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Mondéjar-Parreño G, Cogolludo A, Perez-Vizcaino F. Potassium (K +) channels in the pulmonary vasculature: Implications in pulmonary hypertension Physiological, pathophysiological and pharmacological regulation. Pharmacol Ther 2021; 225:107835. [PMID: 33744261 DOI: 10.1016/j.pharmthera.2021.107835] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 02/06/2023]
Abstract
The large K+ channel functional diversity in the pulmonary vasculature results from the multitude of genes expressed encoding K+ channels, alternative RNA splicing, the post-transcriptional modifications, the presence of homomeric or heteromeric assemblies of the pore-forming α-subunits and the existence of accessory β-subunits modulating the functional properties of the channel. K+ channels can also be regulated at multiple levels by different factors controlling channel activity, trafficking, recycling and degradation. The activity of these channels is the primary determinant of membrane potential (Em) in pulmonary artery smooth muscle cells (PASMC), providing an essential regulatory mechanism to dilate or contract pulmonary arteries (PA). K+ channels are also expressed in pulmonary artery endothelial cells (PAEC) where they control resting Em, Ca2+ entry and the production of different vasoactive factors. The activity of K+ channels is also important in regulating the population and phenotype of PASMC in the pulmonary vasculature, since they are involved in cell apoptosis, survival and proliferation. Notably, K+ channels play a major role in the development of pulmonary hypertension (PH). Impaired K+ channel activity in PH results from: 1) loss of function mutations, 2) downregulation of its expression, which involves transcription factors and microRNAs, or 3) decreased channel current as a result of increased vasoactive factors (e.g., hypoxia, 5-HT, endothelin-1 or thromboxane), exposure to drugs with channel-blocking properties, or by a reduction in factors that positively regulate K+ channel activity (e.g., NO and prostacyclin). Restoring K+ channel expression, its intracellular trafficking and the channel activity is an attractive therapeutic strategy in PH.
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Affiliation(s)
- Gema Mondéjar-Parreño
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain; Ciber Enfermedades Respiratorias (CIBERES), Spain
| | - Angel Cogolludo
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain; Ciber Enfermedades Respiratorias (CIBERES), Spain
| | - Francisco Perez-Vizcaino
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain; Ciber Enfermedades Respiratorias (CIBERES), Spain.
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Liao Y, Yang Y, Pan D, Ding Y, Zhang H, Ye Y, Li J, Zhao L. HSP90α Mediates Sorafenib Resistance in Human Hepatocellular Carcinoma by Necroptosis Inhibition under Hypoxia. Cancers (Basel) 2021; 13:cancers13020243. [PMID: 33440739 PMCID: PMC7827218 DOI: 10.3390/cancers13020243] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/30/2020] [Accepted: 01/04/2021] [Indexed: 12/11/2022] Open
Abstract
Simple Summary Hypoxia is one of the characteristics of most solid tumors and induces cell resistant to chemotherapy. In this paper, we established a hypoxia model in both in vitro and in vivo to investigate the mechanisms of Sorafenib resistance in Hepatocellular carcinoma (HCC). Here, we observed that necroptosis could be an important target of Sorafenib in liver cancer and necroptosis blocking might be important in Sorafenib resistance under hypoxia. Mechanistically, our work suggests that HSP90α plays a pivotal role in Sorafenib-induced necroptosis by binding with necrosome. HSP90α could promote MLKL chaperone-mediated autophagy degradation in hypoxia, which subsequently decreased necroptosis. Consequently, the inhibition of necroptosis contributes to Sorafenib resistant. The Sorafenib resistance was reversed by HSP90α inhibitor-Demethoxygeldanamycin (17-AAG) in vivo and in vitro. This study highlights the important role of HSP90α in Sorafenib resistance under hypoxia microenvironment, and provides a potential therapy target for liver cancer. Abstract As one of the most common malignancies worldwide, Hepatocellular carcinoma (HCC) has been treated by Sorafenib, which is the first approved target drug by FDA for advanced HCC. However, drug resistance is one of the obstacles to its application. As a typical characteristic of most solid tumors, hypoxia has become a key cause of resistance to chemotherapy and radiotherapy. It is important to elucidate the underlying mechanisms of Sorafenib resistance under hypoxia. In this study, the morphological changes of hepatocellular carcinoma cells were observed by Live Cell Imaging System and Transmission Electron Microscope; Sorafenib was found to induce necroptosis in liver cancer. Under hypoxia, the distribution of necroptosis related proteins was changed, which contributed to Sorafenib resistance. HSP90α binds with the necrosome complex and promotes chaperone-mediated autophagy (CMA) degradation, which leads necroptosis blocking and results in Sorafenib resistance. The patient-derived tumor xenograft (PDX) model has been established to investigate the potential therapeutic strategies to overcome Sorafenib resistance. 17-AAG inhibited HSP90α and presented obvious reversal effects of Sorafenib resistance in vivo and in vitro. All the results emphasized that HSP90α plays a critical role in Sorafenib resistance under hypoxia and 17-AAG combined with Sorafenib is a promising therapy for hepatocellular carcinoma.
