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Zhao M, Lei J, Deng F, Zhao C, Xu T, Ji B, Fu M, Wang X, Sun M, Zhang M, Gao Q. Gestational Hypoxia Impaired Endothelial Nitric Oxide Synthesis Via miR-155-5p/NADPH Oxidase/Reactive Oxygen Species Axis in Male Offspring Vessels. J Am Heart Assoc 2024; 13:e032079. [PMID: 38240225 PMCID: PMC11056123 DOI: 10.1161/jaha.123.032079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 12/08/2023] [Indexed: 02/07/2024]
Abstract
BACKGROUND Nitric oxide (NO) is the most important vasodilator secreted by vascular endothelial cells, and its abnormal synthesis is involved in the development of cardiovascular disease. The prenatal period is a critical time for development and largely determines lifelong vascular health in offspring. Given the high incidence and severity of gestational hypoxia in mid-late pregnancy, it is urgent to further explore whether it affects the long-term synthesis of NO in offspring vascular endothelial cells. METHODS AND RESULTS Pregnant Sprague-Dawley rats were housed in a normoxic or hypoxic (10.5% O2) chamber from gestation days 10 to 20. The thoracic aortas of fetal and adult male offspring were isolated for experiments. Gestational hypoxia significantly reduces the NO-dependent vasodilation mediated by acetylcholine in both the fetal and adult offspring thoracic aorta rings. Meanwhile, acetylcholine-induced NO synthesis is impaired in vascular endothelial cells from hypoxic offspring thoracic aortas. We demonstrate that gestational hypoxic offspring exhibit a reduced endothelial NO synthesis capacity, primarily due to increased expression of NADPH oxidase 2 and enhanced reactive oxygen species. Additionally, gestational hypoxic offspring show elevated levels of miR-155-5p in vascular endothelial cells, which is associated with increased expression of NADPH oxidase 2 and reactive oxygen species generation, as well as impaired NO synthesis. CONCLUSIONS The present study is the first to demonstrate that gestational hypoxia impairs endothelial NO synthesis via the miR-155-5p/NADPH oxidase 2/reactive oxygen species axis in offspring vessels. These novel findings indicate that the detrimental effects of gestational hypoxia on fetal vascular function can persist into adulthood, providing new insights into the development of vascular diseases.
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Affiliation(s)
- Meng Zhao
- Key Laboratory of Birth Regulation and Control Technology of National Health Commission of ChinaMaternal and Child Health Care Hospital of Shandong Province Affiliated to Qingdao UniversityJinanShandongChina
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
- Department of Obstetrics and GynecologyThe Third People’s Hospital of Bengbu Affiliated to Bengbu Medical CollegeBengbuAnhui ProvinceChina
| | - Jiahui Lei
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Fengying Deng
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Chenxuan Zhao
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Ting Xu
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Bingyu Ji
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Mengyu Fu
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
| | - Xietong Wang
- Key Laboratory of Birth Regulation and Control Technology of National Health Commission of ChinaMaternal and Child Health Care Hospital of Shandong Province Affiliated to Qingdao UniversityJinanShandongChina
| | - Miao Sun
- Key Laboratory of Birth Regulation and Control Technology of National Health Commission of ChinaMaternal and Child Health Care Hospital of Shandong Province Affiliated to Qingdao UniversityJinanShandongChina
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
- Center for Medical Genetics and Prenatal Diagnosis, Key Laboratory of Birth Defect Prevention and Genetic Medicine of Shandong Health CommissionShandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao UniversityJinanShandongChina
| | - Meihua Zhang
- Key Laboratory of Birth Regulation and Control Technology of National Health Commission of ChinaMaternal and Child Health Care Hospital of Shandong Province Affiliated to Qingdao UniversityJinanShandongChina
| | - Qinqin Gao
- Key Laboratory of Birth Regulation and Control Technology of National Health Commission of ChinaMaternal and Child Health Care Hospital of Shandong Province Affiliated to Qingdao UniversityJinanShandongChina
- Institute for Fetology, The First Affiliated Hospital of Soochow UniversitySuzhouChina
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Intergenerational effects of prenatal hypoxia exposure on uterine artery adaptations to pregnancies in the female offspring. J Dev Orig Health Dis 2022; 13:794-799. [PMID: 35616050 DOI: 10.1017/s2040174422000216] [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] [Indexed: 01/13/2023]
Abstract
Prenatal hypoxia is a common complication of pregnancy and is associated with detrimental health outcomes, such as impaired cardiac and vascular function, in adult offspring. Exposure to prenatal hypoxia reportedly impacts the reproductive system of female offspring. Whether exposure to prenatal hypoxia influences pregnancy adaptations and outcomes in these female offspring is unknown. We hypothesised that prenatal hypoxia impairs uterine artery adaptations in pregnancies of the adult offspring. Pregnancy outcomes and uterine artery function were assessed in 14-16 weeks old non-pregnant and late pregnant (gestational day 20; term = 22 days) adult female offspring born to rats exposed to prenatal normoxia (21% oxygen) or hypoxia (11% oxygen, between days 15-21 of gestation). Compared with normoxia controls, prenatal hypoxia was associated with pregnant adult offspring having reduced placental weights in their litters, and uterine artery circumferential stress that increased with pregnancy. Overall, prenatal hypoxia adversely, albeit mildly, compromised pregnancies of adult offspring.
