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Patil RS, Kovacs-Kasa A, Gorshkov BA, Fulton DJR, Su Y, Batori RK, Verin AD. Serine/Threonine Protein Phosphatases 1 and 2A in Lung Endothelial Barrier Regulation. Biomedicines 2023; 11:1638. [PMID: 37371733 PMCID: PMC10296329 DOI: 10.3390/biomedicines11061638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/28/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023] Open
Abstract
Vascular barrier dysfunction is characterized by increased permeability and inflammation of endothelial cells (ECs), which are prominent features of acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and sepsis, and a major complication of the SARS-CoV-2 infection and COVID-19. Functional impairment of the EC barrier and accompanying inflammation arises due to microbial toxins and from white blood cells of the lung as part of a defensive action against pathogens, ischemia-reperfusion or blood product transfusions, and aspiration syndromes-based injury. A loss of barrier function results in the excessive movement of fluid and macromolecules from the vasculature into the interstitium and alveolae resulting in pulmonary edema and collapse of the architecture and function of the lungs, and eventually culminates in respiratory failure. Therefore, EC barrier integrity, which is heavily dependent on cytoskeletal elements (mainly actin filaments, microtubules (MTs), cell-matrix focal adhesions, and intercellular junctions) to maintain cellular contacts, is a critical requirement for the preservation of lung function. EC cytoskeletal remodeling is regulated, at least in part, by Ser/Thr phosphorylation/dephosphorylation of key cytoskeletal proteins. While a large body of literature describes the role of phosphorylation of cytoskeletal proteins on Ser/Thr residues in the context of EC barrier regulation, the role of Ser/Thr dephosphorylation catalyzed by Ser/Thr protein phosphatases (PPases) in EC barrier regulation is less documented. Ser/Thr PPases have been proposed to act as a counter-regulatory mechanism that preserves the EC barrier and opposes EC contraction. Despite the importance of PPases, our knowledge of the catalytic and regulatory subunits involved, as well as their cellular targets, is limited and under-appreciated. Therefore, the goal of this review is to discuss the role of Ser/Thr PPases in the regulation of lung EC cytoskeleton and permeability with special emphasis on the role of protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A) as major mammalian Ser/Thr PPases. Importantly, we integrate the role of PPases with the structural dynamics of the cytoskeleton and signaling cascades that regulate endothelial cell permeability and inflammation.
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Affiliation(s)
- Rahul S. Patil
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Anita Kovacs-Kasa
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Boris A. Gorshkov
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - David J. R. Fulton
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
- Department of Pharmacology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Yunchao Su
- Department of Pharmacology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Robert K. Batori
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Alexander D. Verin
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
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Barabutis N, Kubra KT, Akhter MS. Growth hormone-releasing hormone antagonists protect against hydrochloric acid-induced endothelial injury in vitro. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2023; 99:104113. [PMID: 36940786 PMCID: PMC10111240 DOI: 10.1016/j.etap.2023.104113] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 03/13/2023] [Accepted: 03/16/2023] [Indexed: 06/18/2023]
Abstract
Growth hormone-releasing hormone (GHRH) regulates the synthesis of growth hormone from the anterior pituitary gland, and it is involved in inflammatory responses. On the other hand, GHRH antagonists (GHRHAnt) exhibit the opposite effects, resulting in endothelial barrier enhancement. Exposure to hydrochloric acid (HCL) is associated with acute and chronic lung injury. In this study, we investigate the effects of GHRHAnt in HCL-induced endothelial barrier dysfunction, utilizing commercially available bovine pulmonary artery endothelial cells (BPAEC). Cell viability was measured by utilizing 3-(4,5-dimethylthiazol2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay. Moreover, fluorescein isothiocyanate (FITC)-dextran was used to assess barrier function. Our observations suggest that GHRHAnt exert protective effects against HCL-induced endothelial breakdown, since those peptides counteract HCL-triggered paracellular hyperpermeability. Based on those findings, we propose that GHRHAnt represent a new therapeutic approach towards HCL-induced endothelial injury.
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Affiliation(s)
- Nektarios Barabutis
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA 71201, USA.
| | - Khadeja-Tul Kubra
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA 71201, USA
| | - Mohammad S Akhter
- School of Basic Pharmaceutical and Toxicological Sciences, College of Pharmacy, University of Louisiana Monroe, Monroe, LA 71201, USA
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Wang D, Li Q, Pan CS, Yan L, Sun K, Wang XY, Anwaier G, Liao QZ, Xie TT, Fan JY, Huo XM, Wang Y, Han JY. Yu-Ping-Feng Formula Ameliorates Alveolar-Capillary Barrier Injury Induced by Exhausted-Exercise via Regulation of Cytoskeleton. Front Pharmacol 2022; 13:891802. [PMID: 35814249 PMCID: PMC9263595 DOI: 10.3389/fphar.2022.891802] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/12/2022] [Indexed: 11/18/2022] Open
Abstract
Background: Yu-ping-feng powder (YPF) is a compound traditional Chinese medicine extensively used in China for respiratory diseases. However, the role of YPF in alveolar-capillary barrier dysfunction remains unknown. This study aimed to explore the effect and potential mechanism of YPF on alveolar-capillary barrier injury induced by exhausted exercise. Methods: Male Sprague–Dawley rats were used to establish an exhausted-exercise model by using a motorized rodent treadmill. YPF at doses of 2.18 g/kg was administrated by gavage before exercise training for 10 consecutive days. Food intake-weight/body weight, blood gas analysis, lung water percent content, BALF protein concentration, morphological observation, quantitative proteomics, real-time PCR, and Western blot were performed. A rat pulmonary microvascular endothelial cell line (PMVEC) subjected to hypoxia was applied for assessing the related mechanism. Results: YPF attenuated the decrease of food intake weight/body weight, improved lung swelling and hemorrhage, alleviated the increase of lung water percent content and BALF protein concentration, and inhibited the impairment of lung morphology. In addition, YPF increased the expression of claudin 3, claudin 18, occludin, VE-cadherin, and β-catenin, attenuated the epithelial and endothelial hyperpermeability in vivo and/or in vitro, and the stress fiber formation in PMVECs after hypoxia. Quantitative proteomics discovered that the effect of YPF implicated the Siah2-ubiquitin-proteasomal pathway, Gng12-PAK1-MLCK, and RhoA/ROCK, which was further confirmed by Western blot. Data are available via ProteomeXchange with identifier PXD032737. Conclusion: YPF ameliorated alveolar-capillary barrier injury induced by exhausted exercise, which is accounted for at least partly by the regulation of cytoskeleton.
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Affiliation(s)
- Di Wang
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Quan Li
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Chun-Shui Pan
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Li Yan
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Kai Sun
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Xiao-Yi Wang
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Gulinigaer Anwaier
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Qian-Zan Liao
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Ting-Ting Xie
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Jing-Yu Fan
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Xin-Mei Huo
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
| | - Yuan Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Jing-Yan Han
- Department of Integration of Chinese and Western Medicine, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
- Tasly Microcirculation Research Center, Peking University Health Science Center, Beijing, China
- Key Laboratory of Microcirculation, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- Key Laboratory of Stasis and Phlegm, State Administration of Traditional Chinese Medicine of the People’s Republic of China, Beijing, China
- State Key Laboratory of Core Technology in Innovative Chinese Medicine, Tianjin, China
- *Correspondence: Jing-Yan Han,
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Endothelial Cell Plasma Membrane Biomechanics Mediates Effects of Pro-Inflammatory Factors on Endothelial Mechanosensors: Vicious Circle Formation in Atherogenic Inflammation. MEMBRANES 2022; 12:membranes12020205. [PMID: 35207126 PMCID: PMC8877251 DOI: 10.3390/membranes12020205] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/31/2022] [Accepted: 02/03/2022] [Indexed: 02/01/2023]
Abstract
Chronic low-grade vascular inflammation and endothelial dysfunction significantly contribute to the pathogenesis of cardiovascular diseases. In endothelial cells (ECs), anti-inflammatory or pro-inflammatory signaling can be induced by different patterns of the fluid shear stress (SS) exerted by blood flow on ECs. Laminar blood flow with high magnitude is anti-inflammatory, while disturbed flow and laminar flow with low magnitude is pro-inflammatory. Endothelial mechanosensors are the key upstream signaling proteins in SS-induced pro- and anti-inflammatory responses. Being transmembrane proteins, mechanosensors, not only experience fluid SS but also become regulated by the biomechanical properties of the lipid bilayer and the cytoskeleton. We review the apparent effects of pro-inflammatory factors (hypoxia, oxidative stress, hypercholesterolemia, and cytokines) on the biomechanics of the lipid bilayer and the cytoskeleton. An analysis of the available data suggests that the formation of a vicious circle may occur, in which pro-inflammatory cytokines enhance and attenuate SS-induced pro-inflammatory and anti-inflammatory signaling, respectively.
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Beckman EJ, Martins F, Suzuki TA, Bi K, Keeble S, Good JM, Chavez AS, Ballinger MA, Agwamba K, Nachman MW. The genomic basis of high-elevation adaptation in wild house mice (Mus musculus domesticus) from South America. Genetics 2022; 220:iyab226. [PMID: 34897431 PMCID: PMC9097263 DOI: 10.1093/genetics/iyab226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/04/2021] [Indexed: 11/14/2022] Open
Abstract
Understanding the genetic basis of environmental adaptation in natural populations is a central goal in evolutionary biology. The conditions at high elevation, particularly the low oxygen available in the ambient air, impose a significant and chronic environmental challenge to metabolically active animals with lowland ancestry. To understand the process of adaptation to these novel conditions and to assess the repeatability of evolution over short timescales, we examined the signature of selection from complete exome sequences of house mice (Mus musculus domesticus) sampled across two elevational transects in the Andes of South America. Using phylogenetic analysis, we show that house mice colonized high elevations independently in Ecuador and Bolivia. Overall, we found distinct responses to selection in each transect and largely nonoverlapping sets of candidate genes, consistent with the complex nature of traits that underlie adaptation to low oxygen availability (hypoxia) in other species. Nonetheless, we also identified a small subset of the genome that appears to be under parallel selection at the gene and SNP levels. In particular, three genes (Col22a1, Fgf14, and srGAP1) bore strong signatures of selection in both transects. Finally, we observed several patterns that were common to both transects, including an excess of derived alleles at high elevation, and a number of hypoxia-associated genes exhibiting a threshold effect, with a large allele frequency change only at the highest elevations. This threshold effect suggests that selection pressures may increase disproportionately at high elevations in mammals, consistent with observations of some high-elevation diseases in humans.
