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Almohanna AM, Noble K, Wray S. Extracellular acidification increases uterine contraction in pregnant mouse by increasing intracellular calcium. Acta Physiol (Oxf) 2024; 240:e14147. [PMID: 38650469 DOI: 10.1111/apha.14147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 03/07/2024] [Accepted: 04/05/2024] [Indexed: 04/25/2024]
Abstract
AIMS As uterine extracellular pH decreases during the ischemic conditions of labor, but its effects on myometrial contraction are largely unknown, there is a need to elucidate its physiological effects and mechanisms of action. Furthermore, it is not known if any of the effects of extracellular acidification are affected by pregnancy, thus we also determined how gestation affects the response to acidification. METHODS Nonpregnant, mid-, and term-pregnant myometrial strips were obtained from humanely killed mice. Contractions were recorded under spontaneous, depolarized, and oxytocin-stimulated conditions. The extracellular pH of the perfusate was changed from 7.4 to 6.9 or 7.9 in HEPES-buffered physiological saline. Intracellular pH was measured using SNARF, and intracellular calcium was measured using Indo-1. Statistical differences were tested using the appropriate t-test. RESULTS Extracellular acidification significantly increased the frequency and amplitude of spontaneous contractions in pregnant, but not nonpregnant, myometrium, whereas alkalinization decreased contractions. Intracellular acidification, via Na-butyrate, transiently increased force in pregnant tissue. Intracellular pH was gradually acidified when extracellular pH was acidified, but extracellular acidification increased contractility before any significant change in intracellular pH. If myometrial force was driven by oxytocin or high-K depolarization, then extracellular pH did not further increase force. Intracellular calcium changes mirrored those of force in the spontaneously contracting pregnant myometrium, and if calcium entry was prevented by nifedipine, extracellular acidification could not induce a rise in force. CONCLUSION Extracellular acidification increases excitability, calcium entry, and thus force in pregnant mouse myometrium, and this may contribute to increasing contractions during labor when ischemic conditions and acidemia occur.
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Affiliation(s)
- Asmaa M Almohanna
- Department of Basic Science, College of Medicine, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Karen Noble
- Department of Veterinary Anatomy, Physiology and Pathology Institute of Infection, Veterinary and Ecological Sciences University of Liverpool, Liverpool, UK
| | - Susan Wray
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
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Yu H, Wang X, Tian R, Li X, Xu C, Fei J, Li T, Yin Z. Myometrium infection decreases TREK1 through NHE1 and increases contraction in pregnant mice. Am J Physiol Cell Physiol 2024; 326:C1106-C1119. [PMID: 38344766 DOI: 10.1152/ajpcell.00598.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 03/23/2024]
Abstract
Intrauterine infection during pregnancy can enhance uterine contractions. A two-pore K+ channel TREK1 is crucial for maintaining uterine quiescence and reducing contractility, with its properties regulated by pH changes in cell microenvironment. Meanwhile, the sodium hydrogen exchanger 1 (NHE1) plays a pivotal role in modulating cellular pH homeostasis, and its activation increases smooth muscle tension. By establishing an infected mouse model of Escherichia coli (E. coli) and lipopolysaccharide (LPS), we used Western blotting, real-time quantitative polymerase chain reaction, and immunofluorescence to detect changes of TREK1 and NHE1 expression in the myometrium, and isometric recording measured the uterus contraction. The NHE1 inhibitor cariporide was used to explore the effect of NHE1 on TREK1. Finally, cell contraction assay and siRNA transfection were performed to clarify the relationship between NHE1 and TREK1 in vitro. We found that the uterine contraction was notably enhanced in infected mice with E. coli and LPS administration. Meanwhile, TREK1 expression was reduced, whereas NHE1 expression was upregulated in infected mice. Cariporide alleviated the increased uterine contraction and promoted myometrium TREK1 expression in LPS-injected mice. Furthermore, suppression of NHE1 with siRNA transfection inhibited the contractility of uterine smooth muscle cells and activated the TREK1. Altogether, our findings indicate that infection increases the uterine contraction by downregulating myometrium TREK1 in mice, and the inhibition of TREK1 is attributed to the activation of NHE1.NEW & NOTEWORTHY Present work found that infection during pregnancy will increase myometrium contraction. Infection downregulated NHE1 and followed TREK1 expression and activation decrease in myometrium, resulting in increased myometrium contraction.
