1
|
Hu MC, Scanni R, Ye J, Zhang J, Shi M, Maique J, Flores B, Moe OW, Krapf R. Dietary vitamin D interacts with high phosphate-induced cardiac remodeling in rats with normal renal function. Nephrol Dial Transplant 2020; 35:411-421. [PMID: 31504790 DOI: 10.1093/ndt/gfz156] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 07/01/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Vitamin D (VD) and phosphate (Pi) load are considered as contributors to cardiovascular disease in chronic kidney disease and the general population, but interactive effects of VD and Pi intake on the heart are not clearly illustrated. METHODS We fed normal male rats with three levels of dietary VD (100, 1100 or 5000 IU/kg chow) and Pi (0.2, 0.6 or 1.6%) (3X3 design) for 8 weeks and examined renal and cardiac function and histology. RESULTS High dietary Pi decreased plasma and renal Klotho and plasma 25-hydroxyvitamin D, and increased plasma Pi, fibroblast growth factor 23 and parathyroid hormone without affecting renal function, while low Pi increased plasma and renal Klotho. Both low and high VD diets enhanced high Pi-reduced Klotho expression. Low dietary VD reduced-plasma Klotho was rescued by a low Pi diet. High dietary Pi reduced-cardiac ejection fraction was not modified by a low or high VD diet, but the dietary VD effects on cardiac pathologic changes were more complex. High dietary Pi-induced cardiac hypertrophy was attenuated by a low VD and exacerbated by a high VD diet. In contrast, high dietary Pi -induced cardiac fibrosis was magnified by a low VD and attenuated by a high VD diet. CONCLUSIONS High Pi diet induces hypertrophy and fibrosis in left ventricles, a low VD diet accelerates high Pi-induced fibrosis, and a high VD diet exacerbated high Pi -induced hypertrophy. Therefore, cardiac phosphotoxicity is exacerbated by either high or low dietary VD in rats with normal kidney function.
Collapse
Affiliation(s)
- Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Roberto Scanni
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Synlab Suisse, Lucerne, Switzerland.,Department of Medicine, University of Basel, Basel, Switzerland
| | - Jianfeng Ye
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jianning Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Mingjun Shi
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jenny Maique
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Brianna Flores
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Orson W Moe
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Physiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Reto Krapf
- Synlab Suisse, Lucerne, Switzerland.,Department of Medicine, University of Basel, Basel, Switzerland
| |
Collapse
|
2
|
Dane DM, Yilmaz C, Gyawali D, Iyer R, Menon J, Nguyen KT, Ravikumar P, Estrera AS, Hsia CCW. Erythropoietin inhalation enhances adult canine alveolar-capillary formation following pneumonectomy. Am J Physiol Lung Cell Mol Physiol 2019; 316:L936-L945. [PMID: 30785346 DOI: 10.1152/ajplung.00504.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Paracrine erythropoietin (EPO) signaling in the lung recruits endothelial progenitor cells, promotes cell maturation and angiogenesis, and is upregulated during canine postpneumonectomy (PNX) compensatory lung growth. To determine whether inhalational delivery of exogenous EPO augments endogenous post-PNX lung growth, adult canines underwent right PNX and received, via a permanent tracheal stoma, weekly nebulization of recombinant human EPO-containing nanoparticles or empty nanoparticles (control) for 16 wk. Lung function was assessed under anesthesia pre- and post-PNX. The remaining lobes were fixed for detailed morphometric analysis. Compared with control treatment, EPO delivery significantly increased serum EPO concentration without altering systemic hematocrit or hemoglobin concentration and abrogated post-PNX lipid oxidative stress damage. EPO delivery modestly increased post-PNX volume densities of the alveolar septum per unit of lung volume and type II epithelium and endothelium per unit of septal tissue volume in selected lobes. EPO delivery also augmented the post-PNX increase in alveolar double-capillary profiles, a marker of intussusceptive capillary formation, in all remaining lobes. EPO treatment did not significantly alter absolute resting lung volumes, lung and membrane diffusing capacities, alveolar-capillary blood volume, pulmonary blood flow, lung compliance, or extravascular alveolar tissue volumes or surface areas. Results established the feasibility of chronic inhalational delivery of growth-modifying biologics in a large animal model. Exogenous EPO selectively enhanced cytoprotection and alveolar angiogenesis in remaining lobes but not whole-lung extravascular tissue growth or resting function; the nonuniform response contributes to structure-function discrepancy, a major challenge for interventions aimed at amplifying the innate potential for compensatory lung growth.