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Affiliation(s)
- Elizabeth J Beckman
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Felipe Martins
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Taichi A Suzuki
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Department of Microbiome Science, Max Planck Institute for Developmental Biology, Tübingen 72076, Germany
| | - Ke Bi
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Sara Keeble
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Jeffrey M Good
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
- Wildlife Biology Program, University of Montana, Missoula, MT 59812, USA
| | - Andreas S Chavez
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
- Department of Evolution, Ecology, and Organismal Biology and the Translational Data Analytics Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Mallory A Ballinger
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Kennedy Agwamba
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Michael W Nachman
- Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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Binding of the Andes Virus Nucleocapsid Protein to RhoGDI Induces the Release and Activation of the Permeability Factor RhoA. J Virol 2021; 95:e0039621. [PMID: 34133221 DOI: 10.1128/jvi.00396-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Andes virus (ANDV) nonlytically infects pulmonary microvascular endothelial cells (PMECs), causing acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). In HPS patients, virtually every PMEC is infected; however, the mechanism by which ANDV induces vascular permeability and edema remains to be resolved. The ANDV nucleocapsid (N) protein activates the GTPase RhoA in primary human PMECs, causing VE-cadherin internalization from adherens junctions and PMEC permeability. We found that ANDV N protein failed to bind RhoA but coprecipitates RhoGDI (Rho GDP dissociation inhibitor), the primary RhoA repressor that normally sequesters RhoA in an inactive state. ANDV N protein selectively binds the RhoGDI C terminus (residues 69 to 204) but fails to form ternary complexes with RhoA or inhibit RhoA binding to the RhoGDI N terminus (residues 1 to 69). However, we found that ANDV N protein uniquely inhibits RhoA binding to an S34D phosphomimetic RhoGDI mutant. Hypoxia and vascular endothelial growth factor (VEGF) increase RhoA-induced PMEC permeability by directing protein kinase Cα (PKCα) phosphorylation of S34 on RhoGDI. Collectively, ANDV N protein alone activates RhoA by sequestering and reducing RhoGDI available to suppress RhoA. In response to hypoxia and VEGF-activated PKCα, ANDV N protein additionally directs the release of RhoA from S34-phosphorylated RhoGDI, synergistically activating RhoA and PMEC permeability. These findings reveal a fundamental edemagenic mechanism that permits ANDV to amplify PMEC permeability in hypoxic HPS patients. Our results rationalize therapeutically targeting PKCα and opposing protein kinase A (PKA) pathways that control RhoGDI phosphorylation as a means of resolving ANDV-induced capillary permeability, edema, and HPS. IMPORTANCE HPS-causing hantaviruses infect pulmonary endothelial cells (ECs), causing vascular leakage, pulmonary edema, and a 35% fatal acute respiratory distress syndrome (ARDS). Hantaviruses do not lyse or disrupt the endothelium but dysregulate normal EC barrier functions and increase hypoxia-directed permeability. Our findings reveal a novel underlying mechanism of EC permeability resulting from ANDV N protein binding to RhoGDI, a regulatory protein that normally maintains edemagenic RhoA in an inactive state and inhibits EC permeability. ANDV N sequesters RhoGDI and enhances the release of RhoA from S34-phosphorylated RhoGDI. These findings indicate that ANDV N induces the release of RhoA from PKC-phosphorylated RhoGDI, synergistically enhancing hypoxia-directed RhoA activation and PMEC permeability. Our data suggest inhibiting PKC and activating PKA phosphorylation of RhoGDI as mechanisms of inhibiting ANDV-directed EC permeability and therapeutically restricting edema in HPS patients. These findings may be broadly applicable to other causes of ARDS.
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Purinergic Regulation of Endothelial Barrier Function. Int J Mol Sci 2021; 22:ijms22031207. [PMID: 33530557 PMCID: PMC7865261 DOI: 10.3390/ijms22031207] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/10/2021] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Increased vascular permeability is a hallmark of several cardiovascular anomalies, including ischaemia/reperfusion injury and inflammation. During both ischaemia/reperfusion and inflammation, massive amounts of various nucleotides, particularly adenosine 5'-triphosphate (ATP) and adenosine, are released that can induce a plethora of signalling pathways via activation of several purinergic receptors and may affect endothelial barrier properties. The nature of the effects on endothelial barrier function may depend on the prevalence and type of purinergic receptors activated in a particular tissue. In this review, we discuss the influence of the activation of various purinergic receptors and downstream signalling pathways on vascular permeability during pathological conditions.
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Martinho S, Adão R, Leite-Moreira AF, Brás-Silva C. Persistent Pulmonary Hypertension of the Newborn: Pathophysiological Mechanisms and Novel Therapeutic Approaches. Front Pediatr 2020; 8:342. [PMID: 32850518 PMCID: PMC7396717 DOI: 10.3389/fped.2020.00342] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/26/2020] [Indexed: 12/13/2022] Open
Abstract
Persistent pulmonary hypertension of the newborn (PPHN) is one of the main causes of neonatal morbidity and mortality. It is characterized by sustained elevation of pulmonary vascular resistance (PVR), preventing an increase in pulmonary blood flow after birth. The affected neonates fail to establish blood oxygenation, precipitating severe respiratory distress, hypoxemia, and eventually death. Inhaled nitric oxide (iNO), the only approved pulmonary vasodilator for PPHN, constitutes, alongside supportive therapy, the basis of its treatment. However, nearly 40% of infants are iNO resistant. The cornerstones of increased PVR in PPHN are pulmonary vasoconstriction and vascular remodeling. A better understanding of PPHN pathophysiology may enlighten targeted and more effective therapies. Sildenafil, prostaglandins, milrinone, and bosentan, acting as vasodilators, besides glucocorticoids, playing a role on reducing inflammation, have all shown potential beneficial effects on newborns with PPHN. Furthermore, experimental evidence in PPHN animal models supports prospective use of emergent therapies, such as soluble guanylyl cyclase (sGC) activators/stimulators, l-citrulline, Rho-kinase inhibitors, peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists, recombinant superoxide dismutase (rhSOD), tetrahydrobiopterin (BH4) analogs, ω-3 long-chain polyunsaturated fatty acids (LC-PUFAs), 5-HT2A receptor antagonists, and recombinant human vascular endothelial growth factor (rhVEGF). This review focuses on current knowledge on alternative and novel pathways involved in PPHN pathogenesis, as well as recent progress regarding experimental and clinical evidence on potential therapeutic approaches for PPHN.
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Affiliation(s)
- Sofia Martinho
- Department of Surgery and Physiology, Cardiovascular Research and Development Center-UnIC, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Rui Adão
- Department of Surgery and Physiology, Cardiovascular Research and Development Center-UnIC, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Adelino F Leite-Moreira
- Department of Surgery and Physiology, Cardiovascular Research and Development Center-UnIC, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Carmen Brás-Silva
- Department of Surgery and Physiology, Cardiovascular Research and Development Center-UnIC, Faculty of Medicine, University of Porto, Porto, Portugal.,Faculty of Nutrition and Food Sciences, University of Porto, Porto, Portugal
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Inhibition of Protein Prenylation of GTPases Alters Endothelial Barrier Function. Int J Mol Sci 2019; 21:ijms21010002. [PMID: 31861297 PMCID: PMC6981884 DOI: 10.3390/ijms21010002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/13/2019] [Accepted: 12/15/2019] [Indexed: 02/07/2023] Open
Abstract
The members of Rho family of GTPases, RhoA and Rac1 regulate endothelial cytoskeleton dynamics and hence barrier integrity. The spatial activities of these GTPases are regulated by post-translational prenylation. In the present study, we investigated the effect of prenylation inhibition on the endothelial cytoskeleton and barrier properties. The study was carried out in human umbilical vein endothelial cells (HUVEC) and protein prenylation is manipulated with various pharmacological inhibitors. Inhibition of either complete prenylation using statins or specifically geranylgeranylation but not farnesylation has a biphasic effect on HUVEC cytoskeleton and permeability. Short-term treatment inhibits the spatial activity of RhoA/Rho kinase (Rock) to actin cytoskeleton resulting in adherens junctions (AJ) stabilization and ameliorates thrombin-induced barrier disruption whereas long-term inhibition results in collapse of endothelial cytoskeleton leading to increased basal permeability. These effects are reversed by supplementing the cells with geranylgeranyl but not farnesyl pyrophosphate. Moreover, long-term inhibition of protein prenylation results in basal hyper activation of RhoA/Rock signaling that is antagonized by a specific Rock inhibitor or an activation of cAMP signaling. In conclusion, inhibition of geranylgeranylation in endothelial cells (ECs) exerts biphasic effect on endothelial barrier properties. Short-term inhibition stabilizes AJs and hence barrier function whereas long-term treatment results in disruption of barrier properties.
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Activation of SIRT1 ameliorates LPS-induced lung injury in mice via decreasing endothelial tight junction permeability. Acta Pharmacol Sin 2019; 40:630-641. [PMID: 30022154 DOI: 10.1038/s41401-018-0045-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Accepted: 05/12/2018] [Indexed: 01/22/2023] Open
Abstract
The integrity of the endothelial barrier is a determinant of the prognosis of lipopolysaccharide (LPS)-induced acute lung injury (ALI). In this study, we investigated whether and how Sirtuin 1 (SIRT1) maintained the vascular integrity during ALI. An experimental model of ALI was established in mice through intratracheal administration of LPS (10 mg/kg). LPS stimulation significantly increased the pulmonary permeability and decreased the expression of SIRT1 and tight junction proteins (TJs), including occludin, claudin-5, tight junction protein 1 and tight junction protein 2. Morphological studies showed that LPS induced obvious lung injury with inflammatory cell infiltration in the interstitial and alveolar space, hemorrhage, edema, and the thickened alveolar wall compared to the control mice. Intratracheal administration of the selective SIRT1 activator SRT1720 (6.25 mg/kg) significantly attenuated LPS-induced lung injury, lung hyper-permeability and increased TJs expression, whereas intratracheal administration of the selective SIRT1 inhibitor EX527 (6.25 mg/kg) aggravated LPS-induced ALI. Similar protective effects of SIRT1 on pulmonary cellular permeability were observed in primary human pulmonary microvascular endothelial cells treated with LPS (2 mg/mL) in vitro. We further demonstrated that the RhoA/ROCK signaling pathway was activated in SIRT1 regulation of tight junction permeability. The RhoA/ROCK inhibitor Y-27632 (10 μM) increased the expression of TJs and reversed LPS- or EX527-induced hyper-permeability. In conclusion, SIRT1 ameliorates LPS-induced lung injury via decreasing endothelial tight junction permeability, possibly via RhoA/ROCK signaling pathway. This finding may contribute to the development of new therapeutic approaches for lung injury.
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Malinovskaya NA, Morgun AV, Pisareva NV, Osipova ED, Boytsova EB, Panina YA, Zhukov EL, Medvedeva NN, Salmina AB. Changes in the Permeability and Expression of Markers of the Structural and Functional Integrity of the Blood–Brain Barrier under Early Postnatal Hypoxia in vivo. NEUROCHEM J+ 2018. [DOI: 10.1134/s1819712418030078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Pi L, Fu C, Lu Y, Zhou J, Jorgensen M, Shenoy V, Lipson KE, Scott EW, Bryant AJ. Vascular Endothelial Cell-Specific Connective Tissue Growth Factor (CTGF) Is Necessary for Development of Chronic Hypoxia-Induced Pulmonary Hypertension. Front Physiol 2018. [PMID: 29535639 PMCID: PMC5835098 DOI: 10.3389/fphys.2018.00138] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Chronic hypoxia frequently complicates the care of patients with interstitial lung disease, contributing to the development of pulmonary hypertension (PH), and premature death. Connective tissue growth factor (CTGF), a matricellular protein of the Cyr61/CTGF/Nov (CCN) family, is known to exacerbate vascular remodeling within the lung. We have previously demonstrated that vascular endothelial-cell specific down-regulation of CTGF is associated with protection against the development of PH associated with hypoxia, though the mechanism for this effect is unknown. In this study, we generated a transgenic mouse line in which the Ctgf gene was floxed and deleted in vascular endothelial cells that expressed Cre recombinase under the control of VE-Cadherin promoter (eCTGF KO mice). Lack of vascular endothelial-derived CTGF protected against the development of PH secondary to chronic hypoxia, as well as in another model of bleomycin-induced pulmonary hypertension. Importantly, attenuation of PH was associated with a decrease in infiltrating inflammatory cells expressing CD11b or integrin αM (ITGAM), a known adhesion receptor for CTGF, in the lungs of hypoxia-exposed eCTGF KO mice. Moreover, these pathological changes were associated with activation of—Rho GTPase family member—cell division control protein 42 homolog (Cdc42) signaling, known to be associated with alteration in endothelial barrier function. These data indicate that endothelial-specific deletion of CTGF results in protection against development of chronic-hypoxia induced PH. This protection is conferred by both a decrease in inflammatory cell recruitment to the lung, and a reduction in lung Cdc42 activity. Based on our studies, CTGF inhibitor treatment should be investigated in patients with PH associated with chronic hypoxia secondary to chronic lung disease.
