Janice Liebler - Academia.edu (original) (raw)
Papers by Janice Liebler
American Journal of Respiratory Cell and Molecular Biology, 2014
Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that ... more Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that regulate paracellular permeability to ions and solutes. Claudin 18, a member of the large claudin family, is highly expressed in lung alveolar epithelium. To elucidate the role of claudin 18 in alveolar epithelial barrier function, we generated claudin 18 knockout (C18 KO) mice. C18 KO mice exhibited increased solute permeability and alveolar fluid clearance (AFC) compared with wild-type control mice. Increased AFC in C18 KO mice was associated with increased β-adrenergic receptor signaling together with activation of cystic fibrosis transmembrane conductance regulator, higher epithelial sodium channel, and Na-K-ATPase (Na pump) activity and increased Na-K-ATPase β1 subunit expression. Consistent with in vivo findings, C18 KO alveolar epithelial cell (AEC) monolayers exhibited lower transepithelial electrical resistance and increased solute and ion permeability with unchanged ion selectivity. Claudin 3 and claudin 4 expression was markedly increased in C18 KO mice, whereas claudin 5 expression was unchanged and occludin significantly decreased. Microarray analysis revealed changes in cytoskeleton-associated gene expression in C18 KO mice, consistent with observed F-actin cytoskeletal rearrangement in AEC monolayers. These findings demonstrate a crucial nonredundant role for claudin 18 in the regulation of alveolar epithelial TJ composition and permeability properties. Increased AFC in C18 KO mice identifies a role for claudin 18 in alveolar fluid homeostasis beyond its direct contributions to barrier properties that may, at least in part, compensate for increased permeability.
American Journal of Respiratory Cell and Molecular Biology, 2014
Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that ... more Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that regulate paracellular permeability to ions and solutes. Claudin 18, a member of the large claudin family, is highly expressed in lung alveolar epithelium. To elucidate the role of claudin 18 in alveolar epithelial barrier function, we generated claudin 18 knockout (C18 KO) mice. C18 KO mice exhibited increased solute permeability and alveolar fluid clearance (AFC) compared with wild-type control mice. Increased AFC in C18 KO mice was associated with increased β-adrenergic receptor signaling together with activation of cystic fibrosis transmembrane conductance regulator, higher epithelial sodium channel, and Na-K-ATPase (Na pump) activity and increased Na-K-ATPase β1 subunit expression. Consistent with in vivo findings, C18 KO alveolar epithelial cell (AEC) monolayers exhibited lower transepithelial electrical resistance and increased solute and ion permeability with unchanged ion selectivity. Claudin 3 and claudin 4 expression was markedly increased in C18 KO mice, whereas claudin 5 expression was unchanged and occludin significantly decreased. Microarray analysis revealed changes in cytoskeleton-associated gene expression in C18 KO mice, consistent with observed F-actin cytoskeletal rearrangement in AEC monolayers. These findings demonstrate a crucial nonredundant role for claudin 18 in the regulation of alveolar epithelial TJ composition and permeability properties. Increased AFC in C18 KO mice identifies a role for claudin 18 in alveolar fluid homeostasis beyond its direct contributions to barrier properties that may, at least in part, compensate for increased permeability.
Distal lung epithelium is maintained by proliferation of alveolar type II (AT2) cells and, for so... more Distal lung epithelium is maintained by proliferation of alveolar type II
(AT2) cells and, for some daughter AT2 cells, transdifferentiation into
alveolar type I (AT1) cells. We investigated if subpopulations of
alveolar epithelial cells (AEC) exist that represent various stages in
transdifferentiation from AT2 to AT1 cell phenotypes in normal adult
lung and if they can be identified using combinations of cell-specific
markers. Immunofluorescence microscopy showed that, in distal rat
and mouse lungs, 20–30% of NKX2.1 (or thyroid transcription
factor 1) cells did not colocalize with pro-surfactant protein C
(pro-SP-C), a highly specific AT2 cell marker. In distal rat lung,
NKX2.1 cells coexpressed either pro-SP-C or the AT1 cell marker
homeodomain only protein x (HOPX). Not all HOPX cells colocalize
with the AT1 cell marker aquaporin 5 (AQP5), and some AQP5
cells were NKX2.1. HOPX was expressed earlier than AQP5 during
transdifferentiation in rat AEC primary culture, with robust expression
of both by day 7. We speculate that NKX2.1 and pro-SP-C colocalize
in AT2 cells, NKX2.1 and HOPX or AQP5 colocalize in intermediate
or transitional cells, and HOPX and AQP5 are expressed without
NKX2.1 in AT1 cells. These findings suggest marked heterogeneity
among cells previously identified as exclusively AT1 or AT2 cells,
implying the presence of subpopulations of intermediate or transitional
AEC in normal adult lung.
