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Algaze C, Chubb H, Deitch AM, Collins T. Electrocardiograms Do Not Detect Myocardial Ischemia in Patients With Williams Syndrome and Nonsyndromic Elastin Arteriopathy With Coronary Artery Stenosis. Am J Cardiol 2024; 215:50-55. [PMID: 37963512 DOI: 10.1016/j.amjcard.2023.11.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/27/2023] [Accepted: 11/09/2023] [Indexed: 11/16/2023]
Abstract
Coronary artery stenosis (CAS) may affect up to 27% of patients with Williams syndrome (WS), which may lead to myocardial ischemia. Patients with WS face a 25- to 100-fold greater risk of sudden cardiac death, frequently linked to anesthesia. Assessing CAS requires either imaging while under general anesthesia or intraoperative assessment, with the latter considered the gold standard. Our study aimed to identify electrocardiogram (ECG) markers of myocardial ischemia in patients with WS or nonsyndromic elastin arteriopathy and documented CAS. We retrospectively reviewed patients with WS/elastin arteriopathy who underwent supravalvar aortic stenosis surgery and CAS assessment from January 1, 2006 to April 30, 2021. A pediatric electrophysiologist, not aware of the patients' CAS status, reviewed their preoperative ECGs for markers of ischemia. We assessed associations of study parameters using Wilcoxon rank-sum and Fisher's exact tests. Of 34 patients, 62% were male, with a median age of 20 months (interquartile range: 8 to 34). CAS was present in 62% (21 of 34), 76% of whom (16 of 21) were male. There were no ECG indicators of myocardial ischemia in patients with CAS. In conclusion, CAS was present in >1/2 the children with WS/elastin arteriopathy who underwent repair of supravalvar aortic stenosis. CAS in WS/nonsyndromic elastin arteriopathy does not appear to exhibit typical ECG-detectable myocardial ischemia. ECGs are not a useful screening tool for CAS in WS/elastin arteriopathy. Given the high anesthesia-related cardiac arrest risk, other noninvasive indicators of CAS are needed.
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Affiliation(s)
- Claudia Algaze
- Division of Pediatric Cardiology, Lucile Packard Children's Hospital, Stanford University, Palo Alto, California.
| | - Henry Chubb
- Division of Pediatric Cardiology, Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - Anna M Deitch
- Division of Pediatric Cardiology, Lucile Packard Children's Hospital, Stanford University, Palo Alto, California
| | - Thomas Collins
- Division of Cardiology, Department of Pediatrics, University of Kentucky College of Medicine, Lexington, Kentucky
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2
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Sanz-de la Garza M, Vaquer-Seguí A, Durán K, Blanco I, Burgos F, Alsina X, Prat-González S, Bijnens B, Sitges M. Pulmonary transit of contrast during exercise is related to improved cardio-pulmonary performance in highly trained endurance athletes. Eur J Prev Cardiol 2019; 27:1504-1514. [PMID: 31801048 DOI: 10.1177/2047487319891779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND The mechanisms underlying the high interindividual variability demonstrated for right-ventricular (RV) adaptation to exercise have not yet been identified, but different pulmonary vascular adaptations among individuals could be involved. Pulmonary transit of agitated saline (PTAS) during exercise has been demonstrated to be a good estimator of vascular reserve. AIM The aim of this study was to evaluate the presence of PTAS among endurance athletes (EAs) of both sexes and its influence on RV adaptation to exercise. METHODS A total of 100 highly trained EAs performed a maximal cardiopulmonary exercise test. Bi-ventricular functional and structural characteristics as well as PTAS were evaluated at baseline and at peak exercise. Athletes were distributed between two groups based on the amount of PTAS during exercise as high (HTPAS; >12 bubbles) and low (LPTAS; ≤12 bubbles). RESULTS Overall, 11 EAs exhibited an intra-cardiac shunt at rest and 1 met the criteria for chronic pulmonary disease and were excluded from the study. Among the remaining 88 EAs (51% women), 47 (53%) athletes were classified as HPTAS and 41 (47%) as LPTAS. HPTAS capability was associated with significantly larger RV contractile reserve, larger pulmonary vascular reserve and an enhanced maximal exercise capacity. On multivariate analysis, females were the only independent correlate of the HPTAS capability. CONCLUSION In highly trained endurance athletes, a HPTAS capability during exercise corresponded to an increase in pulmonary vascular and RV contractile reserves as well as an enhanced maximal exercise capacity. The long-term clinical or performance implications of the absence or presence of pulmonary shunting, and the subsequent RV afterload increase while performing exercise, remains to be determined.