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Selivanova EK, Shvetsova AA, Shilova LD, Tarasova OS, Gaynullina DK. Intrauterine growth restriction weakens anticontractile influence of NO in coronary arteries of adult rats. Sci Rep 2021; 11:14475. [PMID: 34262070 PMCID: PMC8280217 DOI: 10.1038/s41598-021-93491-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/18/2021] [Indexed: 11/09/2022] Open
Abstract
Intrauterine growth restriction (IUGR) is one of the most common pathologies of pregnancy. The cardiovascular consequences of IUGR do not disappear in adulthood and can manifest themselves in pathological alterations of vasomotor control. The hypothesis was tested that IUGR weakens anticontractile influence of NO and augments procontractile influence of Rho-kinase in arteries of adult offspring. To model IUGR in the rat, dams were 50% food restricted starting from the gestational day 11 till delivery. Mesenteric and coronary arteries of male offspring were studied at the age of 3 months using wire myography, qPCR, and Western blotting. Contractile responses of mesenteric arteries to α1-adrenoceptor agonist methoxamine as well as influences of NO and Rho-kinase did not differ between control and IUGR rats. However, coronary arteries of IUGR rats demonstrated elevated contraction to thromboxane A2 receptor agonist U46619 due to weakened anticontractile influence of NO and enhanced role of Rho-kinase in the endothelium. This was accompanied by reduced abundance of SODI protein and elevated content of RhoA protein in coronary arteries of IUGR rats. IUGR considerably changes the regulation of coronary vascular tone in adulthood and, therefore, can serve as a risk factor for the development of cardiac disorders.
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Affiliation(s)
- Ekaterina K Selivanova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Moscow, Russia
| | - Anastasia A Shvetsova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Moscow, Russia
| | - Lyubov D Shilova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Moscow, Russia
| | - Olga S Tarasova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Moscow, Russia
- Institute for Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Dina K Gaynullina
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Moscow, Russia.
- Russian National Research Medical University, Moscow, Russia.
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Zhang W, Feng X, Zhang Y, Sun M, Li L, Gao Q, Tang J, Zhang P, Lv J, Zhou X, Xu Z. Prenatal hypoxia inhibited propionate-evoked BK channels of mesenteric artery smooth muscle cells in offspring. J Cell Mol Med 2020; 24:3192-3202. [PMID: 31975557 PMCID: PMC7077603 DOI: 10.1111/jcmm.14994] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 12/02/2019] [Accepted: 12/21/2019] [Indexed: 12/20/2022] Open
Abstract
As a common complication of pregnancy, gestational hypoxia has been shown to predispose offspring to vascular dysfunction. Propionate, one of short‐chain fatty acids, exerts cardioprotective effects via reducing blood pressure. This study examined whether prenatal hypoxia impaired propionate‐stimulated large‐conductance Ca2+‐activated K+ (BK) channel activities in vascular smooth muscle cells (VSMCs) of offspring. Pregnant rats were exposed to hypoxia (10.5% oxygen) and normoxia (21% oxygen) from gestational day 7‐21. At 6 weeks of age, VSMCs in mesenteric arteries of offspring were analysed for BK channel functions and gene expressions. It was shown firstly that propionate could open significantly BK single channel in VSMCs in a concentration‐dependent manner. Antagonists of G protein βγ subunits and inositol trisphosphate receptor could completely suppress the activation of BK by propionate, respectively. Gαi/o and ryanodine receptor were found to participate in the stimulation on BK. Compared to the control, vasodilation and increments of BK NPo (the open probability) evoked by propionate were weakened in the offspring by prenatal hypoxia with down‐regulated Gβγ and PLCβ. It was indicated that prenatal hypoxia inhibited propionate‐stimulated BK activities in mesenteric VSMCs of offspring via reducing expressions of Gβγ and PLCβ, in which endoplasmic reticulum calcium release might be involved.
