation(s)
| | - Amelia Mazzone
- 1Enteric NeuroScience Program, Division of
Gastroenterology and Hepatology, Mayo Clinic,
Rochester, Minnesota
| | - Seth T. Eisenman
- 1Enteric NeuroScience Program, Division of
Gastroenterology and Hepatology, Mayo Clinic,
Rochester, Minnesota
| | - Peter R. Strege
- 1Enteric NeuroScience Program, Division of
Gastroenterology and Hepatology, Mayo Clinic,
Rochester, Minnesota
| | - Cheryl E. Bernard
- 1Enteric NeuroScience Program, Division of
Gastroenterology and Hepatology, Mayo Clinic,
Rochester, Minnesota
| | - Heather L. Holmes
- 2Physiology and Biomedical Engineering, Nephrology and
Hypertension, Mayo Clinic College of Medicine and
Science, Rochester, Minnesota
| | - Michael F. Romero
- 2Physiology and Biomedical Engineering, Nephrology and
Hypertension, Mayo Clinic College of Medicine and
Science, Rochester, Minnesota
| | - Gianrico Farrugia
- 1Enteric NeuroScience Program, Division of
Gastroenterology and Hepatology, Mayo Clinic,
Rochester, Minnesota,3Department of Physiology and Biomedical Engineering,
Mayo Clinic, Rochester, Minnesota
| | - Simon J. Gibbons
- 1Enteric NeuroScience Program, Division of
Gastroenterology and Hepatology, Mayo Clinic,
Rochester, Minnesota
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22
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Abstract
The c-Kit receptor tyrosine kinase regulates the development and differentiation of
several progenitor cells. In the gastrointestinal (GI) tract, the c-Kit regulates the
development of the interstitial cells of Cajal (ICC) that are responsible for motility
regulation of the GI musculature. W-sash
(Wsh) is an inversion mutation upstream of the
c-kit promoter region that affects a key regulatory element, resulting
in cell-type-specific altered gene expression, leading to a decrease in the number of mast
cells, melanocytes, and ICC. We extensively examined the GI tract of
Wsh/Wsh mice using
immunohistochemistry and electron microscopy. Although the musculature of the
Wsh/Wsh mice did not show any
c-Kit immunoreactivity, we detected intensive immunoreactivity for transmembrane member
16A (TMEM16A, anoctamin-1), another ICC marker. TMEM16A immunopositive cells were observed
as ICC-MY in the gastric corpus-antrum and the large intestine, ICC-DMP in the small
intestine, and ICC-SM in the colon. Electron microscopic analysis revealed these cells as
ICC from their ultrastructural features, such as numerous mitochondria and caveolae, and
their close contact with nerve terminals. In the developmental period, we examined 14.5
and 18.5 day embryos but did not observe c-Kit immunoreactivity in the
Wsh/Wsh small intestine. From
this study, ICC subtypes developed and maturated structurally without c-Kit expression.
Wsh/Wsh mice are a new model
to investigate the effects of c-Kit and unknown signaling on ICC development and
function.
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Affiliation(s)
- Satoshi Iino
- Department of Anatomy, University of Fukui Faculty of Medical Sciences, Eiheiji, Fukui 910-1193, Japan
| | - Satomi Horiguchi
- Department of Anatomy, University of Fukui Faculty of Medical Sciences, Eiheiji, Fukui 910-1193, Japan
| | - Kazuhide Horiguchi
- Department of Anatomy, University of Fukui Faculty of Medical Sciences, Eiheiji, Fukui 910-1193, Japan
| | - Takashi Hashimoto
- Department of Anatomy, University of Fukui Faculty of Medical Sciences, Eiheiji, Fukui 910-1193, Japan
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23
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Foong D, Zhou J, Zarrouk A, Ho V, O’Connor MD. Understanding the Biology of Human Interstitial Cells of Cajal in Gastrointestinal Motility. Int J Mol Sci 2020; 21:ijms21124540. [PMID: 32630607 PMCID: PMC7352366 DOI: 10.3390/ijms21124540] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 06/19/2020] [Accepted: 06/23/2020] [Indexed: 12/11/2022] Open
Abstract
Millions of patients worldwide suffer from gastrointestinal (GI) motility disorders such as gastroparesis. These disorders typically include debilitating symptoms, such as chronic nausea and vomiting. As no cures are currently available, clinical care is limited to symptom management, while the underlying causes of impaired GI motility remain unaddressed. The efficient movement of contents through the GI tract is facilitated by peristalsis. These rhythmic slow waves of GI muscle contraction are mediated by several cell types, including smooth muscle cells, enteric neurons, telocytes, and specialised gut pacemaker cells called interstitial cells of Cajal (ICC). As ICC dysfunction or loss has been implicated in several GI motility disorders, ICC represent a potentially valuable therapeutic target. Due to their availability, murine ICC have been extensively studied at the molecular level using both normal and diseased GI tissue. In contrast, relatively little is known about the biology of human ICC or their involvement in GI disease pathogenesis. Here, we demonstrate human gastric tissue as a source of primary human cells with ICC phenotype. Further characterisation of these cells will provide new insights into human GI biology, with the potential for developing novel therapies to address the fundamental causes of GI dysmotility.
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Affiliation(s)
- Daphne Foong
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (D.F.); (J.Z.); (V.H.)
| | - Jerry Zhou
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (D.F.); (J.Z.); (V.H.)
| | - Ali Zarrouk
- Campbelltown Private Hospital, Campbelltown, NSW 2560, Australia;
| | - Vincent Ho
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (D.F.); (J.Z.); (V.H.)
- Campbelltown Private Hospital, Campbelltown, NSW 2560, Australia;
| | - Michael D. O’Connor
- School of Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia; (D.F.); (J.Z.); (V.H.)
- Correspondence:
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24
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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: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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25
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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26
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Odenweller A, Donner RV. Disentangling synchrony from serial dependency in paired-event time series. Phys Rev E 2020; 101:052213. [PMID: 32575302 DOI: 10.1103/physreve.101.052213] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 03/30/2020] [Indexed: 11/06/2022]
Abstract
Quantifying synchronization phenomena based on the timing of events has recently attracted a great deal of interest in various disciplines such as neuroscience or climatology. A multitude of similarity measures has been proposed for this purpose, including event synchronization (ES) and event coincidence analysis (ECA) as two widely applicable examples. While ES defines synchrony in a data-adaptive local way that does not distinguish between different timescales, ECA requires selecting a specific scale for analysis. In this paper, we use slightly modified versions of both ES and ECA that address previous issues with respect to proper normalization and boundary treatment, which are particularly relevant for short time series with low temporal resolution. By numerically studying threshold crossing events in coupled autoregressive processes, we identify a practical limitation of ES when attempting to study synchrony between serially dependent event sequences exhibiting event clustering in time. Practical implications of this observation are demonstrated for the case of functional network representations of climate extremes based on both ES and ECA, while no marked differences between both measures are observed for the case of epileptic electroencephalogram data. Our findings suggest that careful event detection along with diligent preprocessing is recommended when applying ES while less crucial for ECA. Despite the lack of a general modus operandi for both event definition and detection of synchronization, we suggest ECA as a widely robust method, especially for time-resolved synchronization analyses of event time series from various disciplines.
