mocetinostat has been researched along with Keratitis* in 27 studies
27 other study(ies) available for mocetinostat and Keratitis
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Therapeutic effect of Atractylenolide I on Aspergillus fumigatus keratitis by affecting MyD88/ NF-κB pathway and IL-1β, IL-10 expression.
Atractylenolide I (AT-I) is a natural sesquiterpene with anti-inflammatory effects. The purpose of this study was to research the anti-inflammatory effect of AT-I on Aspergillus fumigatus(A. fumigatus) keratitis in mice.. Cytotoxicity test and cell scratch test were used to determine the therapeutic concentrations of corneal infections. In vivo and in vitro studies, mouse cornea and human corneal epithelial cells (HCECs) infected with A. fumigatus were treated with AT-I or dimethyl sulfoxide (DMSO). Then, to analyze the effect of AT-I on inflammatory response, namely neutrophil or macrophage recruitment and the expression of cytokines involving MyD88, NF-κB, interleukin 1β (IL-1β) and interleukin 10 (IL-10). To study the effects of the drug, the techniques used include slit-lamp photography, immunofluorescence, myeloperoxidase (MPO) detection, quantitative real-time polymerase chain reaction (QRT-PCR), and western blot. At the same time, in order to explore the combined effect of the drug and natamycin, slit-lamp photographs and clinical scores were used to visually display the disease process.. No cytotoxicity was observed under the action of AT-I at a concentration of 800 μM. In mouse models, AT-I significantly suppressed inflammatory responses, reduced neutrophil and macrophage recruitment, and decreased myeloperoxidase levels early in infection. Studies have shown that AT-I may reduce the levels of IL-1β and IL-10 by inhibiting the MyD88/ NF-κB pathway. The drug combined with natamycin can increase corneal transparency in infected mice.. AT-I may inhibit MyD88 / NF-κB pathway and the secretion of inflammatory factors IL-1 β and IL-10 to achieve the therapeutic effect of fungal keratitis. Topics: Adaptor Proteins, Signal Transducing; Animals; Anti-Inflammatory Agents; Aspergillosis; Aspergillus fumigatus; Humans; Interleukin-10; Interleukin-1beta; Keratitis; Mice; Mice, Inbred C57BL; Myeloid Differentiation Factor 88; Natamycin; NF-kappa B; Peroxidase; Sesquiterpenes | 2023 |
0.01% Hypochlorous Acid Treats Aspergillus fumigatus Keratitis in Rats by Reducing Fungal Load and Inhibiting the Inflammatory Response.
To investigate the antifungal and anti-inflammatory effects of 0.01% hypochlorous acid (HCLO) on rats with Aspergillus fumigatus keratitis.. The time-kill assay and broth microdilution procedures were used in vitro to demonstrate that 0.01% HCLO was fungicidal and fungistatic. The severity of the disease was evaluated in vivo using a clinical score and slit-lamp photographs. Fungal load, polymorphonuclear neutrophil infiltration, and the production of related proteins were determined using colony plate counting, in vivo confocal microscopy, periodic acid-Schiff staining, fungal fluorescence staining, immunofluorescence staining, myeloperoxidase assay, and Western blotting.. In vitro, 0.01% HCLO can destroy A. fumigatus spores in 1 minute. The optical density of the 0.01% HCLO group was significantly lower than that of the phosphate-buffered saline control group (P < 0.01), and no visible mycelium was observed using a fluorescence microscope. 0.01% HCLO reduced the severity of A. fumigatus keratitis in rats by decreasing the clinical score, fungal loading (periodic acid-Schiff, plate count, and fungal fluorescence staining), and inhibiting neutrophil infiltration and activity (immunofluorescence staining and myeloperoxidase). Furthermore, the Western blot analysis revealed that 0.01% HCO decreased protein expression levels of tumor necrosis factor-α and IL-1β.. According to our findings, 0.01% HCLO can kill A. fumigatus spores in vitro. It has antifungal and anti-inflammatory effects on A. fumigatus keratitis in rats. It also inhibited A. fumigatus growth; decreased neutrophil infiltration, tumor necrosis factor-α, and IL-1β expression; and provided a potential treatment for fungal keratitis.. This study provides a potential treatment for fungal keratitis in the clinic. Topics: Animals; Anti-Inflammatory Agents; Antifungal Agents; Aspergillosis; Aspergillus fumigatus; Eye Infections, Fungal; Hypochlorous Acid; Keratitis; Periodic Acid; Peroxidase; Rats; Tumor Necrosis Factor-alpha | 2023 |
CLEC-1 Acts as a Negative Regulator of Dectin-1 Induced Host Inflammatory Response Signature in Aspergillus fumigatus Keratitis.