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Affiliation(s)
| | | | - Karina Durán
- Cardiovascular Institute, Hospital Clínic, Barcelona, Spain
| | - Isabel Blanco
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Pulmonary Medicine Department, Hospital Clínic, University of Barcelona, Barcelona, Spain.,Centro de Investigación en Red de Enfermedades Respiratorias (CIBERES), Barcelona, Spain
| | - Felip Burgos
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Pulmonary Medicine Department, Hospital Clínic, University of Barcelona, Barcelona, Spain.,Centro de Investigación en Red de Enfermedades Respiratorias (CIBERES), Barcelona, Spain
| | - Xavier Alsina
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Pulmonary Medicine Department, Hospital Clínic, University of Barcelona, Barcelona, Spain.,Centro de Investigación en Red de Enfermedades Respiratorias (CIBERES), Barcelona, Spain
| | - Susanna Prat-González
- Cardiovascular Institute, Hospital Clínic, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Bart Bijnens
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,ICREA, Barcelona, Spain
| | - Marta Sitges
- Cardiovascular Institute, Hospital Clínic, Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Centro de Investigación Biomèdica en Red Enfermedades Cardiovasculares (CIBERCV), Barcelona, Spain
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Tamosiuniene R, Manouvakhova O, Mesange P, Saito T, Qian J, Sanyal M, Lin YC, Nguyen LP, Luria A, Tu AB, Sante JM, Rabinovitch M, Fitzgerald DJ, Graham BB, Habtezion A, Voelkel NF, Aurelian L, Nicolls MR. Dominant Role for Regulatory T Cells in Protecting Females Against Pulmonary Hypertension. Circ Res 2018; 122:1689-1702. [PMID: 29545367 DOI: 10.1161/circresaha.117.312058] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 03/09/2018] [Accepted: 03/13/2018] [Indexed: 12/18/2022]
Abstract
RATIONALE Pulmonary arterial hypertension (PH) is a life-threatening condition associated with immune dysregulation and abnormal regulatory T cell (Treg) activity, but it is currently unknown whether and how abnormal Treg function differentially affects males and females. OBJECTIVE To evaluate whether and how Treg deficiency differentially affects male and female rats in experimental PH. METHODS AND RESULTS Male and female athymic rnu/rnu rats, lacking Tregs, were treated with the VEGFR2 (vascular endothelial growth factor receptor 2) inhibitor SU5416 or chronic hypoxia and evaluated for PH; some animals underwent Treg immune reconstitution before SU5416 administration. Plasma PGI2 (prostacyclin) levels were measured. Lung and right ventricles were assessed for the expression of the vasoprotective proteins COX-2 (cyclooxygenase 2), PTGIS (prostacyclin synthase), PDL-1 (programmed death ligand 1), and HO-1 (heme oxygenase 1). Inhibitors of these pathways were administered to athymic rats undergoing Treg immune reconstitution. Finally, human cardiac microvascular endothelial cells cocultured with Tregs were evaluated for COX-2, PDL-1, HO-1, and ER (estrogen receptor) expression, and culture supernatants were assayed for PGI2 and IL (interleukin)-10. SU5416-treatment and chronic hypoxia produced more severe PH in female than male athymic rats. Females were distinguished by greater pulmonary inflammation, augmented right ventricular fibrosis, lower plasma PGI2 levels, decreased lung COX-2, PTGIS, HO-1, and PDL-1 expression and reduced right ventricular PDL-1 levels. In both sexes, Treg immune reconstitution protected against PH development and raised levels of plasma PGI2 and cardiopulmonary COX-2, PTGIS, PDL-1, and HO-1. Inhibiting COX-2, HO-1, and PD-1 (programmed death 1)/PDL-1 pathways abrogated Treg protection. In vitro, human Tregs directly upregulated endothelial COX-2, PDL-1, HO-1, ERs and increased supernatant levels of PGI2 and IL-10. CONCLUSIONS In 2 animal models of PH based on Treg deficiency, females developed more severe PH than males. The data suggest that females are especially reliant on the normal Treg function to counteract the effects of pulmonary vascular injury leading to PH.
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Affiliation(s)
- Rasa Tamosiuniene
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | - Olga Manouvakhova
- VA Palo Alto Health Care System, CA (O.M., Y.-C.L., A.L., A.B.T., J.M.S., M.R.N.)
| | - Paul Mesange
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | - Toshie Saito
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | - Jin Qian
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | - Mrinmoy Sanyal
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | - Yu-Chun Lin
- VA Palo Alto Health Care System, CA (O.M., Y.-C.L., A.L., A.B.T., J.M.S., M.R.N.)
| | - Linh P Nguyen
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | - Amir Luria
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.).,VA Palo Alto Health Care System, CA (O.M., Y.-C.L., A.L., A.B.T., J.M.S., M.R.N.)
| | - Allen B Tu
- VA Palo Alto Health Care System, CA (O.M., Y.-C.L., A.L., A.B.T., J.M.S., M.R.N.)
| | - Joshua M Sante
- VA Palo Alto Health Care System, CA (O.M., Y.-C.L., A.L., A.B.T., J.M.S., M.R.N.)
| | - Marlene Rabinovitch
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | | | - Brian B Graham
- University of Colorado Denver, School of Medicine, Department of Medicine, Aurora (B.B.G.)
| | - Aida Habtezion
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.)
| | - Norbert F Voelkel
- Virginia Commonwealth University School of Medicine, Department of Internal Medicine, Richmond (N.F.V.)
| | - Laure Aurelian
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.).,University of Maryland School of Medicine, Baltimore (L.A.)
| | - Mark R Nicolls
- From the Stanford University School of Medicine, Department of Medicine, CA (R.T., P.M., T.S., J.Q., M.S., L.P.N., A.L., M.R., A.H., L.A., M.R.N.) .,VA Palo Alto Health Care System, CA (O.M., Y.-C.L., A.L., A.B.T., J.M.S., M.R.N.)
