scholarly journals Targeted Gene Disruption Reveals the Role of the Cysteinyl Leukotriene 2 Receptor in Increased Vascular Permeability and in Bleomycin-induced Pulmonary Fibrosis in Mice

2004 ◽  
Vol 279 (44) ◽  
pp. 46129-46134 ◽  
Author(s):  
Thomas C. Beller ◽  
Akiko Maekawa ◽  
Daniel S. Friend ◽  
K. Frank Austen ◽  
Yoshihide Kanaoka
Keyword(s):  
Pulmonary Fibrosis ◽  
Vascular Permeability ◽  
Gene Disruption ◽  
Inflammatory Responses ◽  
Lavage Fluid ◽  
Wild Type ◽  
Chronic Injury ◽  
Targeted Disruption ◽  
Targeted Gene Disruption ◽  
Cysteinyl Leukotriene

The cysteinyl leukotrienes (cys-LTs) mediate both acute and chronic inflammatory responses in mice, as demonstrated by the attenuation of the IgE/antigen-mediated increase in microvascular permeability and of bleomycin-induced pulmonary fibrosis, respectively, in a strain with targeted disruption of leukotriene C4synthase to prevent cys-LT synthesis. Our earlier finding that the acute, but not the chronic, injury was attenuated in a strain with targeted disruption of the cysteinyl leukotriene 1 (CysLT1) receptor suggested that the chronic injury might be mediated through the CysLT2receptor. Thus, we generated CysLT2receptor-deficient mice by targeted gene disruption. These mice developed normally and were fertile. The increased vascular permeability associated with IgE-dependent passive cutaneous anaphylaxis was significantly reduced in CysLT2receptor-null mice as compared with wild-type mice, whereas plasma protein extravasation in response to zymosan A-induced peritoneal inflammation was not altered. Alveolar septal thickening after intratracheal injection of bleomycin, characterized by interstitial infiltration with macrophages and fibroblasts and the accumulation of collagen fibers, was significantly reduced in CysLT2receptor-null mice as compared with the wild-type mice. The amounts of cys-LTs in bronchoalveolar lavage fluid after bleomycin injection were similar in the CysLT2receptor-null mice and the wild-type mice. Thus, in response to a particular pathobiologic event the CysLT2receptor can mediate an increase in vascular permeability in some tissues or promote chronic pulmonary inflammation with fibrosis.

Role of melanotransferrin in iron metabolism: studies using targeted gene disruption in vivo

Blood ◽  
2006 ◽  
Vol 107 (7) ◽  
pp. 2599-2601 ◽  
Author(s):  
Eric O. Sekyere ◽  
Louise L. Dunn ◽  
Yohan Suryo Rahmanto ◽  
Des R. Richardson
Keyword(s):  
Metabolic Pathways ◽  
Gene Disruption ◽  
Vital Role ◽  
Plasminogen Activation ◽  
Serum Chemistry ◽  
Wild Type ◽  
Targeted Disruption ◽  
Targeted Gene Disruption

AbstractMelanotransferrin (MTf) or tumor antigen p97 is a transferrin homolog that binds one iron (Fe) atom and has been suggested to play roles in a variety of processes, including Fe metabolism, eosinophil differentiation, and plasminogen activation. Considering the vital role of Fe in many metabolic pathways, such as DNA and heme synthesis, it is important to understand the function of MTf. To define this, a MTf knockout (MTf–/–) mouse was generated through targeted disruption of the MTf gene. The MTf–/– mice were viable and fertile and developed normally, with no morphologic or histologic abnormalities. Assessment of Fe indices, tissue Fe levels, hematology, and serum chemistry parameters demonstrated no differences between MTf–/– and wild-type (MTf+/+) mice, suggesting MTf was not essential for Fe metabolism.

scholarly journals Targeted Gene Disruption of the 14-α Sterol Demethylase (cyp51A) in Aspergillus fumigatus and Its Role in Azole Drug Susceptibility

