Natural surfactant and hyperoxic lung injury in primates. II. Morphometric analyses

1994 ◽  
Vol 76 (3) ◽  
pp. 1002-1010 ◽  
Author(s):  
P. J. Fracica ◽  
S. P. Caminiti ◽  
C. A. Piantadosi ◽  
F. G. Duhaylongsod ◽  
J. D. Crapo ◽  
...  

Diffuse lung injury is accompanied by low compliance and hypoxemia with histological evidence of endothelial and alveolar epithelial cell disruption. The histological effects of treatment of an acute diffuse lung injury with a natural surfactant product were evaluated in a primate model because surfactant function and content have been shown to be abnormal in diffuse lung injury in both animals and humans. Ten baboons were ventilated with 100% O2 for 96 h, and 5 were given an aerosol of natural porcine surfactant. Physiological and biochemical measurements of the effects of hyperoxia and surfactant treatment are presented in a companion paper. After O2 exposure, lungs were fixed and processed for quantitative electron microscopy. The responses to O2 included epithelial and endothelial cell injuries, interstitial edema, and inflammation. The hyperoxic animals treated with surfactant were compared with the untreated animals; the treatments altered neutrophil distribution, fibroblast proliferation, and changes in the volumes of type I epithelial cells and endothelial cells. Surfactant-treated animals also had decreased lamellar body volume density in type II epithelial cells and preservation of endothelial cell integrity. These changes suggest complex effects of natural surfactant on the pulmonary response to hyperoxia, including protection against epithelial and endothelial cell destruction as well as significant interstitial inflammation and fibroblast proliferation. We conclude that natural surfactant treatment of hyperoxic lung injury in primates resulted in partial protection of epithelial and endothelial cells but also increased the accumulation of fibroblasts in the lung.

1998 ◽  
Vol 85 (2) ◽  
pp. 770-772
Author(s):  
Brian A. Hills

The following are the abstracts of the articles discussed in the subsequent letter: Huang, Yuh-Chin T., Aneysa C. Sane, Steven G. Simonson, Thomas A. Fawcett, Richard E. Moon, Philip J. Fracica, Margaret G. Menache, Claude A. Piantadosi, and Stephen L. Young. Artificial surfactant attenuates hyperoxic lung injury in primates. I. Physiology and biochemistry. J. Appl. Physiol. 78(5): 1816–1822, 1995.—Prolonged exposure to O2causes diffuse alveolar damage and surfactant dysfunction that contribute to the pathophysiology of hyperoxic lung injury. We hypothesized that exogenous surfactant would improve lung function during O2exposure in primates. Sixteen healthy male baboons (10–15 kg) were anesthetized and mechanically ventilated for 96 h. The animals received either 100% O2( n = 6) or 100% O2plus aerosolized artificial surfactant (Exosurf; n = 5). A third group of animals ( n = 5) was ventilated with an inspired fraction of O2of 0.21 to control for the effects of sedation and mechanical ventilation. Hemodynamic parameters were obtained every 12 h, and ventilation-perfusion distribution (V˙A/Q˙) was measured daily using a multiple inert-gas elimination technique. Positive end-expiratory pressure was kept at 2.5 cmH2O and was intermittently raised to 10 cmH2O for 30 min to obtain additional measurements ofV˙A/Q˙. After the experiments, lungs were obtained for biochemical and histological assessment of injury. O2exposures altered hemodynamics, progressively worsenedV˙A/Q˙, altered lung phospholipid composition, and produced severe lung edema. Artificial surfactant therapy significantly increased disaturated phosphatidylcholine in lavage fluid and improved intrapulmonary shunt, arterial Po2, and lung edema. Surfactant also enhanced the shunt-reducing effect of positive end-expiratory pressure. We conclude that an aerosolized protein-free surfactant decreased the progression of pulmonary O2toxicity in baboons.Piantadosi, Claude A., Philip J. Fracica, Francis G. Duhaylongsod, Y.-C. T. Huang, Karen E. Welty-Wolf, James D. Crapo, and Stephen L. Young. Artificial surfactant attenuates hyperoxic lung injury in primates. II. Morphometric analysis. J. Appl. Physiol. 78(5): 1823–1831, 1995.—Diffuse lung injury from hyperoxia is accompanied by low compliance and hypoxemia with disruption of endothelial and alveolar epithelial cell layers. Because both function and content of surfactant in diffuse lung injury decrease in animals and in humans, changes in the extent of injury during continuous hyperoxia were evaluated after treatments with a protein-free surfactant in primates. Ten baboons were ventilated with 100% O2for 96 h and five were intermittently given an aerosol of an artificial surfactant (Exosurf). Physiological and biochemical measurements of the effects of the surfactant treatment are presented in a companion paper (Y.-C. T. Huang, A. C. Sane, S. G. Simonson, T. A. Fawcett, R. E. Moon, P. J. Fracica, M. G. Menache, C. A. Piantadosi, and S. L. Young. J. Appl. Physiol. 78: 1823–1829, 1995.) After O2exposures, lungs were fixed and processed for electron microscopy. The cellular responses to O2included epithelial and endothelial cell injuries, interstitial edema, and inflammation. Morphometry was used to quantitate changes in lungs of animals treated with the artificial surfactant during O2exposure and to compare them with the untreated animals. The surfactant decreased neutrophil accumulation, increased fibroblast proliferation, and decreased changes in the volume of type I epithelial cells. Surfactant-treated animals also demonstrated better preservation of endothelial cell integrity. These responses indicate ameliorating effects of the surfactant on the pulmonary response to hyperoxia, including protection against epithelial and endothelial cell destruction. Significant interstitial inflammation and fibroblast proliferation remained, however, in surfactant-treated lungs exposed to continuous hyperoxia.