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Affiliation(s)
- Yan Liao
- School of Basic Medicine and Clinical Pharmacology, China Pharmaceutical University, Nanjing 211100, China; (Y.L.); (Y.Y.); (D.P.); (Y.D.); (H.Z.)
| | - Yue Yang
- School of Basic Medicine and Clinical Pharmacology, China Pharmaceutical University, Nanjing 211100, China; (Y.L.); (Y.Y.); (D.P.); (Y.D.); (H.Z.)
| | - Di Pan
- School of Basic Medicine and Clinical Pharmacology, China Pharmaceutical University, Nanjing 211100, China; (Y.L.); (Y.Y.); (D.P.); (Y.D.); (H.Z.)
| | - Youxiang Ding
- School of Basic Medicine and Clinical Pharmacology, China Pharmaceutical University, Nanjing 211100, China; (Y.L.); (Y.Y.); (D.P.); (Y.D.); (H.Z.)
| | - Heng Zhang
- School of Basic Medicine and Clinical Pharmacology, China Pharmaceutical University, Nanjing 211100, China; (Y.L.); (Y.Y.); (D.P.); (Y.D.); (H.Z.)
| | - Yuting Ye
- Pathology and PDX Efficacy Center, China Pharmaceutical University, Nanjing 211100, China; (Y.Y.); (J.L.)
| | - Jia Li
- Pathology and PDX Efficacy Center, China Pharmaceutical University, Nanjing 211100, China; (Y.Y.); (J.L.)
| | - Li Zhao
- School of Basic Medicine and Clinical Pharmacology, China Pharmaceutical University, Nanjing 211100, China; (Y.L.); (Y.Y.); (D.P.); (Y.D.); (H.Z.)
- Correspondence:
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Huang J, Frid M, Gewitz MH, Fallon JT, Brown D, Krafsur G, Stenmark K, Mathew R. Hypoxia-induced pulmonary hypertension and chronic lung disease: caveolin-1 dysfunction an important underlying feature. Pulm Circ 2019; 9:2045894019837876. [PMID: 30806156 PMCID: PMC6434444 DOI: 10.1177/2045894019837876] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 02/22/2019] [Indexed: 12/30/2022] Open
Abstract
Caveolin-1 (cav-1) has been shown to play a significant role in the pathogenesis of pulmonary hypertension (PH). In the monocrotaline model of PH, the loss of endothelial cav-1 as well as reciprocal activation of proliferative and anti-apoptotic pathways initiate the disease process and facilitate its progression. In order to examine the role of cav-1 in hypoxia-induced PH, we exposed rats and neonatal calves to hypobaric hypoxia and obtained hemodynamic data and assessed the expression of cav-1 and related proteins eNOS, HSP90, PTEN, gp130, PY-STAT3, β-catenin, and Glut1 in the lung tissue. Chronic hypoxic exposure in rats (48 h-4 weeks) and calves (two weeks) did not alter the expression of cav-1, HSP90, or eNOS. PTEN expression was significantly decreased accompanied by PY-STAT3 activation and increased expression of gp130, Glut1, and β-catenin in hypoxic animals. We also examined cav-1 expression in the lung sections from steers with chronic hypoxic disease (Brisket disease) and from patients with chronic lung disease who underwent lung biopsy for medical reasons. There was no cav-1 loss in Brisket disease. In chronic lung disease cases, endothelial cav-1 expression was present, albeit with less intense staining in some cases. In conclusion, hypoxia did not alter the cav-1 expression in experimental models. The presence of cav-1, however, did not suppress hypoxia-induced activation of PY-STAT3 and β catenin, increased gp130 and Glut1 expression, or prevent the PTEN loss, indicating cav-1 dysfunction in hypoxia-induced PH.