2005 ◽  
Vol 49 (6) ◽  
pp. 2536-2538 ◽  
Author(s):  
E. Mellado ◽  
G. Garcia-Effron ◽  
M. J. Buitrago ◽  
L. Alcazar-Fuoli ◽  
M. Cuenca-Estrella ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Type Strain ◽  
Gene Disruption ◽  
Wild Type Strain ◽  
Drug Susceptibility ◽  
Wild Type ◽  
Targeted Disruption ◽  
Targeted Gene Disruption ◽  
Resistant Strains

ABSTRACT The role of Aspergillus fumigatus 14α-sterol demethylase (Cyp51A) in azole drug susceptibility was assessed. Targeted disruption of cyp51A in azole-susceptible and -resistant strains decreased MICs from 2- to 40-fold. The cyp51A mutants were morphologically indistinguishable from the wild-type strain, retaining the ability to cause pulmonary disease in neutropenic mice.

scholarly journals Syndecan-4 Inhibits the Development of Pulmonary Fibrosis by Attenuating TGF-β Signaling

2019 ◽  
Vol 20 (20) ◽  
pp. 4989 ◽  
Author(s):  
Yoshinori Tanino ◽  
Xintao Wang ◽  
Takefumi Nikaido ◽  
Kenichi Misa ◽  
Yuki Sato ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Heparan Sulfate ◽  
Bronchoalveolar Lavage Fluid ◽  
Pulmonary Inflammation ◽  
Lavage Fluid ◽  
Lung Fibroblasts ◽  
Fibrosis Score ◽  
Wild Type ◽  
Deficient Mice

Syndecan-4 is a transmembrane heparan sulfate proteoglycan expressed in a variety of cells, and its heparan sulfate glycosaminoglycan side chains bind to several proteins exhibiting various biological roles. The authors have previously demonstrated syndecan-4′s critical roles in pulmonary inflammation. In the current study, however, its role in pulmonary fibrosis was evaluated. Wild-type and syndecan-4-deficient mice were injected with bleomycin, and several parameters of inflammation and fibrosis were analyzed. The mRNA expression of collagen and α-smooth muscle action (α-SMA) in lung tissues, as well as the histopathological lung fibrosis score and collagen content in lung tissues, were significantly higher in the syndecan-4-deficient mice. However, the total cell count and cell differentiation in bronchoalveolar lavage fluid were equivalent between the wild-type and syndecan-4-deficient mice. Although there was no difference in the TGF-β expression in lung tissues between the wild-type and syndecan-4-deficient mice, significantly more activation of Smad3 in lung tissues was observed in the syndecan-4-deficient mice compared to the wild-type mice. Furthermore, in the in vitro experiments using lung fibroblasts, the co-incubation of syndecan-4 significantly inhibited TGF-β-induced Smad3 activation, collagen and α-SMA upregulation. Moreover, syndecan-4 knock-down by siRNA increased TGF-β-induced Smad3 activation and upregulated collagen and α-SMA expression. These findings showed that syndecan-4 inhibits the development of pulmonary fibrosis, at least in part, through attenuating TGF-β signaling.

scholarly journals Bleomycin and IL-1β–mediated pulmonary fibrosis is IL-17A dependent

2010 ◽  
Vol 207 (3) ◽  
pp. 535-552 ◽  
Author(s):  
Mark S. Wilson ◽  
Satish K. Madala ◽  
Thirumalai R. Ramalingam ◽  
Bernadette R. Gochuico ◽  
Ivan O. Rosas ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Essential Role ◽  
Bronchoalveolar Lavage Fluid ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Γδ T Cells ◽  
Lavage Fluid ◽  
Collagen Deposition ◽  
Potential Utility ◽  
Ifn Γ