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Affiliation(s)
- Adrian Odenweller
- Potsdam Institute for Climate Impact Research (PIK), Germany.,Center for Earth System Research and Sustainability (CEN), University of Hamburg, Germany.,The Land in the Earth System, Max Planck Institute for Meteorology, Hamburg, Germany
| | - Reik V Donner
- Potsdam Institute for Climate Impact Research (PIK), Germany.,Department of Water, Environment, Construction and Safety, Magdeburg-Stendal University of Applied Sciences, Magdeburg, Germany
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27
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Du P, Mazzone A, Calder S, Qian A, Gibbons SJ, Farrugia G, Beyder A. A Method for Multi-day Tracking of Gastrointestinal Smooth Muscle Contractile Patterns in Organotypic Culture. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2019:4791-4794. [PMID: 31946933 DOI: 10.1109/embc.2019.8857365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Gastrointestinal (GI) motility is a key component of digestive health, and it is a complex both rhythmic and arrhythmic process governed by many physiological factors. The ability to accurately track the movements of the GI tissues in vitro over multiple days would provide valuable insights into GI tract physiology. A correlational analysis tracking algorithm was developed and applied to intestinal smooth muscle tissues that were maintained in organotypic culture. Physiologically relevant metrics, such as frequency, amplitude and motility index were independently assayed to quantify smooth muscle contractions. The results were validated by manually detected frequency determined using a standard software package. The algorithm was capable of tracking the changes in contractions of the same tissues over six days. This proof-of-concept study demonstrates the feasibility of long-term tracking of GI motility in organotypic cultures over multiple days. The approach allows study of the effects on GI smooth muscle contractility of direct controlled targeting of the cells and molecules in the GI tunica muscularis.
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28
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Mazzone A, Strege PR, Gibbons SJ, Alcaino C, Joshi V, Haak AJ, Tschumperlin DJ, Bernard CE, Cima RR, Larson DW, Chua HK, Graham RP, El Refaey M, Mohler PJ, Hayashi Y, Ordog T, Calder S, Du P, Farrugia G, Beyder A. microRNA overexpression in slow transit constipation leads to reduced Na V1.5 current and altered smooth muscle contractility. Gut 2020; 69:868-876. [PMID: 31757880 PMCID: PMC7147984 DOI: 10.1136/gutjnl-2019-318747] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 10/16/2019] [Accepted: 11/06/2019] [Indexed: 12/13/2022]
Abstract
OBJECTIVE This study was designed to evaluate the roles of microRNAs (miRNAs) in slow transit constipation (STC). DESIGN All human tissue samples were from the muscularis externa of the colon. Expression of 372 miRNAs was examined in a discovery cohort of four patients with STC versus three age/sex-matched controls by a quantitative PCR array. Upregulated miRNAs were examined by quantitative reverse transcription qPCR (RT-qPCR) in a validation cohort of seven patients with STC and age/sex-matched controls. The effect of a highly differentially expressed miRNA on a custom human smooth muscle cell line was examined in vitro by RT-qPCR, electrophysiology, traction force microscopy, and ex vivo by lentiviral transduction in rat muscularis externa organotypic cultures. RESULTS The expression of 13 miRNAs was increased in STC samples. Of those miRNAs, four were predicted to target SCN5A, the gene that encodes the Na+ channel NaV1.5. The expression of SCN5A mRNA was decreased in STC samples. Let-7f significantly decreased Na+ current density in vitro in human smooth muscle cells. In rat muscularis externa organotypic cultures, overexpression of let-7f resulted in reduced frequency and amplitude of contraction. CONCLUSIONS A small group of miRNAs is upregulated in STC, and many of these miRNAs target the SCN5A-encoded Na+ channel NaV1.5. Within this set, a novel NaV1.5 regulator, let-7f, resulted in decreased NaV1.5 expression, current density and reduced motility of GI smooth muscle. These results suggest NaV1.5 and miRNAs as novel diagnostic and potential therapeutic targets in STC.
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Affiliation(s)
- Amelia Mazzone
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter R Strege
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Simon J Gibbons
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Constanza Alcaino
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Vikram Joshi
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Andrew J Haak
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Daniel J Tschumperlin
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Cheryl E Bernard
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Robert R Cima
- Department of Colon and Rectal Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - David W Larson
- Department of Colon and Rectal Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | - Heidi K Chua
- Department of Colon and Rectal Surgery, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Mona El Refaey
- Departments of Physiology and Cell Biology, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA,Department of Internal Medicine, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Peter J Mohler
- Departments of Physiology and Cell Biology, The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Yujiro Hayashi
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Tamas Ordog
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Stefan Calder
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Gianrico Farrugia
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA .,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
| | - Arthur Beyder
- Enteric NeuroScience Program (ENSP), Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, Minnesota, USA .,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, USA
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29
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Shi S, Pang C, Guo S, Chen Y, Ma B, Qu C, Ji Q, An H. Recent progress in structural studies on TMEM16A channel. Comput Struct Biotechnol J 2020; 18:714-722. [PMID: 32257055 PMCID: PMC7118279 DOI: 10.1016/j.csbj.2020.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 03/12/2020] [Accepted: 03/13/2020] [Indexed: 11/26/2022] Open
Abstract
The calcium-activated chloride channel, also known as TMEM16A, shows both calcium and membrane potential dependent activation. The channel is expressed broadly and contributes to a variety of physiological processes, and it is expected to be a target for the treatment of diseases such as hypertension, pain, cystic fibrosis and lung cancer. A thorough understanding of the structural characteristics of TMEM16A is important to reveal its physiological and pathological roles. Recent studies have released several Cryo-EM structures of the channel, revealed the structural basis and mechanism of the gating of the channel. This review focused on the understandings of the structural basis and molecular mechanism of the gating and permeation of TMEM16A channel, which will provide important basis for the development of drugs targeting TMEM16A.
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Affiliation(s)
- Sai Shi
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
| | - Chunli Pang
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
| | - Shuai Guo
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
| | - Yafei Chen
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
| | - Biao Ma
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
| | - Chang Qu
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
| | - Qiushuang Ji
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
| | - Hailong An
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin 300401, China.,Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Science, Hebei University of Technology, Tianjin, 300401, China
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Parsons SP, Huizinga JD. A myogenic motor pattern in mice lacking myenteric interstitial cells of Cajal explained by a second coupled oscillator network. Am J Physiol Gastrointest Liver Physiol 2020; 318:G225-G243. [PMID: 31813235 PMCID: PMC7052571 DOI: 10.1152/ajpgi.00311.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The interstitial cells of Cajal associated with the myenteric plexus (ICC-MP) are a network of coupled oscillators in the small intestine that generate rhythmic electrical phase waves leading to corresponding waves of contraction, yet rhythmic action potentials and intercellular calcium waves have been recorded from c-kit-mutant mice that lack the ICC-MP, suggesting that there may be a second pacemaker network. The gap junction blocker carbenoxolone induced a "pinstripe" motor pattern consisting of rhythmic "stripes" of contraction that appeared simultaneously across the intestine with a period of ~4 s. The infinite velocity of these stripes suggested they were generated by a coupled oscillator network, which we call X. In c-kit mutants rhythmic contraction waves with the period of X traveled the length of the intestine, before the induction of the pinstripe pattern by carbenoxolone. Thus X is not the ICC-MP and appears to operate under physiological conditions, a fact that could explain the viability of these mice. Individual stripes consisted of a complex pattern of bands of contraction and distension, and between stripes there could be slide waves and v waves of contraction. We hypothesized that these phenomena result from an interaction between X and the circular muscle that acts as a damped oscillator. A mathematical model of two chains of coupled Fitzhugh-Nagumo systems, representing X and circular muscle, supported this hypothesis. The presence of a second coupled oscillator network in the small intestine underlines the complexity of motor pattern generation in the gut.NEW & NOTEWORTHY Physiological experiments and a mathematical model indicate a coupled oscillator network in the small intestine in addition to the c-kit-expressing myenteric interstitial cells of Cajal. This network interacts with the circular muscle, which itself acts as a system of damped oscillators, to generate physiological contraction waves in c-kit (W) mutant mice.