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Affiliation(s)
- Huihui Yu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xingxing Wang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Ruixian Tian
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xuan Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Chenyi Xu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jiajia Fei
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
| | - Tengteng Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zongzhi Yin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, China
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Prendergast C, Wray S, Dungate D, Martin C, Vaida A, Brook E, Chioma CA, Wallace H. Investigating the role of CFTR in human and mouse myometrium. Curr Res Physiol 2024; 7:100122. [PMID: 38501132 PMCID: PMC10945125 DOI: 10.1016/j.crphys.2024.100122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/20/2024] Open
Abstract
Background Abnormal cystic fibrosis transmembrane conductance regulator (CFTR) function in cystic fibrosis (CF) has been linked to airway smooth muscle abnormalities including bronchial hyperresponsiveness. However, a role for CFTR in other types of smooth muscle, including myometrium, remains largely unexplored. As CF life expectancy and the number of pregnancies increases, there is a need for an understanding of the potential role of CFTR in myometrial function. Methods We investigated the role of CFTR in human and mouse myometrium. We used immunofluorescence to identify CFTR expression, and carried out contractility studies on spontaneously contracting term pregnant and non-pregnant mouse myometrium and term pregnant human myometrial biopsies from caesarean sections. Results CFTR was found to be expressed in term pregnant mouse myometrium. Inhibition of CFTR, with the selective inhibitor CFTRinh-172, significantly reduced contractility in pregnant mouse and human myometrium in a concentration-dependent manner (44.89 ± 11.02 term pregnant mouse, 9.23 ± 4.75 term-pregnant human; maximal effect at 60 μM expressed as a percentage of the pre-treatment control period). However, there was no effect of CFTRinh-172 in non-pregnant myometrium. Conclusion These results demonstrate decreased myometrial function when CFTR is inhibited, which may have implications on pregnancy and labour outcome and therapeutic decisions for labour in CF patients.
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Affiliation(s)
- Clodagh Prendergast
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Susan Wray
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Daniella Dungate
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Christine Martin
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Andra Vaida
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Elizabeth Brook
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Cecilia Ani Chioma
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
| | - Helen Wallace
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, UK
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Wray S, Arrowsmith S. Uterine Excitability and Ion Channels and Their Changes with Gestation and Hormonal Environment. Annu Rev Physiol 2020; 83:331-357. [PMID: 33158376 DOI: 10.1146/annurev-physiol-032420-035509] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We address advances in the understanding of myometrial physiology, focusing on excitation and the effects of gestation on ion channels and their relevance to labor. This review moves through pioneering studies to exciting new findings. We begin with the myometrium and its myocytes and describe how excitation might initiate and spread in this myogenic smooth muscle. We then review each of the ion channels in the myometrium: L- and T-type Ca2+ channels, KATP (Kir6) channels, voltage-dependent K channels (Kv4, Kv7, and Kv11), twin-pore domain K channels (TASK, TREK), inward rectifier Kir7.1, Ca2+-activated K+ channels with large (KCNMA1, Slo1), small (KCNN1-3), and intermediate (KCNN4) conductance, Na-activated K channels (Slo2), voltage-gated (SCN) Na+ and Na+ leak channels, nonselective (NALCN) channels, the Na K-ATPase, and hyperpolarization-activated cation channels. We finish by assessing how three key hormones- oxytocin, estrogen, and progesterone-modulate and integrate excitability throughout gestation.
