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Ca 2+-Activated K + Channels and the Regulation of the Uteroplacental Circulation. Int J Mol Sci 2023; 24:ijms24021349. [PMID: 36674858 PMCID: PMC9867535 DOI: 10.3390/ijms24021349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/06/2023] [Accepted: 01/08/2023] [Indexed: 01/13/2023] Open
Abstract
Adequate uteroplacental blood supply is essential for the development and growth of the placenta and fetus during pregnancy. Aberrant uteroplacental perfusion is associated with pregnancy complications such as preeclampsia, fetal growth restriction (FGR), and gestational diabetes. The regulation of uteroplacental blood flow is thus vital to the well-being of the mother and fetus. Ca2+-activated K+ (KCa) channels of small, intermediate, and large conductance participate in setting and regulating the resting membrane potential of vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) and play a critical role in controlling vascular tone and blood pressure. KCa channels are important mediators of estrogen/pregnancy-induced adaptive changes in the uteroplacental circulation. Activation of the channels hyperpolarizes uteroplacental VSMCs/ECs, leading to attenuated vascular tone, blunted vasopressor responses, and increased uteroplacental blood flow. However, the regulation of uteroplacental vascular function by KCa channels is compromised in pregnancy complications. This review intends to provide a comprehensive overview of roles of KCa channels in the regulation of the uteroplacental circulation under physiological and pathophysiological conditions.
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Watkins OC, Yong HEJ, Mah TKL, Cracknell-Hazra VKB, Pillai RA, Selvam P, Sharma N, Cazenave-Gassiot A, Bendt AK, Godfrey KM, Lewis RM, Wenk MR, Chan SY. Sex-Dependent Regulation of Placental Oleic Acid and Palmitic Acid Metabolism by Maternal Glycemia and Associations with Birthweight. Int J Mol Sci 2022; 23:ijms23158685. [PMID: 35955818 PMCID: PMC9369035 DOI: 10.3390/ijms23158685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 01/27/2023] Open
Abstract
Pregnancy complications such as maternal hyperglycemia increase perinatal mortality and morbidity, but risks are higher in males than in females. We hypothesized that fetal sex-dependent differences in placental palmitic-acid (PA) and oleic-acid (OA) metabolism influence such risks. Placental explants (n = 22) were incubated with isotope-labeled fatty acids (13C-PA or 13C-OA) for 24 or 48 h and the production of forty-seven 13C-PA lipids and thirty-seven 13C-OA lipids quantified by LCMS. Linear regression was used to investigate associations between maternal glycemia, BMI and fetal sex with 13C lipids, and between 13C lipids and birthweight centile. Placental explants from females showed greater incorporation of 13C-OA and 13C-PA into almost all lipids compared to males. Fetal sex also influenced relationships with maternal glycemia, with many 13C-OA and 13C-PA acylcarnitines, 13C-PA-diacylglycerols and 13C-PA phospholipids positively associated with glycemia in females but not in males. In contrast, several 13C-OA triacylglycerols and 13C-OA phospholipids were negatively associated with glycemia in males but not in females. Birthweight centile in females was positively associated with six 13C-PA and three 13C-OA lipids (mainly acylcarnitines) and was negatively associated with eight 13C-OA lipids, while males showed few associations. Fetal sex thus influences placental lipid metabolism and could be a key modulator of the impact of maternal metabolic health on perinatal outcomes, potentially contributing toward sex-specific adaptions in which females prioritize survival.