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Affiliation(s)
- Sean P. Parsons
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Jan D. Huizinga
- Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, Ontario, Canada
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Qian A, Means S, Malysz J, Farrugia G, Gibbons SJ, Du P. A Pipeline for the Registration of Calcium Transient Data to Structural Networks of the Interstitial Cells of Cajal. Annu Int Conf IEEE Eng Med Biol Soc 2020; 2019:2765-2768. [PMID: 31946466 DOI: 10.1109/embc.2019.8857103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Interstitial cells of Cajal (ICC) generate electrical pacemaker activity in the gastrointestinal (GI) tract known as slow waves, which regulate GI motility. ICC express both the Kit receptor tyrosine kinase protein and a Ca2+-activated Cl--channel, encoded by the anoctamin1 (Ano1) protein, which is an essential contributor to the Ca2+ cycling of ICC and slow wave pacemaking. Recent dye-loading imaging studies have demonstrated Ca2+ transients in ICC in isolated tissue preparations. The main aim of this study was to develop a method that allows Ca2+ transients to be registered to structural ICC network data. Confocal image stacks of ICC labeled for Kit or Ano1 and Ca2+ recording data were processed using a thresholding protocol. The Ca2+ transients were then registered to the ICC structural network. First, a general idea of the placement was found by mapping the field-of-view of the Ca2+ transient data to the distorted tissue that contained the ICC network image. The errors in the registration were then corrected for by warping the internal Ca2+ transient field according to the structural network. In data sets from tissues with induced, targeted knockdown of Ano1 expression in a subset of ICC, agreement between the Ca2+ transient data and structural network was 68 ± 10%. This level of agreement allowed selective extraction of Ca2+ data from Ano1-positive (Ano1+) and Ano1-negative (Ano1-) ICC. In the future, this technique will allow investigation into the functional properties of ICC in relation to the level of knockdown of specific ICC associated proteins.
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Guo S, Chen YF, Shi S, Pang CL, Wang XZ, Zhang HL, Zhan Y, An HL. The Molecular Mechanism of Ginsenoside Analogs Activating TMEM16A. Biophys J 2019; 118:262-272. [PMID: 31818463 DOI: 10.1016/j.bpj.2019.11.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/02/2019] [Accepted: 11/14/2019] [Indexed: 01/25/2023] Open
Abstract
The calcium-activated chloride channel TMEM16A is involved in many physiological processes, and insufficient function of TMEM16A may lead to the occurrence of various diseases. Therefore, TMEM16A activators are supposed to be potentially useful for treatment of TMEM16A downregulation-inducing diseases. However, the TMEM16A activators are relatively rare, and the underlying activation mechanism of them is unclear. In the previous work, we have proved that ginsenoside Rb1 is a TMEM16A activator. In this work, we explored the activation mechanism of ginsenoside analogs on TMEM16A through analyzing the interactions between six ginsenoside analogs and TMEM16A. We identified GRg2 and GRf can directly activate TMEM16A by screening five novel ginsenosids analogs (GRb2, GRf, GRg2, GRh2, and NGR1). Isolated guinea pig ileum assay showed both GRg2 and GRf increased the amplitude and frequency of ileum contractions. We explored the molecular mechanisms of ginsenosides activating TMEM16A by combining molecular simulation with electrophysiological experiments. We proposed a TMEM16A activation process model based on the results, in which A697 on TM7 and L746 on TM8 bind to the isobutenyl of ginsenosides through hydrophobic interaction to fix the spatial location of ginsenosides. N650 on TM6 and E705 on TM7 bind to ginsenosides through electrostatic interaction, which causes the inner half of α-helix 6 to form physical contact with ginsenosides and leads to the pore opening. It should be emphasized that TMEM16A can be activated by ginsenosides only when both the above two conditions are satisfied. This is the first, to our knowledge, report of TMEM16A opening process activated by small-molecule activators. The mechanism of ginsenosides activating TMEM16A will provide important clues for TMEM16A gating mechanism and for new TMEM16A activators screening.
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Affiliation(s)
- Shuai Guo
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China; Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin, China; Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Yafei F Chen
- Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Sai Shi
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China; Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin, China; Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Chunli L Pang
- Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Xuzhao Z Wang
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China; Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin, China; Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Hailin L Zhang
- Department of Pharmacology, Hebei Medical University, Shijiazhuang, China
| | - Yong Zhan
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China; Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin, China; Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China.
| | - Hailong L An
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China; Key Laboratory of Electromagnetic Field and Electrical Apparatus Reliability of Hebei Province, Hebei University of Technology, Tianjin, China; Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China.
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Flavahan WA, Drier Y, Johnstone SE, Hemming ML, Tarjan DR, Hegazi E, Shareef SJ, Javed NM, Raut CP, Eschle BK, Gokhale PC, Hornick JL, Sicinska ET, Demetri GD, Bernstein BE. Altered chromosomal topology drives oncogenic programs in SDH-deficient GISTs. Nature 2019; 575:229-233. [PMID: 31666694 PMCID: PMC6913936 DOI: 10.1038/s41586-019-1668-3] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 09/10/2019] [Indexed: 12/22/2022]
Abstract
Epigenetic aberrations are widespread in cancer, yet the underlying
mechanisms and causality remain poorly understood1-3.
A subset of gastrointestinal stromal tumors (GISTs) lack canonical kinase
mutations but instead have succinate dehydrogenase (SDH)-deficiency and global
DNA hyper-methylation4,5. Here we associate this hyper-methylation
with changes in genome topology that activate oncogenic programs. To investigate
epigenetic alterations systematically, we mapped DNA methylation, CTCF
insulators, enhancers, and chromosome topology in KIT-mutant,
PDGFRA-mutant, and SDH-deficient GISTs. Although these
respective subtypes shared similar enhancer landscapes, we identified hundreds
of putative insulators where DNA methylation replaced CTCF binding in
SDH-deficient GISTs. We focused on a disrupted insulator that normally
partitions a core GIST super-enhancer from the FGF4 oncogene.
Recurrent loss of this insulator alters locus topology in SDH-deficient GISTs,
allowing aberrant physical interaction between enhancer and oncogene.
CRISPR-mediated excision of the corresponding CTCF motifs in an SDH-intact GIST
model disrupted the boundary and strongly up-regulated FGF4
expression. We also identified a second recurrent insulator loss event near the
KIT oncogene, which is also highly expressed across
SDH-deficient GISTs. Finally, we established a patient-derived xenograft (PDX)
from an SDH-deficient GIST that faithfully maintains the epigenetics of the
parental tumor, including hyper-methylation and insulator defects. This PDX
model is highly sensitive to FGF receptor (FGFR) inhibitor, and more so to
combined FGFR and KIT inhibition, validating the functional significance of the
underlying epigenetic lesions. Our study reveals how epigenetic alterations can
drive oncogenic programs in the absence of canonical kinase mutations, with
implications for mechanistic targeting of aberrant pathways in cancers.
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Affiliation(s)
- William A Flavahan
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Yotam Drier
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA. .,The Lautenberg Center for Immunology and Cancer Research, IMRIC, Faculty of Medicine, The Hebrew University, Jerusalem, Israel.
| | - Sarah E Johnstone
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Matthew L Hemming
- Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.,Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School Boston, Boston, MA, USA
| | - Daniel R Tarjan
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Esmat Hegazi
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Sarah J Shareef
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nauman M Javed
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Chandrajit P Raut
- Department of Surgery, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Benjamin K Eschle
- Experimental Therapeutics Core, Belfer Center for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Prafulla C Gokhale
- Experimental Therapeutics Core, Belfer Center for Applied Cancer Science, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Jason L Hornick
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Ewa T Sicinska
- Department of Oncologic Pathology, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
| | - George D Demetri
- Center for Sarcoma and Bone Oncology, Dana-Farber Cancer Institute, Boston, MA, USA. .,Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School Boston, Boston, MA, USA. .,Ludwig Center at Harvard, Harvard Medical School, Boston, MA, USA.
| | - Bradley E Bernstein
- Department of Pathology and Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA. .,Broad Institute of MIT and Harvard, Cambridge, MA, USA. .,Ludwig Center at Harvard, Harvard Medical School, Boston, MA, USA.