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Affiliation(s)
- Liya Pi
- Department of Pediatrics, University of Florida, Gainesville, FL, United States
| | - Chunhua Fu
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Yuanquing Lu
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Junmei Zhou
- Department of Pediatrics, University of Florida, Gainesville, FL, United States
| | - Marda Jorgensen
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Vinayak Shenoy
- Department of Pharmaceutical and Biomedical Sciences, California Health Sciences University, Clovis, CA, United States
| | | | - Edward W Scott
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States
| | - Andrew J Bryant
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL, United States
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Swaminathan A, Kasiviswanathan D, Balaguru UM, Kolluru GK, SuryaKumar G, Chatterjee S. Hypoxia perturbs endothelium by re-organizing cellular actin architecture: Nitric oxide offers limited protection. Tissue Cell 2018; 50:114-124. [PMID: 29429511 DOI: 10.1016/j.tice.2017.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 12/09/2017] [Accepted: 12/18/2017] [Indexed: 11/26/2022]
Abstract
Exposure to hypoxia causes structural changes in the endothelial cell (EC) monolayer that alter its permeability. There was a report earlier of impairment of nitric oxide (NO) production in endothelium. The intervention of NO in the altered cellular arrangements of actin cytoskeleton in endothelium for rectification of paracellular gaps in endothelium under hypoxia was observed. The present study demonstrates hypoxia inducing paracellular gaps in hypoxia-exposed blood capillaries in chick embryo extravascular model. Phalloidin staining confirmed significant polymerization of actin and unique cellular localization of the F-actin bands under hypoxia treatments. Addition of spermine NONOate (SPNO), a NO donor, or reoxygenation to endothelial monolayer attenuated hypoxia-mediated effects on endothelial permeability with partial recovery of endothelial integrity through actin remodeling. The present study indicates link of hypoxia-induced actin-associated cytoskeletal rearrangements and paracellular gaps in the endothelium with a low NO availability in the hypoxia milieu. The author concludes that NO confers protection against hypoxia-mediated cytoskeletal remodeling and endothelial leakiness.
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Affiliation(s)
- Akila Swaminathan
- Vascular Biology Lab, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | | | - Uma Maheswari Balaguru
- Vascular Biology Lab, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India
| | | | - Geetha SuryaKumar
- Defence Institute of Physiology and Allied Sciences, DIPAS, Delhi, India.
| | - Suvro Chatterjee
- Vascular Biology Lab, AU-KBC Research Centre, MIT Campus of Anna University, Chennai, India; Department of Biotechnology, Anna University, Chennai, India.
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14
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Hemnes AR, Zhao M, West J, Newman JH, Rich S, Archer SL, Robbins IM, Blackwell TS, Cogan J, Loyd JE, Zhao Z, Gaskill C, Jetter C, Kropski JA, Majka SM, Austin ED. Critical Genomic Networks and Vasoreactive Variants in Idiopathic Pulmonary Arterial Hypertension. Am J Respir Crit Care Med 2017; 194:464-75. [PMID: 26926454 DOI: 10.1164/rccm.201508-1678oc] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
RATIONALE Idiopathic pulmonary arterial hypertension (IPAH) is usually without an identified genetic cause, despite clinical and molecular similarity to bone morphogenetic protein receptor type 2 mutation-associated heritable pulmonary arterial hypertension (PAH). There is phenotypic heterogeneity in IPAH, with a minority of patients showing long-term improvement with calcium channel-blocker therapy. OBJECTIVES We sought to identify gene variants (GVs) underlying IPAH and determine whether GVs differ in vasodilator-responsive IPAH (VR-PAH) versus vasodilator-nonresponsive IPAH (VN-PAH). METHODS We performed whole-exome sequencing (WES) on 36 patients with IPAH: 17 with VR-PAH and 19 with VN-PAH. Wnt pathway differences were explored in human lung fibroblasts. MEASUREMENTS AND MAIN RESULTS We identified 1,369 genes with 1,580 variants unique to IPAH. We used a gene ontology approach to analyze variants and identified overrepresentation of several pathways, including cytoskeletal function and ion binding. By mapping WES data to prior genome-wide association study data, Wnt pathway genes were highlighted. Using the connectivity map to define genetic differences between VR-PAH and VN-PAH, we found enrichment in vascular smooth muscle cell contraction pathways and greater genetic variation in VR-PAH versus VN-PAH. Using human lung fibroblasts, we found increased stimulated Wnt activity in IPAH versus controls. CONCLUSIONS A pathway-based analysis of WES data in IPAH demonstrated multiple rare GVs that converge on key biological pathways, such as cytoskeletal function and Wnt signaling pathway. Vascular smooth muscle contraction-related genes were enriched in VR-PAH, suggesting a potentially different genetic predisposition for VR-PAH. This pathway-based approach may be applied to next-generation sequencing data in other diseases to uncover the contribution of unexpected or multiple GVs to a phenotype.
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Affiliation(s)
- Anna R Hemnes
- 1 Division of Allergy, Pulmonary, and Critical Care Medicine
| | - Min Zhao
- 2 Department of Biomedical Informatics
| | - James West
- 1 Division of Allergy, Pulmonary, and Critical Care Medicine
| | - John H Newman
- 1 Division of Allergy, Pulmonary, and Critical Care Medicine
| | - Stuart Rich
- 3 Division of Cardiology, University of Chicago, Chicago, Illinois; and
| | - Stephen L Archer
- 4 Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Ivan M Robbins
- 1 Division of Allergy, Pulmonary, and Critical Care Medicine
| | | | - Joy Cogan
- 5 Department of Pediatric Medical Genetics, and
| | - James E Loyd
- 1 Division of Allergy, Pulmonary, and Critical Care Medicine
| | | | | | | | | | | | - Eric D Austin
- 6 Division of Allergy, Immunology, and Pulmonary Medicine, Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee
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15
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Kim H, Woo DJ, Kim SY, Yang EG. p21-activated kinase 4 regulates HIF-1α translation in cancer cells. Biochem Biophys Res Commun 2017; 486:270-276. [PMID: 28288786 DOI: 10.1016/j.bbrc.2017.03.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 03/08/2017] [Indexed: 12/11/2022]
Abstract
The p21-activated kinases (Paks) interact with Rac/Cdc42 GTPases to regulate the actin cytoskeleton as well as various signaling pathways. Although activation of Paks in many human cancers is known to mediate cancer progression, the role of Pak proteins in hypoxia is poorly understood. In this study, we found that both Pak1 and Pak4 are highly expressed in HeLa cervical cancer cells, but only Pak4 knockdown attenuates expression of hypoxia-inducible factor-1α (HIF-1α) in hypoxia. We further discovered that Pak4 regulates HIF-1α translation via the Akt-mTOR-4E-BP1 pathway under hypoxic conditions. These results support a novel connection between HIF-1α and Pak4 in hypoxic cancer cells, and provide insights into mechanisms whereby tumors respond to and thrive under oxygen-deficient conditions.
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Affiliation(s)
- Hyunju Kim
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Dustin J Woo
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea; Department of Biological Chemistry, KIST Campus, University of Science and Technology (UST), Seoul 02792, Republic of Korea
| | - So Yeon Kim
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea; Department of Biomedical Engineering, KIST Campus, University of Science and Technology (UST), Seoul 02792, Republic of Korea.
| | - Eun Gyeong Yang
- Center for Theragnosis, Biomedical Research Institute, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea; Department of Biological Chemistry, KIST Campus, University of Science and Technology (UST), Seoul 02792, Republic of Korea.
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The Andes Virus Nucleocapsid Protein Directs Basal Endothelial Cell Permeability by Activating RhoA. mBio 2016; 7:mBio.01747-16. [PMID: 27795403 PMCID: PMC5080385 DOI: 10.1128/mbio.01747-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Andes virus (ANDV) predominantly infects microvascular endothelial cells (MECs) and nonlytically causes an acute pulmonary edema termed hantavirus pulmonary syndrome (HPS). In HPS patients, virtually every pulmonary MEC is infected, MECs are enlarged, and infection results in vascular leakage and highly lethal pulmonary edema. We observed that MECs infected with the ANDV hantavirus or expressing the ANDV nucleocapsid (N) protein showed increased size and permeability by activating the Rheb and RhoA GTPases. Expression of ANDV N in MECs increased cell size by preventing tuberous sclerosis complex (TSC) repression of Rheb-mTOR-pS6K. N selectively bound the TSC2 N terminus (1 to 1403) within a complex containing TSC2/TSC1/TBC1D7, and endogenous TSC2 reciprocally coprecipitated N protein from ANDV-infected MECs. TSCs normally restrict RhoA-induced MEC permeability, and we found that ANDV infection or N protein expression constitutively activated RhoA. This suggests that the ANDV N protein alone is sufficient to activate signaling pathways that control MEC size and permeability. Further, RhoA small interfering RNA, dominant-negative RhoA(N19), and the RhoA/Rho kinase inhibitors fasudil and Y27632 dramatically reduced the permeability of ANDV-infected MECs by 80 to 90%. Fasudil also reduced the bradykinin-directed permeability of ANDV and Hantaan virus-infected MECs to control levels. These findings demonstrate that ANDV activation of RhoA causes MEC permeability and reveal a potential edemagenic mechanism for ANDV to constitutively inhibit the basal barrier integrity of infected MECs. The central importance of RhoA activation in MEC permeability further suggests therapeutically targeting RhoA, TSCs, and Rac1 as potential means of resolving capillary leakage during hantavirus infections. HPS is hallmarked by acute pulmonary edema, hypoxia, respiratory distress, and the ubiquitous infection of pulmonary MECs that occurs without disrupting the endothelium. Mechanisms of MEC permeability and targets for resolving lethal pulmonary edema during HPS remain enigmatic. Our findings suggest a novel underlying mechanism of MEC dysfunction resulting from ANDV activation of the Rheb and RhoA GTPases that, respectively, control MEC size and permeability. Our studies show that inhibition of RhoA blocks ANDV-directed permeability and implicate RhoA as a potential therapeutic target for restoring capillary barrier function to the ANDV-infected endothelium. Since RhoA activation forms a downstream nexus for factors that cause capillary leakage, blocking RhoA activation is liable to restore basal capillary integrity and prevent edema amplified by tissue hypoxia and respiratory distress. Targeting the endothelium has the potential to resolve disease during symptomatic stages, when replication inhibitors lack efficacy, and to be broadly applicable to other hemorrhagic and edematous viral diseases.
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17
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Shahjouei S, Ansari S, Pourmotabbed T, Zand R. Potential Roles of Adropin in Central Nervous System: Review of Current Literature. Front Mol Biosci 2016; 3:25. [PMID: 27446928 PMCID: PMC4921473 DOI: 10.3389/fmolb.2016.00025] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/27/2016] [Indexed: 01/04/2023] Open
Abstract
Adropin is a 4.9 kDa peptide that is important for maintenance of metabolic and non-metabolic homeostasis. It regulates glucose and fatty acid metabolism and is involved in endothelial cell function and endothelial nitric oxide (NO) synthase bioactivity as well as physical activity and motor coordination. Adropin is expressed in many tissues and organs including central nervous system (CNS). This peptide plays a crucial role in the development of various CNS disorders such as stroke, schizophrenia, bipolar disorder as well as Alzheimer's, Parkinson's, and Huntington's diseases. In this comprehensive review, the potential roles of adropin in cellular signaling pathways that lead to pathogenesis and/or treatment of CNS disorders will be discussed.