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Affiliation(s)
- Oliver C. Watkins
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
| | - Hannah E. J. Yong
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore 117609, Singapore
| | - Tania Ken Lin Mah
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore 117609, Singapore
| | - Victoria K. B. Cracknell-Hazra
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore 117609, Singapore
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO17 1BJ, UK
| | - Reshma Appukuttan Pillai
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
| | - Preben Selvam
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
| | - Neha Sharma
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
| | - Amaury Cazenave-Gassiot
- Department of Biochemistry and Precision Medicine TRP, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
- Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore 119077, Singapore
| | - Anne K. Bendt
- Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore 119077, Singapore
| | - Keith M. Godfrey
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO17 1BJ, UK
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton SO17 1BJ, UK
| | - Rohan M. Lewis
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton SO17 1BJ, UK
- Institute of Developmental Sciences, Faculty of Medicine, University of Southampton, Southampton SO17 1BJ, UK
| | - Markus R. Wenk
- Department of Biochemistry and Precision Medicine TRP, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
- Singapore Lipidomics Incubator, Life Sciences Institute, National University of Singapore, Singapore 119077, Singapore
| | - Shiao-Yng Chan
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore 117609, Singapore
- Correspondence:
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Sonobe T, Tsuchimochi H, Maeda H, Pearson JT. Increased contribution of KCa channels to muscle contraction induced vascular and blood flow responses in sedentary and exercise trained ZFDM rats. J Physiol 2022; 600:2919-2938. [PMID: 35551673 DOI: 10.1113/jp282981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/04/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Microvascular dysfunction in type 2 diabetes impairs blood flow redistribution during exercise and limits the performance of skeletal muscle and may cause early fatigability. Endothelium-dependent hyperpolarization (EDH), which mediates vasodilation in resistance arteries is known to be depressed in animals with diabetes. Here we report that low-intensity exercise training in ZFDM rats increased KCa channel-derived component in the vasodilator responses to muscle contraction than in sedentary rats, partly due to the increase in KCNN3 expression. These results suggest that low-intensity exercise training improves blood flow redistribution in contracting skeletal muscle in metabolic disease with diabetes via upregulation of EDH. ABSTRACT In resistance arteries, endothelium-dependent hyperpolarization (EDH) mediated vasodilation is depressed in diabetes. We hypothesized that downregulation of KCa channel derived EDH reduces exercise-induced vasodilation and blood flow redistribution in diabetes. To test this hypothesis, we evaluated vascular function in response to hindlimb muscle contraction, and the contribution of KCa channels in anaesthetised ZFDM, metabolic disease rats with type 2 diabetes. We also tested whether exercise training ameliorated the vascular response. Using in vivo microangiography, the hindlimb vasculature was visualized before and after rhythmic muscle contraction (0.5 s tetanus every 3 sec, 20 times) evoked by sciatic nerve stimulation (40 Hz). Femoral blood flow of the contracting hindlimb was simultaneously measured by an ultrasonic flowmeter. The contribution of KCa channels was investigated in the presence and absence of apamin and charybdotoxin. We found that vascular and blood flow responses to muscle contraction were significantly impaired at the level of small artery segments in ZFDM fa/fa rats compared to its lean control fa/+ rats. The contribution of KCa channels was also smaller in fa/fa than in fa/+ rats. Low-intensity exercise training for 12 weeks in fa/fa rats demonstrated minor changes in the vascular and blood flow response to muscle contraction. However, KCa-derived component in the response to muscle contraction was much greater in exercise trained than in sedentary fa/fa rats. These data suggest that exercise training increases the contribution of KCa channels among endothelium-dependent vasodilatory mechanisms to maintain vascular and blood flow responses to muscle contraction in this metabolic disease rat model. Abstract figure legend Low-intensity exercise training in ZFDM, metabolic disease rats with type 2 diabetes increases KCa channel-derived component of endothelium-dependent hyperpolarization in the vascular and blood flow responses to skeletal muscle contraction than the responses in sedentary rats, partly due to upregulation of KCNN3 protein expression. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Takashi Sonobe
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Hirotsugu Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Hisashi Maeda
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.,Victoria Heart Institute and Monash Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Australia
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Endothelium-Dependent Hyperpolarization (EDH) in Diabetes: Mechanistic Insights and Therapeutic Implications. Int J Mol Sci 2019; 20:ijms20153737. [PMID: 31370156 PMCID: PMC6695796 DOI: 10.3390/ijms20153737] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 02/07/2023] Open
Abstract
Diabetes mellitus is one of the major risk factors for cardiovascular disease and is an important health issue worldwide. Long-term diabetes causes endothelial dysfunction, which in turn leads to diabetic vascular complications. Endothelium-derived nitric oxide is a major vasodilator in large-size vessels, and the hyperpolarization of vascular smooth muscle cells mediated by the endothelium plays a central role in agonist-mediated and flow-mediated vasodilation in resistance-size vessels. Although the mechanisms underlying diabetic vascular complications are multifactorial and complex, impairment of endothelium-dependent hyperpolarization (EDH) of vascular smooth muscle cells would contribute at least partly to the initiation and progression of microvascular complications of diabetes. In this review, we present the current knowledge about the pathophysiology and underlying mechanisms of impaired EDH in diabetes in animals and humans. We also discuss potential therapeutic approaches aimed at the prevention and restoration of EDH in diabetes.