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Yu B, Zhu X, Yang X, Jin L, Xu J, Ma T, Yang H. Plumbagin Prevents Secretory Diarrhea by Inhibiting CaCC and CFTR Channel Activities. Front Pharmacol 2019; 10:1181. [PMID: 31649543 PMCID: PMC6795057 DOI: 10.3389/fphar.2019.01181] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 09/13/2019] [Indexed: 12/12/2022] Open
Abstract
Secretory diarrhea, which primarily originates through intestinal pathogens and viruses, is a health burden in many regions worldwide. Enterocyte Cl− channels, as the final step in enterotoxin-induced fluid secretion, constitute an attractive class of targets for diarrhea therapy. Chloride channel inhibitors have become a new class of candidates for antisecretion and anti-intestinal motility agents. In the present study, we identified plumbagin as a transmembrane protein 16A (TMEM16A) inhibitor in a cell-based fluorescence-quenching assay, and the IC50 value was ∼12.46 µM. Short-circuit current measurements showed that plumbagin reversibly inhibited the Eact-induced Cl− current on the apical side of TMEM16A-transfected Fischer rat thyroid (FRT) cells with no significant effect on cytoplasmic Ca2+ signaling. Notably, plumbagin also inhibited the activity of intestinal epithelial calcium-activated chloride channel (CaCC) and cystic fibrosis transmembrane conductance regulator (CFTR) in both HT-29 cells and mouse colons, but had no effects on the activity of the Na+-K+ ATPase or K+ channels. In in vivo experiments, the administration of plumbagin reduced both Escherichia coli heat-stable enterotoxin (STa)- and cholera toxin (CT)-induced intestinal fluid secretion. In neonatal mouse models of CT- and rotavirus infection-induced diarrhea, 0.4 µg plumbagin inhibited secretory diarrhea by >40% and 50%, respectively, without affecting intestinal epithelial integrity or the rotaviral infection. In addition, plumbagin exerted inhibitory effects on the vasoactive intestinal peptide (VIP)-, prostaglandin E2 (PGE2)-, and 5-hydroxytryptamine (5-HT)-stimulated Cl− currents. In the evaluations of intestinal motility, plumbagin significantly delayed intestinal motility and inhibited intestinal smooth muscle contractility without an evident impact on contractive frequency. Collectively, our results indicate that plumbagin inhibits both Ca2+- and cAMP-activated Cl− channels, accounting for the mechanisms of plumbagin inhibition of chloride secretion and intestinal motility. Thus, plumbagin can be a lead compound in the treatment of CT-induced, Traveler’s, and rotaviral diarrhea, as well as other types of secretory diarrhea that result from excessive intestinal fluid secretion and increased intestinal peristalsis.
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Affiliation(s)
- Bo Yu
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
| | - Xiaojuan Zhu
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
| | - Xinyu Yang
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
| | - Lingling Jin
- College of Basic Medical Sciences, Dalian Medical University, Dalian, China
| | - Jia Xu
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
| | - Tonghui Ma
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
| | - Hong Yang
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, China
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Lee B, Hong GS, Lee SH, Kim H, Kim A, Hwang EM, Kim J, Lee MG, Yang JY, Kweon MN, Tse CM, Mark D, Oh U. Anoctamin 1/TMEM16A controls intestinal Cl - secretion induced by carbachol and cholera toxin. Exp Mol Med 2019; 51:1-14. [PMID: 31383845 PMCID: PMC6802608 DOI: 10.1038/s12276-019-0287-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 03/07/2019] [Accepted: 03/11/2019] [Indexed: 12/17/2022] Open
Abstract
Calcium-activated chloride channels (CaCCs) mediate numerous physiological functions and are best known for the transport of electrolytes and water in epithelia. In the intestine, CaCC currents are considered necessary for the secretion of fluid to protect the intestinal epithelium. Although genetic ablation of ANO1/TMEM16A, a gene encoding a CaCC, reduces the carbachol-induced secretion of intestinal fluid, its mechanism of action is still unknown. Here, we confirm that ANO1 is essential for the secretion of intestinal fluid. Carbachol-induced transepithelial currents were reduced in the proximal colon of Ano1-deficient mice. Surprisingly, cholera toxin-induced and cAMP-induced fluid secretion, believed to be mediated by CFTR, were also significantly reduced in the intestine of Ano1-deficient mice. ANO1 is largely expressed in the apical membranes of intestines, as predicted for CaCCs. The Ano1-deficient colons became edematous under basal conditions and had a greater susceptibility to dextran sodium sulfate-induced colitis. However, Ano1 depletion failed to affect tumor development in a model of colorectal cancer. We thus conclude that ANO1 is necessary for cAMP- and carbachol-induced Cl− secretion in the intestine, which is essential for the protection of the intestinal epithelium from colitis. An ion channel, a membrane protein allowing ion transport, that controls the flow of chloride is needed for proper secretion of protective fluids in the intestine. Uhtaek Oh from the Korea Institute of Science & Technology in Seoul, South Korea, and colleagues showed that cells lining the intestinal surface express a calcium-activated chloride channel called anoctamin-1 (ANO1) that regulates fluid secretion in the gut. Compared to control animals, ANO1-deficient mice released less fluid into their intestines following exposure to a diarrhea-inducing toxin or to a chloride transport–stimulating signaling molecule. This fluid secretion was previously thought to be mediated via a different ion channel. The ANO1-deficient mice accumulated fluid within colonic tissues, which increased their susceptibility to colitis. The findings point to ANO1 activation as a potential therapeutic strategy for treating colitis.
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Affiliation(s)
- Byeongjun Lee
- College of Pharmacy, Seoul National University, Seoul, 08826, Korea
| | - Gyu-Sang Hong
- Brain Science Institute, Korea Institute of Science & Technology (KIST), Seoul, 02792, Korea
| | - Sung Hoon Lee
- College of Pharmacy, Chung-Ang University, Seoul, 06974, Korea
| | - Hyungsup Kim
- Brain Science Institute, Korea Institute of Science & Technology (KIST), Seoul, 02792, Korea
| | - Ajung Kim
- Brain Science Institute, Korea Institute of Science & Technology (KIST), Seoul, 02792, Korea
| | - Eun Mi Hwang
- Brain Science Institute, Korea Institute of Science & Technology (KIST), Seoul, 02792, Korea
| | - Jiyoon Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Min Goo Lee
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, 03722, Korea
| | - Jin-Young Yang
- Mucosal Immunology Laboratory, Department of Convergence Medicine, University of Ulsan College of Medicine/Asan Medical Center, Seoul, 05505, Korea
| | - Mi-Na Kweon
- Mucosal Immunology Laboratory, Department of Convergence Medicine, University of Ulsan College of Medicine/Asan Medical Center, Seoul, 05505, Korea
| | - Chung-Ming Tse
- Departments of Physiology and Medicine, Division of Gastroenterois maintained by the opening of plasmalogy, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Donowitz Mark
- Departments of Physiology and Medicine, Division of Gastroenterois maintained by the opening of plasmalogy, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Uhtaek Oh
- College of Pharmacy, Seoul National University, Seoul, 08826, Korea. .,Brain Science Institute, Korea Institute of Science & Technology (KIST), Seoul, 02792, Korea.