Idiopathic pulmonary fibrosis (IPF) is a destructive inflammatory disease with limited therapeutic options. To better understand the inflammatory responses that precede and concur with collagen deposition, we used three models of pulmonary fibrosis and identify a critical mechanistic role for IL-17A. After exposure to bleomycin (BLM), but not Schistosoma mansoni eggs, IL-17A produced by CD4+ and γδ+ T cells induced significant neutrophilia and pulmonary fibrosis. Studies conducted with C57BL/6 il17a−/− mice confirmed an essential role for IL-17A. Mechanistically, using ifnγ−/−, il10−/−, il10−/−il12p40−/−, and il10−/−il17a−/− mice and TGF-β blockade, we demonstrate that IL-17A–driven fibrosis is suppressed by IL-10 and facilitated by IFN-γ and IL-12/23p40. BLM-induced IL-17A production was also TGF-β dependent, and recombinant IL-17A–mediated fibrosis required TGF-β, suggesting cooperative roles for IL-17A and TGF-β in the development of fibrosis. Finally, we show that fibrosis induced by IL-1β, which mimics BLM-induced fibrosis, is also highly dependent on IL-17A. IL-17A and IL-1β were also increased in the bronchoalveolar lavage fluid of patients with IPF. Together, these studies identify a critical role for IL-17A in fibrosis, illustrating the potential utility of targeting IL-17A in the treatment of drug and inflammation-induced fibrosis.

scholarly journals Generation and Analysis of Mice Lacking the Chemokine Fractalkine

2001 ◽  
Vol 21 (9) ◽  
pp. 3159-3165 ◽  
Author(s):  
Donald N. Cook ◽  
Shu-Cheng Chen ◽  
Lee M. Sullivan ◽  
Denise J. Manfra ◽  
Maria T. Wiekowski ◽  
...  
Keyword(s):  
Gene Disruption ◽  
Surface Marker ◽  
Wild Type ◽  
Blood Leukocytes ◽  
Targeted Gene Disruption ◽  
Behavioral Abnormalities ◽  
Inflammatory Stimuli ◽  
Membrane Bound ◽  
Deficient Mice

ABSTRACT Fractalkine (CX3CL1) is the first described chemokine that can exist either as a soluble protein or as a membrane-bound molecule. Both forms of fractalkine can mediate adhesion of cells expressing its receptor, CX3CR1. This activity, together with its expression on endothelial cells, suggests that fractalkine might mediate adhesion of leukocytes to the endothelium during inflammation. Fractalkine is also highly expressed in neurons, and its receptor, CX3CR1, is expressed on glial cells. To determine the biologic role of fractalkine, we used targeted gene disruption to generate fractalkine-deficient mice. These mice did not exhibit overt behavioral abnormalities, and histologic analysis of their brains did not reveal any gross changes compared to wild-type mice. In addition, these mice had normal hematologic profiles except for a decrease in the number of blood leukocytes expressing the cell surface marker F4/80. The cellular composition of their lymph nodes did not differ significantly from that of wild-type mice. Similarly, the responses offractalkine −/− mice to a variety of inflammatory stimuli were indistinguishable from those of wild-type mice.

Macrophage-specific metalloelastase (MMP-12) truncates and inactivates ELR+ CXC chemokines and generates CCL2, -7, -8, and -13 antagonists: potential role of the macrophage in terminating polymorphonuclear leukocyte influx

Blood ◽  
2008 ◽  
Vol 112 (8) ◽  
pp. 3455-3464 ◽  
Author(s):  
Richard A. Dean ◽  
Jennifer H. Cox ◽  
Caroline L. Bellac ◽  
Alain Doucet ◽  
Amanda E. Starr ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Lavage Fluid ◽  
Binding Motif ◽  
Wild Type ◽  
Lps Challenge ◽  
Inflammatory Protein ◽  
Leukocyte Influx ◽  
Cc Chemokines ◽  
Intranasal Instillation

AbstractThrough the activity of macrophage-specific matrix metalloproteinase-12 (MMP-12), we found that macrophages dampen the lipopolysaccharide (LPS)-induced influx of polymorphonuclear leukocytes (PMNs)—thus providing a new mechanism for the termination of PMN recruitment in acute inflammation. MMP-12 specifically cleaves human ELR+ CXC chemokines (CXCL1, -2, -3, -5, and -8) at E-LR, the critical receptor-binding motif or, for CXCL6, carboxyl-terminal to it. Murine (m) MMP-12 also cleaves mCXCL1, -2, and -3 at E-LR. MMP-12-cleaved mCXCL2 (macrophage-inflammatory protein-2 [MIP-2]) and mCXCL3 (dendritic cell inflammatory protein-1 [DCIP-1]) lost chemotactic activity. Furthermore, MMP-12 processed and inactivated monocyte chemotactic proteins CCL2, -7, -8, and -13 at position 4-5 generating CCR antagonists. Indeed, PMNs and macrophages in bronchoalveolar lavage fluid were significantly increased 72 hours after intranasal instillation of LPS in Mmp12−/− mice compared with wild type. Specificity occurred at 2 levels. Macrophage MMP-1 and MMP-9 did not cleave in the ELR motif. Second, unlike human ELR+CXC chemokines, mCXCL5 (LPS-induced CXC chemokine [LIX]) was not inactivated. Rather, mMMP-12 cleavage at Ser4-Val5 activated the chemokine, promoting enhanced PMN early infiltration in wild-type mice compared with Mmp12−/− mice 8 hours after LPS challenge in air pouches. We propose that the macrophage, specifically through MMP-12, assists in orchestrating the regulation of acute inflammatory responses by precise proteolysis of ELR+CXC and CC chemokines.

