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Warrington JP, Fan F, Murphy SR, Roman RJ, Drummond HA, Granger JP, Ryan MJ. Placental ischemia in pregnant rats impairs cerebral blood flow autoregulation and increases blood-brain barrier permeability. Physiol Rep 2014; 2:2/8/e12134. [PMID: 25168877 PMCID: PMC4246592 DOI: 10.14814/phy2.12134] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Cerebrovascular events contribute to ~40% of preeclampsia/eclampsia‐related deaths, and neurological symptoms are common among preeclamptic patients. We previously reported that placental ischemia, induced by reducing utero‐placental perfusion pressure, leads to impaired myogenic reactivity and cerebral edema in the pregnant rat. Whether the impaired myogenic reactivity is associated with altered cerebral blood flow (CBF) autoregulation and the edema is due to altered blood–brain barrier (BBB) permeability remains unclear. Therefore, we tested the hypothesis that placental ischemia leads to impaired CBF autoregulation and a disruption of the BBB. CBF autoregulation, measured in vivo by laser Doppler flowmetry, was significantly impaired in placental ischemic rats. Brain water content was increased in the anterior cerebrum of placental ischemic rats and BBB permeability, assayed using the Evans blue extravasation method, was increased in the anterior cerebrum. The expression of the tight junction proteins: claudin‐1 was increased in the posterior cerebrum, while zonula occludens‐1, and occludin, were not significantly altered in either the anterior or posterior cerebrum. These results are consistent with the hypothesis that placental ischemia mediates anterior cerebral edema through impaired CBF autoregulation and associated increased transmission of pressure to small vessels that increases BBB permeability leading to cerebral edema. Preeclampsia is associated with an increased risk for developing encephalopathies. A prevailing theory is that impaired cerebral blood flow autoregulation contributes to this process. Whether placental ischemia, commonly thought to be a major underlying factor in the development of preeclampsia, can cause impaired cerebral blood flow autoregulation is not clear. In this study, placental ischemia is experimentally induced to test this directly. The results show that placental ischemia in the pregnant rat causes marked impairment of cerebral blood flow autoregulation.
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Affiliation(s)
- Junie P Warrington
- Department of Physiology & Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Sydney R Murphy
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Heather A Drummond
- Department of Physiology & Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Joey P Granger
- Department of Physiology & Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Michael J Ryan
- Department of Physiology & Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
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Cerebrovascular dysfunction and blood-brain barrier permeability induced by oxidized LDL are prevented by apocynin and magnesium sulfate in female rats. J Cardiovasc Pharmacol 2014; 63:33-9. [PMID: 24084218 DOI: 10.1097/fjc.0000000000000021] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Oxidized low-density lipoprotein (oxLDL) is elevated during several neurologic conditions that involve cerebral edema formation, including severe preeclampsia and eclampsia; however, our understanding of its effect on the cerebral vasculature is limited. We hypothesized that oxLDL induced blood-brain barrier (BBB) disruption and changes in cerebrovascular reactivity occur through NADPH oxidase-derived superoxide. We also investigated the effect of MgSO₄ on oxLDL-induced changes in the cerebral vasculature as this is commonly used in preventing cerebral edema formation. Posterior cerebral arteries from female rats were perfused with 5 µg/mL oxLDL in rat serum with or without 50 µM apocynin or 16 mM MgSO₄ and BBB permeability and vascular reactivity were compared. oxLDL increased BBB permeability and decreased myogenic tone that were prevented by apocynin. oxLDL increased constriction to the nitric oxide synthase inhibitor nitro-L-arginine that was unaffected by apocynin. oxLDL enhanced dilation to the NO donor sodium nitroprusside that was prevented by apocynin. MgSO₄ prevented oxLDL-induced BBB permeability without affecting oxLDL-induced changes in myogenic tone. Thus, oxLDL seems to cause BBB disruption and vascular tone dysregulation through NADPH oxidase-derived superoxide. These results highlight oxLDL and NADPH oxidase as potentially important therapeutic targets in neurologic conditions that involve elevated oxLDL.