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36
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Drumm BT, Hwang SJ, Baker SA, Ward SM, Sanders KM. Ca 2+ signalling behaviours of intramuscular interstitial cells of Cajal in the murine colon. J Physiol 2019; 597:3587-3617. [PMID: 31124144 DOI: 10.1113/jp278036] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 05/23/2019] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Colonic intramuscular interstitial cells of Cajal (ICC-IM) exhibit spontaneous Ca2+ transients manifesting as stochastic events from multiple firing sites with propagating Ca2+ waves occasionally observed. Firing of Ca2+ transients in ICC-IM is not coordinated with adjacent ICC-IM in a field of view or even with events from other firing sites within a single cell. Ca2+ transients, through activation of Ano1 channels and generation of inward current, cause net depolarization of colonic muscles. Ca2+ transients in ICC-IM rely on Ca2+ release from the endoplasmic reticulum via IP3 receptors, spatial amplification from RyRs and ongoing refilling of ER via the sarcoplasmic/endoplasmic-reticulum-Ca2+ -ATPase. ICC-IM are sustained by voltage-independent Ca2+ influx via store-operated Ca2+ entry. Some of the properties of Ca2+ in ICC-IM in the colon are similar to the behaviour of ICC located in the deep muscular plexus region of the small intestine, suggesting there are functional similarities between these classes of ICC. ABSTRACT A component of the SIP syncytium that regulates smooth muscle excitability in the colon is the intramuscular class of interstitial cells of Cajal (ICC-IM). All classes of ICC (including ICC-IM) express Ca2+ -activated Cl- channels, encoded by Ano1, and rely upon this conductance for physiological functions. Thus, Ca2+ handling in ICC is fundamental to colonic motility. We examined Ca2+ handling mechanisms in ICC-IM of murine proximal colon expressing GCaMP6f in ICC. Several Ca2+ firing sites were detected in each cell. While individual sites displayed rhythmic Ca2+ events, the overall pattern of Ca2+ transients was stochastic. No correlation was found between discrete Ca2+ firing sites in the same cell or in adjacent cells. Ca2+ transients in some cells initiated Ca2+ waves that spread along the cell at ∼100 µm s-1 . Ca2+ transients were caused by release from intracellular stores, but depended strongly on store-operated Ca2+ entry mechanisms. ICC Ca2+ transient firing regulated the resting membrane potential of colonic tissues as a specific Ano1 antagonist hyperpolarized colonic muscles by ∼10 mV. Ca2+ transient firing was independent of membrane potential and not affected by blockade of L- or T-type Ca2+ channels. Mechanisms regulating Ca2+ transients in the proximal colon displayed both similarities to and differences from the intramuscular type of ICC in the small intestine. Similarities and differences in Ca2+ release patterns might determine how ICC respond to neurotransmission in these two regions of the gastrointestinal tract.
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Affiliation(s)
- Bernard T Drumm
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557, USA
| | - Sung J Hwang
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557, USA
| | - Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557, USA
| | - Sean M Ward
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV, 89557, USA
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Dixon RE, Hwang SJ, Kim BH, Sanders KM, Ward SM. Myosalpinx Contractions Are Essential for Egg Transport Along the Oviduct and Are Disrupted in Reproductive Tract Diseases. In: Hashitani H, Lang RJ, editors. Smooth Muscle Spontaneous Activity. Singapore: Springer; 2019. pp. 265-94. [DOI: 10.1007/978-981-13-5895-1_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Hwang SJ, Pardo DM, Zheng H, Bayguinov Y, Blair PJ, Fortune‐Grant R, Cook RS, Hennig GW, Shonnard MC, Grainger N, Peri LE, Verma SD, Rock J, Sanders KM, Ward SM. Differential sensitivity of gastric and small intestinal muscles to inducible knockdown of anoctamin 1 and the effects on gastrointestinal motility. J Physiol 2019; 597:2337-2360. [PMID: 30843201 PMCID: PMC6487927 DOI: 10.1113/jp277335] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/22/2019] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Electrical pacemaking in gastrointestinal muscles is generated by specialized interstitial cells of Cajal that produce the patterns of contractions required for peristalsis and segmentation in the gut. The calcium-activated chloride conductance anoctamin-1 (Ano1) has been shown to be responsible for the generation of pacemaker activity in GI muscles, but this conclusion is established from studies of juvenile animals in which effects of reduced Ano1 on gastric emptying and motor patterns could not be evaluated. Knocking down Ano1 expression using Cre/LoxP technology caused dramatic changes in in gastric motor activity, with disrupted slow waves, abnormal phasic contractions and delayed gastric emptying; modest changes were noted in the small intestine. Comparison of the effects of Ano1 antagonists on muscles from juvenile and adult small intestinal muscles suggests that conductances in addition to Ano1 may develop with age and contribute to pacemaker activity. ABSTRACT Interstitial cells of Cajal (ICC) generate slow waves and transduce neurotransmitter signals in the gastrointestinal (GI) tract, facilitating normal motility patterns. ICC express a Ca2+ -activated Cl- conductance (CaCC), and constitutive knockout of the channel protein anoctamin-1 leads to loss of slow waves in gastric and intestinal muscles. These knockout experiments were performed on juvenile mice. However, additional experiments demonstrated significant differences in the sensitivity of gastric and intestinal muscles to antagonists of anoctamin-1 channels. Furthermore, the significance of anoctamin-1 and the electrical and mechanical behaviours facilitated by this conductance have not been evaluated on the motor behaviours of adult animals. Cre/loxP technology was used to generate cell-specific knockdowns of anoctamin-1 in ICC (KitCreERT2/+ ;Ano1tm2jrr/+ ) in GI muscles. The recombination efficiency of KitCreERT was evaluated with an eGFP reporter, molecular techniques and immunohistochemistry. Electrical and contractile experiments were used to examine the consequences of anoctamin-1 knockdown on pacemaker activity, mechanical responses, gastric motility patterns, gastric emptying and GI transit. Reduced anoctamin-1 caused loss of gastric, but not intestinal slow waves. Irregular spike complexes developed in gastric muscles, leading to uncoordinated antral contractions, delayed gastric emptying and increased total GI transit time. Slow waves in intestinal muscles of juvenile mice were more sensitive to anoctamin-1 antagonists than slow waves in adult muscles. The low susceptibility to anoctamin-1 knockdown and weak efficacy of anoctamin-1 antagonists in inhibiting slow waves in adult small intestinal muscles suggest that a conductance in addition to anoctamin-1 may develop in small intestinal ICC with ageing and contribute to pacemaker activity.
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Affiliation(s)
- Sung Jin Hwang
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - David M. Pardo
- Department of AnatomyUniversity of CaliforniaSan FranciscoSan FranciscoCA94143USA
| | - Haifeng Zheng
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - Yulia Bayguinov
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - Peter J. Blair
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - Rachael Fortune‐Grant
- Faculty of BiologyMedicine and HealthSchool of Biological SciencesUniversity of ManchesterUK
| | - Robert S. Cook
- School of Molecular and Cellular BiologyUniversity of LeedsLeedsLS2 9JTUK
| | - Grant W. Hennig
- Department of PharmacologyThe University of VermontUVM College of MedicineBurlingtonVT05405USA
| | - Matthew C. Shonnard
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - Nathan Grainger
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - Lauren E. Peri
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - Sonali Deep Verma
- Department of AnatomyUniversity of CaliforniaSan FranciscoSan FranciscoCA94143USA
| | - Jason Rock
- Centre for Regenerative MedicineBoston University School of MedicineBostonMA02118USA
| | - Kenton M. Sanders
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
| | - Sean M. Ward
- Department of Physiology & Cell BiologyUniversity of NevadaReno School of MedicineRenoNV89557USA
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Mazzone A, Gibbons SJ, Eisenman ST, Strege PR, Zheng T, D'Amato M, Ordog T, Fernandez-Zapico ME, Farrugia G. Direct repression of anoctamin 1 ( ANO1) gene transcription by Gli proteins. FASEB J 2019; 33:6632-6642. [PMID: 30802137 DOI: 10.1096/fj.201802373r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Ca2+-activated Cl- channel, anoctamin 1 (Ano1, also known as transmembrane protein 16A) contributes to intestinal pacemaking, fluid secretion, cellular excitability, and tissue development. The human ANO1 promoter contains binding sites for the glioma-associated oncogene (Gli) proteins. We investigated regulation of ANO1 transcription by Gli. ANO1 promoter activity was determined using a luciferase reporter system. Binding and functional effects of Glis on ANO1 transcription and expression were demonstrated by chromatin immunoprecipitation, small interfering RNA knockdown, PCR, immunolabeling, and recordings of Ca2+-activated Cl- currents in human embryonic kidney 293 (HEK293) cells. Results from previous genome-wide association studies were used to test ANO1 promoter polymorphisms for association with disease. Gli1 and Gli2 bound to the promoter and repressed ANO1 transcription. Repression depended on Gli binding to a site close to the ANO1 transcriptional start site. Mutation of this site prevented Gli binding and transcriptional repression. Knockdown of Gli expression and inhibition of Gli activity increased expression of ANO1 RNA and Ca2+-activated Cl- currents in HEK293 cells. A single-nucleotide polymorphism prevented Gli binding and showed association with irritable bowel syndrome. We conclude that Gli1 and Gli2 repress ANO1 by a novel mechanism that is independent of Gli cleavage and that has a role in gastrointestinal function.-Mazzone, A., Gibbons, S. J., Eisenman, S. T., Strege, P. R., Zheng, T., D'Amato, M., Ordog, T., Fernandez-Zapico, M. E., Farrugia, G. Direct repression of anoctamin 1 (ANO1) gene transcription by Gli proteins.