American Journal of Respiratory Cell and Molecular Biology, Aug 1, 2003
To identify genes of known function expressed by type I (AT1) cells, changes in gene expression d... more To identify genes of known function expressed by type I (AT1) cells, changes in gene expression during transdifferentiation of alveolar epithelial cells (AEC) in primary culture from type II (AT2) to type I-like cell phenotype were evaluated. Total RNA from AEC on Day 0 or Day 8 was hybridized to a rat microarray for screening. Eight upregulated genes on Day 8 were selected for further investigation. Northern analysis confirmed upregulation of three of these genes, PAI-1, P2X4, and P15INK4B. The corresponding proteins were evaluated in cultured AEC and results correlated with expression in AT1 cells. In AEC monolayers, all three proteins increased between Day 1 and Day 8. In mixed populations of freshly isolated rat lung cells, concurrent labeling with the AT1 cell-specific antibody, VIIIB2, localized these proteins to AT1 cells. In whole lung, all three proteins were detected in alveolar epithelium in a location consistent with expression in AT1 cells. Identification of novel AT1 cell genes of known function suggests an active role for AT1 cells in alveolar homeostasis. Furthermore, expression of these gene products in AT1-like cells, in freshly isolated AT1 cells, and AT1 cells in whole lung indicates that AT1-like cells reflect many of the properties of AT1 cells in situ.
J Appl Physiol, 2004
Rat alveolar epithelial type II (AT2) cells grown on polycarbonate filters form high resistance m... more Rat alveolar epithelial type II (AT2) cells grown on polycarbonate filters form high resistance monolayers and concurrently acquire many phenotypic properties of type I (AT1) cells. Treatment with epidermal growth factor (EGF) has previously been shown to increase transepithelial resistance (TER) across alveolar epithelial cell (AEC) monolayers. We investigated changes in claudin expression in primary cultured AEC during transdifferentiation to the AT1 cell-like phenotype (days 0, 1 and 8), and on day 5 in culture +/-EGF (10 ng/ml) from day 0 or day 4. Claudins 4 and 7 were increased, while claudins 3 and 5 were decreased, on later compared with earlier days in culture.
Basic fibroblast growth factor (bFGF) is a potent inducer of growth and proliferation for many ce... more Basic fibroblast growth factor (bFGF) is a potent inducer of growth and proliferation for many cell types involved in wound healing. Although bFGF has previously been identified in lung tissue, its role in the pathogenesis of pulmonary fibrosis is unknown. We investigated the distribution of bFGF after bleomycin-induced lung injury in the rat in hope of learning how bFGF might participate in the process of lung injury, repair and fibrosis. Increased immunoreactive bFGF was found in the extracellular matrix after bleomycin and co-localized to a marker of active cell proliferation. This suggests that bFGF may participate in directing cell proliferation following lung injury. In addition, a marked increase in the number of mast cells with strong reactivity for bFGF was found at days 14 and 21 after bleomycin. These cells may represent a source of bFGF during the fibroproliferative stage after lung injury.
Transforming growth factor-1 (TGF-1) may be a critical mediator of lung injury and subsequent rem... more Transforming growth factor-1 (TGF-1) may be a critical mediator of lung injury and subsequent remodeling during recovery. We evaluated the effects of TGF-1 on the permeability and active ion transport properties of alveolar epithelial cell monolayers. Rat alveolar type II cells plated on polycarbonate filters in defined serum-free medium form confluent monolayers and acquire the phenotypic characteristics of alveolar type I cells.