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Affiliation(s)
- Wenna Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xueqin Feng
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Yumeng Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Miao Sun
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Lingjun Li
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Qinqin Gao
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Jiaqi Tang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Pengjie Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Juanxiu Lv
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xiuwen Zhou
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Zhice Xu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
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Spermidine Prevents Heart Injury in Neonatal Rats Exposed to Intrauterine Hypoxia by Inhibiting Oxidative Stress and Mitochondrial Fragmentation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:5406468. [PMID: 31217839 PMCID: PMC6537013 DOI: 10.1155/2019/5406468] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/14/2019] [Accepted: 04/23/2019] [Indexed: 12/11/2022]
Abstract
Intrauterine hypoxia (IUH) is a common intrauterine dysplasia that can cause programming of the offspring cardiovascular system. In this study, we hypothesized that placental treatment with spermidine (SPD) can prevent heart injury in neonatal offspring exposed to IUH. Pregnant rats were exposed to 21% O2 or 10% O2 (hypoxia) for 7 days prior to term or were exposed to hypoxia and intraperitoneally administered SPD or SPD+difluromethylornithine (DFMO) on gestational days 15-21. Seven-day-old offspring were then sacrificed to assess several parameters. Our results demonstrated that IUH led to decreased myocardial ornithine decarboxylase (ODC) and increased spermidine/spermine N1-acetyltransferase (SSAT) expression in the offspring. IUH also resulted in decreased offspring body weight, heart weight, cardiomyocyte proliferation, and antioxidant capacity and increased cardiomyocyte apoptosis and fibrosis. Furthermore, IUH caused mitochondrial structure abnormality, dysfunction, and decreased biogenesis and led to a fission/fusion imbalance in offspring hearts. In vitro, hypoxia induced mitochondrial ROS accumulation, decreased membrane potential, and increased fragmentation. Notably, all hypoxia-induced changes analyzed in this study were prevented by SPD. Thus, in utero SPD treatment is a potential strategy for preventing IUH-induced neonatal cardiac injury.
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Is willingness to exercise programmed in utero? Reviewing sedentary behavior and the benefits of physical activity in intrauterine growth restricted individuals. JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2018. [DOI: 10.1016/j.jpedp.2018.03.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Bischoff AR, Cunha FDS, Dalle Molle R, Maróstica PJC, Silveira PP. Is willingness to exercise programmed in utero? Reviewing sedentary behavior and the benefits of physical activity in intrauterine growth restricted individuals. J Pediatr (Rio J) 2018; 94:582-595. [PMID: 29476706 DOI: 10.1016/j.jped.2017.12.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 12/06/2017] [Accepted: 12/15/2017] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVE The literature suggests that a fetus will adapt to surrounding adversities by optimizing its use of energy to improve survival, ultimately leading to the programming of the individual's energy intake and expenditure. While recent reviews focused on the fetal programming of energy intake and food preferences, there is also some evidence that fetal adversity is associated with diminished physical activity levels. Therefore, we aimed to review (a) the evidence for an association between being born with intrauterine growth restriction and sedentarism over the life-course and (b) the potential benefits of physical activity over cardiometabolic risk factors for this population. SOURCES PubMed, Scielo, Scopus and Embase. SUMMARY OF FINDINGS Most clinical studies that used objective measures found no association between intrauterine growth restriction and physical activity levels, while most studies that used self-reported questionnaires revealed such relationships, particularly leisure time physical activity. Experimental studies support the existence of fetal programming of physical activity, and show that exposure to exercise during IUGR individuals' life improves metabolic outcomes but less effect was seen on muscle architecture or function. CONCLUSIONS Alterations in muscle strength and metabolism, as well as altered aerobic performance, may predispose IUGR individuals to be spontaneously less physically active, suggesting that this population may be an important target for preventive interventions. Although very heterogeneous, the different studies allow us to infer that physical activity may have beneficial effects especially for individuals that are more vulnerable to metabolic modifications such as those with IUGR.