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Affiliation(s)
- Amelia Mazzone
- Enteric NeuroSciences, Mayo Clinic, Rochester, Minnesota, USA
| | - Simon J Gibbons
- Enteric NeuroSciences, Mayo Clinic, Rochester, Minnesota, USA
| | - Seth T Eisenman
- Enteric NeuroSciences, Mayo Clinic, Rochester, Minnesota, USA
| | - Peter R Strege
- Enteric NeuroSciences, Mayo Clinic, Rochester, Minnesota, USA
| | - Tenghao Zheng
- Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Mauro D'Amato
- Department of Medicine Solna and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Biodonostia Health Research Institute, San Sebastián, Spain.,Ikerbasque-Basque Science Foundation, San Sebastián, Spain
| | - Tamas Ordog
- Enteric NeuroSciences, Mayo Clinic, Rochester, Minnesota, USA
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Kunzelmann K, Ousingsawat J, Cabrita I, Doušová T, Bähr A, Janda M, Schreiber R, Benedetto R. TMEM16A in Cystic Fibrosis: Activating or Inhibiting? Front Pharmacol 2019; 10:3. [PMID: 30761000 PMCID: PMC6362895 DOI: 10.3389/fphar.2019.00003] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 01/04/2019] [Indexed: 12/26/2022] Open
Abstract
The inflammatory airway disease cystic fibrosis (CF) is characterized by airway obstruction due to mucus hypersecretion, airway plugging, and bronchoconstriction. The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel is dysfunctional in CF, leading to defects in epithelial transport. Although CF pathogenesis is still disputed, activation of alternative Cl- channels is assumed to improve lung function in CF. Two suitable non-CFTR Cl- channels are present in the airway epithelium, the Ca2+ activated channel TMEM16A and SLC26A9. Activation of these channels is thought to be feasible to improve hydration of the airway mucus and to increase mucociliary clearance. Interestingly, both channels are upregulated during inflammatory lung disease. They are assumed to support fluid secretion, necessary to hydrate excess mucus and to maintain mucus clearance. During inflammation, however, TMEM16A is upregulated particularly in mucus producing cells, with only little expression in ciliated cells. Recently it was shown that knockout of TMEM16A in ciliated cells strongly compromises Cl- conductance and attenuated mucus secretion, but does not lead to a CF-like lung disease and airway plugging. Along this line, activation of TMEM16A by denufosol, a stable purinergic ligand, failed to demonstrate any benefit to CF patients in earlier studies. It rather induced adverse effects such as cough. A number of studies suggest that TMEM16A is essential for mucus secretion and possibly also for mucus production. Evidence is now provided for a crucial role of TMEM16A in fusion of mucus-filled granules with the apical plasma membrane and cellular exocytosis. This is probably due to local Ca2+ signals facilitated by TMEM16A. Taken together, TMEM16A supports fluid secretion by ciliated airway epithelial cells, but also maintains excessive mucus secretion during inflammatory airway disease. Because TMEM16A also supports airway smooth muscle contraction, inhibition rather than activation of TMEM16A might be the appropriate treatment for CF lung disease, asthma and COPD. As a number of FDA-approved and well-tolerated drugs have been shown to inhibit TMEM16A, evaluation in clinical trials appears timely.
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Affiliation(s)
- Karl Kunzelmann
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| | | | - Inês Cabrita
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| | - Tereza Doušová
- Department of Pediatrics, Second Faculty of Medicine, University Hospital Motol, Charles University in Prague, Prague, Czechia
| | - Andrea Bähr
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians-Universität München, Munich, Germany
- Innere Medizin I, Klinikum Rechts der Isar der TU München, München, Germany
| | - Melanie Janda
- Institute of Molecular Animal Breeding and Biotechnology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Rainer Schreiber
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
| | - Roberta Benedetto
- Institut für Physiologie, Universität Regensburg, Regensburg, Germany
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Abstract
The gastrointestinal (GI) tract has multifold tasks of ingesting, processing, and assimilating nutrients and disposing of wastes at appropriate times. These tasks are facilitated by several stereotypical motor patterns that build upon the intrinsic rhythmicity of the smooth muscles that generate phasic contractions in many regions of the gut. Phasic contractions result from a cyclical depolarization/repolarization cycle, known as electrical slow waves, which result from intrinsic pacemaker activity. Interstitial cells of Cajal (ICC) are electrically coupled to smooth muscle cells (SMCs) and generate and propagate pacemaker activity and slow waves. The mechanism of slow waves is dependent upon specialized conductances expressed by pacemaker ICC. The primary conductances responsible for slow waves in mice are Ano1, Ca2+-activated Cl- channels (CaCCs), and CaV3.2, T-type, voltage-dependent Ca2+ channels. Release of Ca2+ from intracellular stores in ICC appears to be the initiator of pacemaker depolarizations, activation of T-type current provides voltage-dependent Ca2+ entry into ICC, as slow waves propagate through ICC networks, and Ca2+-induced Ca2+ release and activation of Ano1 in ICC amplifies slow wave depolarizations. Slow waves conduct to coupled SMCs, and depolarization elicited by these events enhances the open-probability of L-type voltage-dependent Ca2+ channels, promotes Ca2+ entry, and initiates contraction. Phasic contractions timed by the occurrence of slow waves provide the basis for motility patterns such as gastric peristalsis and segmentation. This chapter discusses the properties of ICC and proposed mechanism of electrical rhythmicity in GI muscles.
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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.
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Ji Q, Guo S, Wang X, Pang C, Zhan Y, Chen Y, An H. Recent advances in TMEM16A: Structure, function, and disease. J Cell Physiol 2018; 234:7856-7873. [PMID: 30515811 DOI: 10.1002/jcp.27865] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/13/2018] [Indexed: 12/13/2022]
Abstract
TMEM16A (also known as anoctamin 1, ANO1) is the molecular basis of the calcium-activated chloride channels, with ten transmembrane segments. Recently, atomic structures of the transmembrane domains of mouse TMEM16A (mTMEM16A) were determined by single-particle electron cryomicroscopy. This gives us a solid ground to discuss the electrophysiological properties and functions of TMEM16A. TMEM16A is reported to be dually regulated by Ca2+ and voltage. In addition, the dysfunction of TMEM16A has been found to be involved in many diseases including cystic fibrosis, various cancers, hypertension, and gastrointestinal motility disorders. TMEM16A is overexpressed in many cancers, including gastrointestinal stromal tumors, gastric cancer, head and neck squamous cell carcinoma (HNSCC), colon cancer, pancreatic ductal adenocarcinoma, and esophageal cancer. Furthermore, overexpression of TMEM16A is related to the occurrence, proliferation, and migration of tumor cells. To date, several studies have shown that many natural compounds and synthetic compounds have regulatory effects on TMEM16A. These small molecule compounds might be novel drugs for the treatment of diseases caused by TMEM16A dysfunction in the future. In addition, recent studies have shown that TMEM16A plays different roles in different diseases through different signal transduction pathways. This review discusses the topology, electrophysiological properties, modulators and functions of TMEM16A in mediates nociception, gastrointestinal dysfunction, hypertension, and cancer and focuses on multiple regulatory mechanisms regarding TMEM16A.