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Affiliation(s)
- Shima Shahjouei
- Department of Neurosurgery, Tehran University of Medical Sciences Tehran, Iran
| | - Saeed Ansari
- Department of Neurology, University of Tennessee Health Science Center Memphis, TN, USA
| | - Tayebeh Pourmotabbed
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center Memphis, TN, USA
| | - Ramin Zand
- Department of Neurology, University of Tennessee Health Science CenterMemphis, TN, USA; Biocomplexity Institute, Virginia Polytechnic Institute and State UniversityBlacksburg, VA, USA
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18
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MicroRNAs in Hyperglycemia Induced Endothelial Cell Dysfunction. Int J Mol Sci 2016; 17:518. [PMID: 27070575 PMCID: PMC4848974 DOI: 10.3390/ijms17040518] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 03/17/2016] [Accepted: 03/22/2016] [Indexed: 01/15/2023] Open
Abstract
Hyperglycemia is closely associated with prediabetes and Type 2 Diabetes Mellitus. Hyperglycemia increases the risk of vascular complications such as diabetic retinopathy, diabetic nephropathy, peripheral vascular disease and cerebro/cardiovascular diseases. Under hyperglycemic conditions, the endothelial cells become dysfunctional. In this study, we investigated the miRNA expression changes in human umbilical vein endothelial cells exposed to different glucose concentrations (5, 10, 25 and 40 mM glucose) and at various time intervals (6, 12, 24 and 48 h). miRNA microarray analyses showed that there is a correlation between hyperglycemia induced endothelial dysfunction and miRNA expression. In silico pathways analyses on the altered miRNA expression showed that the majority of the affected biological pathways appeared to be associated to endothelial cell dysfunction and apoptosis. We found the expression of ten miRNAs (miR-26a-5p, -26b-5p, 29b-3p, -29c-3p, -125b-1-3p, -130b-3p, -140-5p, -192-5p, -221-3p and -320a) to increase gradually with increasing concentration of glucose. These miRNAs were also found to be involved in endothelial dysfunction. At least seven of them, miR-29b-3p, -29c-3p, -125b-1-3p, -130b-3p, -221-3p, -320a and -192-5p, can be correlated to endothelial cell apoptosis.
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19
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Ohashi T, Sugaya Y, Sakamoto N, Sato M. Relative contribution of physiological hydrostatic pressure and fluid shear stress to endothelial monolayer integrity. Biomed Eng Lett 2016. [DOI: 10.1007/s13534-016-0210-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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20
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Ma T, Xue YX. MiRNA-200b Regulates RMP7-Induced Increases in Blood-Tumor Barrier Permeability by Targeting RhoA and ROCKII. Front Mol Neurosci 2016; 9:9. [PMID: 26903801 PMCID: PMC4742559 DOI: 10.3389/fnmol.2016.00009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 01/18/2016] [Indexed: 12/20/2022] Open
Abstract
The primary goals of this study were to investigate the potential roles of miR-200b in regulating RMP7-induced increases in blood-tumor barrier (BTB) permeability and some of the possible molecular mechanisms associated with this effect. Microarray analysis revealed 34 significantly deregulated miRNAs including miR-200b in the BTB as induced by RMP7 and 8 significantly up-regulated miRNAs in the BTB by RMP7. RMP7 induced tight junction (TJ) opening of the BTB, thereby increasing BTB permeability. Associated with this effect of RMP7 was a decrease in miR-200b expression within the human cerebral microvascular endothelial cells line hCMEC/D3 (ECs) of the BTB. Overexpression of miR-200b inhibited endothelial leakage and restored normal transendothelial electric resistance values. A simultaneous shift in occludin and claudin-5 distributions from insoluble to soluble fractions were observed to be significantly reduced. In addition, overexpression of miR-200b inhibited the relocation of occludin and claudin-5 from cellular borders into the cytoplasm as well as the production of stress fiber formation in GECs (ECs with U87 glioma cells co-culturing) of the BTB. MiR-200b silencing produced opposite results as that obtained from that of the miR-200b overexpression group. Overexpression of miR-200b was also associated with a down-regulation in RhoA and ROCKII expression, concomitant with a decrease in BTB permeability. Again, results which were opposite to that obtained with the miR-200b silencing group. We further found that miR-200b regulated BTB permeability by directly targeting RhoA and ROCKII. Collectively, these results suggest that miR-200b's contribution to the RMP7-induced increase in BTB permeability was associated with stress fiber formation and TJ disassembly as achieved by directly targeting RhoA and ROCKII.
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Affiliation(s)
- Teng Ma
- Department of Neurobiology, College of Basic Medicine, China Medical UniversityShenyang, China; Institute of Pathology and Pathophysiology, China Medical UniversityShenyang, China
| | - Yi-Xue Xue
- Department of Neurobiology, College of Basic Medicine, China Medical UniversityShenyang, China; Institute of Pathology and Pathophysiology, China Medical UniversityShenyang, China
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21
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Compound C inhibits in vitro angiogenesis and ameliorates thrombin-induced endothelial barrier failure. Eur J Pharmacol 2015; 768:165-72. [DOI: 10.1016/j.ejphar.2015.10.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/05/2015] [Accepted: 10/27/2015] [Indexed: 01/11/2023]
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22
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p21-Activated Kinase 2 Regulates Endothelial Development and Function through the Bmk1/Erk5 Pathway. Mol Cell Biol 2015; 35:3990-4005. [PMID: 26391956 DOI: 10.1128/mcb.00630-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/08/2015] [Indexed: 02/03/2023] Open
Abstract
p21-activated kinases (Paks) have been shown to regulate cytoskeleton rearrangements, cell proliferation, attachment, and migration in a variety of cellular contexts, including endothelial cells. However, the role of endothelial Pak in embryo development has not been reported, and currently, there is no consensus on the endothelial function of individual Pak isoforms, in particular p21-activated kinase 2 (Pak2), the main Pak isoform expressed in endothelial cells. In this work, we employ genetic and molecular studies that show that Pak2, but not Pak1, is a critical mediator of development and maintenance of endothelial cell function. Endothelial depletion of Pak2 leads to early embryo lethality due to flawed blood vessel formation in the embryo body and yolk sac. In adult endothelial cells, Pak2 depletion leads to severe apoptosis and acute angiogenesis defects, and in adult mice, endothelial Pak2 deletion leads to increased vascular permeability. Furthermore, ubiquitous Pak2 deletion is lethal in adult mice. We show that many of these defects are mediated through a newly unveiled Pak2/Bmk1 pathway. Our results demonstrate that endothelial Pak2 is essential during embryogenesis and also for adult blood vessel maintenance, and they also pinpoint the Bmk1/Erk5 pathway as a critical mediator of endothelial Pak2 signaling.
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Capillaries in the olfactory bulb but not the cortex are highly susceptible to virus-induced vascular leak and promote viral neuroinvasion. Acta Neuropathol 2015; 130:233-45. [PMID: 25956408 DOI: 10.1007/s00401-015-1433-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 04/21/2015] [Accepted: 04/23/2015] [Indexed: 01/18/2023]
Abstract
Viral neuroinvasion is a critical step in the pathogenesis of viral encephalitis. Multiple mechanisms of neuroinvasion have been identified, but their relative contribution to central nervous system (CNS) infection remains unclear for many viruses. In this study, we examined neuroinvasion of the mosquito-borne bunyavirus La Crosse (LACV), the leading cause of pediatric viral encephalitis in the USA. We found that the olfactory bulb (OB) and tract were the initial areas of CNS virus infection in mice. Removal of the OB reduced the incidence of LACV-induced disease demonstrating the importance of this area to neuroinvasion. However, we determined that infection of the OB was not due to axonal transport of virus from olfactory sensory neurons as ablation of these cells did not affect viral pathogenesis. Instead, we found that OB capillaries were compromised allowing leakage of virus-sized particles into the brain. Analysis of OB capillaries demonstrated specific alterations in cytoskeletal and Rho GTPase protein expression not observed in capillaries from other brain areas such as the cortex where leakage did not occur. Collectively, these findings indicate that LACV neuroinvasion occurs through hematogenous spread in specific brain regions where capillaries are prone to virus-induced activation such as the OB. Capillaries in these areas may be "hot spots" that are more susceptible to neuroinvasion not only for LACV, but other neurovirulent viruses as well.
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Wu JR, Kao LP, Wu BN, Dai ZK, Wang YY, Chai CY, Chen IJ. Buffered l-ascorbic acid, alone or bound to KMUP-1 or sildenafil, reduces vascular endothelium growth factor and restores endothelium nitric oxide synthase in hypoxic pulmonary artery. Kaohsiung J Med Sci 2015; 31:241-54. [PMID: 25910559 DOI: 10.1016/j.kjms.2015.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 01/28/2015] [Accepted: 01/30/2015] [Indexed: 12/26/2022] Open
Abstract
Ascorbic acid bound to KMUP-1 and sildenafil were examined for their antioxidant effects on vascular endothelium growth factor (VEGF) and endothelium nitric oxide synthase (eNOS) in hypoxic pulmonary artery (PA). Inhaled KMUP-1 and oral sildenafil released NO from eNOS. The effect of buffered l-ascorbic acid, alone and bound to KMUP-1 or sildenafil, for treating pulmonary arterial hypertension (PAH) is unclear. In this study, the antioxidant capacity of ascorbic acid increased the beneficial effects of KMUP-1 on PAH. KMUP-1A and sildenafil-A (5 mg/kg/d) were administered to hypoxic PAH rats. Pulmonary artery blood pressure, and VEGF, Rho kinase II (ROCK II), eNOS, soluble guanylate cyclase (sGC-α), and protein kinase G expression in lung tissues were measured to link PAH and right ventricular hypertrophy. Hypoxic rats had higher pulmonary artery blood pressure, greater PA medial wall thickness and cardiac weight, and a higher right ventricle/left ventricle + septum [RV/(LV+S)] ratio than normoxic rats. Oral KMUP-1A or sildenafil-A for 21 days in hypoxia prevented the rarefaction of eNOS in immunohistochemistry (IHC), reduced the IHC of VEGF in PAs, restored eNOS/protein kinase G/phosphodiesterase 5A; unaffected sGC-α and inactivated ROCK II expression were also found in lung tissues. In normoxic PA, KMUP-1A/Y27632 (10μM) increased eNOS and reduced ROCK II. ROCK II/reactive oxidative species was increased and eNOS was reduced after long-term hypoxia for 21 days. KMUP-1A or Y27632 blunted ROCK II in short-term hypoxic PA at 24 hours. l-Ascorbic acid + l-sodium ascorbate (40, 80μM) buffer alone directly inhibited the IHC of VEGF in hypoxic PA. Finally, KMUP-1A or sildenafil-A reduced PAH and associated right ventricular hypertrophy.
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Affiliation(s)
- Jiunn-Ren Wu
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Li-Pin Kao
- Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Bin-Nan Wu
- Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Zen-Kong Dai
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Ya Wang
- Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chee-Yin Chai
- Department of Pathology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Ing-Jun Chen
- Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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25
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Fediuk J, Sikarwar AS, Nolette N, Dakshinamurti S. Thromboxane-induced actin polymerization in hypoxic neonatal pulmonary arterial myocytes involves Cdc42 signaling. Am J Physiol Lung Cell Mol Physiol 2014; 307:L877-87. [DOI: 10.1152/ajplung.00036.2014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In hypoxic pulmonary arterial (PA) myocytes, challenge with thromboxane mimetic U46619 induces marked actin polymerization and contraction, phenotypic features of persistent pulmonary hypertension of the newborn (PPHN). Rho GTPases regulate the actin cytoskeleton. We previously reported that U46619-induced actin polymerization in hypoxic PA myocytes occurs independently of the RhoA pathway and hypothesized involvement of the Cdc42 pathway. PA myocytes grown in normoxia or hypoxia for 72 h were stimulated with U46619, then analyzed for Rac/Cdc42 activation by affinity precipitation, phosphatidylinositide-3-kinase (PI3K) activity by phospho-Akt, phospho-p21-activated kinase (PAK) by immunoblot, and association of Cdc42 with neuronal Wiskott Aldrich Syndrome protein (N-WASp) by immunoprecipitation. The effect of Rac or PAK inhibition on filamentous actin was quantified by laser-scanning cytometry and by cytoskeletal fractionation; effects of actin-modifying agents were measured by isometric myography. Basal Cdc42 activity increased in hypoxia, whereas Rac activity decreased. U46619 challenge increased Cdc42 and Rac activity in hypoxic cells, independently of PI3K. Hypoxia increased phospho-PAK, unaltered by U46619. Association of Cdc42 with N-WASp decreased in hypoxia but increased after U46619 exposure. Hypoxia doubled filamentous-to-globular ratios of α- and γ-actin isoforms. Jasplakinolide stabilized γ-filaments, increasing force; cytochalasin D depolymerized all actin isoforms, decreasing force. Rac and PAK inhibition decreased filamentous actin in tissues although without decrease in force. Rho inhibition decreased myosin phosphorylation and force. Hypoxia induces actin polymerization in PA myocytes, particularly increasing filamentous α- and γ-actin, contributing to U46619-induced contraction. Hypoxic PA myocytes challenged with a thromboxane mimetic polymerize actin via the Cdc42 pathway, reflecting increased Cdc42 association with N-WASp. Mechanisms regulating thromboxane-mediated actin polymerization are potential targets for future PPHN pharmacotherapy.