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Kurlak LO, Green A, Loughna P, Broughton Pipkin F. Oxidative stress markers in hypertensive states of pregnancy: preterm and term disease. Front Physiol 2014; 5:310. [PMID: 25202276 PMCID: PMC4142431 DOI: 10.3389/fphys.2014.00310] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 07/30/2014] [Indexed: 01/08/2023] Open
Abstract
Discussion continues as to whether de novo hypertension in pregnancy with significant proteinuria (pre-eclampsia; PE) and non-proteinuric new hypertension (gestational hypertension; GH) are parts of the same disease spectrum or represent different conditions. Non-pregnant hypertension, pregnancy and PE are all associated with oxidative stress. We have established a 6 weeks postpartum clinic for women who experienced a hypertensive pregnancy. We hypothesized that PE and GH could be distinguished by markers of oxidative stress; thiobarbituric acid reactive substances (TBARS) and antioxidants (ferric ion reducing ability of plasma; FRAP). Since the severity of PE and GH is greater pre-term, we also compared pre-term and term disease. Fifty-eight women had term PE, 23 pre-term PE, 60 had term GH and 6 pre-term GH, 11 pre-existing (essential) hypertension (EH) without PE. Limited data were available from normotensive pregnancies (n = 7) and non-pregnant controls (n = 14). There were no differences in postpartum TBARS or FRAP between hypertensive states; TBARS (P = 0.001) and FRAP (P = 0.009) were lower in plasma of non-pregnant controls compared to recently-pregnant women. Interestingly FRAP was higher in preterm than term GH (P = 0.013). In PE and GH, TBARS correlated with low density lipoprotein (LDL)-cholesterol (P = 0.036); this association strengthened with inclusion of EH (P = 0.011). The 10 year Framingham index for cardiovascular risk was positively associated with TBARS (P = 0.003). Oxidative stress profiles do not differ between hypertensive states but appear to distinguish between recently-pregnant and non-pregnant states. This suggests that pregnancy may alter vascular integrity with changes remaining 6 weeks postpartum. LDL-cholesterol is a known determinant of oxidative stress in cardiovascular disease and we have shown this association to be present in hypertensive pregnancy further emphasizing that such a pregnancy may be revealing a pre-existing cardiovascular risk.
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Affiliation(s)
- Lesia O Kurlak
- Department of Obstetrics and Gynaecology, School of Medicine, University of Nottingham, City Hospital Nottingham, UK
| | - Amanda Green
- Department of Obstetrics and Gynaecology, School of Medicine, University of Nottingham, City Hospital Nottingham, UK
| | - Pamela Loughna
- Department of Obstetrics and Gynaecology, School of Medicine, University of Nottingham, City Hospital Nottingham, UK
| | - Fiona Broughton Pipkin
- Department of Obstetrics and Gynaecology, School of Medicine, University of Nottingham, City Hospital Nottingham, UK
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Zuniga FA, Ormazabal V, Gutierrez N, Aguilera V, Radojkovic C, Veas C, Escudero C, Lamperti L, Aguayo C. Role of lectin-like oxidized low density lipoprotein-1 in fetoplacental vascular dysfunction in preeclampsia. BIOMED RESEARCH INTERNATIONAL 2014; 2014:353616. [PMID: 25110674 PMCID: PMC4109675 DOI: 10.1155/2014/353616] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 04/24/2014] [Indexed: 11/30/2022]
Abstract
The bioavailability of nitric oxide (NO) represents a key marker in vascular health. A decrease in NO induces a pathological condition denominated endothelial dysfunction, syndrome observed in different pathologies, such as obesity, diabetes, kidney disease, cardiovascular disease, and preeclampsia (PE). PE is one of the major risks for maternal death and fetal loss. Recent studies suggest that the placenta of pregnant women with PE express high levels of lectin-like oxidized LDL receptor-1 (LOX-1), which induces endothelial dysfunction by increasing reactive oxygen species (ROS) and decreasing intracellular NO. Besides LOX-1 activation induces changes in migration and apoptosis of syncytiotrophoblast cells. However, the role of this receptor in placental tissue is still unknown. In this review we will describes the physiological roles of LOX-1 in normal placenta development and the potential involvement of this receptor in the pathophysiology of PE.