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Affiliation(s)
- Jing Huang
- Department of Pediatrics, Maria Fareri Children’s Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, USA
| | - Maria Frid
- Cardiovascular Pulmonary Research Laboratories, Departments of Pediatrics and Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Michael H. Gewitz
- Department of Pediatrics, Maria Fareri Children’s Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, USA
| | - John T. Fallon
- Department of Pathology, New York Medical College, Valhalla, NY, USA
| | - Dale Brown
- Cardiovascular Pulmonary Research Laboratories, Departments of Pediatrics and Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Greta Krafsur
- Cardiovascular Pulmonary Research Laboratories, Departments of Pediatrics and Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kurt Stenmark
- Cardiovascular Pulmonary Research Laboratories, Departments of Pediatrics and Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Rajamma Mathew
- Department of Pediatrics, Maria Fareri Children’s Hospital at Westchester Medical Center, New York Medical College, Valhalla, NY, USA
- Department of Physiology, New York Medical College, Valhalla, NY, USA
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Gao Y, Cornfield DN, Stenmark KR, Thébaud B, Abman SH, Raj JU. Unique aspects of the developing lung circulation: structural development and regulation of vasomotor tone. Pulm Circ 2017; 6:407-425. [PMID: 27942377 DOI: 10.1086/688890] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
This review summarizes our current knowledge on lung vasculogenesis and angiogenesis during normal lung development and the regulation of fetal and postnatal pulmonary vascular tone. In comparison to that of the adult, the pulmonary circulation of the fetus and newborn displays many unique characteristics. Moreover, altered development of pulmonary vasculature plays a more prominent role in compromised pulmonary vasoreactivity than in the adult. Clinically, a better understanding of the developmental changes in pulmonary vasculature and vasomotor tone and the mechanisms that are disrupted in disease states can lead to the development of new therapies for lung diseases characterized by impaired alveolar structure and pulmonary hypertension.
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Affiliation(s)
- Yuangsheng Gao
- Department of Pediatrics, University of Illinois College of Medicine at Chicago, Chicago, Illinois, USA
| | - David N Cornfield
- Section of Pulmonary and Critical Care Medicine, Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Kurt R Stenmark
- Section of Critical Care Medicine, Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado, USA
| | - Bernard Thébaud
- Sinclair Centre for Regenerative Medicine, Ottawa Hospital Research Institute; and Children's Hospital of Eastern Ontario Research Institute; University of Ottawa, Ottawa, Ontario, Canada
| | - Steven H Abman
- Section of Pulmonary Medicine, Department of Pediatrics, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, Colorado, USA
| | - J Usha Raj
- Department of Pediatrics, University of Illinois College of Medicine at Chicago, Chicago, Illinois, USA
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Chalupsky K, Kračun D, Kanchev I, Bertram K, Görlach A. Folic Acid Promotes Recycling of Tetrahydrobiopterin and Protects Against Hypoxia-Induced Pulmonary Hypertension by Recoupling Endothelial Nitric Oxide Synthase. Antioxid Redox Signal 2015; 23:1076-91. [PMID: 26414244 PMCID: PMC4657514 DOI: 10.1089/ars.2015.6329] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 09/21/2015] [Accepted: 09/21/2015] [Indexed: 01/29/2023]
Abstract