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Affiliation(s)
- Adrianne Rahde Bischoff
- University of Toronto, Department of Pediatrics, Division of Neonatology, Toronto, Canada; Hospital for Sick Children, Toronto, Canada.
| | - Fábio da Silva Cunha
- Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Departamento de Pediatria, Programa de Pós-Graduação em Saúde da Criança e do Adolescente, Porto Alegre, RS, Brazil
| | - Roberta Dalle Molle
- Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Departamento de Pediatria, Programa de Pós-Graduação em Saúde da Criança e do Adolescente, Porto Alegre, RS, Brazil
| | - Paulo José Cauduro Maróstica
- Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Departamento de Pediatria, Programa de Pós-Graduação em Saúde da Criança e do Adolescente, Porto Alegre, RS, Brazil
| | - Patrícia Pelufo Silveira
- Universidade Federal do Rio Grande do Sul, Faculdade de Medicina, Departamento de Pediatria, Programa de Pós-Graduação em Saúde da Criança e do Adolescente, Porto Alegre, RS, Brazil; McGill University, Douglas Mental Health University Institute, Ludmer Centre for Neuroinformatics and Mental Health, Montreal, Canada
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Ducsay CA, Goyal R, Pearce WJ, Wilson S, Hu XQ, Zhang L. Gestational Hypoxia and Developmental Plasticity. Physiol Rev 2018; 98:1241-1334. [PMID: 29717932 PMCID: PMC6088145 DOI: 10.1152/physrev.00043.2017] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Hypoxia is one of the most common and severe challenges to the maintenance of homeostasis. Oxygen sensing is a property of all tissues, and the response to hypoxia is multidimensional involving complicated intracellular networks concerned with the transduction of hypoxia-induced responses. Of all the stresses to which the fetus and newborn infant are subjected, perhaps the most important and clinically relevant is that of hypoxia. Hypoxia during gestation impacts both the mother and fetal development through interactions with an individual's genetic traits acquired over multiple generations by natural selection and changes in gene expression patterns by altering the epigenetic code. Changes in the epigenome determine "genomic plasticity," i.e., the ability of genes to be differentially expressed according to environmental cues. The genomic plasticity defined by epigenomic mechanisms including DNA methylation, histone modifications, and noncoding RNAs during development is the mechanistic substrate for phenotypic programming that determines physiological response and risk for healthy or deleterious outcomes. This review explores the impact of gestational hypoxia on maternal health and fetal development, and epigenetic mechanisms of developmental plasticity with emphasis on the uteroplacental circulation, heart development, cerebral circulation, pulmonary development, and the hypothalamic-pituitary-adrenal axis and adipose tissue. The complex molecular and epigenetic interactions that may impact an individual's physiology and developmental programming of health and disease later in life are discussed.