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Sanz-de la Garza M, Giraldeau G, Marin J, Grazioli G, Esteve M, Gabrielli L, Brambila C, Sanchis L, Bijnens B, Sitges M. Influence of gender on right ventricle adaptation to endurance exercise: an ultrasound two-dimensional speckle-tracking stress study. Eur J Appl Physiol 2017; 117:389-396. [PMID: 28150069 DOI: 10.1007/s00421-017-3546-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 01/10/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND Characteristic right ventricle (RV) remodelling is related to endurance exercise in male athletes (MAs), but data in female athletes (FAs) are scarce. Our aim was to evaluate sex-related influence on exercise-induced RV remodelling and on RV performance during exercise. METHODS Forty endurance athletes (>10 training hours/week, 50% female) and 40 age-matched controls (<3 h moderate exercise/week, 50% female) were included. Echocardiography was performed at rest and at maximum cycle-ergometer effort. Both ventricles were analysed by standard and speckle-tracking echocardiography. RESULTS Endurance training induced similar structural and functional cardiac remodelling in MAs and FAs, characterized by bi-ventricular dilatation [~34%, left ventricle (LV); 29%, RV] and normal bi-ventricular function. However, males had larger RV size (p < 0.01), compared to females: RV end-diastolic area (cm2/m2): 15.6 ± 2.2 vs 11.6 ± 1.7 in athletes; 12.2 ± 2.7 vs 8.6 ± 1.6 in controls, respectively, and lower bi-ventricular deformation (RV global longitudinal strain (GLS) (%): -24.0 ± 3.6 vs -29.2 ± 3.1 in athletes; -24.9 ± 2.5 vs -30.0 ± 1.9 in controls, and LVGLS: -17.5 ± 1.4 vs -21.9 ± 1.9 in athletes; -18.7 ± 1.2 vs -22.5 ± 1.5 in controls, respectively, p < 0.01). During exercise, the increase in LV function was positively correlated (p < 0.01) with increased cardiac output (∆%LV ejection fraction, r = +0.46 and ∆%LVGLS, r = +0.36). Improvement in RV performance was blunted at high workloads, especially in MAs. CONCLUSION Long-term endurance training induced similar bi-ventricular remodelling in MAs and FAs. Independently of training load, males had larger RV size and lower bi-ventricular deformation. Improvement in RV performance during exercise was blunted at high workloads, especially in MAs. The potential mechanisms underlying these findings warrant further investigation.
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Affiliation(s)
| | | | - Josefa Marin
- Cardiology Department, IDIBAPS, Hospital Clínic, Barcelona, Spain
| | - Gonzalo Grazioli
- Cardiology Department, IDIBAPS, Hospital Clínic, Barcelona, Spain
| | | | | | | | - Laura Sanchis
- Cardiology Department, IDIBAPS, Hospital Clínic, Barcelona, Spain.,Montreal Heart Institute, Montreal, Canada.,Catolic University of Chile, Santiago De Chile, Chile.,Angeles del Carmen Hospital, Guadalajara, Mexico.,ICREA, Universitat Pompeu Fabra, Barcelona, Spain
| | - Bart Bijnens
- ICREA, Universitat Pompeu Fabra, Barcelona, Spain
| | - Marta Sitges
- Cardiology Department, IDIBAPS, Hospital Clínic, Barcelona, Spain
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5
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Dean A, Nilsen M, Loughlin L, Salt IP, MacLean MR. Metformin Reverses Development of Pulmonary Hypertension via Aromatase Inhibition. Hypertension 2016; 68:446-54. [DOI: 10.1161/hypertensionaha.116.07353] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/13/2016] [Indexed: 11/16/2022]
Abstract
Females are more susceptible to pulmonary arterial hypertension than males, although the reasons remain unclear. The hypoglycemic drug, metformin, is reported to have multiple actions, including the inhibition of aromatase and stimulation of AMP-activated protein kinase. Inhibition of aromatase using anastrazole is protective in experimental pulmonary hypertension but whether metformin attenuates pulmonary hypertension through this mechanism remains unknown. We investigated whether metformin affected aromatase activity and if it could reduce the development of pulmonary hypertension in the sugen 5416/hypoxic rat model. We also investigated its influence on proliferation in human pulmonary arterial smooth muscle cells. Metformin reversed right ventricular systolic pressure, right ventricular hypertrophy, and decreased pulmonary vascular remodeling in the rat. Furthermore, metformin increased rat lung AMP-activated protein kinase signaling, decreased lung and circulating estrogen levels, levels of aromatase, the estrogen metabolizing enzyme; cytochrome P450 1B1 and its transcription factor; the aryl hydrocarbon receptor. In human pulmonary arterial smooth muscle cells, metformin decreased proliferation and decreased estrogen synthesis by decreasing aromatase activity through the PII promoter site of
Cyp19a1
. Thus, we report for the first time that metformin can reverse pulmonary hypertension through inhibition of aromatase and estrogen synthesis in a manner likely to be mediated by AMP-activated protein kinase.
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Affiliation(s)
- Afshan Dean
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Margaret Nilsen
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Lynn Loughlin
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Ian P. Salt
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Margaret R. MacLean
- From the Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Martin YN, Pabelick CM. Sex differences in the pulmonary circulation: implications for pulmonary hypertension. Am J Physiol Heart Circ Physiol 2014; 306:H1253-64. [PMID: 24610923 DOI: 10.1152/ajpheart.00857.2013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Pulmonary arterial hypertension (PAH), a form of pulmonary hypertension, is a complex disease of multifactorial origin. While new developments regarding pathophysiological features and therapeutic options in PAH are being reported, one important fact has emerged over the years: there is a sex difference in the incidence of this disease such that while there is a higher incidence in females, disease outcomes are much worse in males. Accordingly, recent attention has been focused on understanding the features of sex differences in the pulmonary circulation and the contributory mechanisms, particularly sex hormones and their role in the pathological and pathophysiological features of PAH. However, to date, there is no clear consensus whether sex hormones (particularly female sex steroids) are beneficial or detrimental in PAH. In this review, we highlight some of the most recent evidence regarding the influence of sex hormones (estrogen, testosterone, progesterone, dehydroepiandrosterone) and estrogen metabolites on key pathophysiological features of PAH such as proliferation, vascular remodeling, vasodilation/constriction, and inflammation, thus setting the stage for research avenues to identify novel therapeutic target for PAH as well as potentially other forms of pulmonary hypertension.