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Li L, Wu CS, Hou GM, Dong MZ, Wang ZB, Hou Y, Schatten H, Zhang GR, Sun QY. Type 2 diabetes increases oocyte mtDNA mutations which are eliminated in the offspring by bottleneck effect. Reprod Biol Endocrinol 2018; 16:110. [PMID: 30390692 PMCID: PMC6215660 DOI: 10.1186/s12958-018-0423-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 10/14/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Diabetes induces many complications including reduced fertility and low oocyte quality, but whether it causes increased mtDNA mutations is unknown. METHODS We generated a T2D mouse model by using high-fat-diet (HFD) and Streptozotocin (STZ) injection. We examined mtDNA mutations in oocytes of diabetic mice by high-throughput sequencing techniques. RESULTS T2D mice showed glucose intolerance, insulin resistance, low fecundity compared to the control group. T2D oocytes showed increased mtDNA mutation sites and mutation numbers compared to the control counterparts. mtDNA mutation examination in F1 mice showed that the mitochondrial bottleneck could eliminate mtDNA mutations. CONCLUSIONS T2D mice have increased mtDNA mutation sites and mtDNA mutation numbers in oocytes compared to the counterparts, while these adverse effects can be eliminated by the bottleneck effect in their offspring. This is the first study using a small number of oocytes to examine mtDNA mutations in diabetic mothers and offspring.
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Affiliation(s)
- Li Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Chang-Sheng Wu
- Peking Medriv Academy of Genetics and Reproduction, Beijing, 102629, China
| | - Guan-Mei Hou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- College of Life Science, Qingdao Agricultural University, Qingdao, 266109, China
| | - Ming-Zhe Dong
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhen-Bo Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Yi Hou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Heide Schatten
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, 65211, USA
| | - Gui-Rong Zhang
- Peking Medriv Academy of Genetics and Reproduction, Beijing, 102629, China.
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100101, China.
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Zhang B, Paffett ML, Naik JS, Jernigan NL, Walker BR, Resta TC. Cholesterol Regulation of Pulmonary Endothelial Calcium Homeostasis. CURRENT TOPICS IN MEMBRANES 2018; 82:53-91. [PMID: 30360783 DOI: 10.1016/bs.ctm.2018.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cholesterol is a key structural component and regulator of lipid raft signaling platforms critical for cell function. Such regulation may involve changes in the biophysical properties of lipid microdomains or direct protein-sterol interactions that alter the function of ion channels, receptors, enzymes, and membrane structural proteins. Recent studies have implicated abnormal membrane cholesterol levels in mediating endothelial dysfunction that is characteristic of pulmonary hypertensive disorders, including that resulting from long-term exposure to hypoxia. Endothelial dysfunction in this setting is characterized by impaired pulmonary endothelial calcium entry and an associated imbalance that favors production vasoconstrictor and mitogenic factors that contribute to pulmonary hypertension. Here we review current knowledge of cholesterol regulation of pulmonary endothelial Ca2+ homeostasis, focusing on the role of membrane cholesterol in mediating agonist-induced Ca2+ entry and its components in the normal and hypertensive pulmonary circulation.
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Affiliation(s)
- Bojun Zhang
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States
| | - Michael L Paffett
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States
| | - Jay S Naik
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States
| | - Nikki L Jernigan
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States
| | - Benjimen R Walker
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States
| | - Thomas C Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, University of New Mexico, Albuquerque, NM, United States.