1995 ◽  
Vol 78 (5) ◽  
pp. 1823-1831 ◽  
Author(s):  
C. A. Piantadosi ◽  
P. J. Fracica ◽  
F. G. Duhaylongsod ◽  
Y. C. Huang ◽  
K. E. Welty-Wolf ◽  
...  

Diffuse lung injury from hyperoxia is accompanied by low compliance and hypoxemia with disruption of endothelial and alveolar epithelial cell layers. Because both function and content of surfactant in diffuse lung injury decrease in animals and in humans, changes in the extent of injury during continuous hyperoxia were evaluated after treatments with a protein-free surfactant in primates. Ten baboons were ventilated with 100% O2 for 96 h and five were intermittently given an aerosol of an artificial surfactant (Exosurf). Physiological and biochemical measurements of the effects of the surfactant treatment are presented in a companion paper (Y.-C. T. Huang, A. C. Sane, S. G. Simonson, T. A. Fawcett, R. E. Moon, P. J. Fracica, M. G. Menache, C. A. Piantadosi, and S. L. Young. J. Appl. Physiol. 78: 1823–1829, 1995.) After O2 exposures, lungs were fixed and processed for electron microscopy. The cellular responses to O2 included epithelial and endothelial cell injuries, interstitial edema, and inflammation. Morphometry was used to quantitate changes in lungs of animals treated with the artificial surfactant during O2 exposure and to compare them with the untreated animals. The surfactant decreased neutrophil accumulation, increased fibroblast proliferation, and decreased changes in the volume of type I epithelial cells. Surfactant-treated animals also demonstrated better preservation of endothelial cell integrity. These responses indicate ameliorating effects of the surfactant on the pulmonary response to hyperoxia, including protection against epithelial and endothelial cell destruction. Significant interstitial inflammation and fibroblast proliferation remained, however, in surfactant-treated lungs exposed to continuous hyperoxia.


1988 ◽  
Vol 64 (2) ◽  
pp. 689-696 ◽  
Author(s):  
J. P. Mastin ◽  
J. D. Shelburne ◽  
L. A. Thet

We studied the changes in subcellular ultrastructure associated with the hypertrophy of capillary endothelial cells during repair of hyperoxic (100% O2) lung injury in rats. We used stereologic-morphometric measurements at different magnifications to determine the absolute volume of each subcellular compartment per average capillary endothelial cell. The increases in this value during the first 3 days of postexposure repair were 118% for cytoplasm, 786% for polyribosomes, 310% for rough endoplasmic reticulum, and 79% for mitochondria; the volume of pinocytotic vesicles did not change. By day 7 of repair, only the polyribosomes and rough endoplasmic reticulum were still increased; by day 14 all values were normal. We conclude that the capillary endothelial cell hypertrophy that develops during repair of hyperoxic lung injury is associated with large and heterogeneous increases in subcellular organelles and is not merely due to increases in the cytosol or to cellular edema. These increases seem to be an integral part of the repair process and may be important in the development of tolerance to subsequent oxygen exposure.