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Affiliation(s)
- Yvette N Martin
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota; and
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7
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Xu D, Niu W, Luo Y, Zhang B, Liu M, Dong H, Liu Y, Li Z. Endogenous estrogen attenuates hypoxia-induced pulmonary hypertension by inhibiting pulmonary arterial vasoconstriction and pulmonary arterial smooth muscle cells proliferation. Int J Med Sci 2013; 10:771-81. [PMID: 23630443 PMCID: PMC3638302 DOI: 10.7150/ijms.5906] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/15/2013] [Indexed: 12/02/2022] Open
Abstract
Exogenous estrogen was shown to exert various beneficial effects on multiple diseases including hypoxia-induced pulmonary hypertension (HPH). However, the effect of endogenous estrogen on HPH was seldom investigated. In the present study, we explored the protective effects and mechanisms of endogenous estrogen on hypoxia-induced pulmonary hypertension. Male, female, pregnant and ovariectomized rats were housed in a hypoxic condition for 21 days, and then hemodynamic together with morphologic indexes of pulmonary circulation were measured. The right ventricular systolic pressure, mean pulmonary artery pressure, right ventricular hypertrophy index, and arterial remodeling index were significantly elevated after chronic hypoxia exposure. Experimental data showed less severity in female, especially in pregnant rats. In vitro, artery rings of different sex or estrus cycle rats were obtained, and then artery rings experiments were performed to investigate pulmonary vasoconstriction by recording the maximum phase II vasoconstriction. Data showed that the vasoconstriction was milder in proestrus female than diestrus female or male groups, which could be leveled by treating U0126 (a MAPK pathway inhibitor). Pulmonary arterial smooth muscle cells isolated from different sex or estrus cycle rats were cultured in the condition of 2% oxygen for 24 hours, and cell proliferation was evaluated by the [3H]-thymidine incorporation assay. Cells from proestrus rats exhibited lower proliferation than the other groups, which could be countered by both U0126 and raloxifene (a selective estrogen receptor modulator). Serum estradiol levels were detected, and rats with higher levels showed less severity of pulmonary hypertension. Conclusively, endogenous estrogen may alleviate hypoxia-induced pulmonary hypertension by attenuating vasoconstriction through non-genomic mechanisms and inhibiting smooth muscle cells proliferation through both genomic and non-genomic mechanisms.
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Affiliation(s)
- Dunquan Xu
- Department of Pathology & Pathophysiology, Xijing Hospital, Fourth Military Medical University, NO.169 of Changle Western Street, Xi'an 710032, China
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Xu DQ, Luo Y, Liu Y, Wang J, Zhang B, Xu M, Wang YX, Dong HY, Dong MQ, Zhao PT, Niu W, Liu ML, Gao YQ, Li ZC. Beta-estradiol attenuates hypoxic pulmonary hypertension by stabilizing the expression of p27kip1 in rats. Respir Res 2010; 11:182. [PMID: 21182801 PMCID: PMC3022723 DOI: 10.1186/1465-9921-11-182] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Accepted: 12/24/2010] [Indexed: 12/29/2022] Open
Abstract
Background Pulmonary vascular structure remodeling (PVSR) is a hallmark of pulmonary hypertension. P27kip1, one of critical cyclin-dependent kinase inhibitors, has been shown to mediate anti-proliferation effects on various vascular cells. Beta-estradiol (β-E2) has numerous biological protective effects including attenuation of hypoxic pulmonary hypertension (HPH). In the present study, we employed β-E2 to investigate the roles of p27kip1 and its closely-related kinase (Skp-2) in the progression of PVSR and HPH. Methods Sprague-Dawley rats treated with or without β-E2 were challenged by intermittent chronic hypoxia exposure for 4 weeks to establish hypoxic pulmonary hypertension models, which resemble moderate severity of hypoxia-induced PH in humans. Subsequently, hemodynamic and pulmonary pathomorphology data were gathered. Additionally, pulmonary artery smooth muscle cells (PASMCs) were cultured to determine the anti-proliferation effect of β-E2 under hypoxia exposure. Western blotting or reverse transcriptional polymerase chain reaction (RT-PCR) were adopted to test p27kip1, Skp-2 and Akt-P changes in rat lung tissue and cultured PASMCs. Results Chronic hypoxia significantly increased right ventricular systolic pressures (RVSP), weight of right ventricle/left ventricle plus septum (RV/LV+S) ratio, medial width of pulmonary arterioles, accompanied with decreased expression of p27kip1 in rats. Whereas, β-E2 treatment repressed the elevation of RVSP, RV/LV+S, attenuated the PVSR of pulmonary arterioles induced by chronic hypoxia, and stabilized the expression of p27kip1. Study also showed that β-E2 application suppressed the proliferation of PASMCs and elevated the expression of p27kip1 under hypoxia exposure. In addition, experiments both in vivo and in vitro consistently indicated an escalation of Skp-2 and phosphorylated Akt under hypoxia condition. Besides, all these changes were alleviated in the presence of β-E2. Conclusions Our results suggest that β-E2 can effectively attenuate PVSR and HPH. The underlying mechanism may partially be through the increased p27kip1 by inhibiting Skp-2 through Akt signal pathway. Therefore, targeting up-regulation of p27kip1 or down-regulation of Skp-2 might provide new strategies for treatment of HPH.