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Affiliation(s)
- Felipe A. Zuniga
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Valeska Ormazabal
- Department of Basic Science, Faculty of Medicine, Universidad Católica de la Santísima Concepción, 4090541 Concepcion, Chile
| | - Nicolas Gutierrez
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Valeria Aguilera
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Claudia Radojkovic
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Carlos Veas
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Carlos Escudero
- Vascular Physiology Laboratory, Group of Investigation in Tumor Angiogenesis (GIANT), Group of Research and Innovation in Vascular Health (GRIVAS Health), Department of Basic Sciences, Faculty of Sciences, Universidad del Bío-Bío, 4081112 Chillán, Chile
| | - Liliana Lamperti
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
| | - Claudio Aguayo
- Department of Clinical Biochemistry and Immunology, Faculty of Pharmacy, University of Concepción, 4070386 Concepcion, Chile
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Akamatsu T, Dai H, Mizuguchi M, Goto YI, Oka A, Itoh M. LOX-1 Is a Novel Therapeutic Target in Neonatal Hypoxic-Ischemic Encephalopathy. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:1843-52. [DOI: 10.1016/j.ajpath.2014.02.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 01/31/2014] [Accepted: 02/19/2014] [Indexed: 12/31/2022]
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The effects of superoxide dismutase mimetic MnTMPyP on the altered blood–brain barrier integrity in experimental preeclampsia with or without seizures in rats. Brain Res 2014; 1563:91-102. [DOI: 10.1016/j.brainres.2014.03.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 02/26/2014] [Accepted: 03/18/2014] [Indexed: 12/22/2022]
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Wang F, Shi Z, Wang P, You W, Liang G. Comparative proteome profile of human placenta from normal and preeclamptic pregnancies. PLoS One 2013; 8:e78025. [PMID: 24205073 PMCID: PMC3799759 DOI: 10.1371/journal.pone.0078025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 09/09/2013] [Indexed: 12/17/2022] Open
Abstract
To better understand the molecular mechanisms involved in pathological development of placenta in preeclampsia, we used LC-MS/MS to construct a large-scale comparative proteome profile of human placentas from normal and preeclamptic pregnancies. A total of 2636 proteins were detected in human placentas, and 171 different proteins were definitively identified between control and preeclamptic placentas. Further bioinformatics analysis indicated that these differentially expressed proteins correlate with several specific cellular processes which occur during pathological changes of preeclamptic placenta. 6 proteins were randomly selected to verify their expression patterns with Western blotting. Of which, 3 proteins’ cellular localizations were validated with immunohistochemistry. Elucidation of how protein-expression changes coordinate the pathological development would provide researchers with a better understanding of the critical biological processes of preeclampsia and potential targets for therapeutic agents to regulate placenta function, and eventually benefit the treatment of preeclampsia.
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Affiliation(s)
- Fuqiang Wang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, China
- State Key Laboratory of Reproductive Medicine, Analysis Center, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Zhonghua Shi
- State Key Laboratory of Reproductive Medicine, Analysis Center, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Ping Wang
- Key Laboratory of Living Donor Liver Transplantation, Ministry of Public Health, Department of Liver Transplantation Center, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China;
| | - Wei You
- Key Laboratory of Living Donor Liver Transplantation, Ministry of Public Health, Department of Liver Transplantation Center, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China;
- * E-mails: (GL); (WY)
| | - Gaolin Liang
- CAS Key Laboratory of Soft Matter Chemistry, Department of Chemistry, University of Science and Technology of China, Hefei, Anhui, China
- * E-mails: (GL); (WY)
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Abstract
Clinical epidemiological studies have revealed relatively weak, yet statistically significant, associations between dyslipidemia/dyslipoproteinemia and diabetic retinopathy (DR). Recent large interventional studies, however, demonstrated an unexpectedly robust efficacy of fenofibrate on the development of DR, possibly independent of plasma lipids. To unify the apparent discrepancies, we hypothesize that plasma lipoproteins play an indirect but important role in DR, contingent on the integrity of the blood-retina-barrier (BRB). In retinas with an intact BRB, plasma lipoproteins may be largely irrelevant; however, important effects become operative after the BRB is impaired in diabetes, leading to lipoprotein extravasation and subsequent modification, hence toxicity to the neighbouring retinal cells. In this hypothesis, BRB leakage is the key, plasma lipoprotein concentrations mainly modulate its consequences, and fenofibrate has intra-retinal actions. This review summarizes our current knowledge of the direct effects and mechanisms of modified lipoproteins on retinal cells and their potential contribution to the pathogenesis of DR.
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Affiliation(s)
- Jeremy Y Yu
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, UK
| | - Timothy J Lyons
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, UK ; Harold Hamm Diabetes Center and Section of Endocrinology and Diabetes, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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