American Journal Of Pathology
Mast cells play an essential role during development of inflammation after chemical and immunolog... more Mast cells play an essential role during development of inflammation after chemical and immunological insults and have been implicated in tissue fibrosis and angiogenesis. The exact contribution of mast cells to these conditions is largely unknown. In this study, we found that a potent angiogenic and mitogenic polypeptide, basic fibroblast growth factor (bFGF), is localized to the majority of mast cells from normal skin and lung and in tissue samples characterized by fibrosis, hyperplasia, and neovascularization. Using specific antibodies to mast cell tryptase, tissue macrophage, and bFGF, we demonstrate that cytoplasmic bFGF immunoreactivity is localized to 96.8 +/- 9.6% of tryptase-positive cells in human fibrotic lung tissue (n = 10), 82.3 +/- 6.9% of tryptase-positive cells in rheumatoid synovia (n = 6), and 93.1 +/- 4.8% of tryptase-positive cells in skin hemangioma (n = 5). Moreover, these tryptase-positive cells comprise a major portion (86 to 97%) of nonvascular cells exhibi...
The Annals of otology, rhinology, and laryngology
Basic fibroblast growth factor (bFGF) is a polypeptide that is mitogenic for a wide variety of ce... more Basic fibroblast growth factor (bFGF) is a polypeptide that is mitogenic for a wide variety of cell types. We used Northern blot analysis and immunohistochemistry to determine if bFGF is expressed in the nasal polyp tissue; bFGF messenger RNA was detectable in the polyps examined by Northern blot analysis. Strong immunostaining for bFGF was found in blood vessels and along the basement membrane of the epithelial cell layers. Basal epithelial cells and some infiltrating mononuclear cells also stained for bFGF. Proliferating cell nuclear antigen colocalized with bFGF to basal epithelial cells, endothelial cells, and areas of focal epithelial metaplasia. The polyp tissue was double-labeled with a mouse monoclonal antitryptase, a specific mast cell marker, and anti-bFGF. A significant number (65% +/- 19%) of the bFGF-positive mononuclear cells in the polyp tissues were positive for tryptase. These findings suggest that bFGF may contribute to the endothelial and epithelial proliferation ...
B67. ION TRANSPORT IN LUNG CELLS: IMPACT ON LUNG FUNCTION AND DISEASE, 2012
Critical care medicine, Jan 24, 2015
Clinical protocols may decrease unnecessary variation in care and improve compliance with desirab... more Clinical protocols may decrease unnecessary variation in care and improve compliance with desirable therapies. We evaluated whether highly protocolized ICUs have superior patient outcomes compared with less highly protocolized ICUs. Observational study in which participating ICUs completed a general assessment and enrolled new patients 1 day each week. A total of 6,179 critically ill patients. Fifty-nine ICUs in the United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study. None. The primary exposure was the number of ICU protocols; the primary outcome was hospital mortality. A total of 5,809 participants were followed prospectively, and 5,454 patients in 57 ICUs had complete outcome data. The median number of protocols per ICU was 19 (interquartile range, 15-21.5). In single-variable analyses, there were no differences in ICU and hospital mortality, length of stay, use of mechanical ventilation, vasopressors, or continuous sedation among individuals in ...
C59. STEM CELLS, PROGENITOR CELLS AND TISSUE REGENERATION, 2010
Transfusion, 1996
Blood components are often given prophylactically before the placement of invasive lines in patie... more Blood components are often given prophylactically before the placement of invasive lines in patients with coagulation defects. Little, however, is known about the epidemiology of defects in these patients. The purpose of this study is to ascertain what proportion of intensive care patients who receive invasive lines have hemostatic defects, what actions are taken by physicians to correct these abnormalities before invasive line insertion, and what the incidence is of bleeding complications after invasive line placement. Charts were retrospectively reviewed for 490 intensive care patients in whom 938 arterial, pulmonary artery, and central venous lines were placed. At least one defect in hemostasis was documented for 388 patients (41%) before line placement, with 253 (27%) of these patients evidencing severe abnormalities. Seventeen percent of patients had no preprocedure laboratory evaluation. Trauma patients showed the highest numbers of abnormalities in hemostatic testing, but med...