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Affiliation(s)
- Dun-Quan Xu
- Department of Pathology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
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9
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Tofovic SP. Estrogens and development of pulmonary hypertension: interaction of estradiol metabolism and pulmonary vascular disease. J Cardiovasc Pharmacol 2010; 56:696-708. [PMID: 20881610 PMCID: PMC3027839 DOI: 10.1097/fjc.0b013e3181f9ea8d] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Severe pulmonary arterial hypertension (PAH) is characterized by clustered proliferation of endothelial cells (ECs) in the lumina of small size pulmonary arteries resulting in concentric obliteration of the lumina and formation of complex vascular structures known as plexiform lesions. This debilitating disease occurs more frequently in women, yet both animal studies in classical models of PAH and limited clinical data suggest protective effects of estrogens: the estrogen paradox in pulmonary hypertension. Little is known about the role of estrogens in PAH, but one line of evidence strongly suggests that the vascular protective effects of 17β-estradiol (estradiol; E2) are mediated largely by its downstream metabolites. Estradiol is metabolized to 2-hydroxyestradiol (2HE) by CYP1A1/CYP1B1, and 2HE is converted to 2-methoxyestradiol (2ME) by catechol-O-methyl transferase. 2ME is extensively metabolized to 2-methoxyestrone, a metabolite that lacks biologic activity, but which may be converted back to 2ME. 2ME has no estrogenic activity, and its effects are mediated by estrogen receptors–independent mechanism(s). Notably, in systemic and pulmonary vascular ECs, smooth muscle cells, and fibroblasts, 2ME exerts stronger antimitotic effects than E2 itself. E2 and 2ME, despite having similar effects on other cardiovascular cells, have opposing effects on ECs; that is, in ECs, E2 is promitogenic, proangiogenic, and antiapoptotic, whereas 2ME is antimitogenic, antiangiogenic, and proapoptotic. This may have significant ramifications in severe PAH that involves uncontrolled proliferation of monoclonal apoptosis-resistant ECs. Based on its cellular effects, 2ME should be expected to attenuate the progression of disease and provide protection in severe PAH. In contrast, E2, due to its mitogenic, angiogenic, and antiapoptotic effects (otherwise desirable in normal quiescent ECs), may even adversely affect endothelial remodeling in PAH, and this may be even more significant if the E2's effects on injured endothelium are not opposed by 2ME (eg, in the event of reduced E2 conversion to 2ME due to hypoxia, inflammation, drugs, environmental factors, or genetic polymorphism of metabolizing enzymes). This review focuses on the effects of estrogens and their metabolites on pulmonary vascular pathobiology and the development of experimental PAH and offers potential explanation for the estrogen paradox in PAH. Furthermore, we propose that unbalanced estradiol metabolism may lead to the development of PAH. Recent animal data and studies in patients with PAH support this concept.
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Affiliation(s)
- Stevan P Tofovic
- Division of Pulmonary, Allergy and Critical Care Medicine, and Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Bridge side 542, 100 Technology Drive, Pittsburgh, PA 15219, USA.
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Tofovic SP, Zhang X, Zhu H, Jackson EK, Rafikova O, Petrusevska G. 2-Ethoxyestradiol is antimitogenic and attenuates monocrotaline-induced pulmonary hypertension and vascular remodeling. Vascul Pharmacol 2008; 48:174-83. [DOI: 10.1016/j.vph.2008.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 01/27/2008] [Accepted: 02/04/2008] [Indexed: 10/22/2022]
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Patel KM, Lahm T, Crisostomo PR, Herring C, Markel T, Wang M, Meldrum DR. The effects of endogenous sex hormones and acute hypoxia on vasoconstriction in isolated rat pulmonary artery rings. J Surg Res 2008; 146:121-6. [PMID: 18243242 DOI: 10.1016/j.jss.2007.05.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 04/30/2007] [Accepted: 05/01/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Studies have noted gender differences in various models but have not investigated whether hormone depletion will abolish these differences. Therefore, we measured isometric force displacement in normal males, castrated males, normal females, and ovarectomized females. MATERIALS AND METHODS Adult male, adult female, castrated male, and ovarectomized female (250-350 g) Sprague Dawley rat pulmonary arteries (n = 7-8/group) were isolated and suspended in physiological organ baths. Force displacement was continuously recorded for 60 min of hypoxia. Data (mean +/- SEM) was analyzed with two-way analysis of variance with post-hoc Bonferroni test or Student's t-test. RESULTS Maximum vasodilation of normal males was -79.47 +/- 3.34%, while normal adult females exhibited a maximum vasodilation of -88.70 +/- 6.21% (P = 0.8149). In addition, delayed, phase II vasoconstriction of male pulmonary arteries rings was 89.79 +/- 7.25%, while adult females demonstrated a maximum phase II vasoconstriction of 95.90 +/- 14.23% (P = 0.9342). Hormone depletion of males exhibited a maximum vasodilation of -70.45 +/- 5.08% for castrated males as compared to -79.47 +/- 3.34% for normal adult males (P = 0.3805). Castrated males exhibited a maximum phase II vasoconstriction of 86.20 +/- 15.76% compared to 89.79 +/- 7.25% exhibited by normal adult males (P = 0.9516). CONCLUSIONS Hormone depletion in males and females did not alter pulmonary vasoreactivity in acute hypoxia.
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Affiliation(s)
- Ketan M Patel
- Department of Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
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12
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Tofovic SP, Zhang X, Jackson EK, Dacic S, Petrusevska G. 2-Methoxyestradiol mediates the protective effects of estradiol in monocrotaline-induced pulmonary hypertension. Vascul Pharmacol 2006; 45:358-67. [PMID: 16872912 DOI: 10.1016/j.vph.2006.05.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 05/14/2006] [Accepted: 05/16/2006] [Indexed: 01/20/2023]
Abstract
When exposed to chronic hypoxia or toxin monocrotaline (MCT), female animals develop less severe pulmonary arterial hypertension (PH) compared to males; ovariectomy (OVX) exacerbates PH, and OVX animals treated with estradiol (E2) develop less severe disease. There is a line of evidence suggesting that cardiovascular protective effects of E2 are mediated by its major metabolite, 2-methoxyestradiol (2ME). Recently, we have shown that 2ME attenuates the development and retards the progression of MCT-induced pulmonary hypertension in male rats. We hypothesized that the protective effects of E2 in experimental PH are mediated by 2ME. Subsets of intact and OVX female rats were injected saline (Cont and OXV groups) or MCT (60 mg/kg; MCT and OVX-MCT groups) and some of OVX-MCT animals were treated with 2ME (10 microg/kg/h via osmotic minipumps; OVX-MCT+2ME). After 28 days, MCT caused PH, i.e., increased right ventricular peak systolic pressure (RVPSP) and right ventricle/left ventricle+septum (RV/LV+S) ratio, induced inflammatory response in the lungs and caused media hypertrophy (media thickness and % media index) and adventitia widening of small size pulmonary arteries. Ovariectomy exacerbated the disease, i.e., further increased RVPSP, and RV/LV+S ratio, and augmented vascular remodeling and inflammatory response. In diseased OVX rats, treatment with 2ME prevented the worsening of PH and attenuated the inflammatory response and vascular remodeling. No mortality was recorded in the OVX-MCT+2ME group vs. 10% and 36% mortality in the MCT and OVX-MCT group, respectively. This study suggests that 2-methoxyestradiol (a major non-estrogenic metabolite of E2) may mediate the protective effects of estradiol in MCT-induced PH, and warrants further evaluation of 2ME for treatment of PH.