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Affiliation(s)
- Charles A. Ducsay
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Ravi Goyal
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - William J. Pearce
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Sean Wilson
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Xiang-Qun Hu
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
| | - Lubo Zhang
- The Lawrence D. Longo, MD Center for Perinatal Biology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California
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Spearman AD, Loomba RS, Danduran M, Kovach J. Intrauterine growth restriction is not associated with decreased exercise capacity in adolescents with congenital heart disease. CONGENIT HEART DIS 2018; 13:369-376. [DOI: 10.1111/chd.12577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/20/2017] [Accepted: 12/26/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Andrew D. Spearman
- Division of Cardiology, Children's Hospital of Wisconsin, Medical College of Wisconsin; Milwaukee Wisconsin, USA
| | - Rohit S. Loomba
- Division of Cardiology, Cincinnati Children's Hospital Medical Center; Ohio, USA
| | - Michael Danduran
- Division of Cardiology, Children's Hospital of Wisconsin, Medical College of Wisconsin; Milwaukee Wisconsin, USA
| | - Joshua Kovach
- Division of Cardiology, Children's Hospital of Wisconsin, Medical College of Wisconsin; Milwaukee Wisconsin, USA
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The role of the tumor necrosis factor (TNF)-related weak inducer of apoptosis (TWEAK) in offspring exposed to prenatal hypoxia. J Dev Orig Health Dis 2017; 9:661-669. [DOI: 10.1017/s2040174417001003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Exposure to prenatal hypoxia in rats leads to intrauterine growth restriction (IUGR), decreases fetal cardiomyocyte proliferation and increases the risk to develop cardiovascular diseases (CVD) later in life. The tumor necrosis factor-related weak inducer of apoptosis (TWEAK) induces cardiomyocyte proliferation through activation of the fibroblast growth factor-inducible molecule 14 (Fn-14) receptor. The TWEAK/Fn-14 pathway becomes quiescent shortly after birth, however, it becomes upregulated with CVD; suggesting that it could be a link between the increased susceptibility to CVD in pregnancies complicated by hypoxia/IUGR. We hypothesized that offspring exposed to prenatal hypoxia will exhibit reduced cardiomyocyte proliferation due to reduced Fn-14 expression and that the TWEAK/Fn-14 pathway will be expressed in those adult offspring. We exposed pregnant Sprague Dawley rats to control (21% oxygen) or hypoxic (11% oxygen) conditions from gestational days 15 to 21. Ventricular cardiomyocytes were isolated from male and female, control and hypoxic offspring at postnatal day 1. Proliferation was assessed in the presence or absence of r-TWEAK (72 h, 100 ng/ml). Prenatal hypoxia was not associated with differences in Fn-14 protein expression in either male or female offspring. Cardiomyocytes from prenatal hypoxic male, but not female, offspring had decreased proliferation compared with controls. Addition of r-TWEAK increased cardiomyocyte proliferation in all offspring. In adult offspring of all groups, the TWEAK/Fn-14 pathway was not detectable. Cardiomyocyte proliferation was reduced in only male offspring exposed to prenatal hypoxia but this was not due to changes in the Fn-14 pathway. Studies addressing other pathways associated with CVD and prenatal hypoxia are needed.
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Coleman HA, Tare M, Parkington HC. Nonlinear effects of potassium channel blockers on endothelium-dependent hyperpolarization. Acta Physiol (Oxf) 2017; 219:324-334. [PMID: 27639255 DOI: 10.1111/apha.12805] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/12/2016] [Accepted: 09/13/2016] [Indexed: 12/17/2022]
Abstract
In a number of published studies on endothelium-dependent hyperpolarization and relaxation, the results of the effects of K+ blockers have been difficult to interpret. When the effects of two blockers have been studied, often either blocker by itself had little effect, whereas the two blockers combined tended to abolish the responses. Explanations suggested in the literature include an unusual pharmacology of the K+ channels, and possible blocker binding interactions. In contrast, when we applied the same blockers to segments of small blood vessels under voltage clamp, the blockers reduced the endothelium-dependent K+ current in a linearly additive manner. Resolution of these contrasting results is important as endothelium-derived hyperpolarization (EDH) makes its greatest contribution to vasorelaxation in arterioles and small resistance arteries, where it can exert a significant role in tissue perfusion and blood pressure regulation. Furthermore, EDH is impaired in various diseases. Here, we consider why the voltage-clamp results differ from earlier free-running membrane potential and contractility studies. We fitted voltage-clamp-derived current-voltage relationships with mathematical functions and considered theoretically the effects of partial and total block of endothelium-derived K+ -currents on the membrane potential of small blood vessels. When the K+ -conductance was partially reduced, equivalent to applying a single blocker, the effect on EDH was small. Total block of the endothelium-dependent K+ conductance abolished the hyperpolarization, in agreement with various published studies. We conclude that nonlinear summation of the hyperpolarizing response evoked by endothelial stimulation can explain the variable effectiveness of individual K+ channel blockers on endothelium-dependent hyperpolarization and resulting relaxation.