Collapse
Affiliation(s)
- D Merrill Dane
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Cuneyt Yilmaz
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Dipendra Gyawali
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Roshni Iyer
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Jyothi Menon
- Department of Bioengineering, University of Texas at Arlington , Arlington, Texas
| | - Kytai T Nguyen
- Department of Bioengineering, University of Texas at Arlington , Arlington, Texas
| | - Priya Ravikumar
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Aaron S Estrera
- Department of Cardiothoracic Surgery, University of Texas Southwestern Medical Center , Dallas, Texas
| | - Connie C W Hsia
- Department of Internal Medicine, University of Texas Southwestern Medical Center , Dallas, Texas
| |
Collapse
|
3
|
Auberson M, Stadelmann S, Stoudmann C, Seuwen K, Koesters R, Thorens B, Bonny O. SLC2A9 (GLUT9) mediates urate reabsorption in the mouse kidney. Pflugers Arch 2018; 470:1739-1751. [PMID: 30105595 PMCID: PMC6224025 DOI: 10.1007/s00424-018-2190-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/17/2018] [Accepted: 08/01/2018] [Indexed: 02/07/2023]
Abstract
Uric acid (UA) is a metabolite of purine degradation and is involved in gout flairs and kidney stones formation. GLUT9 (SLC2A9) was previously shown to be a urate transporter in vitro. In vivo, humans carrying GLUT9 loss-of-function mutations have familial renal hypouricemia type 2, a condition characterized by hypouricemia, UA renal wasting associated with kidney stones, and an increased propensity to acute renal failure during strenuous exercise. Mice carrying a deletion of GLUT9 in the whole body are hyperuricemic and display a severe nephropathy due to intratubular uric acid precipitation. However, the precise role of GLUT9 in the kidney remains poorly characterized. We developed a mouse model in which GLUT9 was deleted specifically along the whole nephron in a tetracycline-inducible manner (subsequently called kidney-inducible KO or kiKO). The urate/creatinine ratio was increased as early as 4 days after induction of the KO and no GLUT9 protein was visible on kidney extracts. kiKO mice are morphologically identical to their wild-type littermates and had no spontaneous kidney stones. Twenty-four-hour urine collection revealed a major increase of urate urinary excretion rate and of the fractional excretion of urate, with no difference in urate concentration in the plasma. Polyuria was observed, but kiKO mice were still able to concentrate urine after water restriction. KiKO mice displayed lower blood pressure accompanied by an increased heart rate. Overall, these results indicate that GLUT9 is a crucial player in renal handling of urate in vivo and a putative target for uricosuric drugs.
Collapse
Affiliation(s)
- Muriel Auberson
- Department of Pharmacology and Toxicology, University of Lausanne, 27 rue du Bugnon, 1011, Lausanne, Switzerland
| | - Sophie Stadelmann
- Department of Pharmacology and Toxicology, University of Lausanne, 27 rue du Bugnon, 1011, Lausanne, Switzerland
| | - Candice Stoudmann
- Department of Pharmacology and Toxicology, University of Lausanne, 27 rue du Bugnon, 1011, Lausanne, Switzerland
| | - Klaus Seuwen
- Novartis Institutes for Biomedical Research, CH-4002, Basel, Switzerland
| | | | - Bernard Thorens
- Centre for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Olivier Bonny
- Department of Pharmacology and Toxicology, University of Lausanne, 27 rue du Bugnon, 1011, Lausanne, Switzerland. .,Service of Nephrology, Department of Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
| |
Collapse
|
4
|
Hsia CCW. Comparative analysis of the mechanical signals in lung development and compensatory growth. Cell Tissue Res 2017; 367:687-705. [PMID: 28084523 PMCID: PMC5321790 DOI: 10.1007/s00441-016-2558-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2016] [Accepted: 12/13/2016] [Indexed: 12/16/2022]
Abstract
This review compares the manner in which physical stress imposed on the parenchyma, vasculature and thorax and the thoraco-pulmonary interactions, drive both developmental and compensatory lung growth. Re-initiation of anatomical lung growth in the mature lung is possible when the loss of functioning lung units renders the existing physiologic-structural reserves insufficient for maintaining adequate function and physical stress on the remaining units exceeds a critical threshold. The appropriate spatial and temporal mechanical interrelationships and the availability of intra-thoracic space, are crucial to growth initiation, follow-on remodeling and physiological outcome. While the endogenous potential for compensatory lung growth is retained and may be pharmacologically augmented, supra-optimal mechanical stimulation, unbalanced structural growth, or inadequate remodeling may limit functional gain. Finding ways to optimize the signal-response relationships and resolve structure-function discrepancies are major challenges that must be overcome before the innate compensatory ability could be fully realized. Partial pneumonectomy reproducibly removes a known fraction of functioning lung units and remains the most robust model for examining the adaptive mechanisms, structure-function consequences and plasticity of the remaining functioning lung units capable of regeneration. Fundamental mechanical stimulus-response relationships established in the pneumonectomy model directly inform the exploration of effective approaches to maximize compensatory growth and function in chronic destructive lung diseases, transplantation and bioengineered lungs.
Collapse
Affiliation(s)
- Connie C W Hsia
- Department of Internal Medicine, Pulmonary and Critical Care Medicine, University of Texas Southwestern Medical Center, Dallas, 5323 Harry Hines Blvd., Dallas, TX, 75390-9034, USA.
| |
Collapse
|
5
|
Abstract
Structural and functional complexities of the mammalian lung evolved to meet a unique set of challenges, namely, the provision of efficient delivery of inspired air to all lung units within a confined thoracic space, to build a large gas exchange surface associated with minimal barrier thickness and a microvascular network to accommodate the entire right ventricular cardiac output while withstanding cyclic mechanical stresses that increase several folds from rest to exercise. Intricate regulatory mechanisms at every level ensure that the dynamic capacities of ventilation, perfusion, diffusion, and chemical binding to hemoglobin are commensurate with usual metabolic demands and periodic extreme needs for activity and survival. This article reviews the structural design of mammalian and human lung, its functional challenges, limitations, and potential for adaptation. We discuss (i) the evolutionary origin of alveolar lungs and its advantages and compromises, (ii) structural determinants of alveolar gas exchange, including architecture of conducting bronchovascular trees that converge in gas exchange units, (iii) the challenges of matching ventilation, perfusion, and diffusion and tissue-erythrocyte and thoracopulmonary interactions. The notion of erythrocytes as an integral component of the gas exchanger is emphasized. We further discuss the signals, sources, and limits of structural plasticity of the lung in alveolar hypoxia and following a loss of lung units, and the promise and caveats of interventions aimed at augmenting endogenous adaptive responses. Our objective is to understand how individual components are matched at multiple levels to optimize organ function in the face of physiological demands or pathological constraints.