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MESH Headings
- 2-Methoxyestradiol
- Analysis of Variance
- Animals
- Blood Pressure/drug effects
- Disease Progression
- Estradiol/analogs & derivatives
- Estradiol/metabolism
- Estradiol/pharmacology
- Estradiol/therapeutic use
- Female
- Heart Ventricles/drug effects
- Heart Ventricles/pathology
- Hypertension, Pulmonary/chemically induced
- Hypertension, Pulmonary/pathology
- Hypertension, Pulmonary/physiopathology
- Hypertension, Pulmonary/prevention & control
- Hypertrophy, Right Ventricular/chemically induced
- Hypertrophy, Right Ventricular/pathology
- Hypertrophy, Right Ventricular/physiopathology
- Hypertrophy, Right Ventricular/prevention & control
- Lung/drug effects
- Lung/pathology
- Monocrotaline
- Ovariectomy
- Pulmonary Artery/drug effects
- Pulmonary Artery/pathology
- Rats
- Time Factors
- Ventricular Function, Left/drug effects
- Ventricular Function, Right/drug effects
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Affiliation(s)
- Stevan P Tofovic
- Center for Clinical Pharmacology, University of Pittsburgh School of Medicine, PA 15219, United States.
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13
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Tofovic SP, Salah EM, Mady HH, Jackson EK, Melhem MF. Estradiol metabolites attenuate monocrotaline-induced pulmonary hypertension in rats. J Cardiovasc Pharmacol 2006; 46:430-7. [PMID: 16160593 DOI: 10.1097/01.fjc.0000175878.32920.17] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Pulmonary arterial hypertension (PH) is a deadly disease characterized by pulmonary arterial vasoconstriction and hypertension, pulmonary vasculature remodeling, and right ventricular hypertrophy. Our previous in vivo studies, performed in several models of cardiac, vascular, and/or renal injury, suggest that the metabolites of 17beta-estradiol may inhibit vascular and cardiac remodeling. The goal of this study was to determine whether 2-methoxyestradiol (2ME), major non-estrogenic estradiol metabolite, prevents the development and/or retards the progression of monocrotaline (MCT)-induced PH. First, a total of 27 male Sprague Dawley rats were injected with distillated water (Cont, n=6) or monocrotaline (MCT; 60 mg/kg, i.p.; n=21). Subsets of MCT animals (n=7 per group) received 2ME or its metabolic precursor 2-hydroxyestradiol (2HE; 10 microg/kg/h via osmotic minipumps) for 21 days. Next, an additional set (n=24) of control and MCT rats was monitored for 28 days, before right ventricular peak systolic pressure (RVPSP) was measured. Some pulmonary hypertensive animals (n=8) were treated with 2ME (10 microg/kg/h) beginning from day 14 after MCT administration. MCT caused pulmonary hypertension (ie, increased right ventricle/left ventricle+septum [RV/LV+S] ratio and wall thickness of small-sized pulmonary arteries, and elevated RVPSP) and produced high and late (days 22 to 27) mortality. Pulmonary hypertension was associated with strong proliferative response (PCNA staining) and marked inflammation (ED1+cells) in lungs. Both metabolites significantly attenuated the RV/LV+S ratio and pulmonary arteries media hypertrophy and reduced proliferative and inflammatory responses in the lungs. Furthermore, in diseased animals, 2ME (given from day 14 to 28) significantly decreased RVPSP, RV/LV+S ratio and wall thickness, and reduced mortality by 80% (mortality rate: 62.5% vs. 12.5%, MCT vs. MCT+2ME day 14 to 28). This study provides the first evidence that 2ME, a major non-estrogenic, non-carcinogenic metabolite of estradiol, prevents the development and retards the progression of monocrotaline-induced pulmonary hypertension. Further evaluation of 2ME for management of pulmonary arterial hypertension is warranted.
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Affiliation(s)
- Stevan P Tofovic
- Center for Clinical Pharmacology, University of Pittsburgh School of Medicine, and the VA Pittsburgh Health System, Pittsburgh, PA 15219-3138, USA.