AIMS Nitric oxide (NO) derived from endothelial NO synthase (eNOS) has been implicated in the adaptive response to hypoxia. An imbalance between 5,6,7,8-tetrahydrobiopterin (BH4) and 7,8-dihydrobiopterin (BH2) can result in eNOS uncoupling and the generation of superoxide instead of NO. Dihydrofolate reductase (DHFR) can recycle BH2 to BH4, leading to eNOS recoupling. However, the role of DHFR and eNOS recoupling in the response to hypoxia is not well understood. We hypothesized that increasing the capacity to recycle BH4 from BH2 would improve NO bioavailability as well as pulmonary vascular remodeling (PVR) and right ventricular hypertrophy (RVH) as indicators of pulmonary hypertension (PH) under hypoxic conditions. RESULTS In human pulmonary artery endothelial cells and murine pulmonary arteries exposed to hypoxia, eNOS was uncoupled as indicated by reduced superoxide production in the presence of the nitric oxide synthase inhibitor, L-(G)-nitro-L-arginine methyl ester (L-NAME). Concomitantly, NO levels, BH4 availability, and expression of DHFR were diminished under hypoxia. Application of folic acid (FA) restored DHFR levels, NO bioavailability, and BH4 levels under hypoxia. Importantly, FA prevented the development of hypoxia-induced PVR, right ventricular pressure increase, and RVH. INNOVATION FA-induced upregulation of DHFR recouples eNOS under hypoxia by improving BH4 recycling, thus preventing hypoxia-induced PH. CONCLUSION FA might serve as a novel therapeutic option combating PH.
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Affiliation(s)
- Karel Chalupsky
- Experimental and Molecular Pediatric Cardiology, German Heart Center Munich at the Technical University Munich, Munich, Germany
| | - Damir Kračun
- Experimental and Molecular Pediatric Cardiology, German Heart Center Munich at the Technical University Munich, Munich, Germany
| | - Ivan Kanchev
- Experimental and Molecular Pediatric Cardiology, German Heart Center Munich at the Technical University Munich, Munich, Germany
| | - Katharina Bertram
- Experimental and Molecular Pediatric Cardiology, German Heart Center Munich at the Technical University Munich, Munich, Germany
| | - Agnes Görlach
- Experimental and Molecular Pediatric Cardiology, German Heart Center Munich at the Technical University Munich, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Munich Heart Alliance, Munich, Germany
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Mutchler SM, Straub AC. Compartmentalized nitric oxide signaling in the resistance vasculature. Nitric Oxide 2015; 49:8-15. [PMID: 26028569 DOI: 10.1016/j.niox.2015.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 05/15/2015] [Accepted: 05/20/2015] [Indexed: 01/23/2023]
Abstract
Nitric oxide (NO) was first described as a bioactive molecule through its ability to stimulate soluble guanylate cyclase, but the revelation that NO was the endothelium derived relaxation factor drove the field to its modern state. The wealth of research conducted over the past 30 years has provided us with a picture of how diverse NO signaling can be within the vascular wall, going beyond simple vasodilation to include such roles as signaling through protein S-nitrosation. This expanded view of NO's actions requires highly regulated and compartmentalized production. Importantly, resistance arteries house multiple proteins involved in the production and transduction of NO allowing for efficient movement of the molecule to regulate vascular tone and reactivity. In this review, we focus on the many mechanisms regulating NO production and signaling action in the vascular wall, with a focus on the control of endothelial nitric oxide synthase (eNOS), the enzyme responsible for synthesizing most of the NO within these confines. We also explore how cross talk between the endothelium and smooth muscle in the microcirculation can modulate NO signaling, illustrating that this one small molecule has the capability to produce a plethora of responses.
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Affiliation(s)
- Stephanie M Mutchler
- Heart, Lung, Blood and Vascular Medicine Institute, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15216, USA
| | - Adam C Straub
- Heart, Lung, Blood and Vascular Medicine Institute, USA; Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15216, USA.