1995 ◽  
Vol 269 (1) ◽  
pp. L127-L135 ◽  
Author(s):  
W. W. Barton ◽  
S. Wilcoxen ◽  
P. J. Christensen ◽  
R. Paine

Intercellular adhesion molecule-1 (ICAM-1) is expressed at high levels on type I alveolar epithelial cells in the normal lung and is induced in vitro as type II cells spread in primary culture. In contrast, in most nonhematopoetic cells ICAM-1 expression is induced in response to inflammatory cytokines. We have formed the hypothesis that the signals that control ICAM-1 expression in alveolar epithelial cells are fundamentally different from those controlling expression in most other cells. To test this hypothesis, we have investigated the influence of inflammatory cytokines on ICAM-1 expression in isolated type II cells that have spread in culture and compared this response to that of rat pulmonary artery endothelial cells (RPAEC). ICAM-1 protein, determined both by a cell-based enzyme-linked immunosorbent assay and by Western blot analysis, and mRNA were minimally expressed in unstimulated RPAEC but were significantly induced in a time- and dose-dependent manner by treatment with tumor necrosis factor-alpha, interleukin-1 beta, or interferon-gamma. In contrast, these cytokines did not influence the constitutive high level ICAM-1 protein expression in alveolar epithelial cells and only minimally affected steady-state mRNA levels. ICAM-1 mRNA half-life, measured in the presence of actinomycin D, was relatively long at 7 h in alveolar epithelial cells and 4 h in RPAEC. The striking lack of response of ICAM-1 expression by alveolar epithelial cells to inflammatory cytokines is in contrast to virtually all other epithelial cells studied to date and supports the hypothesis that ICAM-1 expression by these cells is a function of cellular differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)


Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 67-67
Author(s):  
Kimon Argyropoulos ◽  
Enrico Velardi ◽  
Jennifer Tsai ◽  
Amina Lazrak ◽  
Lorenz Jahn ◽  
...  

Abstract The thymus is extremely sensitive to exogenous insults but has a remarkable capacity to regenerate which is lost with age. Reactive oxygen species (ROS) accumulate early after tissue damage and despite their toxic potential, ROS and their byproducts (such as lipid peroxidation products-LPPs) can act as regeneration signals by activating membrane or intracellular sensors and subsequent stress-response signalling pathways. Using Sublethal Total Body Irradiation (SL-TBI) as a model of acute thymic injury, we found a rapid accumulation of thymic ROS as well as lipid peroxidation products on cell membranes after SLTBI (Figure 1A&B). The damage-sensing ion channel Transient Receptor Potential cation channel family A member 1 (TRPA1) represents one of the major damage sensing receptors that can mediate cellular responses to oxidative stress mediators, such as LPPs. Using immunofluorescence (IF) microscopy we found that TRPA1 is enriched in the thymic medulla. Interestingly, although TRPA1 has been classically identified in nociceptive fibers, the major TRPA1 expressing structures in the thymus were not nerve fiber terminals, but primarily thymic endothelial cells (Figure1C), fibroblasts and subsets of epithelial cells. We have recently demonstrated that thymic endothelial cells can regulate regeneration through secretion of BMP-4, which can enhance Foxn1 expression and proliferation of thymic epithelial cells. In order to assess the functional role of TRPA1 in thymic regeneration after injury, we utilized TRPA1 knockout (TRPA1-/-) mice and quantified thymic reconstitution after SL-TBI. TRPA1-/- mice had significantly lower thymic cellularity compared to their age- and sex-matched WT controls, suggesting an association between TRPA1 deficiency and delayed endogenous thymic recovery (Figure 1D). The major deficit in thymocyte counts primarily affected double negative-4 (DN4), double positive (DP) and CD4+ single positive (SP-CD4+) thymocyte numbers. The thymic stroma of TRPA1-/- mice had lower endothelial cell and fibroblast counts (Figure 1D). In accordance with these findings drinking water administration of the TRPA1 agonist Allyl-Isothiocyanate (AITC), resulted in enhanced thymic regeneration after radiation exposure. Besides its positive effects on thymocyte counts, AITC significantly augmented endothelial cell counts after irradiation (Figure 1E). In conclusion these results suggest that TRPA1 plays a non-redundant role in thymic regeneration and that exogenous TRPA1 stimulation can enhance immune recovery after damage. Disclosures van den Brink: Seres: Research Funding; Jazz Pharmaceuticals: Consultancy; PureTech Health: Consultancy; Therakos Institute: Other: Speaking engagement.