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Affiliation(s)
- Qiushuang Ji
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Shuai Guo
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Xuzhao Wang
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Chunli Pang
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Yong Zhan
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Yafei Chen
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
| | - Hailong An
- Key Laboratory of Molecular Biophysics, Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin, China
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Singh RD, Hillestad ML, Livia C, Li M, Alekseev AE, Witt TA, Stalboerger PG, Yamada S, Terzic A, Behfar A. M 3RNA Drives Targeted Gene Delivery in Acute Myocardial Infarction. Tissue Eng Part A 2018; 25:145-158. [PMID: 30047313 DOI: 10.1089/ten.tea.2017.0445] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
IMPACT STATEMENT The M3RNA (microencapsulated modified messenger RNA) platform is an approach to deliver messenger RNA (mRNA) in vivo, achieving a nonintegrating and viral-free approach to gene therapy. This technology was, in this study, tested for its utility in the myocardium, providing a unique avenue for targeted gene delivery into the freshly infarcted myocardial tissue. This study provides the evidentiary basis for the use of M3RNA in the heart through depiction of its performance in cultured cells, healthy rodent myocardium, and acutely injured porcine hearts. By testing the technology in large animal models of infarction, compatibility of M3RNA with current coronary intervention procedures was verified.
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Affiliation(s)
- Raman Deep Singh
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Matthew L Hillestad
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Christopher Livia
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota.,3 Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Mark Li
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota.,3 Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Alexey E Alekseev
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota.,4 Institute of Theoretical and Experimental Biophysics, Russian Academy of Science, Moscow, Russia
| | - Tyra A Witt
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Paul G Stalboerger
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Satsuki Yamada
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota
| | - Andre Terzic
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota.,3 Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | - Atta Behfar
- 1 Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota.,2 VanCleve Cardiac Regenerative Medicine Program, Center for Regenerative Medicine, Mayo Clinic, Rochester, Minnesota.,3 Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
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O'Grady G, Angeli TR, Paskaranandavadivel N, Erickson JC, Wells CI, Gharibans AA, Cheng LK, Du P. Methods for High-Resolution Electrical Mapping in the Gastrointestinal Tract. IEEE Rev Biomed Eng 2018; 12:287-302. [PMID: 30176605 DOI: 10.1109/rbme.2018.2867555] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Over the last two decades, high-resolution (HR) mapping has emerged as a powerful technique to study normal and abnormal bioelectrical events in the gastrointestinal (GI) tract. This technique, adapted from cardiology, involves the use of dense arrays of electrodes to track bioelectrical sequences in fine spatiotemporal detail. HR mapping has now been applied in many significant GI experimental studies informing and clarifying both normal physiology and arrhythmic behaviors in disease states. This review provides a comprehensive and critical analysis of current methodologies for HR electrical mapping in the GI tract, including extracellular measurement principles, electrode design and mapping devices, signal processing and visualization techniques, and translational research strategies. The scope of the review encompasses the broad application of GI HR methods from in vitro tissue studies to in vivo experimental studies, including in humans. Controversies and future directions for GI mapping methodologies are addressed, including emerging opportunities to better inform diagnostics and care in patients with functional gut disorders of diverse etiologies.
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Okada Y, Okada T, Islam MR, Sabirov RZ. Molecular Identities and ATP Release Activities of Two Types of Volume-Regulatory Anion Channels, VSOR and Maxi-Cl. Curr Top Membr 2018; 81:125-76. [PMID: 30243431 DOI: 10.1016/bs.ctm.2018.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An elaborate volume regulation system based on interplay of ion channels and transporters was evolved to cope with constant osmotic challenges caused by intensive metabolism, transport and other physiological/pathophysiological events. In animal cells, two types of anion channels are directly activated by cell swelling and involved in the regulatory volume decrease (RVD): volume-sensitive outwardly rectifying anion channel (VSOR), also called volume-regulated anion channel (VRAC), and Maxi-Cl which is the most major type of maxi-anion channel (MAC). These two channels have very different biophysical profiles and exhibit opposite dependence on intracellular ATP. After several decades of verifying many false-positive candidates for VSOR and Maxi-Cl, LRRC8 family proteins emerged as major VSOR components, and SLCO2A1 protein as a core of Maxi-Cl. Still, neither of these proteins alone can fully reproduce the native channel phenotypes suggesting existence of missing components. Although both VSOR and Maxi-Cl have pores wide enough to accommodate bulky ATP4- and MgATP2- anions, evidence accumulated hitherto, based on pharmacological and gene silencing experiments, suggests that Maxi-Cl, but not VSOR, serves as one of the major pathways for the release of ATP from swollen and ischemic/hypoxic cells. Relations of VSOR and Maxi-Cl with diseases and their selective pharmacology are the topics promoted by recent advance in molecular identification of the two volume-activated, volume-regulatory anion channels.
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Sung TS, Hwang SJ, Koh SD, Bayguinov Y, Peri LE, Blair PJ, Webb TI, Pardo DM, Rock JR, Sanders KM, Ward SM. The cells and conductance mediating cholinergic neurotransmission in the murine proximal stomach. J Physiol 2018; 596:1549-1574. [PMID: 29430647 PMCID: PMC5924836 DOI: 10.1113/jp275478] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 01/26/2018] [Indexed: 12/23/2022] Open
Abstract
KEY POINTS Enteric neurotransmission is essential for gastrointestinal (GI) motility, although the cells and conductances responsible for post-junctional responses are controversial. The calcium-activated chloride conductance (CaCC), anoctamin-1 (Ano1), was expressed by intramuscular interstitial cells of Cajal (ICC-IM) in proximal stomach and not resolved in smooth muscle cells (SMCs). Cholinergic nerve fibres were closely apposed to ICC-IM. Conductances activated by cholinergic stimulation in isolated ICC-IM and SMCs were determined. A CaCC was activated by carbachol in ICC-IM and a non-selective cation conductance in SMCs. Responses to cholinergic nerve stimulation were studied. Excitatory junction potentials (EJPs) and mechanical responses were evoked in wild-type mice but absent or greatly reduced with knockout/down of Ano1. Drugs that block Ano1 inhibited the conductance activated by carbachol in ICC-IM and EJPs and mechanical responses in tissues. The data of the present study suggest that electrical and mechanical responses to cholinergic nerve stimulation are mediated by Ano1 expressed in ICC-IM and not SMCs. ABSTRACT Enteric motor neurotransmission is essential for normal gastrointestinal (GI) motility. Controversy exists regarding the cells and ionic conductance(s) that mediate post-junctional neuroeffector responses to motor neurotransmitters. Isolated intramuscular ICC (ICC-IM) and smooth muscle cells (SMCs) from murine fundus muscles were used to determine the conductances activated by carbachol (CCh) in each cell type. The calcium-activated chloride conductance (CaCC), anoctamin-1 (Ano1) is expressed by ICC-IM but not resolved in SMCs, and CCh activated a Cl- conductance in ICC-IM and a non-selective cation conductance in SMCs. We also studied responses to nerve stimulation using electrical-field stimulation (EFS) of intact fundus muscles from wild-type and Ano1 knockout mice. EFS activated excitatory junction potentials (EJPs) in wild-type mice, although EJPs were absent in mice with congenital deactivation of Ano1 and greatly reduced in animals in which the CaCC-Ano1 was knocked down using Cre/loxP technology. Contractions to cholinergic nerve stimulation were also greatly reduced in Ano1 knockouts. SMCs cells also have receptors and ion channels activated by muscarinic agonists. Blocking acetylcholine esterase with neostigmine revealed a slow depolarization that developed after EJPs in wild-type mice. This depolarization was still apparent in mice with genetic deactivation of Ano1. Pharmacological blockers of Ano1 also inhibited EJPs and contractile responses to muscarinic stimulation in fundus muscles. The data of the present study are consistent with the hypothesis that ACh released from motor nerves binds muscarinic receptors on ICC-IM with preference and activates Ano1. If metabolism of acetylcholine is inhibited, ACh overflows and binds to extrajunctional receptors on SMCs, eliciting a slower depolarization response.