Journal of immunology (Baltimore, Md. : 1950), 1994
The temporal recruitment of leukocytes to a site of inflammation is dependent on a complex interp... more The temporal recruitment of leukocytes to a site of inflammation is dependent on a complex interplay of a number of soluble mediators. Recently, two families of chemotactic cytokines have been discovered. The -C-X-C-family, which includes IL-8, appears to recruit neutrophils and lymphocytes. In contrast, the -C-C-family, which includes monocyte chemotactic peptide-1 (MCP-1), appears to recruit predominantly monocytes. Monocytes, after their arrival at a site of inflammation, could further amplify the immune response by secreting IL-8 and MCP-1. We sought to define conditions under which human peripheral blood monocytes produce IL-8 and MCP-1. Using serum-free media, we found that PHA-stimulated monocytes expressed MCP-1 and IL-8 protein and mRNA in a dose-dependent manner. However, the onset of mRNA expression for MCP-1 occurred at least 3 h later than did the onset of IL-8 mRNA expression. IL-8 and MCP-1 gene expression by monocytes appeared to require de novo protein synthesis, in...
American journal of physiology. Lung cellular and molecular physiology, 2002
Despite a presumptive role for type I (AT1) cells in alveolar epithelial transport, specific Na t... more Despite a presumptive role for type I (AT1) cells in alveolar epithelial transport, specific Na transporters have not previously been localized to these cells. To evaluate expression of Na transporters in AT1 cells, double labeling immunofluorescence microscopy was utilized in whole lung and in cytocentrifuged preparations of partially purified alveolar epithelial cells (AEC). Expression of Na pump subunit isoforms and the alpha-subunit of the rat (r) epithelial Na channel (alpha-ENaC) was evaluated in isolated AT1 cells identified by their immunoreactivity with AT1 cell-specific antibody markers (VIIIB2 and/or anti-aquaporin-5) and lack of reactivity with antibodies specific for AT2 cells (anti-surfactant protein A) or leukocytes (anti-leukocyte common antigen). Expression of the Na pump alpha(1)-subunit in AEC was assessed in situ. Na pump subunit isoform and alpha-rENaC expression was also evaluated by RT-PCR in highly purified (approximately 95%) AT1 cell preparations. Labeling ...
American journal of physiology. Lung cellular and molecular physiology, 2003
Transforming growth factor-beta1 (TGF-beta 1) may be a critical mediator of lung injury and subse... more Transforming growth factor-beta1 (TGF-beta 1) may be a critical mediator of lung injury and subsequent remodeling during recovery. We evaluated the effects of TGF-beta 1 on the permeability and active ion transport properties of alveolar epithelial cell monolayers. Rat alveolar type II cells plated on polycarbonate filters in defined serum-free medium form confluent monolayers and acquire the phenotypic characteristics of alveolar type I cells. Exposure to TGF-beta 1 (0.1-100 pM) from day 0 resulted in a concentration- and time-dependent decrease in transepithelial resistance (Rt) and increase in short-circuit current (Isc). Apical amiloride or basolateral ouabain on day 6 inhibited Isc by 80 and 100%, respectively. Concurrent increases in expression of Na+-K+-ATPase alpha 1- and beta 1-subunits were observed in TGF-beta 1-treated monolayers. No change in the alpha-subunit of the rat epithelial sodium channel (alpha-rENaC) was seen. Exposure of confluent monolayers to TGF-beta 1 fro...
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society, 2004
Beta2-Adrenergic agonists stimulate alveolar epithelial sodium (Na(+)) transport and lung fluid c... more Beta2-Adrenergic agonists stimulate alveolar epithelial sodium (Na(+)) transport and lung fluid clearance. Alveolar type II (AT2) cells have been reported to express beta2-adrenergic receptors (beta2AR). Given the large surface area covered by alveolar type I (AT1) cells and their potential role in alveolar fluid removal, we were interested in learning if AT1 cells express beta2AR as well. Because beta2AR is potentially susceptible to desensitization by G-protein-coupled receptor kinase 2 (GRK2), we also undertook localization of GRK2. beta2AR and GRK2 expression was evaluated in whole lung, isolated alveolar epithelial cells (AECs), and AECs in primary culture, and was localized to specific AEC phenotypes by immunofluorescence techniques. beta2AR is highly expressed in AT1 cells. beta2AR mRNA increases with time in culture as AT2 cells transdifferentiate towards the AT1 cell phenotype. Immunoreactive GRK2 is seen in both AT1 and AT2 cells in similar amounts. These data suggest that...