scholarly journals Role of Group V Phospholipase A2in Zymosan-induced Eicosanoid Generation and Vascular Permeability Revealed by Targeted Gene Disruption

2004 ◽  
Vol 279 (16) ◽  
pp. 16488-16494 ◽  
Author(s):  
Yoshiyuki Satake ◽  
Bruno L. Diaz ◽  
Barbara Balestrieri ◽  
Bing K. Lam ◽  
Yoshihide Kanaoka ◽  
...  
Keyword(s):  
Vascular Permeability ◽  
Gene Disruption ◽  
Group V ◽  
Targeted Gene Disruption

scholarly journals Cysteinyl Leukotrienes Impair Hypoxic Pulmonary Vasoconstriction in Endotoxemic Mice

2011 ◽  
Vol 115 (4) ◽  
pp. 804-811 ◽  
Author(s):  
Bodil Petersen ◽  
K. Frank Austen ◽  
Kenneth D. Bloch ◽  
Yukako Hotta ◽  
Fumito Ichinose ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Bronchoalveolar Lavage Fluid ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Lavage Fluid ◽  
Wild Type ◽  
Cysteinyl Leukotrienes ◽  
Endotoxin Challenge ◽  
Cysteinyl Leukotriene ◽  
Leukotriene Receptor ◽  
Cysteinyl Leukotriene Receptor

Background Sepsis impairs hypoxic pulmonary vasoconstriction (HPV) in patients and animal models, contributing to systemic hypoxemia. Concentrations of cysteinyl leukotrienes are increased in the bronchoalveolar lavage fluid of patients with sepsis, but the contribution of cysteinyl leukotrienes to the impairment of HPV is unknown. Methods Wild-type mice, mice deficient in leukotriene C(4) synthase, the enzyme responsible for cysteinyl leukotriene synthesis, and mice deficient in cysteinyl leukotriene receptor 1 were studied 18 h after challenge with either saline or endotoxin. HPV was measured by the increase in left pulmonary vascular resistance induced by left mainstem bronchus occlusion. Concentrations of cysteinyl leukotrienes were determined in the bronchoalveolar lavage fluid. Results In the bronchoalveolar lavage fluid of all three strains, cysteinyl leukotrienes were not detectable after saline challenge; whereas endotoxin challenge increased cysteinyl leukotriene concentrations in wild-type mice and mice deficient in cysteinyl leukotriene receptor 1, but not in mice deficient in leukotriene C(4) synthase. HPV did not differ among the three mouse strains after saline challenge (120 ± 26, 114 ± 16, and 115 ± 24%, respectively; mean ± SD). Endotoxin challenge markedly impaired HPV in wild-type mice (41 ± 20%) but only marginally in mice deficient in leukotriene C(4) synthase (96 ± 16%, P < 0.05 vs. wild-type mice), thereby preserving systemic oxygenation. Although endotoxin modestly decreased HPV in mice deficient in cysteinyl leukotriene receptor 1 (80 ± 29%, P < 0.05 vs. saline challenge), the magnitude of impairment was markedly less than in endotoxin-challenged wild-type mice. Conclusion Cysteinyl leukotrienes importantly contribute to endotoxin-induced impairment of HPV in part via a cysteinyl leukotriene receptor 1-dependent mechanism.

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