Collapse
Affiliation(s)
- Connie C.W. Hsia
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Dallas M. Hyde
- California National Primate Research Center, University of California at Davis, Davis, California, USA
| | | |
Collapse
|
6
|
Ravikumar P, Menon JU, Punnakitikashem P, Gyawali D, Togao O, Takahashi M, Zhang J, Ye J, Moe OW, Nguyen KT, Hsia CCW. Nanoparticle facilitated inhalational delivery of erythropoietin receptor cDNA protects against hyperoxic lung injury. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 12:811-821. [PMID: 26518603 DOI: 10.1016/j.nano.2015.10.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 10/12/2015] [Accepted: 10/15/2015] [Indexed: 11/27/2022]
Abstract
UNLABELLED Our goals were to develop and establish nanoparticle (NP)-facilitated inhalational gene delivery, and to validate its biomedical application by testing the hypothesis that targeted upregulation of pulmonary erythropoietin receptor (EpoR) expression protects against lung injury. Poly-lactic-co-glycolic acid (PLGA) NPs encapsulating various tracers were characterized and nebulizated into rat lungs. Widespread NP uptake and distribution within alveolar cells were visualized by magnetic resonance imaging, and fluorescent and electron microscopy. Inhalation of nebulized NPs bearing EpoR cDNA upregulated pulmonary EpoR expression and downstream signal transduction (ERK1/2 and STAT5 phosphorylation) in rats for up to 21 days, and attenuated hyperoxia-induced damage in lung tissue based on apoptosis, oxidative damage of DNA, protein and lipid, tissue edema, and alveolar morphology compared to vector-treated control animals. These results establish the feasibility and therapeutic efficacy of NP-facilitated cDNA delivery to the lung, and demonstrate that targeted pulmonary EpoR upregulation mitigates acute oxidative lung damage. FROM THE CLINICAL EDITOR Acute lung injury often results in significant morbidity and mortality, and current therapeutic modalities have proven to be ineffective. In this article, the authors developed nanocarrier based gene therapy in an attempt to upregulate the expression of pulmonary erythropoietin receptor in an animal model. Inhalation delivery resulted in reduction of lung damage.
Collapse
Affiliation(s)
- Priya Ravikumar
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jyothi U Menon
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, USA
| | | | - Dipendra Gyawali
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Osamu Togao
- Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Masaya Takahashi
- Department of Radiology and Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jianning Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jianfeng Ye
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Orson W Moe
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kytai T Nguyen
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, USA.
| | - Connie C W Hsia
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| |
Collapse
|
7
|
Yilmaz C, Ravikumar P, Gyawali D, Iyer R, Unger RH, Hsia CCW. Alveolar-capillary adaptation to chronic hypoxia in the fatty lung. Acta Physiol (Oxf) 2015; 213:933-46. [PMID: 25363080 DOI: 10.1111/apha.12419] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 09/17/2014] [Accepted: 10/26/2014] [Indexed: 12/18/2022]
Abstract
AIM Obese diabetic (ZDF fa/fa) rats with genetic leptin resistance suffer chronic lipotoxicity associated with age-related lung restriction and abnormal alveolar ultrastructure. We hypothesized that these abnormalities impair adaptation to ambient hypoxia. METHODS Male fa/fa and lean (+/+) ZDF rats (4-months old) were exposed to 21 or 13% O2 for 3 weeks. Lung function was measured under anaesthesia. Lung tissue was assayed for DNA damage and ultrastructure measured by morphometry. RESULTS In normoxia, lung volume, compliance and diffusing capacity were lower, while blood flow was higher in fa/fa than +/+ rats. In hypoxia, fa/fa animals lost more weight, circulating hematocrit rose higher, and lung volume failed to increase compared to +/+. In fa/fa, the hypoxia-induced increase in post-mortem lung volume was attenuated (19%) vs. +/+ (39%). Alveolar ducts were 35% smaller in normoxia but enlarged twofold more in hypoxia compared to +/+. Hypoxia induced broad increases (90-100%) in the volumes and surface areas of alveolar septal components in +/+ lungs; these increases were moderately attenuated in fa/fa lungs (58-75%), especially that of type II epithelium volume (16 vs. 61% in +/+). In fa/fa compared to +/+ lungs, oxidative DNA damage was greater with increased hypoxia induced efflux of alveolar macrophages. Harmonic mean thickness of the diffusion barrier was higher, indicating higher structural resistance to gas transfer. CONCLUSION Chronic lipotoxicity impaired hypoxia-induced lung expansion and compensatory alveolar growth with disproportionate effect on resident alveolar progenitor cells. The moderate structural impairment was offset by physiological adaptation primarily via a higher hematocrit.
Collapse
Affiliation(s)
- C. Yilmaz
- Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas TX USA
| | - P. Ravikumar
- Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas TX USA
| | - D. Gyawali
- Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas TX USA
| | - R. Iyer
- Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas TX USA
| | - R. H. Unger
- Touchstone Diabetes Center; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas TX USA
| | - C. C. W. Hsia
- Pulmonary and Critical Care Medicine; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas TX USA
| |
Collapse
|
8
|
Persistent structural adaptation in the lungs of guinea pigs raised at high altitude. Respir Physiol Neurobiol 2014; 208:37-44. [PMID: 25534146 DOI: 10.1016/j.resp.2014.12.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/18/2014] [Accepted: 12/15/2014] [Indexed: 11/20/2022]
Abstract
Laboratory guinea pigs raised at high altitude (HA, 3800 m) for up to 6 mo exhibit enhanced alveolar growth and remodeling (Hsia et al., 2005. Resp. Physiol. Neurobiol. 147, 105-115). To determine whether initial HA-induced structural enhancement persists following return to intermediate altitude (IA), we raised weanling guinea pigs at (a) HA for 11-12 mo, (b) IA (1200 m) for 11-12 mo, and (c) HA for 4 mo followed by IA for 7-8 mo (HA-to-IA). Morphometric analysis was performed under light and electron microscopy. Body weight and lung volume were similar among groups. Prolonged HA residence increased alveolar epithelium and interstitium volumes while reducing alveolar-capillary blood volume. The HA-induced gains in type-1 epithelium volume and alveolar surface area were no longer present following return to IA whereas volume increases in type-2 epithelium and interstitium and the reduction in alveolar duct volume persisted. Results demonstrate persistent augmentation of some but not all aspects of lung structure throughout prolonged HA residence, with partial reversibility following re-acclimatization to IA.