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Altered prostanoid metabolism contributes to impaired angiogenesis in persistent pulmonary hypertension in a fetal lamb model. Pediatr Res 2015; 77:455-62. [PMID: 25521916 PMCID: PMC4346417 DOI: 10.1038/pr.2014.209] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 09/30/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND Persistent pulmonary hypertension of the newborn (PPHN) is associated with decreased lung angiogenesis and impaired pulmonary vasodilatation at birth. Prostanoids are important modulators of vascular tone and angiogenesis. We hypothesized that altered levels of prostacyclin (PGI₂), a potent vasodilator, and thromboxane A₂ (TXA₂), a vasoconstrictor, contribute to impaired angiogenesis of pulmonary artery endothelial cells (PAEC) in PPHN. METHODS PAEC were isolated from fetal lambs with PPHN induced by prenatal ductus arteriosus constriction or from sham operated controls. Expression and activity of PGI₂ synthase (PGIS) and TXA₂ synthase (TXAS), expression of cyclooxygenases 1 and 2 (COX-1 and COX-2), and the role of PGIS/TXAS alterations in angiogenesis were investigated in PAEC from PPHN and control lambs. RESULTS PGIS protein and activity were decreased and PGIS protein tyrosine nitration was increased in PPHN PAEC. In contrast, TXAS protein and its stimulated activity were increased in PPHN PAEC. COX-1 and COX-2 proteins were decreased in PPHN PAEC. Addition of PGI₂ improved in vitro tube formation by PPHN PAEC, whereas indomethacin decreased tube formation by control PAEC. PGIS knockdown decreased the in vitro angiogenesis in control PAEC, whereas TXAS knockdown increased the in vitro angiogenesis in PPHN PAEC. CONCLUSION Reciprocal alterations in PGI₂ and TXA₂ may contribute to impaired angiogenesis in PPHN.
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Yao C, Yu J, Taylor L, Polgar P, McComb ME, Costello CE. Protein Expression by Human Pulmonary Artery Smooth Muscle Cells Containing a BMPR2 Mutation and the Action of ET-1 as Determined by Proteomic Mass Spectrometry. INTERNATIONAL JOURNAL OF MASS SPECTROMETRY 2015; 378:347-359. [PMID: 25866469 PMCID: PMC4387548 DOI: 10.1016/j.ijms.2014.10.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a disease characterized by increased pulmonary vascular resistance and remodeling. Increase in the population of vascular smooth muscle cells is among the key events contributing to the remodeling. Endothelin-1 (ET-1), a potent vasoconstrictor, is linked to the etiology and progression of PAH. Here we analyze changes in protein expressions in response to ET-1 in pulmonary arterial smooth muscle cells (PASMC) from a healthy Control (non-PAH) and a PAH subject presenting a bone morphogenetic protein type II receptor (BMPR2) mutation with exon 1-8 deletion. Protein expressions were analyzed by proteomic mass spectrometry using label-free quantitation and the correlations were subjected to Ingenuity™ Pathway Analysis. The results point to eIF2/mTOR/p70S6K, RhoA/actin cytoskeleton/integrin and protein unbiquitination as canonical pathways whose protein expressions increase with the development of PAH. These pathways have an intimal function in the PAH-related physiology of smooth muscle proliferation, apoptosis, contraction and cellular stress. Exposure of the cells to ET-1 further increases protein expression within these pathways. Thus our results show changes in signaling pathways as a consequence of PAH and the effect of ET-1 interference on Control and PAH-affected cells.