C-type lectin-like receptor-1 (CLEC-1) is a member of the Dectin-1 cluster of pattern recognition receptors (PRRs). It is involved in host immunity, has immunoregulatory function, and supports allograft tolerance. Our study aimed to describe the role of CLEC-1 in response to fungal keratitis, in situ, in vivo, and in vitro.. Quantitative polymerase chain reaction (qRT-PCR) and immunofluorescence were used to detect the expression of CLEC-1 in corneas of patients with Aspergillus fumigatus (A. fumigatus) keratitis. In vitro and in vivo experiments were designed in THP-1 macrophages and C57BL/6 mouse models, respectively. The expression of CLEC-1 in corneas of mice model was determined by qRT-PCR, Western blot, and immunofluorescence. CLEC-1 overexpression in mouse corneas was achieved by intrastromal injection of adeno-associated virus (AAV) vectors. Disease response was evaluated by slit-lamp photography, clinical score, and colony forming unit (CFU). Bioluminescence imaging system image acquisition, myeloperoxidase (MPO) assays, immunofluorescence staining, qRT-PCR, and Western blot were used to investigate the role of CLEC-1. To further define the role of CLEC-1, we used lentivirus vectors to overexpress CLEC-1 or/and Dectin-1 in THP-1 macrophages.. The expression of CLEC-1 was increased in corneas of patients with A. fumigatus keratitis. In corneas of mice from the A. fumigatus keratitis model, the expression of CLEC-1 was decreased in the acute inflammatory stage and increased during convalescence. Following Natamycin treatment, CLEC-1 was upregulated in A. fumigatus keratitis mice. Compared with normal C57BL/6 mice, overexpression of CLEC-1 converted the characteristic susceptible response to resistance, as demonstrated by slit-lamp photography and clinical score. In vivo studies revealed decreased MPO levels and neutrophils recruitment and higher fungal load after the upregulation of CLEC-1. Compared with control corneas, CLEC-1 overexpression impaired corneal pro-inflammatory cytokine IL-1β production.. These findings demonstrate that CLEC-1 may act as a negative regulator of Dectin-1 induced host inflammatory response via suppressing neutrophils recruitment and production of pro-inflammatory cytokine IL-1β production in response to A. fumigatus keratitis. Topics: Animals; Aspergillosis; Aspergillus fumigatus; Blotting, Western; Cytokines; Dependovirus; Disease Models, Animal; Eye Infections, Fungal; Female; Gene Expression Regulation; Genetic Vectors; Humans; Keratitis; Lectins, C-Type; Macrophages; Membrane Proteins; Mice; Mice, Inbred C57BL; Microscopy, Fluorescence; Neutrophil Infiltration; Peroxidase; Real-Time Polymerase Chain Reaction; Receptors, Mitogen; Slit Lamp Microscopy | 2021 |
Wedelolactone suppresses IL-1β maturation and neutrophil infiltration in Aspergillus fumigatus keratitis.
Wedelolactone, a chemical compound extracted from Wedelia calendulacea or Eclipta alba, has been reported to regulate key steps in inflammation. However, the effects of wedelolactone on fungal keratitis are not known. Hence, we aimed to characterize the impact of wedelolactone in Aspergillus fumigatus keratitis.. Aspergillus fumigatus was used to establish an in vivo mouse model of fungal keratitis and an in vitro model of THP-1 macrophages. Mice and THP-1 macrophages were pre-treated with wedelolactone. Clinical evaluation, myeloperoxidase (MPO) assay, neutrophil staining, western blot and quantitative polymerase chain reaction (qRT-PCR) were used to assess the effect of wedelolactone on A. fumigatus infection. Therapeutic effect of natamycin treatment with or without wedelolactone was measured via slit lamp microscopy.. We confirmed that wedelolactone attenuated the infiltration of neutrophils and decreased MPO level at earlier time points in mice with A. fumigatus keratitis. Pre-treatment with wedelolactone decreased pro-inflammatory cytokine interleukin 1 beta (IL-1β) maturation by inhibiting caspase-1 activity. Combined with natamycin, wedelolactone protected corneal transparency in mouse with fungal keratitis.. Present findings indicated that wedelolactone reduced host immune responses by attenuating neutrophil recruitment and IL-1β maturation in Aspergillus fumigatus keratitis. Wedelolactone combined with an antifungal medicine could be a potential therapy for reducing lesion severity in fungal keratitis. Topics: Animals; Antifungal Agents; Aspergillosis; Aspergillus fumigatus; Cornea; Coumarins; Disease Models, Animal; Eye Infections, Fungal; Female; Humans; Interleukin-1beta; Keratitis; Mice, Inbred C57BL; Natamycin; Neutrophil Infiltration; Peroxidase; THP-1 Cells | 2019 |
Osteopontin contributes to effective neutrophil recruitment, IL-1β production and apoptosis in Aspergillus fumigatus keratitis.