Collapse
|
9
|
Peng S, Wang Y, Peng H, Chen D, Shen S, Peng B, Chen M, Lencioni R, Kuang M. Autocrine vascular endothelial growth factor signaling promotes cell proliferation and modulates sorafenib treatment efficacy in hepatocellular carcinoma. Hepatology 2014; 60:1264-77. [PMID: 24849467 DOI: 10.1002/hep.27236] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Accepted: 05/19/2014] [Indexed: 01/31/2023]
Abstract
UNLABELLED Tumor cells express vascular endothelial growth factor (VEGF) that can activate VEGF receptors (VEGFRs) on or within tumor cells to promote growth in an angiogenesis-independent fashion; however, this autocrine VEGF pathway has not been reported in hepatocellular carcinoma (HCC). Sorafenib, an angiogenic inhibitor, is the only drug approved for use in advanced HCC patients. Yet the treatment efficacy is diverse and the mechanism behind it remains undetermined. Our aims were to study the molecular mechanisms underlying autocrine VEGF signaling in HCC cells and evaluate the critical role of autocrine VEGF signaling on sorafenib treatment efficacy. By immunohistochemistry, we found robust nuclear and cytoplasmic staining for active, phosphorylated VEGF receptor 1 (pVEGFR1) and phosphorylated VEGF receptor 2 (pVEGFR2), and by western blotting we found that membrane VEGFR1 and VEGFR2 increased in HCC tissues. We showed that autocrine VEGF promoted phosphorylation of VEGFR1 and VEGFR2 and internalization of pVEGFR2 in HCC cells, which was both pro-proliferative through a protein lipase C-extracellular kinase pathway and self-sustaining through increasing VEGF, VEGFR1, and VEGFR2 mRNA expressions. In high VEGFR1/2-expressing HepG2 cells, sorafenib treatment inhibited cell proliferation, reduced VEGFR2 mRNA expression in vitro, and delayed xenograft tumor growth in vivo. These results were not found in low VEGFR1/2-expressing Hep3B cells. In an advanced HCC population on sorafenib treatment for postoperative recurrence, we found that the absence of VEGFR1 or VEGFR2 expression in resected tumor tissues before sorafenib treatment was associated with poorer overall survival. CONCLUSION Autocrine VEGF signaling directly promotes HCC cell proliferation and affects the sorafenib treatment outcome in vitro and in vivo, which may enable better stratification for clinical treatment decisions.
Collapse
Affiliation(s)
- Sui Peng
- Department of Gastroenterology and Hepatology
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Thane K, Ingenito EP, Hoffman AM. Lung regeneration and translational implications of the postpneumonectomy model. Transl Res 2014; 163:363-76. [PMID: 24316173 DOI: 10.1016/j.trsl.2013.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 10/30/2013] [Accepted: 11/18/2013] [Indexed: 10/26/2022]
Abstract
Lung regeneration research is yielding data with increasing translational value. The classical models of lung development, postnatal alveolarization, and postpneumonectomy alveolarization have contributed to a broader understanding of the cellular participants including stem-progenitor cells, cell-cell signaling pathways, and the roles of mechanical deformation and other physiologic factors that have the potential to be modulated in human and animal patients. Although recent information is available describing the lineage fate of lung fibroblasts, genetic fate mapping, and clonal studies are lacking in the study of lung regeneration and deserve further examination. In addition to increasing knowledge concerning classical alveolarization (postnatal, postpneumonectomy), there is increasing evidence for remodeling of the adult lung after partial pneumonectomy. Though limited in scope, compelling data have emerged describing restoration of lung tissue mass in the adult human and in large animal models. The basis for this long-term adaptation to pneumonectomy is poorly understood, but investigations into mechanisms of lung regeneration in older animals that have lost their capacity for rapid re-alveolarization are warranted, as there would be great translational value in modulating these mechanisms. In addition, quantitative morphometric analysis has progressed in conjunction with developments in advanced imaging, which allow for longitudinal and nonterminal evaluation of pulmonary regenerative responses in animals and humans. This review focuses on the cellular and molecular events that have been observed in animals and humans after pneumonectomy because this model is closest to classical regeneration in other mammalian systems and has revealed several new fronts of translational research that deserve consideration.