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John L, Ko NL, Gokin A, Gokina N, Mandalà M, Osol G. The Piezo1 cation channel mediates uterine artery shear stress mechanotransduction and vasodilation during rat pregnancy. Am J Physiol Heart Circ Physiol 2018; 315:H1019-H1026. [PMID: 30004235 DOI: 10.1152/ajpheart.00103.2018] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
During mammalian pregnancy, the uterine circulation must undergo substantial vasodilation and growth to maintain sufficient uteroplacental perfusion. Although we and others have shown that nitric oxide (NO) is a key mediator of these processes, the mechanisms that augment uterine artery NO signaling during gestation have not been identified. We hypothesized that Piezo1, a recently discovered cation channel, may be involved in the process of shear stress mechanotransduction, as other studies have shown that it is both mechanosensitive and linked to NO production. Surprisingly, there are no studies on Piezo1 in the uterine circulation. Our aims in the present study were to determine whether this novel channel is 1) present in uterine arteries, 2) regulated by gestation, 3) functionally relevant (able to elicit rises in intracellular Ca2+ concentration and vasodilation), and 4) linked to NO. Immunohistochemistry confirmed that Piezo1 is present in uterine arteries, primarily but not exclusively in endothelial cells. Western blot analysis showed that its protein expression was elevated during gestation. In pressurized main uterine arteries, pharmacological activation of Piezo1 by Yoda1 produced near maximal vasodilation and was associated with significant increases in intracellular Ca2+ concentration in endothelial cell sheets. Shear stress induced by intraluminal flow produced reversible vasodilations that were inhibited >50% by GsMTx-4, a Piezo1 inhibitor, and by Nω-nitro-l-arginine methyl ester/ Nω-nitro-l-arginine, inhibitors of NO synthase. These findings are the first to implicate a functional role for Piezo1 in the uterine circulation as a mechanosensor of endothelial shear stress. Moreover, our data demonstrate that Piezo1 activation leads to vasodilation via NO and indicate that its molecular expression is upregulated during pregnancy. NEW & NOTEWORTHY This is the first study to highlight Piezo1 in the uterine circulation. As a potentially important endothelial mechanosensor of shear stress, Piezo1 may be linked to mechanisms that support increased uteroplacental perfusion during pregnancy. Listen to this article's corresponding podcast at https://ajpheart.podbean.com/e/piezo1-mechanotransduction-in-the-uterine-circulation/ .
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Affiliation(s)
- Liam John
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Nga Ling Ko
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Alexander Gokin
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Natalia Gokina
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
| | - Maurizio Mandalà
- Department of Biology, Ecology and Earth Science, University of Calabria , Cosenza , Italy
| | - George Osol
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Larner College of Medicine, University of Vermont , Burlington, Vermont
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Affiliation(s)
- Styliani Goulopoulou
- From the Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth
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Vanhoutte PM, Shimokawa H, Feletou M, Tang EHC. Endothelial dysfunction and vascular disease - a 30th anniversary update. Acta Physiol (Oxf) 2017; 219:22-96. [PMID: 26706498 DOI: 10.1111/apha.12646] [Citation(s) in RCA: 556] [Impact Index Per Article: 79.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/27/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023]
Abstract
The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H2 O2 ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive Gi (e.g. responses to α2 -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive Gq (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H2 O2 ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.
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Affiliation(s)
- P. M. Vanhoutte
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
| | - H. Shimokawa
- Department of Cardiovascular Medicine; Tohoku University; Sendai Japan
| | - M. Feletou
- Department of Cardiovascular Research; Institut de Recherches Servier; Suresnes France
| | - E. H. C. Tang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
- School of Biomedical Sciences; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
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Gokina NI, Bonev AD, Phillips J, Gokin AP, Veilleux K, Oppenheimer K, Goloman G. Impairment of IKCa channels contributes to uteroplacental endothelial dysfunction in rat diabetic pregnancy. Am J Physiol Heart Circ Physiol 2015; 309:H592-604. [PMID: 26092991 DOI: 10.1152/ajpheart.00901.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 06/19/2015] [Indexed: 12/18/2022]
Abstract
Diabetes in rat pregnancy is associated with impaired vasodilation of the maternal uteroplacental vasculature. In the present study, we explored the role of endothelial cell (EC) Ca(2+)-activated K(+) channels of small conductance (SKCa channels) and intermediate conductance (IKCa channels) in diabetes-induced uterine vascular dysfunction. Diabetes was induced by injection of streptozotocin to second-day pregnant rats and confirmed by the development of maternal hyperglycemia. Control rats were injected with citrate buffer. Changes in smooth muscle cell intracellular Ca(2+) concentration, membrane potential, and vasodilation induced by SKCa/IKCa channel activators were studied in uteroplacental arteries of control and diabetic rats. The impact of diabetes on SKCa- and IKCa-mediated currents was explored in freshly dissociated ECs. NS309 evoked a potent vasodilation that was effectively inhibited by TRAM-34 but not by apamin. NS309-induced smooth muscle cell intracellular Ca(2+) concentration, membrane potential, and dilator responses were significantly diminished by diabetes; N-cyclohexyl-N-2-(3,5-dimethyl-pyrazol-1-yl)-6-methyl-4-pyrimidinamine (CyPPA)-evoked responses were not affected. Ca(2+)-activated ion currents in ECs were insensitive to paxilline, markedly inhibited by charybdotoxin (ChTX), and diminished by apamin. NS309-induced EC currents were generated mostly due to activation of ChTX-sensitive channels. Maternal diabetes resulted in a significant reduction in ChTX-sensitive currents with no effect on apamin-sensitive or CyPPA-induced currents. We concluded that IKCa channels play a prevalent role over SKCa channels in the generation of endothelial K(+) currents and vasodilation of uteroplacental arteries. Impaired function of IKCa channels importantly contributes to diabetes-induced uterine endothelial dysfunction. Therapeutic restoration of IKCa channel function may be a novel strategy for improvement of maternal uteroplacental blood flow in pregnancies complicated by diabetes.