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Affiliation(s)
- Chunxiang Yao
- Center for Biomedical Mass Spectrometry, Boston University School of Medicine, 670 Albany St., Boston, MA 02118 USA
| | - Jun Yu
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 USA
| | - Linda Taylor
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 USA
| | - Peter Polgar
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 USA
| | - Mark E. McComb
- Center for Biomedical Mass Spectrometry, Boston University School of Medicine, 670 Albany St., Boston, MA 02118 USA
| | - Catherine E. Costello
- Center for Biomedical Mass Spectrometry, Boston University School of Medicine, 670 Albany St., Boston, MA 02118 USA
- Department of Biochemistry, Boston University School of Medicine, Boston, MA 02118 USA
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Sedivy V, Joshi S, Ghaly Y, Mizera R, Zaloudikova M, Brennan S, Novotna J, Herget J, Gurney AM. Role of Kv7 channels in responses of the pulmonary circulation to hypoxia. Am J Physiol Lung Cell Mol Physiol 2014; 308:L48-57. [PMID: 25361569 PMCID: PMC4281702 DOI: 10.1152/ajplung.00362.2013] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hypoxic pulmonary vasoconstriction (HPV) is a beneficial mechanism that diverts blood from hypoxic alveoli to better ventilated areas of the lung, but breathing hypoxic air causes the pulmonary circulation to become hypertensive. Responses to airway hypoxia are associated with depolarization of smooth muscle cells in the pulmonary arteries and reduced activity of K+ channels. As Kv7 channels have been proposed to play a key role in regulating the smooth muscle membrane potential, we investigated their involvement in the development of HPV and hypoxia-induced pulmonary hypertension. Vascular effects of the selective Kv7 blocker, linopirdine, and Kv7 activator, flupirtine, were investigated in isolated, saline-perfused lungs from rats maintained for 3–5 days in an isobaric hypoxic chamber (FiO2 = 0.1) or room air. Linopirdine increased vascular resistance in lungs from normoxic, but not hypoxic rats. This effect was associated with reduced mRNA expression of the Kv7.4 channel α-subunit in hypoxic arteries, whereas Kv7.1 and Kv7.5 were unaffected. Flupirtine had no effect in normoxic lungs but reduced vascular resistance in hypoxic lungs. Moreover, oral dosing with flupirtine (30 mg/kg/day) prevented short-term in vivo hypoxia from increasing pulmonary vascular resistance and sensitizing the arteries to acute hypoxia. These findings suggest a protective role for Kv7.4 channels in the pulmonary circulation, limiting its reactivity to pressor agents and preventing hypoxia-induced pulmonary hypertension. They also provide further support for the therapeutic potential of Kv7 activators in pulmonary vascular disease.
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Affiliation(s)
- Vojtech Sedivy
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic; Department of Paediatrics, Charles University - Second Faculty of Medicine and University Hospital Motol, Prague, Czech Republic; and
| | - Shreena Joshi
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Youssef Ghaly
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Roman Mizera
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Marie Zaloudikova
- Department of Pathophysiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Sean Brennan
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Jana Novotna
- Department of Biochemistry, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Jan Herget
- Department of Physiology, Charles University - Second Faculty of Medicine, Prague, Czech Republic
| | - Alison M Gurney
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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Fike CD, Summar M, Aschner JL. L-citrulline provides a novel strategy for treating chronic pulmonary hypertension in newborn infants. Acta Paediatr 2014; 103:1019-26. [PMID: 24862864 DOI: 10.1111/apa.12707] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 03/23/2014] [Accepted: 05/23/2014] [Indexed: 02/05/2023]
Abstract
UNLABELLED Effective therapies are urgently needed for infants with forms of pulmonary hypertension that develop or persist beyond the first week of life. The L-arginine nitric oxide (NO) precursor, L-citrulline, improves NO signalling and ameliorates pulmonary hypertension in newborn animals. In vitro studies demonstrate that manipulating L-citrulline transport alters NO production. CONCLUSION Strategies that increase the supply and transport of L-citrulline merit pursuit as novel approaches to managing infants with chronic, progressive pulmonary hypertension.
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Affiliation(s)
- Candice D. Fike
- Department of Pediatrics; Vanderbilt University Medical Center; Nashville TN USA
- Monroe Carell Jr. Children's Hospital at Vanderbilt; Nashville TN USA
| | - Marshall Summar
- Division of Genetics and Metabolism; Children's National Medical Center; Washington DC USA
| | - Judy L. Aschner
- Department of Pediatrics; Albert Einstein College of Medicine and the Children's Hospital at Montefiore; New York NY USA
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11
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Abstract
Oxidative stress has many implications in the pathogenesis of lung diseases. In this review, we provide an overview of Reactive Oxygen Species (ROS) and nitrogen (RNS) species and antioxidants, how they relate to normal physiological function and the pathophysiology of different lung diseases, and therapeutic strategies. The production of ROS/RNS from endogenous and exogenous sources is first discussed, followed by antioxidant systems that restore oxidative balance and cellular homeostasis. The contribution of oxidant/antioxidant imbalance in lung disease pathogenesis is also discussed. An overview of therapeutic strategies is provided, such as augmenting NO bioactivity, blocking the production of ROS/RNS and replacement of deficient antioxidants. The limitations of current strategies and failures of clinical trials are then addressed, followed by discussion of novel experimental approaches for the development of improved antioxidant therapies.