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14
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Miller AA, Hislop AA, Vallance PJ, Haworth SG. Deletion of the eNOS gene has a greater impact on the pulmonary circulation of male than female mice. Am J Physiol Lung Cell Mol Physiol 2005; 289:L299-306. [PMID: 15821017 DOI: 10.1152/ajplung.00022.2005] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nitric oxide is involved in development and postnatal adaptation of the pulmonary circulation. This study aimed to determine whether genetic deletion of nitric oxide synthase (NOS) would lead to maldevelopment of the pulmonary arteries in fetal life, compromise adaptation to extrauterine life, and be associated with a pulmonary hypertensive phenotype in adult life and if any abnormalities were detected, were they sex dependent. Morphometric analyses were made on lung tissue from male and female fetal, newborn, 14-day-old, and adult endothelial NOS-deficient (eNOS−/−) or inducible NOS-deficient (iNOS−/−) and wild-type mice. Hemodynamic studies were carried out on adult mice with deletion of either eNOS or iNOS genes. We found that in eNOS−/− mice, lung development was normal in fetal, newborn, and adult lungs. Pulmonary arterial muscularity was greater than normal in both male and female eNOS−/− during fetal life and at birth, but the abnormality persisted only in male mice. Right ventricular hypertrophy was present in 14-day-old and adult male eNOS−/− but not in female mice. Adult male eNOS−/− mice had higher mean right ventricular and systemic pressures than female eNOS−/− mice ( P < 0.05). Thus deletion of the eNOS gene was associated with structural evidence of pulmonary hypertension in both sexes during fetal life, but pulmonary hypertension persisted only in the male. In neither sex did iNOS or neuronal NOS appear to compensate for the eNOS deletion. Adult iNOS−/− mice did not have structural or hemodynamic evidence of pulmonary hypertension. Possible compensatory mechanisms are discussed.
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MESH Headings
- Actins/metabolism
- Animals
- Female
- Gene Deletion
- Hypertension, Pulmonary/enzymology
- Hypertension, Pulmonary/etiology
- Hypertension, Pulmonary/pathology
- Hypertrophy, Right Ventricular/enzymology
- Hypertrophy, Right Ventricular/etiology
- Hypertrophy, Right Ventricular/pathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Nerve Tissue Proteins/metabolism
- Nitric Oxide Synthase/genetics
- Nitric Oxide Synthase/metabolism
- Nitric Oxide Synthase Type I
- Nitric Oxide Synthase Type II
- Nitric Oxide Synthase Type III
- Pulmonary Artery/pathology
- Pulmonary Circulation
- Sex Factors
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Affiliation(s)
- Alyson A Miller
- Inst. of Child Health, University College London, 30 Guilford St., London WC1N 1EH, UK
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15
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Budhiraja R, Kayyali US, Karamsetty M, Fogel M, Hill NS, Chalkley R, Finlay GA, Hassoun PM. Estrogen modulates xanthine dehydrogenase/xanthine oxidase activity by a receptor-independent mechanism. Antioxid Redox Signal 2003; 5:705-11. [PMID: 14588143 DOI: 10.1089/152308603770380007] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Hypoxia causes up-regulation and activation of xanthine dehydrogenase/xanthine oxidase (XDH/XO) in vitro and in the lungs in vivo. This up-regulation, and the likely corresponding production of reactive oxygen species, may underlie the pathogenesis of an array of disorders. Thus, compounds that prevent hypoxia-induced increase in XDH/XO activity may provide a therapeutic strategy in such disorders. The antioxidant properties of estrogens have been demonstrated in several studies. However, the effect of these compounds on XDH/XO has not been explored previously. The aim of this study was to investigate the effects of estrogen on hypoxia-induced increase in XDH/XO activity. Rat pulmonary artery microvascular endothelial cells were exposed to normoxia or hypoxia in the presence or absence of 17beta- or 17alpha-estradiol. The XDH/XO enzyme and gene promoter activities were measured in different groups of cells. Hypoxia caused a twofold increase in XDH/XO enzymatic and promoter activity. Either of the estradiol stereoisomers prevented the hypoxia-induced increase in XDH/XO enzymatic activity, but not the promoter activity. ICI 182,780, an antagonist of the estrogen receptor, failed to block the inhibitory effect of estradiol on XDH/XO. In conclusion, 17alpha- and 17beta-estradiol modulate the hypoxia-induced regulation of XDH/XO activity at a posttranscriptional level by a receptor-independent mechanism.
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Affiliation(s)
- Rohit Budhiraja
- Pulmonary and Critical Care Division, Tupper Research Institute, Tufts-New England Medical Center, Tufts University School of Medicine, Boston, MA, USA
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16
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Hampl V, Bibova J, Ostadalova I, Povysilova V, Herget J. Gender differences in the long-term effects of perinatal hypoxia on pulmonary circulation in rats. Am J Physiol Lung Cell Mol Physiol 2003; 285:L386-92. [PMID: 12691957 DOI: 10.1152/ajplung.00389.2002] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Some effects of perinatal hypoxia on pulmonary circulation are permanent. Since pulmonary vascular sensitivity to hypoxia in adults differs between sexes, we hypothesized that gender-based variability also exists in the long-term effects of perinatal hypoxia. Rats spent 1 wk before and 1 wk after birth in hypoxia (12% O2) and then lived in normoxia. When adult, females, but not males, with the perinatal experience of hypoxia had right ventricle hypertrophy. To assess the role of sex hormones, some rats were gonadectomized in ether anesthesia as newborns. Compared with intact, perinatally normoxic controls, muscularization of peripheral pulmonary vessels in adulthood was augmented in perinatally hypoxic, neonatally gonadectomized males (by 85%) and much more so in females (by 533%). Pulmonary artery pressure was elevated in perinatally hypoxic, neonatally gonadectomized females (24.4 +/- 1.7 mmHg) but not males (17.2 +/- 0.6 mmHg). Gonadectomy in adulthood had no effect. We conclude that female pulmonary circulation is more sensitive to late effects of perinatal hypoxia, and these effects are blunted by the presence of ovaries during maturation.
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Affiliation(s)
- Vaclav Hampl
- Department of Physiology, Charles University Second Medical School, 150 00Prague 5, Czech Republic.