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Affiliation(s)
- Jena Fediuk
- Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
- Department of Physiology University of Manitoba, Winnipeg, Manitoba, Canada
| | - Anurag S. Sikarwar
- Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
- Department of Physiology University of Manitoba, Winnipeg, Manitoba, Canada
| | - Nora Nolette
- Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
| | - Shyamala Dakshinamurti
- Biology of Breathing Group, Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
- Department of Physiology University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Pediatrics, University of Manitoba, Winnipeg, Manitoba, Canada
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Wu F, Szczepaniak WS, Shiva S, Liu H, Wang Y, Wang L, Wang Y, Kelley EE, Chen AF, Gladwin MT, McVerry BJ. Nox2-dependent glutathionylation of endothelial NOS leads to uncoupled superoxide production and endothelial barrier dysfunction in acute lung injury. Am J Physiol Lung Cell Mol Physiol 2014; 307:L987-97. [PMID: 25326583 DOI: 10.1152/ajplung.00063.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Microvascular barrier integrity is dependent on bioavailable nitric oxide (NO) produced locally by endothelial NO synthase (eNOS). Under conditions of limited substrate or cofactor availability or by enzymatic modification, eNOS may become uncoupled, producing superoxide in lieu of NO. This study was designed to investigate how eNOS-dependent superoxide production contributes to endothelial barrier dysfunction in inflammatory lung injury and its regulation. C57BL/6J mice were challenged with intratracheal LPS. Bronchoalveolar lavage fluid was analyzed for protein accumulation, and lung tissue homogenate was assayed for endothelial NOS content and function. Human lung microvascular endothelial cell (HLMVEC) monolayers were exposed to LPS in vitro, and barrier integrity and superoxide production were measured. Biopterin species were quantified, and coimmunoprecipitation (Co-IP) assays were performed to identify protein interactions with eNOS that putatively drive uncoupling. Mice exposed to LPS demonstrated eNOS-dependent increased alveolar permeability without evidence for altered canonical NO signaling. LPS-induced superoxide production and permeability in HLMVEC were inhibited by the NOS inhibitor nitro-l-arginine methyl ester, eNOS-targeted siRNA, the eNOS cofactor tetrahydrobiopterin, and superoxide dismutase. Co-IP indicated that LPS stimulated the association of eNOS with NADPH oxidase 2 (Nox2), which correlated with augmented eNOS S-glutathionylation both in vitro and in vivo. In vitro, Nox2-specific inhibition prevented LPS-induced eNOS modification and increases in both superoxide production and permeability. These data indicate that eNOS uncoupling contributes to superoxide production and barrier dysfunction in the lung microvasculature after exposure to LPS. Furthermore, the results implicate Nox2-mediated eNOS-S-glutathionylation as a mechanism underlying LPS-induced eNOS uncoupling in the lung microvasculature.
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Affiliation(s)
- Feng Wu
- University of Pittsburgh School of Medicine Department of Medicine, Division of Pulmonary Allergy and Critical Care Medicine, Pittsburgh, Pennsylvania
| | - William S Szczepaniak
- University of Pittsburgh School of Medicine Department of Medicine, Division of Pulmonary Allergy and Critical Care Medicine, Pittsburgh, Pennsylvania
| | - Sruti Shiva
- University of Pittsburgh Vascular Medicine Institute, Pittsburgh, Pennsylvania; University of Pittsburgh School of Medicine Department of Pharmacology, Pittsburgh, Pennsylvania
| | - Huanbo Liu
- University of Pittsburgh School of Medicine Department of Surgery, Pittsburgh, Pennsylvania
| | - Yinna Wang
- University of Pittsburgh Vascular Medicine Institute, Pittsburgh, Pennsylvania
| | - Ling Wang
- University of Pittsburgh Vascular Medicine Institute, Pittsburgh, Pennsylvania
| | - Ying Wang
- University of Pittsburgh School of Medicine Department of Medicine, Division of Pulmonary Allergy and Critical Care Medicine, Pittsburgh, Pennsylvania
| | - Eric E Kelley
- University of Pittsburgh Vascular Medicine Institute, Pittsburgh, Pennsylvania; University of Pittsburgh School of Medicine Department of Anesthesiology, Pittsburgh, Pennsylvania
| | - Alex F Chen
- University of Pittsburgh Vascular Medicine Institute, Pittsburgh, Pennsylvania; University of Pittsburgh School of Medicine Department of Surgery, Pittsburgh, Pennsylvania
| | - Mark T Gladwin
- University of Pittsburgh School of Medicine Department of Medicine, Division of Pulmonary Allergy and Critical Care Medicine, Pittsburgh, Pennsylvania; University of Pittsburgh Vascular Medicine Institute, Pittsburgh, Pennsylvania
| | - Bryan J McVerry
- University of Pittsburgh School of Medicine Department of Medicine, Division of Pulmonary Allergy and Critical Care Medicine, Pittsburgh, Pennsylvania; University of Pittsburgh Vascular Medicine Institute, Pittsburgh, Pennsylvania;
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Duluc L, Wojciak-Stothard B. Rho GTPases in the regulation of pulmonary vascular barrier function. Cell Tissue Res 2014; 355:675-85. [PMID: 24599334 DOI: 10.1007/s00441-014-1805-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 01/10/2014] [Indexed: 12/12/2022]
Abstract
Pulmonary endothelial permeability is an important determinant of vascular adaptation to changes in oxygen tension, blood pressure, levels of growth factors or inflammatory cytokines. The Ras homologous (Rho) family of guanosine triphosphate phosphatases (Rho GTPases), key regulators of the actin cytoskeleton, regulate endothelial barrier function in response to a variety of environmental factors and signalling agents via the reorganization of the actin cytoskeleton, changes in receptor trafficking or the phosphorylation of junctional proteins. This review provides a brief summary of recent knowledge on Rho-GTPase-mediated effects on pulmonary endothelial barrier function and focuses in particular on their role in pulmonary vascular disorders, including pulmonary hypertension, chronic obstructive pulmonary disease, acute lung injury and acute respiratory distress syndrome.
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Affiliation(s)
- Lucie Duluc
- Centre for Pharmacology & Therapeutics, Imperial College London, London, UK
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Xiang L, Lu S, Mittwede PN, Clemmer JS, Hester RL. Inhibition of NADPH oxidase prevents acute lung injury in obese rats following severe trauma. Am J Physiol Heart Circ Physiol 2014; 306:H684-9. [PMID: 24414071 DOI: 10.1152/ajpheart.00868.2013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Lung capillary filtration coefficient (Kf) and impacts of oxidative stress have not been determined in the setting of severe trauma, especially in obese patients who exhibit increased lung injury. We hypothesized that severe trauma leads to a greater increase in lung Kf in obesity due to exacerbated production of and/or vulnerability to oxidative stress. Severe trauma was induced in lean and obese Zucker rats by muscle injury, fibula fracture, and bone component injection to both hindlimbs, with or without 24-h treatments of apocynin, a NADPH oxidase (NOX) inhibitor. Lung wet/dry weight ratios, lung vascular Kf, lung neutrophil counts, lung NOX and myeloperoxidase (MPO) activity, and plasma IL-6 levels were measured 24 h after trauma. In an additional study, lungs were isolated from nontrauma lean and obese rats to determine the acute effect of phenazime methosulfate, a superoxide donor, on pulmonary vascular Kf. After trauma, compared with lean rats, obese rats exhibited greater increases in lung capillary Kf, neutrophil accumulation, NOX and MPO activity, and plasma IL-6. The lung wet/dry weight ratio was increased in obese rats but not in lean rats. Apocynin treatment decreased lung Kf, neutrophil counts, NOX and MPO activities, wet/dry weight ratio, and plasma IL-6 in obese rats. Phenazime methosulfate treatment resulted in a greater increase in lung Kf in nontrauma obese rats compared with nontrauma lean rats. These results suggest that obese rats are susceptible to lung injury following severe trauma due to increased production of and responsiveness to pulmonary oxidative stress.
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Affiliation(s)
- Lusha Xiang
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
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Abstract
p21-Activated kinases (PAKs) are positioned at the nexus of several oncogenic signalling pathways. Overexpression or mutational activation of PAK isoforms frequently occurs in various human tumours, and recent data suggest that excessive PAK activity drives many of the cellular processes that are the hallmarks of cancer. In this Review, we discuss the mechanisms of PAK activation in cancer, the key substrates that mediate the developmental and oncogenic effects of this family of kinases, and how small-molecule inhibitors of these enzymes might be best developed and deployed for the treatment of cancer.
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Affiliation(s)
- Maria Radu
- Cancer Biology Program; Fox Chase Cancer Center; Philadelphia, PA, USA
| | - Galina Semenova
- Cancer Biology Program; Fox Chase Cancer Center; Philadelphia, PA, USA
| | - Rachelle Kosoff
- Cancer Biology Program; Fox Chase Cancer Center; Philadelphia, PA, USA
- Cancer Biology program, University of Pennsylvania, Philadelphia, PA, USA
| | - Jonathan Chernoff
- Cancer Biology Program; Fox Chase Cancer Center; Philadelphia, PA, USA
- To whom correspondence should be addressed: Jonathan Chernoff, Cancer Biology Program, Fox Chase Cancer Center, 333 Cottman Ave, Philadelphia, PA 19111, USA, Tel.: (215) 728 5319; Fax: (215) 728 3616;
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Weidemann A, Breyer J, Rehm M, Eckardt KU, Daniel C, Cicha I, Giehl K, Goppelt-Struebe M. HIF-1α activation results in actin cytoskeleton reorganization and modulation of Rac-1 signaling in endothelial cells. Cell Commun Signal 2013; 11:80. [PMID: 24144209 PMCID: PMC3895861 DOI: 10.1186/1478-811x-11-80] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 10/10/2013] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Hypoxia is a major driving force in vascularization and vascular remodeling. Pharmacological inhibition of prolyl hydroxylases (PHDs) leads to an oxygen-independent and long-lasting activation of hypoxia-inducible factors (HIFs). Whereas effects of HIF-stabilization on transcriptional responses have been thoroughly investigated in endothelial cells, the molecular details of cytoskeletal changes elicited by PHD-inhibition remain largely unknown. To investigate this important aspect of PHD-inhibition, we used a spheroid-on-matrix cell culture model. RESULTS Microvascular endothelial cells (glEND.2) were organized into spheroids. Migration of cells from the spheroids was quantified and analyzed by immunocytochemistry. The PHD inhibitor dimethyloxalyl glycine (DMOG) induced F-actin stress fiber formation in migrating cells, but only weakly affected microvascular endothelial cells firmly attached in a monolayer. Compared to control spheroids, the residual spheroids were larger upon PHD inhibition and contained more cells with tight VE-cadherin positive cell-cell contacts. Morphological alterations were dependent on stabilization of HIF-1α and not HIF-2α as shown in cells with stable knockdown of HIF-α isoforms. DMOG-treated endothelial cells exhibited a reduction of immunoreactive Rac-1 at the migrating front, concomitant with a diminished Rac-1 activity, whereas total Rac-1 protein remained unchanged. Two chemically distinct Rac-1 inhibitors mimicked the effects of DMOG in terms of F-actin fiber formation and orientation, as well as stabilization of residual spheroids. Furthermore, phosphorylation of p21-activated kinase PAK downstream of Rac-1 was reduced by DMOG in a HIF-1α-dependent manner. Stabilization of cell-cell contacts associated with decreased Rac-1 activity was also confirmed in human umbilical vein endothelial cells. CONCLUSIONS Our data demonstrates that PHD inhibition induces HIF-1α-dependent cytoskeletal remodeling in endothelial cells, which is mediated essentially by a reduction in Rac-1 signaling.