Collapse
Affiliation(s)
- Kristen Thane
- Department of Clinical Sciences, Regenerative Medicine Laboratory, Tufts University Cummings School of Veterinary Medicine, North Grafton, Mass
| | - Edward P Ingenito
- Division of Pulmonary, Critical Care, and Sleep Medicine, Brigham and Women's Hospital, Boston, Mass
| | - Andrew M Hoffman
- Department of Clinical Sciences, Regenerative Medicine Laboratory, Tufts University Cummings School of Veterinary Medicine, North Grafton, Mass.
| |
Collapse
|
11
|
Zhang Q, Yu C, Peng S, Xu H, Wright E, Zhang X, Huo X, Cheng E, Pham TH, Asanuma K, Hatanpaa KJ, Rezai D, Wang DH, Sarode V, Melton S, Genta RM, Spechler SJ, Souza RF. Autocrine VEGF signaling promotes proliferation of neoplastic Barrett's epithelial cells through a PLC-dependent pathway. Gastroenterology 2014; 146:461-72.e6. [PMID: 24120473 PMCID: PMC3899829 DOI: 10.1053/j.gastro.2013.10.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 10/03/2013] [Accepted: 10/03/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Tumor cells express vascular endothelial growth factor (VEGF), which induces angiogenesis. VEGF also activates VEGF receptors (VEGFRs) on or within tumor cells to promote their proliferation in an autocrine fashion. We studied the mechanisms of autocrine VEGF signaling in Barrett's esophagus cells. METHODS Using Barrett's epithelial cell lines, we measured VEGF and VEGFR messenger RNA and protein, and studied the effects of VEGF signaling on cell proliferation and VEGF secretion. We studied the effects of inhibiting factors in this pathway on levels of phosphorylated phospholipase Cγ1 (PLCG1), protein kinase C, and extracellular signal-regulated kinases (ERK)1/2. We performed immunohistochemical analysis of phosphorylated VEGFR2 on esophageal adenocarcinoma tissues. We studied effects of sunitinib, a VEGFR2 inhibitor, on proliferation of neoplastic cells and growth of xenograft tumors in mice. RESULTS Neoplastic and non-neoplastic Barrett's cells expressed VEGF and VEGFR2 messenger RNA and protein, with higher levels in neoplastic cells. Incubation with recombinant human VEGF significantly increased secretion of VEGF protein and cell number; knockdown of PLCG1 markedly reduced the recombinant human VEGF-stimulated increase in levels of phosphorylated PLCG1 and phosphorylated ERK1/2 in neoplastic cells. Esophageal adenocarcinoma tissues showed immunostaining for phosphorylated VEGFR2. Sunitinib inhibited VEGF signaling in neoplastic cells and reduced weight and volume of xenograft tumors in mice. CONCLUSIONS Neoplastic and non-neoplastic Barrett's epithelial cells have autocrine VEGF signaling. In neoplastic Barrett's cells, VEGF activation of VEGFR2 initiates a PLCG1-protein kinase C-ERK pathway that promotes proliferation and is self-sustaining (by causing more VEGF production). Strategies to reduce autocrine VEGF signaling (eg, with sunitinib) might be used to prevent or treat cancer in patients with Barrett's esophagus.
Collapse
Affiliation(s)
- Qiuyang Zhang
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Chunhua Yu
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Sui Peng
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Division of Gastroenterology and Hepatology, The First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Hao Xu
- Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Ellen Wright
- Department of Research and Development, VA North Texas Heath Care System, Dallas, Texas
| | - Xi Zhang
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Xiaofang Huo
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Edaire Cheng
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Pediatrics, Children's Medical Center, Dallas, Texas
| | - Thai H Pham
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Surgery, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Kiyotaka Asanuma
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Kimmo J Hatanpaa
- Department of Pathology, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Davood Rezai
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Research and Development, VA North Texas Heath Care System, Dallas, Texas
| | - David H Wang
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Venetia Sarode
- Department of Pathology, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Shelby Melton
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Pathology, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas
| | - Robert M Genta
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Pathology, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Miraca Life Sciences, Inc., Irving, Texas
| | - Stuart J Spechler
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Rhonda F Souza
- Center for Esophageal Diseases, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Department of Internal Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical School, Dallas, Texas; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas.
| |
Collapse
|
12
|
McLoughlin P, Keane MP. Physiological and pathological angiogenesis in the adult pulmonary circulation. Compr Physiol 2013; 1:1473-508. [PMID: 23733650 DOI: 10.1002/cphy.c100034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Angiogenesis occurs during growth and physiological adaptation in many systemic organs, for example, exercise-induced skeletal and cardiac muscle hypertrophy, ovulation, and tissue repair. Disordered angiogenesis contributes to chronic inflammatory disease processes and to tumor growth and metastasis. Although it was previously thought that the adult pulmonary circulation was incapable of supporting new vessel growth, over that past 10 years new data have shown that angiogenesis within this circulation occurs both during physiological adaptive processes and as part of the pathogenic mechanisms of lung diseases. Here we review the expression of vascular growth factors in the adult lung, their essential role in pulmonary vascular homeostasis and the changes in their expression that occur in response to physiological challenges and in disease. We consider the evidence for adaptive neovascularization in the pulmonary circulation in response to alveolar hypoxia and during lung growth following pneumonectomy in the adult lung. In addition, we review the role of disordered angiogenesis in specific lung diseases including idiopathic pulmonary fibrosis, acute adult distress syndrome and both primary and metastatic tumors of the lung. Finally, we examine recent experimental data showing that therapeutic enhancement of pulmonary angiogenesis has the potential to treat lung diseases characterized by vessel loss.
Collapse
Affiliation(s)
- Paul McLoughlin
- University College Dublin, School of Medicine and Medical Sciences, Conway Institute, and St. Vincent's University Hospital, Dublin, Ireland.
| | | |
Collapse
|
13
|
Paisley D, Bevan L, Choy KJ, Gross C. The pneumonectomy model of compensatory lung growth: insights into lung regeneration. Pharmacol Ther 2013; 142:196-205. [PMID: 24333263 DOI: 10.1016/j.pharmthera.2013.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 11/19/2013] [Indexed: 10/25/2022]
Abstract
Pneumonectomy (PNX) in experimental animals leads to a species- and age-dependent compensatory growth of the remaining lung lobes. PNX mimics the loss of functional gas exchange units observed in a number of chronic destructive lung diseases. However, unlike in disease models, this tissue loss is well defined, reproducible and lacks accompanying inflammation. Furthermore, compensatory responses to the tissue loss can be easily quantified. This makes PNX a potentially useful model for the study of the cellular and molecular events which occur during realveolarisation. It may therefore help to get a better understanding of how to manipulate these pathways, in order to promote the generation of new alveolar tissue as therapies for destructive lung diseases. This review will explore the insights that experimental PNX has provided into the physiological factors which promote compensatory lung growth as well as the importance of age and species in the rate and extent of compensation. In addition, more recent studies which are beginning to uncover the key cellular and molecular pathways involved in realveolarisation will be discussed. The potential relevance of experimental pneumonectomy to novel therapeutic strategies which aim to promote lung regeneration will also be highlighted.