B23. OUTCOMES, HEALTH SERVICES AND PATIENT-CENTERED RESEARCH IN THE INTENSIVE CARE UNIT, 2012
American Journal of Respiratory Cell and Molecular Biology, 2014
Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that ... more Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that regulate paracellular permeability to ions and solutes. Claudin 18, a member of the large claudin family, is highly expressed in lung alveolar epithelium. To elucidate the role of claudin 18 in alveolar epithelial barrier function, we generated claudin 18 knockout (C18 KO) mice. C18 KO mice exhibited increased solute permeability and alveolar fluid clearance (AFC) compared with wild-type control mice. Increased AFC in C18 KO mice was associated with increased β-adrenergic receptor signaling together with activation of cystic fibrosis transmembrane conductance regulator, higher epithelial sodium channel, and Na-K-ATPase (Na pump) activity and increased Na-K-ATPase β1 subunit expression. Consistent with in vivo findings, C18 KO alveolar epithelial cell (AEC) monolayers exhibited lower transepithelial electrical resistance and increased solute and ion permeability with unchanged ion selectivity. Claudin 3 and claudin 4 expression was markedly increased in C18 KO mice, whereas claudin 5 expression was unchanged and occludin significantly decreased. Microarray analysis revealed changes in cytoskeleton-associated gene expression in C18 KO mice, consistent with observed F-actin cytoskeletal rearrangement in AEC monolayers. These findings demonstrate a crucial nonredundant role for claudin 18 in the regulation of alveolar epithelial TJ composition and permeability properties. Increased AFC in C18 KO mice identifies a role for claudin 18 in alveolar fluid homeostasis beyond its direct contributions to barrier properties that may, at least in part, compensate for increased permeability.
American Journal of Respiratory Cell and Molecular Biology, 2014
Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that ... more Claudin proteins are major constituents of epithelial and endothelial tight junctions (TJs) that regulate paracellular permeability to ions and solutes. Claudin 18, a member of the large claudin family, is highly expressed in lung alveolar epithelium. To elucidate the role of claudin 18 in alveolar epithelial barrier function, we generated claudin 18 knockout (C18 KO) mice. C18 KO mice exhibited increased solute permeability and alveolar fluid clearance (AFC) compared with wild-type control mice. Increased AFC in C18 KO mice was associated with increased β-adrenergic receptor signaling together with activation of cystic fibrosis transmembrane conductance regulator, higher epithelial sodium channel, and Na-K-ATPase (Na pump) activity and increased Na-K-ATPase β1 subunit expression. Consistent with in vivo findings, C18 KO alveolar epithelial cell (AEC) monolayers exhibited lower transepithelial electrical resistance and increased solute and ion permeability with unchanged ion selectivity. Claudin 3 and claudin 4 expression was markedly increased in C18 KO mice, whereas claudin 5 expression was unchanged and occludin significantly decreased. Microarray analysis revealed changes in cytoskeleton-associated gene expression in C18 KO mice, consistent with observed F-actin cytoskeletal rearrangement in AEC monolayers. These findings demonstrate a crucial nonredundant role for claudin 18 in the regulation of alveolar epithelial TJ composition and permeability properties. Increased AFC in C18 KO mice identifies a role for claudin 18 in alveolar fluid homeostasis beyond its direct contributions to barrier properties that may, at least in part, compensate for increased permeability.
Distal lung epithelium is maintained by proliferation of alveolar type II (AT2) cells and, for so... more Distal lung epithelium is maintained by proliferation of alveolar type II
(AT2) cells and, for some daughter AT2 cells, transdifferentiation into
alveolar type I (AT1) cells. We investigated if subpopulations of
alveolar epithelial cells (AEC) exist that represent various stages in
transdifferentiation from AT2 to AT1 cell phenotypes in normal adult
lung and if they can be identified using combinations of cell-specific
markers. Immunofluorescence microscopy showed that, in distal rat
and mouse lungs, 20–30% of NKX2.1 (or thyroid transcription
factor 1) cells did not colocalize with pro-surfactant protein C
(pro-SP-C), a highly specific AT2 cell marker. In distal rat lung,
NKX2.1 cells coexpressed either pro-SP-C or the AT1 cell marker
homeodomain only protein x (HOPX). Not all HOPX cells colocalize
with the AT1 cell marker aquaporin 5 (AQP5), and some AQP5
cells were NKX2.1. HOPX was expressed earlier than AQP5 during
transdifferentiation in rat AEC primary culture, with robust expression
of both by day 7. We speculate that NKX2.1 and pro-SP-C colocalize
in AT2 cells, NKX2.1 and HOPX or AQP5 colocalize in intermediate
or transitional cells, and HOPX and AQP5 are expressed without
NKX2.1 in AT1 cells. These findings suggest marked heterogeneity
among cells previously identified as exclusively AT1 or AT2 cells,
implying the presence of subpopulations of intermediate or transitional
AEC in normal adult lung.