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12
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Papamatheakis DG, Blood AB, Kim JH, Wilson SM. Antenatal hypoxia and pulmonary vascular function and remodeling. Curr Vasc Pharmacol 2014; 11:616-40. [PMID: 24063380 DOI: 10.2174/1570161111311050006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 06/25/2012] [Accepted: 07/12/2012] [Indexed: 01/02/2023]
Abstract
This review provides evidence that antenatal hypoxia, which represents a significant and worldwide problem, causes prenatal programming of the lung. A general overview of lung development is provided along with some background regarding transcriptional and signaling systems of the lung. The review illustrates that antenatal hypoxic stress can induce a continuum of responses depending on the species examined. Fetuses and newborns of certain species and specific human populations are well acclimated to antenatal hypoxia. However, antenatal hypoxia causes pulmonary vascular disease in fetuses and newborns of most mammalian species and humans. Disease can range from mild pulmonary hypertension, to severe vascular remodeling and dangerous elevations in pressure. The timing, length, and magnitude of the intrauterine hypoxic stress are important to disease development, however there is also a genetic-environmental relationship that is not yet completely understood. Determining the origins of pulmonary vascular remodeling and pulmonary hypertension and their associated effects is a challenging task, but is necessary in order to develop targeted therapies for pulmonary hypertension in the newborn due to antenatal hypoxia that can both treat the symptoms and curtail or reverse disease progression.
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Affiliation(s)
- Demosthenes G Papamatheakis
- Center for Perinatal Biology, Loma Linda University School of Medicine, 11234 Anderson Street, Loma Linda, 92350 CA, USA.
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13
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Su Y. Regulation of endothelial nitric oxide synthase activity by protein-protein interaction. Curr Pharm Des 2014; 20:3514-20. [PMID: 24180383 PMCID: PMC7039309 DOI: 10.2174/13816128113196660752] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 10/21/2013] [Indexed: 02/07/2023]
Abstract
Endothelial nitric oxide synthase (eNOS) is expressed in vascular endothelial cells and plays an important role in the regulation of vascular tone, platelet aggregation and angiogenesis. Protein-protein interactions represent an important posttranslational mechanism for eNOS regulation. eNOS has been shown to interact with a variety of regulatory and structural proteins which provide fine tuneup of eNOS activity and eNOS protein trafficking between plasma membrane and intracellular membranes in a number of physiological and pathophysiological processes. eNOS interacts with calmodulin, heat shock protein 90 (Hsp90), dynamin-2, β-actin, tubulin, porin, high-density lipoprotein (HDL) and apolipoprotein AI (ApoAI), resulting in increases in eNOS activity. The negative eNOS interacting proteins include caveolin, G protein-coupled receptors (GPCR), nitric oxide synthase-interacting protein (NOSIP), and nitric oxide synthase trafficking inducer (NOSTRIN). Dynamin-2, NOSIP, NOSTRIN, and cytoskeleton are also involved in eNOS trafficking in endothelial cells. In addition, eNOS associations with cationic amino acid transporter-1 (CAT-1), argininosuccinate synthase (ASS), argininosuccinate lyase (ASL), and soluble guanylate cyclase (sGC) facilitate directed delivery of substrate (L-arginine) to eNOS and optimizing NO production and NO action on its target. Regulation of eNOS by protein-protein interactions would provide potential targets for pharmacological interventions in NO-compromised cardiovascular diseases.
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Affiliation(s)
- Yunchao Su
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1120 15th Street, Augusta, GA 30912.
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