Collapse
Affiliation(s)
- Derek Paisley
- Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB, United Kingdom.
| | - Luke Bevan
- Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB, United Kingdom
| | - Katherine J Choy
- Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB, United Kingdom
| | - Carina Gross
- Respiratory Disease Area, Novartis Institutes for Biomedical Research, Wimblehurst Road, Horsham, West Sussex RH12 5AB, United Kingdom
| |
Collapse
|
14
|
Suga A, Ueda K, Takemoto Y, Nishimoto A, Hosoyama T, Li TS, Hamano K. Significant role of bone marrow–derived cells in compensatory regenerative lung growth. J Surg Res 2013; 183:84-90. [DOI: 10.1016/j.jss.2012.12.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 11/14/2012] [Accepted: 12/07/2012] [Indexed: 11/30/2022]
|
15
|
Dane DM, Yilmaz C, Estrera AS, Hsia CCW. Separating in vivo mechanical stimuli for postpneumonectomy compensation: physiological assessment. J Appl Physiol (1985) 2012; 114:99-106. [PMID: 23104695 DOI: 10.1152/japplphysiol.01213.2012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Following right pneumonectomy (PNX), the remaining lung expands and its perfusion doubles. Tissue and microvascular mechanical stresses are putative stimuli for initiating compensatory lung growth and remodeling, but their relative contributions to overall compensation remain uncertain. To temporally isolate the stimuli related to post-PNX lung expansion (parenchyma deformation) from those related to the sustained increase in perfusion (microvascular distention and shear), we replaced the right lung of adult dogs with a custom-shaped inflated prosthesis. Following stabilization of perfusion and wound healing 4 mo later, the prosthesis was either acutely deflated (DEF group) or kept inflated (INF group). Physiological studies were performed pre-PNX, 4 mo post-PNX (inflated prosthesis, INF1), and again 4 mo postdeflation (DEF) compared with controls with simultaneous INF prosthesis (INF2). Perfusion to the remaining lung increased ~76-113% post-PNX (INF1 and INF2) and did not change postdeflation. Post-PNX (INF prosthesis) end-expiratory lung volume (EELV) and lung and membrane diffusing capacities (DL(CO) and DM(CO)) at a given perfusion were 25-40% below pre-PNX baseline. In the INF group EELV, DL(CO) and DM(CO) remained stable or declined slightly with time. In contrast, all of these parameters increased significantly after deflation and were 157%, 26%, and 47%, respectively, above the corresponding control values (INF2). Following delayed deflation, lung expansion accounted for 44%-48% of total post-PNX compensatory increase in exercise DL(CO) and peak O(2) uptake; the remainder fraction is likely attributable to the increase in perfusion. Results suggest that expansion-related parenchyma mechanical stress and perfusion-related microvascular stress contribute in equal proportions to post-PNX alveolar growth and remodeling.
Collapse
Affiliation(s)
- D Merrill Dane
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9034, USA
| | | | | | | |
Collapse
|
16
|
Velázque-Amado RM, Escamilla-Chimal EG, Fanjul-Moles ML. Daily Light-Dark Cycles Influence Hypoxia-Inducible Factor 1 and Heat Shock Protein Levels in the Pacemakers of Crayfish. Photochem Photobiol 2011; 88:81-9. [DOI: 10.1111/j.1751-1097.2011.01012.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
|
17
|
Hu MC, Shi M, Zhang J, Quiñones H, Griffith C, Kuro-o M, Moe OW. Klotho deficiency causes vascular calcification in chronic kidney disease. J Am Soc Nephrol 2011; 22:124-36. [PMID: 21115613 PMCID: PMC3014041 DOI: 10.1681/asn.2009121311] [Citation(s) in RCA: 685] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2009] [Accepted: 09/03/2010] [Indexed: 12/12/2022] Open
Abstract
Soft-tissue calcification is a prominent feature in both chronic kidney disease (CKD) and experimental Klotho deficiency, but whether Klotho deficiency is responsible for the calcification in CKD is unknown. Here, wild-type mice with CKD had very low renal, plasma, and urinary levels of Klotho. In humans, we observed a graded reduction in urinary Klotho starting at an early stage of CKD and progressing with loss of renal function. Despite induction of CKD, transgenic mice that overexpressed Klotho had preserved levels of Klotho, enhanced phosphaturia, better renal function, and much less calcification compared with wild-type mice with CKD. Conversely, Klotho-haploinsufficient mice with CKD had undetectable levels of Klotho, worse renal function, and severe calcification. The beneficial effect of Klotho on vascular calcification was a result of more than its effect on renal function and phosphatemia, suggesting a direct effect of Klotho on the vasculature. In vitro, Klotho suppressed Na(+)-dependent uptake of phosphate and mineralization induced by high phosphate and preserved differentiation in vascular smooth muscle cells. In summary, Klotho is an early biomarker for CKD, and Klotho deficiency contributes to soft-tissue calcification in CKD. Klotho ameliorates vascular calcification by enhancing phosphaturia, preserving glomerular filtration, and directly inhibiting phosphate uptake by vascular smooth muscle. Replacement of Klotho may have therapeutic potential for CKD.