Fungal keratitis is a major cause of corneal ulcers, resulting in significant visual impairment and blindness. A phosphorylated glycoprotein secreted by immunocompetent cells, osteopontin (OPN) mediates cluster formation of the host fungal receptors and enhances the phagocytosis and clearance of pathogenic fungi. However, whether OPN production and function occurs in fungal keratitis is unknown. OPN expression in Aspergillus fumigatus keratitis patient corneas was assessed by quantitative polymerase chain reaction (qRT-PCR) and immunofluorescence. Human neutrophils, THP-1 macrophages and corneal epithelial cells (HCECs) stimulated with A. fumigatus were utilized for in vitro experiments. Mouse models of A. fumigatus keratitis were developed by intrastromal injection for in vivo experiments. Using siRNAs, neutralizing antibodies, recombinant proteins and inhibitors, the production and role of OPN in A. fumigatus infection was assessed by clinical evaluation, qRT-PCR, immunofluorescence, western blotting and bioluminescence image acquisition. We observed increased corneal OPN expression in A. fumigatus keratitis patients and mouse models compared to controls. OPN production in response to A. fumigatus infection was dependent on LOX-1 and Erk1/2. Compared to controls, OPN knockdown impaired proinflammatory cytokine IL-1β production, which was dependent on 4E-BP1. OPN knockdown decreased myeloperoxidase levels, and resulted in decreased neutrophil recruitment, higher fungal load and increased apoptosis in mouse A. fumigatus keratitis. Our results indicate that OPN is a critical component of the antifungal immune response and is essential for effective neutrophil recruitment, inflammatory cytokine production and apoptosis in A. fumigatus keratitis. Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis; Aspergillus fumigatus; Carrier Proteins; Cell Cycle Proteins; Epithelial Cells; Epithelium, Corneal; Eukaryotic Initiation Factors; Female; Humans; Interleukin-1beta; Keratitis; Lectins, C-Type; Macrophages; MAP Kinase Signaling System; Mice, Inbred C57BL; Neutrophil Infiltration; Neutrophils; Osteopontin; Peroxidase; Phosphoproteins; RNA, Small Interfering; Scavenger Receptors, Class E; THP-1 Cells | 2018 |
Methods for In Vivo/Ex Vivo Analysis of Antimicrobial Peptides in Bacterial Keratitis: siRNA Knockdown, Colony Counts, Myeloperoxidase, Immunostaining, and RT-PCR Assays.
Antimicrobial peptides (AMPs) are essential components of the innate immune response. They have direct killing ability as well as immunomodulatory functions. Here, we describe techniques to identify specific AMPs involved in the protection against microbial keratitis, a vision threatening infection of the cornea of the eye which is the most serious complication of contact lens wear. Specifically we detail the use of siRNA technology to temporarily knockdown AMP expression at the murine ocular surface in vivo and then describe ex vivo assays to determine the level of bacteria, relative number of neutrophils, and levels of cytokines, chemokines, and AMPs in infected corneas. Topics: Animals; Antimicrobial Cationic Peptides; Bacterial Infections; Bacterial Load; Cytokines; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Gene Expression Regulation; Gene Knockdown Techniques; Host-Pathogen Interactions; Inflammation Mediators; Keratitis; Mice; Microbial Viability; Neutrophils; Peroxidase; Real-Time Polymerase Chain Reaction; RNA Interference; RNA, Small Interfering | 2017 |
Ocular inflammation and corneal permeability alteration by benzalkonium chloride in rats: a protective effect of a myosin light chain kinase inhibitor.