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Affiliation(s)
| | | | | | | | | | | | | | - Margarete Goppelt-Struebe
- Department of Nephrology and Hypertension, Universitätsklinikum Erlangen, Universität Erlangen-Nürnberg, Loschgestrasse 8, 91054 Erlangen, Germany.
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Solodushko V, Khader HA, Fouty BW. Serum can overcome contact inhibition in confluent human pulmonary artery smooth muscle cells. PLoS One 2013; 8:e71490. [PMID: 23940764 PMCID: PMC3735496 DOI: 10.1371/journal.pone.0071490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 07/06/2013] [Indexed: 11/18/2022] Open
Abstract
Pulmonary artery endothelial cells (PAEC) in an intact vessel are continually exposed to serum, but unless injured, do not proliferate, constrained by confluence. In contrast, pulmonary artery smooth muscle cells (PASMC) attain, and maintain, confluence in the presence of minimal serum, protected from serum's stimulatory effects except when the endothelial barrier becomes more permeable. We hypothesized therefore, that confluent PASMC may be less constrained by contact inhibition in the presence of serum than PAEC and tested this idea by exposing confluent non-transformed human PAEC and PASMC to media containing increasing concentrations of fetal bovine serum (FBS) and determining cell growth over 7 days. PAEC that had attained confluence in low serum did not proliferate even when exposed to 5% serum, the highest concentration tested. In contrast, PASMC that attained confluence in low serum did proliferate once serum levels were increased, an effect that was dose dependent. Consistent with this observation, PASMC had more BrdU incorporation and a greater percentage of cells in S phase in 5% compared to 0.2% FBS, whereas no such difference was seen in PAEC. These results suggest that confluent human PAEC are resistant to the stimulatory effects of serum, whereas confluent PASMC can proliferate when serum levels are increased, an effect mediated in part by differences in phosphoinositide 3-kinase activation. This observation may be relevant to understanding the PASMC hyperplasia observed in humans and animals with pulmonary hypertension in which changes in endothelial permeability due to hypoxia or injury expose the underlying smooth muscle to serum.
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MESH Headings
- Cell Proliferation/drug effects
- Cells, Cultured
- Contact Inhibition/drug effects
- Culture Media/pharmacology
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiology
- Humans
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/physiology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/physiology
- Oncogene Protein v-akt/metabolism
- Pulmonary Artery/cytology
- Pulmonary Artery/drug effects
- Pulmonary Artery/physiology
- Retinoblastoma Protein/metabolism
- Serum/physiology
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Affiliation(s)
- Victor Solodushko
- Center for Lung Biology, University of South Alabama School of Medicine, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama School of Medicine, Mobile, Alabama, United States of America
| | - Heba A. Khader
- Department of Pharmacology, University of South Alabama School of Medicine, Mobile, Alabama, United States of America
| | - Brian W. Fouty
- Center for Lung Biology, University of South Alabama School of Medicine, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama School of Medicine, Mobile, Alabama, United States of America
- Department of Medicine/Division of Pulmonary and Critical Care Medicine, University of South Alabama School of Medicine, Mobile, Alabama, United States of America
- * E-mail:
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32
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Yang Y, Chen D, Yuan Z, Fang F, Cheng X, Xia J, Fang M, Xu Y, Gao Y. Megakaryocytic leukemia 1 (MKL1) ties the epigenetic machinery to hypoxia-induced transactivation of endothelin-1. Nucleic Acids Res 2013; 41:6005-17. [PMID: 23625963 PMCID: PMC3695508 DOI: 10.1093/nar/gkt311] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Increased synthesis of endothelin-1 (ET-1) by human vascular endothelial cells (HVECs) in response to hypoxia underscores persistent vasoconstriction observed in patients with pulmonary hypertension. The molecular mechanism whereby hypoxia stimulates ET-1 gene transcription is not well understood. Here we report that megakaryocytic leukemia 1 (MKL1) potentiated hypoxia-induced ET-1 transactivation in HVECs. Disruption of MKL1 activity by either a dominant negative mutant or small interfering RNA mediated knockdown dampened ET-1 synthesis. MKL1 was recruited to the proximal ET-1 promoter region (−81/+150) in HVECs challenged with hypoxic stress by the sequence-specific transcription factor serum response factor (SRF). Depletion of SRF blocked MKL1 recruitment and blunted ET-1 transactivation by hypoxia. Chromatin immunoprecipitation analysis of the ET-1 promoter revealed that MKL1 loss-of-function erased histone modifications consistent with transcriptional activation. In addition, MKL1 was indispensable for the occupancy of Brg1 and Brm, key components of the chromatin remodeling complex, on the ET-1 promoter. Brg1 and Brm modulated ET-1 transactivation by impacting histone modifications. In conclusion, our data have delineated a MKL1-centered complex that links epigenetic maneuverings to ET-1 transactivation in HVECs under hypoxic conditions.
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Affiliation(s)
- Yuyu Yang
- Key Laboratory of Cardiovascular Disease, Nanjing Medical University, Nanjing, Jiangsu 210029, China
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33
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Umapathy SN, Kaczmarek E, Fatteh N, Burns N, Lucas R, Stenmark KR, Verin AD, Gerasimovskaya EV. Adenosine A1 receptors promote vasa vasorum endothelial cell barrier integrity via Gi and Akt-dependent actin cytoskeleton remodeling. PLoS One 2013; 8:e59733. [PMID: 23613714 PMCID: PMC3628712 DOI: 10.1371/journal.pone.0059733] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 02/21/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND In a neonatal model of hypoxic pulmonary hypertension, a dramatic pulmonary artery adventitial thickening, accumulation of inflammatory cells in the adventitial compartment, and angiogenic expansion of the vasa vasorum microcirculatory network are observed. These pathophysiological responses suggest that rapidly proliferating vasa vasorum endothelial cells (VVEC) may exhibit increased permeability for circulating blood cells and macromolecules. However, the molecular mechanisms underlying these observations remain unexplored. Some reports implicated extracellular adenosine in the regulation of vascular permeability under hypoxic and inflammatory conditions. Thus, we aimed to determine the role of adenosine in barrier regulation of VVEC isolated from the pulmonary arteries of normoxic (VVEC-Co) or chronically hypoxic (VVEC-Hyp) neonatal calves. PRINCIPAL FINDINGS We demonstrate via a transendothelial electrical resistance measurement that exogenous adenosine significantly enhanced the barrier function in VVEC-Co and, to a lesser extent, in VVEC-Hyp. Our data from a quantitative reverse transcription polymerase chain reaction show that both VVEC-Co and VVEC-Hyp express all four adenosine receptors (A1, A2A, A2B, and A3), with the highest expression level of A1 receptors (A1Rs). However, A1R expression was significantly lower in VVEC-Hyp compared to VVEC-Co. By using an A1R-specific agonist/antagonist and siRNA, we demonstrate that A1Rs are mostly responsible for adenosine-induced enhancement in barrier function. Adenosine-induced barrier integrity enhancement was attenuated by pretreatment of VVEC with pertussis toxin and GSK690693 or LY294002, suggesting the involvement of Gi proteins and the PI3K-Akt pathway. Moreover, we reveal a critical role of actin cytoskeleton in VVEC barrier regulation by using specific inhibitors of actin and microtubule polymerization. Further, we show that adenosine pretreatment blocked the tumor necrosis factor alpha (TNF-α)-induced permeability in VVEC-Co, validating its anti-inflammatory effects. CONCLUSIONS We demonstrate for the first time that stimulation of A1Rs enhances the barrier function in VVEC by activation of the Gi/PI3K/Akt pathway and remodeling of actin microfilament.
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Lyberopoulou A, Mylonis I, Papachristos G, Sagris D, Kalousi A, Befani C, Liakos P, Simos G, Georgatsou E. MgcRacGAP, a cytoskeleton regulator, inhibits HIF-1 transcriptional activity by blocking its dimerization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1378-87. [PMID: 23458834 DOI: 10.1016/j.bbamcr.2013.02.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 02/19/2013] [Accepted: 02/21/2013] [Indexed: 01/22/2023]
Abstract
Hypoxia inducible factor-1 (HIF-1), a dimeric transcription factor of the bHLH-PAS family, is comprised of HIF-1α, which is inducible by hypoxia and ARNT or HIF-1β, which is constitutively expressed. HIF-1 is involved in cellular homeostasis under hypoxia, in development and in several diseases affected by oxygen availability, particularly cancer. Since its expression is positively correlated with poor outcome prognosis for cancer patients, HIF-1 is a target for pharmaceutical therapy. We have previously shown that male germ cell Rac GTPase activating protein (MgcRacGAP), a regulator of Rho proteins which are principally involved in cytoskeletal organization, binds to HIF-1α and inhibits its transcriptional activity. In this work, we have explored the mechanism of the MgcRacGAP-mediated HIF-1 inactivation. We show that the Myo domain of MgcRacGAP, which is both necessary and sufficient for HIF-1 repression, binds to the PAS-B domain of HIF-1α. Furthermore MgcRacGAP competes with ARNT for binding to the HIF-1α PAS-B domain, as shown by in vitro binding pull down assays. In mammalian cells, ARNT overexpression can overcome the MgcRacGAP-mediated inhibition and MgcRacGAP binding to HIF-1α in vivo inhibits its dimerization with ARNT. We additionally present results indicating that MgcRacGAP binding to HIF-1α is specific, since it does not affect the transcriptional activity of HIF-2, a close evolutionary relative of HIF-1 also involved in hypoxia regulation and cancer. Our results reveal a new mechanism for HIF-1 transcriptional activity regulation, suggest a novel hypoxia-cytoskeleton link and provide new tools for selective HIF-1 inhibition.
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35
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Abbasi T, Garcia JGN. Sphingolipids in lung endothelial biology and regulation of vascular integrity. Handb Exp Pharmacol 2013:201-26. [PMID: 23563658 DOI: 10.1007/978-3-7091-1511-4_10] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Of the multiple and diverse homeostatic events that involve the lung vascular endothelium, participation in preserving vascular integrity and therefore organ function is paramount. We were the first to show that the lipid growth factor and angiogenic factor, sphingosine-1-phosphate, is a critical agonist involved in regulation of human lung vascular barrier function (Garcia et al. J Clin Invest, 2011). Utilizing both in vitro models and preclinical murine, rat, and canine models of acute and chronic inflammatory lung injury, we have shown that S1Ps, as well as multiple S1P analogues such as FTY720 and ftysiponate, serve as protective agents limiting the disruption of the vascular EC monolayer in the pulmonary microcirculation and attenuate parenchymal accumulation of inflammatory cells and high protein containing extravasated fluid, thereby reducing interstitial and alveolar edema. The vasculo-protective mechanism of these therapeutic effects occurs via ligation of specific G-protein-coupled receptors and an intricate interplay of S1P with other factors (such as MAPKS, ROCKs, Rho, Rac1) with rearrangement of the endothelial cytoskeleton to form strong cortical actin rings in the cell periphery and enhanced cell-to-cell and cell-to-matrix tethering dynamics. This cascade leads to reinforcement of focal adhesions and paracellular junctional complexes via cadherin, paxillin, catenins, and zona occludens. S1P through its interaction with Rac and Rho influences the cytoskeletal rearrangement indicated in the later stages of angiogenesis as a stabilizing force, preventing excessive vascular permeability. These properties translate into a therapeutic potential for acute and chronic inflammatory lung injuries. S1P has potential for providing a paradigm shift in the approach to disruption of critical endothelial gatekeeper function, loss of lung vascular integrity, and increased vascular permeability, defining features of acute lung injury (ALI), and may prove to exhibit an intrinsically protective role in the pulmonary vasculature ameliorating agonist- or sepsis-induced pulmonary injury and vascular leakage.