Collapse
Affiliation(s)
- Ming Chang Hu
- Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-8885, USA.
| | | | | | | | | | | | | |
Collapse
|
18
|
Hansen AE, Kristensen AT, Law I, Jørgensen JT, Engelholm SA. Hypoxia-inducible factors--regulation, role and comparative aspects in tumourigenesis. Vet Comp Oncol 2010; 9:16-37. [PMID: 21303451 DOI: 10.1111/j.1476-5829.2010.00233.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hypoxia-inducible factors (HIFs) play a key role in the cellular response experienced in hypoxic tumours, mediating adaptive responses that allow hypoxic cells to survive in the hostile environment. Identification and understanding of tumour hypoxia and the influence on cellular processes carries important prognostic information and may help identify potential hypoxia circumventing and targeting strategies. This review summarizes current knowledge on HIF regulation and function in tumour cells and discusses the aspects of using companion animals as comparative spontaneous cancer models. Spontaneous tumours in companion animals hold a great research potential for the evaluation and understanding of tumour hypoxia and in the development of hypoxia-targeting therapeutics.
Collapse
Affiliation(s)
- A E Hansen
- Department of Small Animal Clinical Sciences, The Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark.
| | | | | | | | | |
Collapse
|
19
|
Grek CL, Newton DA, Spyropoulos DD, Baatz JE. Hypoxia up-regulates expression of hemoglobin in alveolar epithelial cells. Am J Respir Cell Mol Biol 2010; 44:439-47. [PMID: 20508070 DOI: 10.1165/rcmb.2009-0307oc] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Alveolar epithelial cells are directly exposed to acute and chronic fluctuations in alveolar oxygen tension. Previously, we found that the oxygen-binding protein hemoglobin is expressed in alveolar Type II cells (ATII). Here, we report that ATII cells also express a number of highly specific transcription factors and other genes normally associated with hemoglobin biosynthesis in erythroid precursors. Because hypoxia-inducible factors (HIFs) were shown to play a role in hypoxia-induced changes in ATII homeostasis, we hypothesized that the hypoxia-induced increase in intracellular HIF exerts a concomitant effect on ATII hemoglobin expression. Treatment of cells from the ATII-like immortalized mouse lung epithelial cell line-15 (MLE-15) with hypoxia for 20 hours resulted in dramatic increases in cellular levels of HIF-2α protein and parallel significant increases in hemoglobin messenger RNA (mRNA) and protein expression, as compared with that of control cells cultured in normoxia. Significant increases in the mRNA of globin-associated transcription factors were also observed, and RNA interference (RNAi) experiments demonstrated that the expression of hemoglobin is at least partially dependent on the cellular levels of globin-associated transcription factor isoform 1 (GATA-1). Conversely, levels of prosurfactant proteins B and C significantly decreased in the same cells after exposure to hypoxia. The treatment of MLE-15 cells cultured in normoxia with prolyl 4-hydroxylase inhibitors, which mimic the effects of hypoxia, resulted in increases of hemoglobin and decreases of surfactant proteins. Taken together, these results suggest a relationship between hypoxia, HIFs, and the expression of hemoglobin, and imply that hemoglobin may be involved in the oxygen-sensing pathway in alveolar epithelial cells.
Collapse
Affiliation(s)
- Christina L Grek
- Department of Pediatrics and Neonatology, Medical University of South Carolina, Charleston, SC 29425, USA.
| | | | | | | |
Collapse
|
20
|
Synergistic upregulation of erythropoietin receptor (EPO-R) expression by sense and antisense EPO-R transcripts in the canine lung. Proc Natl Acad Sci U S A 2008; 105:7612-7. [PMID: 18495932 DOI: 10.1073/pnas.0802467105] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
We previously found increased erythropoietin receptor (EPO-R) protein levels in vigorously growing canine lungs after pneumonectomy (PNX), suggesting a role for paracrine EPO signaling in lung growth and remodeling. Now we find that sense and antisense EPO-R transcripts (sEPO-R and asEPO-R, respectively) are concordantly up-regulated in the post-PNX remaining lung, leading to the hypothesis that sEPO-R and asEPO-R interactions enhance EPO signaling during lung growth. We cloned a canine asEPO-R cDNA, which is fully complementary to the sense strand of the EPO-R gene from 2.5kb 3' to the sense stop codon, and extends into the 5' UTR of the sEPO-R transcript. Both asEPO-R and sEPO-R transcripts colocalize with EPO-R protein in the same lung cells. In cultured human embryonic kidney (HEK293) cells, transfection with sEPO-R (+FLAG tag) cDNA alone increased EPO-R protein expression (anti-EPO-R and anti-FLAG). At constant sEPO-R cDNA levels, cotransfection with escalating asEPO-R cDNA further increased recombinant EPO-R protein expression. The asEPO-R transcript harbors two putative opening reading frames (ORFs). Separate transfection of each asEPO-R ORF cDNA resulted in differential stimulatory effects on EPO-R protein expression. We conclude that both sEPO-R and asEPO-R transcripts contribute to in vivo up-regulation of EPO-R protein expression in the post-PNX remaining lung. This demonstrates synergism between sense-antisense EPO-R transcripts in response to physiological stimulation in a robust model of induced lung growth.