American Journal of Respiratory Cell and Molecular Biology, Aug 1, 2003
To identify genes of known function expressed by type I (AT1) cells, changes in gene expression d... more To identify genes of known function expressed by type I (AT1) cells, changes in gene expression during transdifferentiation of alveolar epithelial cells (AEC) in primary culture from type II (AT2) to type I-like cell phenotype were evaluated. Total RNA from AEC on Day 0 or Day 8 was hybridized to a rat microarray for screening. Eight upregulated genes on Day 8 were selected for further investigation. Northern analysis confirmed upregulation of three of these genes, PAI-1, P2X4, and P15INK4B. The corresponding proteins were evaluated in cultured AEC and results correlated with expression in AT1 cells. In AEC monolayers, all three proteins increased between Day 1 and Day 8. In mixed populations of freshly isolated rat lung cells, concurrent labeling with the AT1 cell-specific antibody, VIIIB2, localized these proteins to AT1 cells. In whole lung, all three proteins were detected in alveolar epithelium in a location consistent with expression in AT1 cells. Identification of novel AT1 cell genes of known function suggests an active role for AT1 cells in alveolar homeostasis. Furthermore, expression of these gene products in AT1-like cells, in freshly isolated AT1 cells, and AT1 cells in whole lung indicates that AT1-like cells reflect many of the properties of AT1 cells in situ.
J Appl Physiol, 2004
Rat alveolar epithelial type II (AT2) cells grown on polycarbonate filters form high resistance m... more Rat alveolar epithelial type II (AT2) cells grown on polycarbonate filters form high resistance monolayers and concurrently acquire many phenotypic properties of type I (AT1) cells. Treatment with epidermal growth factor (EGF) has previously been shown to increase transepithelial resistance (TER) across alveolar epithelial cell (AEC) monolayers. We investigated changes in claudin expression in primary cultured AEC during transdifferentiation to the AT1 cell-like phenotype (days 0, 1 and 8), and on day 5 in culture +/-EGF (10 ng/ml) from day 0 or day 4. Claudins 4 and 7 were increased, while claudins 3 and 5 were decreased, on later compared with earlier days in culture.
Basic fibroblast growth factor (bFGF) is a potent inducer of growth and proliferation for many ce... more Basic fibroblast growth factor (bFGF) is a potent inducer of growth and proliferation for many cell types involved in wound healing. Although bFGF has previously been identified in lung tissue, its role in the pathogenesis of pulmonary fibrosis is unknown. We investigated the distribution of bFGF after bleomycin-induced lung injury in the rat in hope of learning how bFGF might participate in the process of lung injury, repair and fibrosis. Increased immunoreactive bFGF was found in the extracellular matrix after bleomycin and co-localized to a marker of active cell proliferation. This suggests that bFGF may participate in directing cell proliferation following lung injury. In addition, a marked increase in the number of mast cells with strong reactivity for bFGF was found at days 14 and 21 after bleomycin. These cells may represent a source of bFGF during the fibroproliferative stage after lung injury.
Transforming growth factor-1 (TGF-1) may be a critical mediator of lung injury and subsequent rem... more Transforming growth factor-1 (TGF-1) may be a critical mediator of lung injury and subsequent remodeling during recovery. We evaluated the effects of TGF-1 on the permeability and active ion transport properties of alveolar epithelial cell monolayers. Rat alveolar type II cells plated on polycarbonate filters in defined serum-free medium form confluent monolayers and acquire the phenotypic characteristics of alveolar type I cells.