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Affiliation(s)
- Taimur Abbasi
- Department of Medicine, The University of Illinois, Chicago, IL 60612, USA
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36
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Identification of an essential endogenous regulator of blood-brain barrier integrity, and its pathological and therapeutic implications. Proc Natl Acad Sci U S A 2012; 110:832-41. [PMID: 23277546 DOI: 10.1073/pnas.1209362110] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The blood-brain barrier (BBB), a critical guardian of communication between the periphery and the brain, is frequently compromised in neurological diseases such as multiple sclerosis (MS), resulting in the inappropriate passage of molecules and leukocytes into the brain. Here we show that the glucocorticoid anti-inflammatory messenger annexin A1 (ANXA1) is expressed in brain microvascular endothelial cells, where it regulates BBB integrity. In particular, ANXA1(-/-) mice exhibit significantly increased BBB permeability as a result of disrupted interendothelial cell tight junctions, essentially related to changes in the actin cytoskeleton, which stabilizes tight and adherens junctions. This situation is reminiscent of early MS pathology, a relationship confirmed by our detection of a selective loss of ANXA1 in the plasma and cerebrovascular endothelium of patients with MS. Importantly, this loss is swiftly restored by i.v. administration of human recombinant ANXA1. Analysis in vitro confirms that treatment of cerebrovascular endothelial cells with recombinant ANXA1 restores cell polarity, cytoskeleton integrity, and paracellular permeability through inhibition of the small G protein RhoA. We thus propose ANXA1 as a critical physiological regulator of BBB integrity and suggest it may have utility in the treatment of MS, correcting BBB function and hence ameliorating disease.
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37
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Chang JM, Hwang DY, Chen SC, Kuo MC, Hung CC, Hwang SJ, Tsai JC, Chen HC. B7-1 expression regulates the hypoxia-driven cytoskeleton rearrangement in glomerular podocytes. Am J Physiol Renal Physiol 2012; 304:F127-36. [PMID: 23019228 DOI: 10.1152/ajprenal.00108.2012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Chronic hypoxia has been recognized as a common mechanism driving the progression of many glomerular diseases. Glomerular cells, although susceptible to hypoxic injuries, are less studied to unravel the hypoxia-related influences. In the present study, we showed that both lipopolysaccharide (LPS) and hypoxia induced B7-1 and hypoxia-inducible factor (HIF)-1α expression in podocytes. B7-1, an essential player in the regulation of podocyte stress fibers, interacted directly with the NH(2)-terminal oxygenation domain of HIF-1α protein and, therefore, might interfere with the HIF-related oxidative events. The suggestion was supported by the changes in the expression of inducible nitric oxide synthase and nitric oxide. The orderly arranged stress fibers in differentiated podocytes were disrupted by either LPS or hypoxic stimulation, and the disruption could be rescued if they were brought back to normal oxygen tension. Cell motility increased with the stimulation by LPS and hypoxia, most probably mediated by the induction of B7-1 and HIF-1α, respectively. We generated a B7-1 knockdown podocyte cell line using the lentiviral small interfering RNA system. The LPS- and hypoxia-induced stress fiber disruption was largely prevented in the B7-1 knockdown podocytes. The increased cell motility by LPS and hypoxia stimulations was also ameliorated in the B7-knockdown podocytes. In summary, we found that both B7-1 and HIF were upregulated by LPS and hypoxic stimulations in podocytes and they interacted with each other. Hypoxia disrupted the abundant stress fibers and increased cell motility. These hypoxia-induced changes were prevented in B7-knockdown podocytes, and they highlighted the importance of B7-1 expression in the hypoxia-related podocyte injuries.
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Affiliation(s)
- Jer-Ming Chang
- Department of Internal Medicine, Kaohsiung Municipal Hsiao-Kango Hospital, Kaohsiung, Taiwan
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Schmit MA, Mirakaj V, Stangassinger M, König K, Köhler D, Rosenberger P. Vasodilator phosphostimulated protein (VASP) protects endothelial barrier function during hypoxia. Inflammation 2012; 35:566-73. [PMID: 21607702 PMCID: PMC3314830 DOI: 10.1007/s10753-011-9347-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The endothelial barrier controls the passage of solutes from the vascular space. This is achieved through active reorganization of the actin cytoskeleton. A central cytoskeletal protein involved into this is vasodilator-stimulated phosphoprotein (VASP). However, the functional role of endothelial VASP during hypoxia has not been thoroughly elucidated. We determined endothelial VASP expression through real-time PCR (Rt-PCR), immunhistochemistry, and Western blot analysis during hypoxia. VASP promoter studies were performed using a PGL3 firefly luciferase containing plasmid. Following approval by the local authorities, VASP ( -/- ) mice and littermate controls were subjected to normobaric hypoxia (8% O(2), 92% N(2)) after intravenous injection of Evans blue dye. In in vitro studies, we found significant VASP repression in human microvascular and human umbilical vein endothelial cells through Rt-PCR, immunhistochemistry, and Western blot analysis. The VASP promoter construct demonstrated significant repression in response to hypoxia, which was abolished when the binding of hypoxia-inducible factor 1 alpha was excluded. Exposure of wild-type (WT) and VASP ( -/- ) animals to normobaric hypoxia for 4 h resulted in an increase in Evans blue tissue extravasation that was significantly increased in VASP ( -/- ) animals compared to WT controls. In summary, we demonstrate here that endothelial VASP holds significant importance for endothelial barrier properties during hypoxia.
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Affiliation(s)
- Marthe A Schmit
- Department of Anesthesiology and Intensive Care Medicine, Tübingen University Hospital, Eberhard-Karls University Tübingen, Tübingen, Germany
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Firth AL, Choi IW, Park WS. Animal models of pulmonary hypertension: Rho kinase inhibition. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2012; 109:67-75. [PMID: 22713173 DOI: 10.1016/j.pbiomolbio.2012.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 05/17/2012] [Accepted: 05/21/2012] [Indexed: 10/28/2022]
Abstract
Pulmonary Hypertension is a terminology encompassing a range of etiologically different pulmonary vascular diseases. The most common is that termed pulmonary arterial hypertension or PAH; a rare but often fatal disease characterized by a mean pulmonary arterial pressure of >25 mmHg. PAH is associated with a complex etiology highlighted by core characteristics of increased pulmonary vascular resistance and elevation of mean pulmonary artery pressure. When sustained, pulmonary vascular remodeling occurs and eventually patients pass away due to right heart failure. Hypoxic pulmonary vasoconstriction is an early event occurring in pulmonary hypertension due to chronic exposure to hypoxia. While the underlying mechanisms of hypoxic pulmonary vasoconstriction may be controversial, a role for RhoA/Rho kinase mediated regulation of intracellular Ca(2+) has been recently identified. Further study suggests that RhoA may have an integral role in other pathophysiological processes such as cell proliferation and migration occurring in all forms of PH. Indeed Rho proteins are known to play essential roles in actin cytoskeleton organization in all eukaryotic cells and thus Rho and Rho-GTPases are implicated in fundamental cellular processes such as cellular proliferation, migration, adhesion, apoptosis and gene expression. This review focuses on providing an overview of the role of RhoA/Rho kinase in currently available animal models of pulmonary hypertension.
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Affiliation(s)
- Amy L Firth
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
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Fan XL, Liu WQ, Mao Y, Kang M. Association of HIF-1a and Tiam1 expression with tumor invasion, lymph node metastasis, and prognosis in patients with esophageal carcinoma. Shijie Huaren Xiaohua Zazhi 2012; 20:590-595. [DOI: 10.11569/wcjd.v20.i7.590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the association of expression of hypoxia inducible factor-1 alpha (HIF-1a) and T-cell lymphoma invasion and metastasis factor1 (Tiam1) with tumor invasion, lymph node metastasis, and prognosis in patients with esophageal carcinoma.
METHODS: The protein expression of HIF-1a and Tiam1 was detected by immunohistochemistry in 33 esophageal carcinoma specimens and 15 normal esophageal mucosal specimens.
RESULTS: The positive rates of HIF-1a and Tiam1 protein expression in esophageal carcinoma were significantly higher than those in normal esophageal mucosa (66.7% vs 6.7%, 72.7% vs 6.7%, both P < 0.05). High expression of HIF-1a was positively correlated with N stage (P < 0.05), while high expression of Tiam1 was positively correlated with TNM stage and N stage (both P < 0.05). The expression of HIF-1a and Tiam1 did not correlate with age, gender, tumor length or T stage. The complete effective rate and mean survival period after radiotherapy were significantly lower in HIF-1a-positive patients than in HIF-1α-negative ones (9.1% vs 63.6%, 9 months vs 25 months, both P < 0.05). The 1-, 2-, and 3-year survival rates were also significantly lower in the HIF-1a-positive group than in the HIF-1a-negative group (40.9% vs 90.9%, 13.6% vs 54.5%, 6.8% vs 36.4%), and log-rank test suggested that the difference was significant (P = 0.007). The expression of HIF-1a protein was significantly correlated with that of Tiam1 protein in esophageal carcinoma (r = 0.433, P = 0.012).
CONCLUSION: High expression of HIF-1a and Tiam1 proteins is associated with lymph node metastasis in patients with esophageal carcinoma. Overexpression of HIF-1a may be linked to resistance to radiotherapy in patients with esophageal carcinoma and may affect the efficacy of radiotherapy.
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Han J, Shuvaev VV, Muzykantov VR. Targeted interception of signaling reactive oxygen species in the vascular endothelium. Ther Deliv 2012; 3:263-76. [PMID: 22834201 PMCID: PMC5333711 DOI: 10.4155/tde.11.151] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) are implicated as injurious and as signaling agents in human maladies including inflammation, hyperoxia, ischemia-reperfusion and acute lung injury. ROS produced by the endothelium play an important role in vascular pathology. They quench, for example, nitric oxide, and mediate pro-inflammatory signaling. Antioxidant interventions targeted for the vascular endothelium may help to control these mechanisms. Animal studies have demonstrated superiority of targeting ROS-quenching enzymes catalase and superoxide dismutase to endothelial cells over nontargeted formulations. A diverse arsenal of targeted antioxidant formulations devised in the last decade shows promising results for specific quenching of endothelial ROS. In addition to alleviation of toxic effects of excessive ROS, these targeted interventions suppress pro-inflammatory mechanisms, including endothelial cytokine activation and barrier disruption. These interventions may prove useful in experimental biomedicine and, perhaps, in translational medicine.
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Affiliation(s)
- Jingyan Han
- Institute for Translational Medicine & Therapeutics & Department of Pharmacology, University of Pennsylvania School of Medicine, TRC 10–125, 3400 Civic Center Blvd, Bldg 421, Philadelphia, PA 19104–5158, USA
| | - Vladimir V Shuvaev
- Institute for Translational Medicine & Therapeutics & Department of Pharmacology, University of Pennsylvania School of Medicine, TRC 10–125, 3400 Civic Center Blvd, Bldg 421, Philadelphia, PA 19104–5158, USA
| | - Vladimir R Muzykantov
- Institute for Translational Medicine & Therapeutics & Department of Pharmacology, University of Pennsylvania School of Medicine, TRC 10–125, 3400 Civic Center Blvd, Bldg 421, Philadelphia, PA 19104–5158, USA
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Fang X, Ueno M, Yamashita T, Ikuno Y. RhoA Activation and Effect of Rho-kinase Inhibitor in the Development of Retinal Neovascularization in a Mouse Model of Oxygen-induced Retinopathy. Curr Eye Res 2011; 36:1028-36. [DOI: 10.3109/02713683.2011.593110] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Johnson J, Loyd J, West J. Effective treatments for PAH will require detailed knowledge of molecular aetiology. Int J Clin Pract 2011:3-4. [PMID: 20939840 DOI: 10.1111/j.1742-1241.2010.02526.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Therapies for idiopathic pulmonary arterial hypertension will need to address the underlying molecular defects, or they will be incapable of halting progression. Identification of the familial PAH gene, BMPR2, and determinants of penetrance in families with BMPR2 mutation, has provided a mechanism for discovering this underlying aetiology not just in those with BMPR2 mutation, but in all patients. These studies suggest that the fundamental defects are in cytoskeletal organization, energy metabolism, and inflammation, with mode of estrogen metabolism acting as the most significant modifier. A detailed understanding of these defects, and a determination of the correct points for intervention, will be required to produce effective treatments for idiopathic PAH.