2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Anastasia Sacharidou ◽  
Wan-Ru Lee ◽  
Philip E Shaul ◽  
Chieko Mineo

High density lipoprotein cholesterol (HDL) has direct atheroprotective actions on endothelium. These are mediated by scavenger receptor class B, type I (SR-BI) and its adaptor protein PDZK1, and they entail the activation of Akt kinase, which phosphorylates and thereby stimulates endothelial nitric oxide synthase (eNOS). In the present work we sought to determine how PDZK1 couples HDL/SR-BI to Akt and eNOS to modulate endothelial function. Using tandem affinity purification (TAP) following the infection of the human endothelial cell line EAhy926 with adenovirus expressing TAP-tagged PDZK1, we identified Breakpoint Cluster Region (Bcr) kinase as a PDZK1 interacting protein in endothelium. Whereas Bcr is well-known as a component of the Bcr-Abl fusion protein that results from translocation of the Philadelphia chromosome in chronic myelogenous leukemia, little is known of its function in endothelial cells. Bcr contains several distinctive domains including a C-terminal PDZ binding motif and a serine/threonine protein kinase domain. In primary human aortic endothelial cells (HAEC), we determined that endogenous Bcr interacts with PDZK1 in an HDL-dependent manner, and that Bcr is required for HDL-induced activation of eNOS and HDL stimulation of endothelial cell migration, which underlies the ability of the lipoprotein to promote endothelial monolayer integrity. Studies of mutant forms of Bcr with disruption of PDZK1 binding or kinase activity introduced into endothelial cells further revealed that Bcr-PDZK1 interaction and its kinase function are required for HDL activation of Akt and eNOS. Using a novel kinase assay that we recently developed that employs time-resolved Forster resonance energy transfer, we found that via SR-BI and PDZK1, HDL stimulates Bcr kinase activity in endothelial cells more than 20-fold. In addition, using Akt-based peptides in studies of the two known kinases for Akt, mTOR and PDK1, we determined that HDL activates Bcr kinase to directly phosphorylate Akt-Ser473 in an mTOR independent manner, and that Akt-Thr308 is a direct substrate of PDK1. These collective findings have identified Bcr to be a novel kinase for Akt, and they have revealed that Bcr is critically involved in HDL modulation of endothelial cell phenotype.


Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 70 ◽  
Author(s):  
Gerna ◽  
Kabanova ◽  
Lilleri

In the 1970s–1980s, a striking increase in the number of disseminated human cytomegalovirus (HCMV) infections occurred in immunosuppressed patient populations. Autopsy findings documented the in vivo disseminated infection (besides fibroblasts) of epithelial cells, endothelial cells, and polymorphonuclear leukocytes. As a result, multiple diagnostic assays, such as quantification of HCMV antigenemia (pp65), viremia (infectious virus), and DNAemia (HCMV DNA) in patient blood, were developed. In vitro experiments showed that only low passage or endothelial cell-passaged clinical isolates, and not laboratory-adapted strains, could reproduce both HCMV leuko- and endothelial cell-tropism, which were found through genetic analysis to require the three viral genes UL128, UL130, and UL131 of the HCMV UL128 locus (UL128L). Products of this locus, together with gH/gL, were shown to form the gH/gL/pUL128L pentamer complex (PC) required for infection of epithelial cells/endothelial cells, whereas gH/gL and gO form the gH/gL/gO trimer complex (TC) required for infection of all cell types. In 2016, following previous work, a receptor for the TC that mediates entry into fibroblasts was identified as PDGFRα, while in 2018, a receptor for the PC that mediates entry into endothelial/epithelial cells was identified as neuropilin2 (Nrp2). Furthermore, the olfactory receptor family member OR14I1 was recently identified as a possible additional receptor for the PC in epithelial cells. Thus, current data support two models of viral entry: (i) in fibroblasts, following interaction of PDGFRα with TC, the latter activates gB to fuse the virus envelope with the cell membrane, whereas (ii) in epithelial cells/endothelial cells, interaction of Nrp2 (and OR14I1) with PC promotes endocytosis of virus particles, followed by gB activation by gH/gL/gO (or gH/gL) and final low-pH entry into the cell.