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17
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Sundstrom JB, Fett JD, Carraway RD, Ansari AA. Is peripartum cardiomyopathy an organ-specific autoimmune disease? Autoimmun Rev 2002; 1:73-7. [PMID: 12849062 DOI: 10.1016/s1568-9972(01)00009-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Peripartum cardiomyopathy (PPCM) is a rare and serious heart disease that exclusively afflicts women during childbearing years. Symptoms include rapid onset of cardiovascular insufficiency occurring during pregnancy, initiated anytime between the third trimester until 5 months post-partum in the absence of any other signs or history of heart disease. The rare incidence of PPCM and the absence of any relevant animal models have limited research and understanding of the pathogenic mechanisms involved. Several compelling sets of data support the view that PPCM is a form of autoimmune IDCM. However, PPCM differs from autoimmune IDCM in that (a) it is associated with unique sets of autoantibodies and autoantigens, (b) it has a relatively rapid onset, and (c) it exclusively affects pregnant women. Furthermore, the etiology of PPCM is dependent on the interaction of pregnancy associated factors, e.g. increased hemodynamic stress, vasoactive hormones and fetal microchimerism, that co-operate in the context of essential immune and genetic environments for disease progression. Our model of PPCM attempts to represent how multiple factors, e.g. pregnancy, genetics, immune dysregulation, and fetal microchimerism are held in a complex dynamic balance that can co-operate towards the maintenance of cardiovascular health or disease in the mother (Fig. 1). A more thorough study of the precise nature of the cardiac tissue autoantigens may lead to the identification of the mechanisms of breakdown of self-tolerance and perhaps also the putative etiologic agent(s). Further studies of the precise nature of the cardiac tissue autoantigens and the specific factors governing the balance between tolerance and autoimmunity in the periphery, e.g. expression of PD-L1 on cardiac tissues and the role of regulatory T cells, may help to elucidate the autoimmune mechanisms of PPCM.
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Affiliation(s)
- J Bruce Sundstrom
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA.
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18
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Atwal OS, Minhas KJ, Williams CS. Ultrastructural response of pulmonary intravascular macrophages to exogenous oestrogen in the bovine lung: translocation of the surface-coat and enhanced cell membrane plasticity and angiogenesis. J Anat 2001; 198:611-24. [PMID: 11430700 PMCID: PMC1468250 DOI: 10.1046/j.1469-7580.2001.19850611.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pulmonary intravascular macrophages (PIMs) of domestic ungulates are recognised by their specific surface coat, consisting of linearly arranged globules along the external leaf of the plasma membrane. The coat is sensitive to in vitro digestion with lipolytic lipase (LPL), intravenous heparin and clinical exposure to halothane anaesthesia. The sensitivity to these experimental manipulations suggests that the globules of the coat are predominantly composed of lipoproteins (LDL). The present administration of oestradiol proprionate in castrated male calves potentiated the translocation of the surface coat into the endocytotic pathway of the PIMs. Concurrently with mobilisation of the coat, the plasma membrane was thrown into prominent arrays of lamellipodial extensions. The sprawling macrophages made extensive adhesive contacts with the lining endothelium of the capillaries. Consequently, the endothelial cells were highly attenuated and precariously maintained the integrity of the vascular wall. At some focal points, the vascular wall was penetrated by the filopodial processes of PIMs, which protruded into the perivascular space. Furthermore, there were signs of neovascularisation in the form of overt mitotic changes, sprouting and precursor capillary formation. It is conceivable that the evolving profile of angiogenesis is due to the vascular endothelial growth factor (VEGF) paracrine function of PIMs. Endothelial cell specificity has been considered an important advantage of VEGF for neovascularisation. It allows pleotrophic response of endothelial cells to proliferate and to assemble into endothelial tubes.
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Affiliation(s)
- O S Atwal
- Department of Biomedical Sciences, University of Guelph, ON, Canada
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19
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Resta TC, Kanagy NL, Walker BR. Estradiol-induced attenuation of pulmonary hypertension is not associated with altered eNOS expression. Am J Physiol Lung Cell Mol Physiol 2001; 280:L88-97. [PMID: 11133498 DOI: 10.1152/ajplung.2001.280.1.l88] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Female rats develop less severe pulmonary hypertension (PH) in response to chronic hypoxia compared with males, thus implicating a potential role for ovarian hormones in mediating this gender difference. Considering that estrogen upregulates endothelial nitric oxide (NO) synthase (eNOS) in systemic vascular tissue, we hypothesized that estrogen inhibits hypoxic PH by increasing eNOS expression and activity. To test this hypothesis, we examined responses to the endothelium-derived NO-dependent dilator ionomycin and the NO donors S-nitroso-N-acetylpenicillamine and spermine NONOate in U-46619-constricted, isolated, saline-perfused lungs from the following groups: 1) normoxic rats with intact ovaries, 2) chronic hypoxic (CH) rats with intact ovaries, 3) CH ovariectomized rats given 17 beta-estradiol (E(2)beta), and 4) CH ovariectomized rats given vehicle. Additional experiments assessed pulmonary eNOS levels in each group by Western blotting. Our findings indicate that E(2)beta attenuated chronic hypoxia-induced right ventricular hypertrophy, pulmonary arterial remodeling, and polycythemia. Furthermore, although CH augmented vasodilatory responsiveness to ionomycin and increased pulmonary eNOS expression, these responses were not potentiated by E(2)beta. Finally, responses to S-nitroso-N-acetylpenicillamine and spermine NONOate were similarly attenuated in all CH groups compared with normoxic control groups. We conclude that the inhibitory influence of E(2)beta on chronic hypoxia-induced PH is not associated with increased eNOS expression or activity.
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Affiliation(s)
- T C Resta
- Vascular Physiology Group, Department of Cell Biology and Physiology, Health Sciences Center, University of New Mexico, Albuquerque, New Mexico 87131-5218, USA.
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