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Affiliation(s)
- H. A. Coleman
- Department of Physiology; Biomedicine Discovery Institute; Cardiovascular Disease Program; Monash University; Clayton Vic. Australia
| | - M. Tare
- Department of Physiology; Biomedicine Discovery Institute; Cardiovascular Disease Program; Monash University; Clayton Vic. Australia
| | - H. C. Parkington
- Department of Physiology; Biomedicine Discovery Institute; Cardiovascular Disease Program; Monash University; Clayton Vic. Australia
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Intrauterine growth restriction increases circulating mitochondrial DNA and Toll-like receptor 9 expression in adult offspring: could aerobic training counteract these adaptations? J Dev Orig Health Dis 2016; 8:236-243. [PMID: 28004624 DOI: 10.1017/s2040174416000714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
It has been demonstrated that intrauterine growth restriction (IUGR) can program increase cardiometabolic risk. There are also evidences of the correlation between IUGR with low-grade inflammation and, thus can contribute to development of several cardiometabolic comorbidities. Therefore, we investigated the influence of IUGR on circulating mitochondrial DNA (mtDNA)/Toll-like receptor 9 (TLR9) and TNF-α expression in adult offspring. Considering that the aerobic training has anti-inflammatory actions, we also investigated whether aerobic training would improve these inflammatory factors. Pregnant Wistar rats received ad libitum or 50% of ad libitum diet throughout gestation. At 8 weeks of age, male offspring from both groups were randomly assigned to control, trained control, restricted and trained restricted. Aerobic training protocol was performed on a treadmill and after that, we evaluated circulating mtDNA, cardiac protein expression of TLR9, plasma and cardiac TNF-α levels, and left ventricle (LV) mass. We found that IUGR promoted an increase in the circulating mtDNA, TLR9 expression and plasma TNF-α levels. Further, our results revealed that aerobic training can restore mtDNA/TLR9 content and plasma levels of TNF-α among restricted rats. The cardiac TNF-α content and LV mass were not influenced either by IUGR or aerobic training. In conclusion, IUGR can program mtDNA/TLR9 content, which may lead to high levels of TNF-α. However, aerobic training was able to normalize these alterations. These findings evidenced that the association of IUGR and aerobic training seems to exert an important interaction effect regarding pro-inflammatory condition and, aerobic training may be used as a strategy to reduce deleterious adaptations in IUGR offspring.
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Morton JS, Cooke CL, Davidge ST. In Utero Origins of Hypertension: Mechanisms and Targets for Therapy. Physiol Rev 2016; 96:549-603. [DOI: 10.1152/physrev.00015.2015] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The developmental origins of health and disease theory is based on evidence that a suboptimal environment during fetal and neonatal development can significantly impact the evolution of adult-onset disease. Abundant evidence exists that a compromised prenatal (and early postnatal) environment leads to an increased risk of hypertension later in life. Hypertension is a silent, chronic, and progressive disease defined by elevated blood pressure (>140/90 mmHg) and is strongly correlated with cardiovascular morbidity/mortality. The pathophysiological mechanisms, however, are complex and poorly understood, and hypertension continues to be one of the most resilient health problems in modern society. Research into the programming of hypertension has proposed pharmacological treatment strategies to reverse and/or prevent disease. In addition, modifications to the lifestyle of pregnant women might impart far-reaching benefits to the health of their children. As more information is discovered, more successful management of hypertension can be expected to follow; however, while pregnancy complications such as fetal growth restriction, preeclampsia, preterm birth, etc., continue to occur, their offspring will be at increased risk for hypertension. This article reviews the current knowledge surrounding the developmental origins of hypertension, with a focus on mechanistic pathways and targets for therapeutic and pharmacologic interventions.