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Affiliation(s)
- J Johnson
- Vanderbilt University, Nashville, TN, USA
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Bone morphogenetic protein receptor II regulates pulmonary artery endothelial cell barrier function. Blood 2011; 117:333-41. [PMID: 20724539 DOI: 10.1182/blood-2010-05-285973] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Mutations in bone morphogenetic protein receptor II (BMPR-II) underlie most heritable cases of pulmonary arterial hypertension (PAH). However, less than half the individuals who harbor mutations develop the disease. Interestingly, heterozygous null BMPR-II mice fail to develop PAH unless an additional inflammatory insult is applied, suggesting that BMPR-II plays a fundamental role in dampening inflammatory signals in the pulmonary vasculature. Using static- and flow-based in vitro systems, we demonstrate that BMPR-II maintains the barrier function of the pulmonary artery endothelial monolayer suppressing leukocyte transmigration. Similar findings were also observed in vivo using a murine model with loss of endothelial BMPR-II expression. In vitro, the enhanced transmigration of leukocytes after tumor necrosis factor α or transforming growth factor β1 stimulation was CXCR2 dependent. Our data define how loss of BMPR-II in the endothelial layer of the pulmonary vasculature could lead to a heightened susceptibility to inflammation by promoting the extravasation of leukocytes into the pulmonary artery wall. We speculate that this may be a key mechanism involved in the initiation of the disease in heritable PAH that results from defects in BMPR-II expression.
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Control of MCT1 function in cerebrovascular endothelial cells by intracellular pH. Brain Res 2010; 1376:10-22. [PMID: 21192921 DOI: 10.1016/j.brainres.2010.12.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 12/08/2010] [Accepted: 12/20/2010] [Indexed: 02/03/2023]
Abstract
Monocarboxylic Acid Transporter 1 (MCT1) is expressed on the plasma membrane of cerebrovascular endothelial cells where it is the only known facilitator of lactic acid transport across the blood brain barrier. During stroke, brain injury, and certain other brain pathologies, anaerobic glycolysis produces severe lactic acidosis of brain tissue leading to brain cell damage. Therefore, a better understanding of factors that control MCT1 function may be the key to better understanding the origins and treatment of pathological lactic acidosis. In this study, we characterized the effects of intracellular pH in controlling MCT1 function and showed that microtubule disruption targeted this mechanism in rat cerebrovascular endothelial cells. Acidic intracellular pH values were shown to strongly inhibit lactic acid transport into the cytoplasmic space, while alkalinization of the cytoplasm significantly enhanced this transport function. These results support a better understanding of how cerebrovascular endothelial MCT1 may contribute to the development of lactic acidosis in brain pathologies, and suggest targeting it as a novel therapy.
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Kraft P, Benz PM, Austinat M, Brede ME, Schuh K, Walter U, Stoll G, Kleinschnitz C. Deficiency of vasodilator-stimulated phosphoprotein (VASP) increases blood-brain-barrier damage and edema formation after ischemic stroke in mice. PLoS One 2010; 5:e15106. [PMID: 21151938 PMCID: PMC2997079 DOI: 10.1371/journal.pone.0015106] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 10/21/2010] [Indexed: 12/14/2022] Open
Abstract
Background Stroke-induced brain edema formation is a frequent cause of secondary infarct growth and deterioration of neurological function. The molecular mechanisms underlying edema formation after stroke are largely unknown. Vasodilator-stimulated phosphoprotein (VASP) is an important regulator of actin dynamics and stabilizes endothelial barriers through interaction with cell-cell contacts and focal adhesion sites. Hypoxia has been shown to foster vascular leakage by downregulation of VASP in vitro but the significance of VASP for regulating vascular permeability in the hypoxic brain in vivo awaits clarification. Methodology/Principal Findings Focal cerebral ischemia was induced in Vasp−/− mice and wild-type (WT) littermates by transient middle cerebral artery occlusion (tMCAO). Evan's Blue tracer was applied to visualize the extent of blood-brain-barrier (BBB) damage. Brain edema formation and infarct volumes were calculated from 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain slices. Both mouse groups were carefully controlled for anatomical and physiological parameters relevant for edema formation and stroke outcome. BBB damage (p<0.05) and edema volumes (1.7 mm3±0.5 mm3 versus 0.8 mm3±0.4 mm3; p<0.0001) were significantly enhanced in Vasp−/− mice compared to controls on day 1 after tMCAO. This was accompanied by a significant increase in infarct size (56.1 mm3±17.3 mm3 versus 39.3 mm3±10.7 mm3, respectively; p<0.01) and a non significant trend (p>0.05) towards worse neurological outcomes. Conclusion Our study identifies VASP as critical regulator of BBB maintenance during acute ischemic stroke. Therapeutic modulation of VASP or VASP-dependent signalling pathways could become a novel strategy to combat excessive edema formation in ischemic brain damage.
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Affiliation(s)
- Peter Kraft
- Department of Neurology, University of Würzburg, Würzburg, Germany
| | - Peter Michael Benz
- Institute for Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
- Department of Physiology, University of Würzburg, Würzburg, Germany
| | | | - Marc Elmar Brede
- Department of Anesthesiology, University of Würzburg, Würzburg, Germany
| | - Kai Schuh
- Institute for Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
- Department of Physiology, University of Würzburg, Würzburg, Germany
| | - Ulrich Walter
- Institute for Clinical Biochemistry and Pathobiochemistry, University of Würzburg, Würzburg, Germany
| | - Guido Stoll
- Department of Neurology, University of Würzburg, Würzburg, Germany
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Peng H, Wang C, Ye ZC, Chen YR, Zhang J, Chen ZJ, Yu XQ, Lou TQ. How increased VEGF induces glomerular hyperpermeability: a potential signaling pathway of Rac1 activation. Acta Diabetol 2010; 47 Suppl 1:57-63. [PMID: 19404567 DOI: 10.1007/s00592-009-0121-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 04/08/2009] [Indexed: 01/20/2023]
Abstract
Despite growing evidence for a pathogenic role of vascular endothelial growth factor (VEGF) in microvascular complications of diabetes, the underlying mechanism responsible for its detrimental effect remains unknown. In the current study, we hypothesized that some of the detrimental effects of VEGF on microvascular endothelial cells in the diabetic milieu stem from its aberrant signaling, which leads to perturbed tight junction assembly and increased endothelial permeability. Using an integrated in vitro approach, we investigated whether the effect of VEGF on endothelial cell permeability involves Rac1 GTPase activation and tight junction disassembly. Rac1 activity was detected by Western blotting in cell membrane protein as well as pull-down assay. The permeability of glomerular endothelial cells monolayer was detected as transendothelial electronic resistance. Then tyrosine phosphorylated occludin protein was detected by Western blotting after immunoprecipitation. N17Rac1 cells are obtained by transfection of glomerular endothelial cells with a dominant negative mutant of Rac1. The data obtained in this study indicate that activation of Rac1 GTPase contributes to VEGF-induced endothelial cell hyperpermeability. We also observed that Rac1 activation leads to increased endothelial permeability through tyrosine phosphorylation of occludin. Indeed, N17Rac1 cells dramatically attenuated the effect of VEGF on phospho-occludin and endothelial cell permeability. These results, when taken together, provide a framework for understanding the role of VEGF-induced Rac1/phospho-occludin pathway in the integrity of endothelial barrier function in the glomerulus.
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Affiliation(s)
- Hui Peng
- Division of Nephrology, Department of Medicine, The Third Affiliated Hospital of Sun Yat-sen University, 600 Tianhe Av, 510630, Guangzhou, GD, People's Republic of China
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Abstract
Female predominance in pulmonary arterial hypertension (PAH) has been known for several decades and recent interest in the effects of sex hormones on the development of disease has substantially increased our understanding of this epidemiologic observation. Basic science data suggest a beneficial effect of estrogens in the pulmonary vasculature both acutely and chronically, which seems to contradict the known predilection in women. Recent human and rodent data have suggested that altered levels of estrogen, differential signaling and altered metabolism of estrogens in PAH may underlie the gender difference in this disease. Studies of the effects of sex hormones on the right ventricle in animal and human disease will further aid in understanding gender differences in PAH. This article focuses on the effects of sex hormones on the pulmonary vasculature and right ventricle on both a basic science and translational level.
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Affiliation(s)
- Meredith E Pugh
- Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, T1218 MCN, 1161 21st Avenue South, Nashville, TN 37232, USA.
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Abstract
During the development of the pulmonary vasculature in the fetus, many structural and functional changes occur to prepare the lung for the transition to air breathing. The development of the pulmonary circulation is genetically controlled by an array of mitogenic factors in a temporo-spatial order. With advancing gestation, pulmonary vessels acquire increased vasoreactivity. The fetal pulmonary vasculature is exposed to a low oxygen tension environment that promotes high intrinsic myogenic tone and high vasocontractility. At birth, a dramatic reduction in pulmonary arterial pressure and resistance occurs with an increase in oxygen tension and blood flow. The striking hemodynamic differences in the pulmonary circulation of the fetus and newborn are regulated by various factors and vasoactive agents. Among them, nitric oxide, endothelin-1, and prostaglandin I2 are mainly derived from endothelial cells and exert their effects via cGMP, cAMP, and Rho kinase signaling pathways. Alterations in these signaling pathways may lead to vascular remodeling, high vasocontractility, and persistent pulmonary hypertension of the newborn.
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Affiliation(s)
- Yuansheng Gao
- Department of Physiology and Pathophysiology, Peking University, Health Science Center, Beijing, China; and Department of Pediatrics, University of Illinois, College of Medicine at Chicago, Chicago, Illinois
| | - J. Usha Raj
- Department of Physiology and Pathophysiology, Peking University, Health Science Center, Beijing, China; and Department of Pediatrics, University of Illinois, College of Medicine at Chicago, Chicago, Illinois
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Fuchs B, Sommer N, Dietrich A, Schermuly RT, Ghofrani HA, Grimminger F, Seeger W, Gudermann T, Weissmann N. Redox signaling and reactive oxygen species in hypoxic pulmonary vasoconstriction. Respir Physiol Neurobiol 2010; 174:282-91. [PMID: 20801235 DOI: 10.1016/j.resp.2010.08.013] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 08/20/2010] [Accepted: 08/20/2010] [Indexed: 11/16/2022]
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is an essential physiological mechanism of the lung that matches blood perfusion with alveolar ventilation to optimize gas exchange. Perturbations of HPV, as may occur in pneumonia or adult respiratory distress syndrome, can cause life-threatening hypoxemia. Despite intensive research for decades, the molecular mechanisms of HPV have not been fully elucidated. Reactive oxygen species (ROS) and changes in the cellular redox state are proposed to link O2 sensing and pulmonary arterial smooth muscle cell contraction underlying HPV. In this regard, mitochondria and NAD(P)H oxidases are discussed as sources of ROS. However, there is controversy whether ROS levels decrease or increase during hypoxia. With this background we summarize the current knowledge on the role of ROS and redox state in HPV.
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Affiliation(s)
- Beate Fuchs
- Excellence Cluster Cardio-Pulmonary System, University of Giessen Lung Center, Department of Internal Medicine II, Justus-Liebig-University Giessen, Aulweg 130, 35392 Giessen, Germany
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