2019 ◽  
Vol 99 (2) ◽  
pp. 1281-1324 ◽  
Author(s):  
Sonsoles Piera-Velazquez ◽  
Sergio A. Jimenez

Numerous studies have demonstrated that endothelial cells are capable of undergoing endothelial to mesenchymal transition (EndMT), a newly recognized type of cellular transdifferentiation. EndMT is a complex biological process in which endothelial cells adopt a mesenchymal phenotype displaying typical mesenchymal cell morphology and functions, including the acquisition of cellular motility and contractile properties. Endothelial cells undergoing EndMT lose the expression of endothelial cell-specific proteins such as CD31/platelet-endothelial cell adhesion molecule, von Willebrand factor, and vascular-endothelial cadherin and initiate the expression of mesenchymal cell-specific genes and the production of their encoded proteins including α-smooth muscle actin, extra domain A fibronectin, N-cadherin, vimentin, fibroblast specific protein-1, also known as S100A4 protein, and fibrillar type I and type III collagens. Transforming growth factor-β1 is considered the main EndMT inducer. However, EndMT involves numerous molecular and signaling pathways that are triggered and modulated by multiple and often redundant mechanisms depending on the specific cellular context and on the physiological or pathological status of the cells. EndMT participates in highly important embryonic development processes, as well as in the pathogenesis of numerous genetically determined and acquired human diseases including malignant, vascular, inflammatory, and fibrotic disorders. Despite intensive investigation, many aspects of EndMT remain to be elucidated. The identification of molecules and regulatory pathways involved in EndMT and the discovery of specific EndMT inhibitors should provide novel therapeutic approaches for various human disorders mediated by EndMT.


2000 ◽  
Vol 279 (1) ◽  
pp. H293-H302 ◽  
Author(s):  
Maria Luiza C. Albuquerque ◽  
Christopher M. Waters ◽  
Ushma Savla ◽  
H. William Schnaper ◽  
Annette S. Flozak

Repair of the endothelium occurs in the presence of continued blood flow, yet the mechanisms by which shear forces affect endothelial wound closure remain elusive. Therefore, we tested the hypothesis that shear stress enhances endothelial cell wound closure. Human umbilical vein endothelial cells (HUVEC) or human coronary artery endothelial cells (HCAEC) were cultured on type I collagen-coated coverslips. Cell monolayers were sheared for 18 h in a parallel-plate flow chamber at 12 dyn/cm2 to attain cellular alignment and then wounded by scraping with a metal spatula. Subsequently, the monolayers were exposed to a laminar shear stress of 3, 12, or 20 dyn/cm2 under shear-wound-shear (S-W-sH) or shear-wound-static (S-W-sT) conditions for 6 h. Wound closure was measured as a percentage of original wound width. Cell area, centroid-to-centroid distance, and cell velocity were also measured. HUVEC wounds in the S-W-sH group exposed to 3, 12, or 20 dyn/cm2 closed to 21, 39, or 50%, respectively, compared with only 59% in the S-W-sT cells. Similarly, HCAEC wounds closed to 29, 49, or 33% (S-W-sH) compared with 58% in the S-W-sT cells. Cell spreading and migration, but not proliferation, were the major mechanisms accounting for the increases in wound closure rate. These results suggest that physiological levels of shear stress enhance endothelial repair.


2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Jillian M. Carr ◽  
Liam M. Ashander ◽  
Julie K. Calvert ◽  
Yuefang Ma ◽  
Amanda Aloia ◽  
...  

Recent clinical reports indicate that infection with dengue virus (DENV) commonly has ocular manifestations. The most serious threat to vision is dengue retinopathy, including retinal vasculopathy and macular edema. Mechanisms of retinopathy are unstudied, but observations in patients implicate retinal pigment epithelial cells and retinal endothelial cells. Human retinal cells were inoculated with DENV-2 and monitored for up to 72 hours. Epithelial and endothelial cells supported DENV replication and release, but epithelial cells alone demonstrated clear cytopathic effect, and infection was more productive in those cells. Infection induced type I interferon responses from both cells, but this was stronger in epithelial cells. Endothelial cells increased expression of adhesion molecules, with sustained overexpression of vascular adhesion molecule-1. Transcellular impedance decreased for epithelial monolayers, but not endothelial monolayers, coinciding with cytopathic effect. This reduction was accompanied by disorganization of intracellular filamentous-actin and decreased expression of junctional molecules, zonula occludens 1, and catenin-β1. Changes in endothelial expression of adhesion molecules are consistent with the retinal vasculopathy seen in patients infected with DENV; decreases in epithelial junctional protein expression, paralleling loss of integrity of the epithelium, provide a molecular basis for DENV-associated macular edema. These molecular processes present potential therapeutic targets for vision-threatening dengue retinopathy.


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