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Affiliation(s)
- Susan Wray
- Department of Women's and Children's Health, University of Liverpool, Liverpool L69 3BX, United Kingdom;
| | - Sarah Arrowsmith
- Department of Women's and Children's Health, University of Liverpool, Liverpool L69 3BX, United Kingdom;
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Lee SE, Kim DH, Son SM, Choi SY, You RY, Kim CH, Choi W, Kim HS, Lim YJ, Han JY, Kim HW, Yang IJ, Xu WX, Lee SJ, Kim YC, Yun HY. Physiological function and molecular composition of ATP-sensitive K + channels in human gastric smooth muscle. J Smooth Muscle Res 2020; 56:29-45. [PMID: 32581184 PMCID: PMC7324727 DOI: 10.1540/jsmr.56.29] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Gastric motility is controlled by slow waves. In general, the activation of the
ATP-sensitive K+ (KATP) channels in the smooth muscle
opposes the membrane excitability and produces relaxation. Since metabolic
inhibition and/or diabetes mellitus are accompanied by dysfunctions of gastric
smooth muscle, we examined the possible roles of KATP channels in
human gastric motility. We used human gastric corpus and antrum smooth muscle
preparations and recorded the mechanical activities with a conventional
contractile measuring system. We also identified the subunits of the
KATP channels using Western blot. Pinacidil (10 μM), a
KATP channel opener, suppressed contractions to 30% (basal tone
to −0.2 g) of the control. The inhibitory effect of pinacidil on contraction was
reversed to 59% of the control by glibenclamide (20 μM), a KATP
channel blocker. The relaxation by pinacidil was not affected by a pretreatment
with L-arginine methyl ester, tetraethylammonium, or 4-aminopyridine. Pinacidil
also inhibited the acetylcholine (ACh)-induced tonic and phasic contractions in
a glibenclamide-sensitive manner (42% and 6% of the control, respectively).
Other KATP channel openers such as diazoxide, cromakalim and
nicorandil also inhibited the spontaneous and ACh-induced contractions.
Calcitonin gene-related peptide (CGRP), a gastric neuropeptide, induced muscle
relaxation by the activation of KATP channels in human gastric smooth
muscle. Finally, we have found with Western blot studies, that human gastric
smooth muscle expressed KATP channels which were composed of Kir 6.2
and SUR2B subunits.
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Affiliation(s)
- Sang Eok Lee
- Department of Surgery, College of Medicine, Konyang University, 158 Gwanjeodong-ro, Seo-gu, Daejeon 35365, Korea
| | - Dae Hoon Kim
- Department of Surgery, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Seung Myeung Son
- Department of Pathology, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Song-Yi Choi
- Department of Pathology, School of Medicine, Chungnam National University, Daejeon, Chungnam 35015, Korea
| | - Ra Young You
- Department of Physiology, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Chan Hyung Kim
- Department of Pharmacology, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Woong Choi
- Department of Pharmacology, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Hun Sik Kim
- Department of Pharmacology, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Yung Ji Lim
- College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Ji Young Han
- CheongDam I Plastic surgery, 21, Sinheung-ro 240, Uijeonbu-si, Gyronggido 11651, Korea
| | - Hyun Woo Kim
- College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - In Jun Yang
- Department of Surgery, Seoul Nantional University Bundang Hospital, 166 Gumi-ro, Bundang-gu 13620, Seongnam, Korea
| | - Wen-Xie Xu
- Department of Physiology, College of Medcine, Shanghai Jiaotong University, 800 Dongchun Rd. Shanghai, 200240, P.R. China
| | - Sang Jin Lee
- Department of Physiology, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Young Chul Kim
- Department of Physiology, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
| | - Hyo-Yung Yun
- Department of Surgery, College of Medicine, Chungbuk National University, Chungdae-ro 1, Seowon-gu, Cheongju, Chungbuk 28644, Korea
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