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Affiliation(s)
- Jude S. Morton
- Departments of Obstetrics and Gynaecology and of Physiology, University of Alberta, Edmonton, Canada; Women and Children's Health Research Institute, Edmonton, Canada; and Cardiovascular Research Centre, Edmonton, Canada
| | - Christy-Lynn Cooke
- Departments of Obstetrics and Gynaecology and of Physiology, University of Alberta, Edmonton, Canada; Women and Children's Health Research Institute, Edmonton, Canada; and Cardiovascular Research Centre, Edmonton, Canada
| | - Sandra T. Davidge
- Departments of Obstetrics and Gynaecology and of Physiology, University of Alberta, Edmonton, Canada; Women and Children's Health Research Institute, Edmonton, Canada; and Cardiovascular Research Centre, Edmonton, Canada
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Reyes LM, Kirschenman R, Quon A, Morton JS, Shah A, Davidge ST. Aerobic exercise training reduces cardiac function in adult male offspring exposed to prenatal hypoxia. Am J Physiol Regul Integr Comp Physiol 2015; 309:R489-98. [DOI: 10.1152/ajpregu.00201.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/03/2015] [Indexed: 12/19/2022]
Abstract
Intrauterine growth restriction (IUGR) has been associated with increased susceptibility to myocardial ischemia-reperfusion (I/R) injury. Exercise is an effective preventive intervention for cardiovascular diseases; however, it may be detrimental in conditions of compromised health. The aim of this study was to determine whether exercise training can improve cardiac performance after I/R injury in IUGR offspring. We used a hypoxia-induced IUGR model by exposing pregnant Sprague-Dawley rats to 21% oxygen (control) or hypoxic (11% oxygen; IUGR) conditions from gestational day 15 to 21. At 10 wk of age, offspring were randomized to a sedentary group or to a 6-wk exercise protocol. Transthoracic echocardiography assessments were performed after 6 wk. Twenty-four hours after the last bout of exercise, ex vivo cardiac function was determined using a working heart preparation. With exercise training, there was improved baseline cardiac performance in male control offspring but a reduced baseline cardiac performance in male IUGR exercised offspring ( P < 0.05). In male offspring, exercise decreased superoxide generation in control offspring, while in IUGR offspring, it had the polar opposite effect (interaction P ≤ 0.05). There was no effect of IUGR or exercise on cardiac function in female offspring. In conclusion, in male IUGR offspring, exercise may be a secondary stressor on cardiac function. A reduction in cardiac performance along with an increase in superoxide production in response to exercise was observed in this susceptible group.
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Affiliation(s)
- Laura M. Reyes
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada; and
- Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Raven Kirschenman
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada; and
- Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Anita Quon
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada; and
- Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Jude S. Morton
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada; and
- Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Amin Shah
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada; and
- Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Sandra T. Davidge
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Alberta, Canada; and
- Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Jang EA, Longo LD, Goyal R. Antenatal maternal hypoxia: criterion for fetal growth restriction in rodents. Front Physiol 2015; 6:176. [PMID: 26106333 PMCID: PMC4458570 DOI: 10.3389/fphys.2015.00176] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 05/25/2015] [Indexed: 12/24/2022] Open
Abstract
Rodents are a useful model for life science research. Accumulating evidence suggests that the offspring of mice and rats suffer from similar disorders as humans when exposed to hypoxia during pregnancy. Importantly, with antenatal hypoxic exposure, human neonates demonstrate low birth weight or growth restriction. Similarly, with antenatal hypoxic exposure rodents also demonstrate the fetal growth restriction (FGR). Surprisingly, there is no consensus on the minimum duration or degree of hypoxic exposure required to cause FGR in rodents. Thus, we have reviewed the available literature in an attempt to answer these questions. Based on studies in rats, birth weight reduction of 31% corresponded to 10th percentile reduction in birth weight curve. With the similar criterion (10th percentile), in mice 3 days or more and in rats 7 days or more of 14% or lower hypoxia administration was required to produce statistically significant FGR.
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Affiliation(s)
- Eeun Amy Jang
- Department of Basic Sciences, Center for Perinatal Biology, School of Medicine, Loma Linda University Loma Linda, CA, USA
| | - Lawrence D Longo
- Department of Basic Sciences, Center for Perinatal Biology, School of Medicine, Loma Linda University Loma Linda, CA, USA ; Epigenuity LLC Loma Linda, CA, USA
| | - Ravi Goyal
- Department of Basic Sciences, Center for Perinatal Biology, School of Medicine, Loma Linda University Loma Linda, CA, USA ; Epigenuity LLC Loma Linda, CA, USA
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