American Journal Of Pathology
Mast cells play an essential role during development of inflammation after chemical and immunolog... more Mast cells play an essential role during development of inflammation after chemical and immunological insults and have been implicated in tissue fibrosis and angiogenesis. The exact contribution of mast cells to these conditions is largely unknown. In this study, we found that a potent angiogenic and mitogenic polypeptide, basic fibroblast growth factor (bFGF), is localized to the majority of mast cells from normal skin and lung and in tissue samples characterized by fibrosis, hyperplasia, and neovascularization. Using specific antibodies to mast cell tryptase, tissue macrophage, and bFGF, we demonstrate that cytoplasmic bFGF immunoreactivity is localized to 96.8 +/- 9.6% of tryptase-positive cells in human fibrotic lung tissue (n = 10), 82.3 +/- 6.9% of tryptase-positive cells in rheumatoid synovia (n = 6), and 93.1 +/- 4.8% of tryptase-positive cells in skin hemangioma (n = 5). Moreover, these tryptase-positive cells comprise a major portion (86 to 97%) of nonvascular cells exhibi...
The Annals of otology, rhinology, and laryngology
Basic fibroblast growth factor (bFGF) is a polypeptide that is mitogenic for a wide variety of ce... more Basic fibroblast growth factor (bFGF) is a polypeptide that is mitogenic for a wide variety of cell types. We used Northern blot analysis and immunohistochemistry to determine if bFGF is expressed in the nasal polyp tissue; bFGF messenger RNA was detectable in the polyps examined by Northern blot analysis. Strong immunostaining for bFGF was found in blood vessels and along the basement membrane of the epithelial cell layers. Basal epithelial cells and some infiltrating mononuclear cells also stained for bFGF. Proliferating cell nuclear antigen colocalized with bFGF to basal epithelial cells, endothelial cells, and areas of focal epithelial metaplasia. The polyp tissue was double-labeled with a mouse monoclonal antitryptase, a specific mast cell marker, and anti-bFGF. A significant number (65% +/- 19%) of the bFGF-positive mononuclear cells in the polyp tissues were positive for tryptase. These findings suggest that bFGF may contribute to the endothelial and epithelial proliferation ...
B67. ION TRANSPORT IN LUNG CELLS: IMPACT ON LUNG FUNCTION AND DISEASE, 2012
Critical care medicine, Jan 24, 2015
Clinical protocols may decrease unnecessary variation in care and improve compliance with desirab... more Clinical protocols may decrease unnecessary variation in care and improve compliance with desirable therapies. We evaluated whether highly protocolized ICUs have superior patient outcomes compared with less highly protocolized ICUs. Observational study in which participating ICUs completed a general assessment and enrolled new patients 1 day each week. A total of 6,179 critically ill patients. Fifty-nine ICUs in the United States Critical Illness and Injury Trials Group Critical Illness Outcomes Study. None. The primary exposure was the number of ICU protocols; the primary outcome was hospital mortality. A total of 5,809 participants were followed prospectively, and 5,454 patients in 57 ICUs had complete outcome data. The median number of protocols per ICU was 19 (interquartile range, 15-21.5). In single-variable analyses, there were no differences in ICU and hospital mortality, length of stay, use of mechanical ventilation, vasopressors, or continuous sedation among individuals in ...
C59. STEM CELLS, PROGENITOR CELLS AND TISSUE REGENERATION, 2010
Transfusion, 1996
Blood components are often given prophylactically before the placement of invasive lines in patie... more Blood components are often given prophylactically before the placement of invasive lines in patients with coagulation defects. Little, however, is known about the epidemiology of defects in these patients. The purpose of this study is to ascertain what proportion of intensive care patients who receive invasive lines have hemostatic defects, what actions are taken by physicians to correct these abnormalities before invasive line insertion, and what the incidence is of bleeding complications after invasive line placement. Charts were retrospectively reviewed for 490 intensive care patients in whom 938 arterial, pulmonary artery, and central venous lines were placed. At least one defect in hemostasis was documented for 388 patients (41%) before line placement, with 253 (27%) of these patients evidencing severe abnormalities. Seventeen percent of patients had no preprocedure laboratory evaluation. Trauma patients showed the highest numbers of abnormalities in hemostatic testing, but med...