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Affiliation(s)
- Natalia I Gokina
- Department of Obstetrics, Gynecology and Reproductive Sciences, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Adrian D Bonev
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, Vermont
| | - Julie Phillips
- Department of Obstetrics, Gynecology and Reproductive Sciences, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Alexander P Gokin
- Department of Obstetrics, Gynecology and Reproductive Sciences, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Kelsey Veilleux
- Department of Obstetrics, Gynecology and Reproductive Sciences, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Karen Oppenheimer
- Department of Obstetrics, Gynecology and Reproductive Sciences, College of Medicine, University of Vermont, Burlington, Vermont; and
| | - Gabriela Goloman
- Department of Obstetrics, Gynecology and Reproductive Sciences, College of Medicine, University of Vermont, Burlington, Vermont; and
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Lashley CJ, Supik DA, Atkinson JT, Murphy RJ, O'Hagan KP. Effect of pregnancy on the uterine vasoconstrictor response to exercise in rats. Physiol Rep 2015; 3:3/3/e12337. [PMID: 25804264 PMCID: PMC4393170 DOI: 10.14814/phy2.12337] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A major maternal adaptation in pregnancy is the large increase in uteroplacental blood flow that supplies the growing fetus with oxygen and nutrients. The impact of gestation on the dynamic uterine vasoconstrictor response to exercise in the rat, a common model for pathophysiological disorders in pregnancy remains unknown. We hypothesized that rats exhibit a robust uterine vasoconstrictor response to acute exercise that is attenuated in late pregnancy. Pregnant (P, N = 12) and nonpregnant (NP, N = 8) rats were instrumented chronically with a ultrasonic transit-time flowprobe and carotid arterial catheter to directly measure uterine artery blood flow (UtBF) and blood pressure (BP), respectively, at day 20 of gestation for 5 min of treadmill exercise (7 m/min; 6% grade). Preexercise UtBF [P, 2.1 (SD1.6) vs. NP, 0.5 (SD0.3) mL/min P < 0.01) and uterine artery conductance (UtC) [P, 2.1(SD1.7) vs. NP, 0.4 (SD0.2) mL/min × mmHg−1 × 10−2, P < 0.01] were higher in pregnant rats, whereas preexercise BP was lower in the pregnant rats [P, 111 (SD13) vs. NP, 126 (SD13) mmHg, P = 0.02]. Preexercise heart rate was similar [P, 457 (SD30) vs. NP, 454 (SD42), P = 0.3]. Exercise initiated rapid and sustained decreases in UtBF [Δ−47% (SD12)] and UtC [Δ−49% (SD12)] that were attenuated in the pregnant rats [UtBF, Δ−25% (SD20) and UtC, Δ−30% (SD20), P = 0.02]. The BP and heart rate responses to exercise were unaffected in late pregnancy (interaction term, P = 0.3). In rats, dynamic exercise induces a uterine vasoconstrictor response that is blunted during late gestation, a response that we observed previously in pregnant rabbits.