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Affiliation(s)
- Tae Sik Sung
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - Sung Jin Hwang
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - Sang Don Koh
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - Yulia Bayguinov
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - Lauen E. Peri
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - Peter J. Blair
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - Timothy I. Webb
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - David M. Pardo
- Department of AnatomyUniversity of CaliforniaSan FranciscoCAUSA
| | - Jason R. Rock
- Center for Regenerative MedicineBoston University School of MedicineBostonMAUSA
| | - Kenton M. Sanders
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
| | - Sean M. Ward
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNVUSA
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Kaji N, Nakayama S, Horiguchi K, Iino S, Ozaki H, Hori M. Disruption of the pacemaker activity of interstitial cells of Cajal via nitric oxide contributes to postoperative ileus. Neurogastroenterol Motil 2018; 30. [PMID: 29542843 DOI: 10.1111/nmo.13334] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 02/11/2018] [Indexed: 12/21/2022]
Abstract
BACKGROUND Interstitial cells of Cajal (ICC) serve as intestinal pacemakers. Postoperative ileus (POI) is a gastrointestinal motility disorder that occurs following abdominal surgery, which is caused by inflammation-induced dysfunction of smooth muscles and enteric neurons. However, the participation of ICC in POI is not well understood. In this study, we investigated the functional changes of ICC in a mouse model of POI. METHODS Intestinal manipulation (IM) was performed to induce POI. At 24 h or 48 h after IM, the field potential of the intestinal tunica muscularis was investigated. Tissues were also examined by immunohistochemistry and electron microscopic analysis. KEY RESULTS Gastrointestinal transit was significantly decreased with intestinal tunica muscularis inflammation at 24 h after IM, which was ameliorated at 48 h after IM. The generation and propagation of pacemaker potentials were disrupted at 24 h after IM and recovered to the control level at 48 h after IM. ICC networks, detected by c-Kit immunoreactivity, were remarkably disrupted at 24 h after IM. Electron microscopic analysis revealed abnormal vacuoles in the ICC cytoplasm. Interestingly, the ICC networks recovered at 48 h after IM. Administration of aminoguanidine, an inducible nitric oxide synthase inhibitor, suppressed the disruption of ICC networks. Ileal smooth muscle tissue cultured in the presence of nitric oxide donor, showed disrupted ICC networks. CONCLUSIONS AND INFERENCES The generation and propagation of pacemaker potentials by ICC are disrupted via nitric oxide after IM, and this disruption may contribute to POI. When inflammation is ameliorated, ICC can recover their pacemaker function.
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Affiliation(s)
- N Kaji
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - S Nakayama
- Department of Cell Physiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - K Horiguchi
- Division of Anatomy and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - S Iino
- Division of Anatomy and Neuroscience, Department of Morphological and Physiological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui, Japan
| | - H Ozaki
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - M Hori
- Department of Veterinary Pharmacology, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
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Iskander SM, Feeney MM, Yee K, Rosenblum ND. Protein Kinase 2 β Is Expressed in Neural Crest-Derived Urinary Pacemaker Cells and Required for Pyeloureteric Contraction. J Am Soc Nephrol 2018; 29:1198-1209. [PMID: 29436516 DOI: 10.1681/asn.2017090951] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/10/2018] [Indexed: 01/31/2023] Open
Abstract
Nonobstructive hydronephrosis, defined as dilatation of the renal pelvis with or without dilatation of the ureter, is the most common antenatal abnormality detected by fetal ultrasound. Yet, the etiology of nonobstructive hydronephrosis is poorly defined. We previously demonstrated that defective development of urinary tract pacemaker cells (utPMCs) expressing hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3) and the stem cell marker cKIT causes abnormal ureteric peristalsis and nonobstructive hydronephrosis. However, further investigation of utPMC development and function is limited by lack of knowledge regarding the embryonic derivation, development, and molecular apparatus of these cells. Here, we used lineage tracing in mice to identify cells that give rise to utPMCs. Neural crest cells (NCCs) indelibly labeled with tdTomato expressed HCN3 and cKIT. Furthermore, purified HCN3+ and cKIT+ utPMCs were enriched in Sox10 and Tfap-2α, markers of NCCs. Sequencing of purified RNA from HCN3+ cells revealed enrichment of a small subset of RNAs, including RNA encoding protein kinase 2β (PTK2β), a Ca2+-dependent tyrosine kinase that regulates ion channel activity in neurons. Immunofluorescence analysis in situ revealed PTK2β expression in NCCs as early as embryonic day 12.5 and in HCN3+ and cKIT+ utPMCs as early as embryonic day 15.5, with sustained expression in HCN3+ utPMCs until postnatal week 8. Pharmacologic inhibition of PTK2β in murine pyeloureteral tissue explants inhibited contraction frequency. Together, these results demonstrate that utPMCs are derived from NCCs, identify new markers of utPMCs, and demonstrate a functional contribution of PTK2β to utPMC function.
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Affiliation(s)
- Samir M Iskander
- Program in Developmental and Stem Cell Biology and.,Departments of Laboratory Medicine and Pathobiology and
| | - Meghan M Feeney
- Program in Developmental and Stem Cell Biology and.,Departments of Laboratory Medicine and Pathobiology and
| | - Kirby Yee
- Program in Developmental and Stem Cell Biology and
| | - Norman D Rosenblum
- Program in Developmental and Stem Cell Biology and .,Departments of Laboratory Medicine and Pathobiology and.,Division of Nephrology, The Hospital for Sick Children, Toronto, Ontario, Canada; and.,Paediatrics, University of Toronto, Toronto, Ontario, Canada
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50
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Drumm BT, Sung TS, Zheng H, Baker SA, Koh SD, Sanders KM. The effects of mitochondrial inhibitors on Ca 2+ signalling and electrical conductances required for pacemaking in interstitial cells of Cajal in the mouse small intestine. Cell Calcium 2018; 72:1-17. [PMID: 29748128 DOI: 10.1016/j.ceca.2018.01.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 01/26/2018] [Accepted: 01/27/2018] [Indexed: 01/16/2023]
Abstract
Interstitial cells of Cajal (ICC-MY) are pacemakers that generate and propagate electrical slow waves in gastrointestinal (GI) muscles. Slow waves appear to be generated by the release of Ca2+ from intracellular stores and activation of Ca2+-activated Cl- channels (Ano1). Conduction of slow waves to smooth muscle cells coordinates rhythmic contractions. Mitochondrial Ca2+ handling is currently thought to be critical for ICC pacemaking. Protonophores, inhibitors of the electron transport chain (FCCP, CCCP or antimycin) or mitochondrial Na+/Ca2+ exchange blockers inhibited slow waves in several GI muscles. Here we utilized Ca2+ imaging of ICC in small intestinal muscles in situ to determine the effects of mitochondrial drugs on Ca2+ transients in ICC. Muscles were obtained from mice expressing a genetically encoded Ca2+ indicator (GCaMP3) in ICC. FCCP, CCCP, antimycin, a uniporter blocker, Ru360, and a mitochondrial Na+/Ca2+ exchange inhibitor, CGP-37157 inhibited Ca2+ transients in ICC-MY. Effects were not due to depletion of ATP, as oligomycin did not affect Ca2+ transients. Patch-clamp experiments were performed to test the effects of the mitochondrial drugs on key pacemaker conductances, Ano1 and T-type Ca2+ (CaV3.2), in HEK293 cells. Antimycin blocked Ano1 and reduced CaV3.2 currents. CCCP blocked CaV3.2 current but did not affect Ano1 current. Ano1 and Cav3.2 currents were inhibited by CGP-37157. Inhibitory effects of mitochondrial drugs on slow waves and Ca2+ signalling in ICC can be explained by direct antagonism of key pacemaker conductances in ICC that generate and propagate slow waves. A direct obligatory role for mitochondria in pacemaker activity is therefore questionable.
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Affiliation(s)
- Bernard T Drumm
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | - Tae S Sung
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | - Haifeng Zheng
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | - Salah A Baker
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | - Sang D Koh
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
| | - Kenton M Sanders
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA.
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