Journal of immunology (Baltimore, Md. : 1950), 1994
The temporal recruitment of leukocytes to a site of inflammation is dependent on a complex interp... more The temporal recruitment of leukocytes to a site of inflammation is dependent on a complex interplay of a number of soluble mediators. Recently, two families of chemotactic cytokines have been discovered. The -C-X-C-family, which includes IL-8, appears to recruit neutrophils and lymphocytes. In contrast, the -C-C-family, which includes monocyte chemotactic peptide-1 (MCP-1), appears to recruit predominantly monocytes. Monocytes, after their arrival at a site of inflammation, could further amplify the immune response by secreting IL-8 and MCP-1. We sought to define conditions under which human peripheral blood monocytes produce IL-8 and MCP-1. Using serum-free media, we found that PHA-stimulated monocytes expressed MCP-1 and IL-8 protein and mRNA in a dose-dependent manner. However, the onset of mRNA expression for MCP-1 occurred at least 3 h later than did the onset of IL-8 mRNA expression. IL-8 and MCP-1 gene expression by monocytes appeared to require de novo protein synthesis, in...
American journal of physiology. Lung cellular and molecular physiology, 2002
Despite a presumptive role for type I (AT1) cells in alveolar epithelial transport, specific Na t... more Despite a presumptive role for type I (AT1) cells in alveolar epithelial transport, specific Na transporters have not previously been localized to these cells. To evaluate expression of Na transporters in AT1 cells, double labeling immunofluorescence microscopy was utilized in whole lung and in cytocentrifuged preparations of partially purified alveolar epithelial cells (AEC). Expression of Na pump subunit isoforms and the alpha-subunit of the rat (r) epithelial Na channel (alpha-ENaC) was evaluated in isolated AT1 cells identified by their immunoreactivity with AT1 cell-specific antibody markers (VIIIB2 and/or anti-aquaporin-5) and lack of reactivity with antibodies specific for AT2 cells (anti-surfactant protein A) or leukocytes (anti-leukocyte common antigen). Expression of the Na pump alpha(1)-subunit in AEC was assessed in situ. Na pump subunit isoform and alpha-rENaC expression was also evaluated by RT-PCR in highly purified (approximately 95%) AT1 cell preparations. Labeling ...
American journal of physiology. Lung cellular and molecular physiology, 2003
Transforming growth factor-beta1 (TGF-beta 1) may be a critical mediator of lung injury and subse... more Transforming growth factor-beta1 (TGF-beta 1) may be a critical mediator of lung injury and subsequent remodeling during recovery. We evaluated the effects of TGF-beta 1 on the permeability and active ion transport properties of alveolar epithelial cell monolayers. Rat alveolar type II cells plated on polycarbonate filters in defined serum-free medium form confluent monolayers and acquire the phenotypic characteristics of alveolar type I cells. Exposure to TGF-beta 1 (0.1-100 pM) from day 0 resulted in a concentration- and time-dependent decrease in transepithelial resistance (Rt) and increase in short-circuit current (Isc). Apical amiloride or basolateral ouabain on day 6 inhibited Isc by 80 and 100%, respectively. Concurrent increases in expression of Na+-K+-ATPase alpha 1- and beta 1-subunits were observed in TGF-beta 1-treated monolayers. No change in the alpha-subunit of the rat epithelial sodium channel (alpha-rENaC) was seen. Exposure of confluent monolayers to TGF-beta 1 fro...
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society, 2004
Beta2-Adrenergic agonists stimulate alveolar epithelial sodium (Na(+)) transport and lung fluid c... more Beta2-Adrenergic agonists stimulate alveolar epithelial sodium (Na(+)) transport and lung fluid clearance. Alveolar type II (AT2) cells have been reported to express beta2-adrenergic receptors (beta2AR). Given the large surface area covered by alveolar type I (AT1) cells and their potential role in alveolar fluid removal, we were interested in learning if AT1 cells express beta2AR as well. Because beta2AR is potentially susceptible to desensitization by G-protein-coupled receptor kinase 2 (GRK2), we also undertook localization of GRK2. beta2AR and GRK2 expression was evaluated in whole lung, isolated alveolar epithelial cells (AECs), and AECs in primary culture, and was localized to specific AEC phenotypes by immunofluorescence techniques. beta2AR is highly expressed in AT1 cells. beta2AR mRNA increases with time in culture as AT2 cells transdifferentiate towards the AT1 cell phenotype. Immunoreactive GRK2 is seen in both AT1 and AT2 cells in similar amounts. These data suggest that...
B23. OUTCOMES, HEALTH SERVICES AND PATIENT-CENTERED RESEARCH IN THE INTENSIVE CARE UNIT, 2012