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Affiliation(s)
- Christopher J Lashley
- Program in Biomedical Sciences, College of Health Sciences, Midwestern University, Downers Grove, Illinois, USA Department of Physiology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois, USA
| | - David A Supik
- Program in Biomedical Sciences, College of Health Sciences, Midwestern University, Downers Grove, Illinois, USA
| | - James T Atkinson
- Program in Biomedical Sciences, College of Health Sciences, Midwestern University, Downers Grove, Illinois, USA
| | - Robert J Murphy
- Department of Physiology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois, USA
| | - Kathleen P O'Hagan
- Department of Physiology, Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois, USA
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Endoplasmic reticulum stress in insulin resistance and diabetes. Cell Calcium 2014; 56:311-22. [PMID: 25239386 DOI: 10.1016/j.ceca.2014.08.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 08/07/2014] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum is the main intracellular Ca(2+) store for Ca(2+) release during cell signaling. There are different strategies to avoid ER Ca(2+) depletion. Release channels utilize first Ca(2+)-bound to proteins and this minimizes the reduction of the free luminal [Ca(2+)]. However, if release channels stay open after exhaustion of Ca(2+)-bound to proteins, then the reduction of the free luminal ER [Ca(2+)] (via STIM proteins) activates Ca(2+) entry at the plasma membrane to restore the ER Ca(2+) load, which will work provided that SERCA pump is active. Nevertheless, there are several noxious conditions that result in decreased activity of the SERCA pump such as oxidative stress, inflammatory cytokines, and saturated fatty acids, among others. These conditions result in a deficient restoration of the ER [Ca(2+)] and lead to the ER stress response that should facilitate recovery of the ER. However, if the stressful condition persists then ER stress ends up triggering cell death and the ensuing degenerative process leads to diverse pathologies; particularly insulin resistance, diabetes and several of the complications associated with diabetes. This scenario suggests that limiting ER stress should decrease the incidence of diabetes and the mobility and mortality associated with this illness.
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Nobe K, Takenouchi Y, Kasono K, Hashimoto T, Honda K. Two Types of Overcontraction Are Involved in Intrarenal Artery Dysfunction in Type II Diabetic Mouse. J Pharmacol Exp Ther 2014; 351:77-86. [DOI: 10.1124/jpet.114.216747] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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15
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Goulopoulou S, Hannan JL, Matsumoto T, Ergul A, Webb RC. Augmented dilation to nitric oxide in uterine arteries from rats with type 2 diabetes: implications for vascular adaptations to pregnancy. Am J Physiol Heart Circ Physiol 2013; 306:H610-8. [PMID: 24337459 DOI: 10.1152/ajpheart.00588.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Pre-existing diabetes increases the risk of maternal and fetal complications during pregnancy, which may be due to underlying maternal vascular dysfunction and impaired blood supply to the uteroplacental unit. Endothelial dysfunction and reduced vascular smooth muscle responsiveness to nitric oxide (NO) are common vascular impairments in type 2 diabetes (T2D). We hypothesized that uterine arteries from diabetic rats would have reduced vascular smooth muscle sensitivity to NO compared with nondiabetic rats due to impairment in the NO/soluble guanylate cyclase (sGC)/cGMP signaling pathway. Uterine arteries from pregnant Goto-Kakizaki (GK; model of T2D) and Wistar (nondiabetic) rats were studied in a wire myograph. GK nonpregnant uterine arteries had reduced responses to ACh and sodium nitroprusside (SNP) but increased responses to propylamine propylamine NONOate and greater sensitivity to sildenafil compared with Wistar nonpregnant arteries. In late pregnancy, Wistar rats had reduced uterine vascular smooth muscle responsiveness to SNP, but GK rats failed to show this adaptation and had reduced expression of sGC compared with the nonpregnant state. GK rats had a smaller litter size (13.9 ± 0.48 vs. 9.8 ± 0.75; P < 0.05) and a greater number of resorptions compared with Wistar controls (0.8 ± 0.76% vs. 19.9 ± 6.06%; P < 0.05). These results suggest that uterine arteries from rats with T2D show reduced sensitivity of uterine vascular smooth muscle sGC to NO. During pregnancy, the GK uterine vascular smooth muscle fails to show relaxation responses similar to those of arteries from nondiabetic rats.
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