Collapse
|
21
|
Tuder RM, Yun JH, Bhunia A, Fijalkowska I. Hypoxia and chronic lung disease. J Mol Med (Berl) 2007; 85:1317-24. [PMID: 18040654 DOI: 10.1007/s00109-007-0280-4] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 10/23/2007] [Accepted: 10/24/2007] [Indexed: 01/15/2023]
Abstract
The lung is both the conduit for oxygen uptake and is also affected by hypoxia and hypoxia signaling. Decreased ventilatory drive, airway obstructive processes, intra-alveolar exudates, septal thickening by edema, inflammation, fibrosis, or damage to alveolar capillaries will all interpose a significant and potentially life-threatening barrier to proper oxygenation, therefore enhancing the alveolar/arterial pO2 gradient. These processes result in decreased blood and tissue oxygenation. This review addresses the relationship of hypoxia with lung development and with lung diseases. We particularly focus on molecular mechanisms underlying hypoxia-driven physiological and pathophysiological lung processes, specifically in the infant lung, pulmonary hypertension, and chronic obstructive pulmonary disease.
Collapse
Affiliation(s)
- Rubin M Tuder
- Division of Cardiopulmonary Pathology, Department of Pathology, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Research Building, Room 519, Baltimore, MD, 21205, USA.
| | | | | | | |
Collapse
|
22
|
Torday JS, Rehan VK, Hicks JW, Wang T, Maina J, Weibel ER, Hsia CC, Sommer RJ, Perry SF. Deconvoluting lung evolution: from phenotypes to gene regulatory networks. Integr Comp Biol 2007; 47:601-9. [PMID: 20607138 PMCID: PMC2895359 DOI: 10.1093/icb/icm069] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Speakers in this symposium presented examples of respiratory regulation that broadly illustrate principles of evolution from whole organ to genes. The swim bladder and lungs of aquatic and terrestrial organisms arose independently from a common primordial "respiratory pharynx" but not from each other. Pathways of lung evolution are similar between crocodiles and birds but a low compliance of mammalian lung may have driven the development of the diaphragm to permit lung inflation during inspiration. To meet the high oxygen demands of flight, bird lungs have evolved separate gas exchange and pump components to achieve unidirectional ventilation and minimize dead space. The process of "screening" (removal of oxygen from inspired air prior to entering the terminal units) reduces effective alveolar oxygen tension and potentially explains why nonathletic large mammals possess greater pulmonary diffusing capacities than required by their oxygen consumption. The "primitive" central admixture of oxygenated and deoxygenated blood in the incompletely divided reptilian heart is actually co-regulated with other autonomic cardiopulmonary responses to provide flexible control of arterial oxygen tension independent of ventilation as well as a unique mechanism for adjusting metabolic rate. Some of the most ancient oxygen-sensing molecules, i.e., hypoxia-inducible factor-1alpha and erythropoietin, are up-regulated during mammalian lung development and growth under apparently normoxic conditions, suggesting functional evolution. Normal alveolarization requires pleiotropic growth factors acting via highly conserved cell-cell signal transduction, e.g., parathyroid hormone-related protein transducing at least partly through the Wingless/int pathway. The latter regulates morphogenesis from nematode to mammal. If there is commonality among these diverse respiratory processes, it is that all levels of organization, from molecular signaling to structure to function, co-evolve progressively, and optimize an existing gas-exchange framework.
Collapse
Affiliation(s)
- John S. Torday
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - Virender K. Rehan
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - James W. Hicks
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - Tobias Wang
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - John Maina
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - Ewald R. Weibel
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - Connie C.W. Hsia
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - Ralf J. Sommer
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| | - Steven F. Perry
- *David Geffen School of Medicine at UCLA, Los Angeles, California, USA; Department of Ecology and Evolutionary Biology, University of California, Irvine, USA; Department of Zoophysiology, Aarhus University, Denmark; University of Witwatersrand, Johannesburg, South Africa; University of Berne, Berne, Switzerland; University of Texas Southwestern Medical Center, Dallas, Texas, USA; Max Planck Institute for Developmental Biology, Tuebingen, Germany; University of Bonn, Bonn, Germany
| |
Collapse
|
23
|
Zhang Q, Bellotto DJ, Ravikumar P, Moe OW, Hogg RT, Hogg DC, Estrera AS, Johnson RL, Hsia CCW. Postpneumonectomy lung expansion elicits hypoxia-inducible factor-1α signaling. Am J Physiol Lung Cell Mol Physiol 2007; 293:L497-504. [PMID: 17513452 DOI: 10.1152/ajplung.00393.2006] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We ( 42 ) previously reported differential regulation of hypoxia-inducible factors (HIF-1α, -2α, and -3α) mRNA in canine lungs during normal maturation and postpneumonectomy (PNX) compensatory growth in the absence of overt hypoxia. To test the hypothesis that lung expansion activates HIF signaling, we replaced the right lung of six adult foxhounds with inflated custom-shaped silicone prosthesis to keep the mediastinum in the midline and minimize lateral expansion of the remaining lung. After 3 wk of recovery and stabilization of perfusion, the prosthesis was acutely deflated in three animals, causing the remaining lung to expand by 114%. In three other animals, the prosthesis remained inflated. Three days following deflation, we observed significant elevation in the mRNA and nuclear protein levels of HIF-1α (∼60%) as well as activation of its transcriptional regulator, the serine/threonine protein kinase B (phospho-Akt-to-total Akt ratio, 124%), and the mRNA and protein levels of its downstream targets, erythropoietin receptor (71–183%) as well as VEGF (33–58%) compared with the pre-PNX control lung from the same animal. The mRNA of HIF-2α, HIF-3α, and VEGF receptors did not change with acute deflation. We conclude that in vivo lung expansion by post-PNX deflation of space-occupying prosthesis elicits coordinated activation of HIF-1α signaling in adult lungs. This pathway could play an important role in mediating lung growth and remodeling during maturation and post-PNX compensation.
Collapse
Affiliation(s)
- Quiyang Zhang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9034, USA
| | | | | | | | | | | | | | | | | |
Collapse
|