The aim of this study was to evaluate the interest of an ophthalmic eyedrop preparation containing a myosin light chain kinase (MLCK) inhibitor, ML-7, in the treatment of ocular surface. The local protective effect on the inflammation and the increase of corneal permeability induced by benzalkonium (BAK) was evaluated.. An ocular instillation of 10 lL BAK at a concentration of 0.1% in PBS was performed on rats. The eyes were rinsed with sterilized water, 10 minutes after BAK preceded by instillation at T -24, -12, and -0.5 hours of 10 lL ofML-7: 100 μg (10 μL) into a gel form vehicle. All animals were sacrificed 6 hours after BAK instillation. The eyes were isolated for study in a masked manner. The ocular surface inflammation was assessed by measuring the inflammatory cell infiltration by a histologic quantitative analysis and for total ocular myeloperoxidase (MPO) activity. The tight junction permeability was tested.. Instillation of 0.1% BAK increased the inflammation of the eye. The quantitative analysis showed an increase in the number of eosinophil and neutrophil polynuclears, and MPO activity. Pretreatment with ML-7 reduced inflammation (P < 0.05). The vehicle alone produced no notable effects. BAK instillation also thickened the fluorescent corneal front on frozen sections, indicating an increase of tight junction permeability. Pretreatment with ML-7 suppressed BAK-induced alterations of paracellular permeability while the vehicle had no visible effects.. Our study indicates that the inhibition of corneal cytoskeleton contraction by an MLCK inhibitor prevents BAK-induced ocular inflammatory response, and that ML-7 may be a new and original preparation in the treatment of ocular surface pathologies. Topics: Animals; Azepines; Benzalkonium Compounds; Cornea; Dry Eye Syndromes; Enzyme Inhibitors; Eosinophils; Keratitis; Male; Myosin-Light-Chain Kinase; Naphthalenes; Neutrophils; Ophthalmic Solutions; Permeability; Peroxidase; Preservatives, Pharmaceutical; Rats; Rats, Wistar; Tight Junctions | 2013 |
Mammalian target of rapamycin regulates IL-10 and resistance to Pseudomonas aeruginosa corneal infection.
IL-10 is important in the resistance response of BALB/c mice to experimental Pseudomonas aeruginosa corneal infection. However, the cellular mechanisms by which this anti-inflammatory cytokine is regulated remain unknown. Because the mammalian target of rapamycin (mTOR) regulates IL-10 in other disease models, the present study tested its role in bacterial keratitis. After infection, corneas of rapamycin versus control-treated BALB/c mice showed worsened disease, and real-time RT-PCR confirmed that mTOR mRNA levels were significantly decreased. Rapamycin treatment also increased clinical score, polymorphonuclear neutrophil (PMN) infiltration (determined by myeloperoxidase assay), and bacterial load, but it diminished PMN bactericidal activity. Inhibition of mTOR also led to elevated mRNA and protein levels of IL-12p40, matrix metalloproteinase 9, and inducible NO synthase, whereas mRNA and protein levels of IL-10, its regulator/effector STAT-3, and suppressor of cytokine signaling 3 (a proinflammatory cytokine regulator) were decreased. Furthermore, mTOR inhibition reduced levels of proapoptotic caspase-3 and increased levels of B cell lymphoma-2 (antiapoptotic), indicative of delayed apoptosis. mTOR inhibition also altered genes related to TLR signaling, including elevation of TLR4, TLR5, and IL-1R1, with decreases in IL-1R-associated kinase 1 and an inhibitor of NF-κB, NF-κB inhibitor-like 1. Rapamycin treatment also increased levels of IFN-γ and CCAAT/enhancer binding protein, β, a gene that regulates expression of preprotachykinin-A (the precursor of substance P). Collectively, these data, as well as a rescue experiment using rIL-10 together with rapamycin, which decreased PMN in cornea, provide concrete evidence that mTOR regulates IL-10 in P. aeruginosa-induced bacterial keratitis and is critical to balancing pro- and anti-inflammatory events, resulting in better disease outcome. Topics: Animals; Apoptosis; Bacterial Load; CCAAT-Enhancer-Binding Protein-beta; Cytokines; Female; Gene Expression Regulation; Interleukin-10; Keratitis; Mice; Neutrophil Infiltration; Neutrophils; Nitrites; Peroxidase; Phagocytosis; Pseudomonas aeruginosa; Pseudomonas Infections; RNA, Messenger; Sirolimus; STAT3 Transcription Factor; Toll-Like Receptors; TOR Serine-Threonine Kinases | 2013 |
Fungal antioxidant pathways promote survival against neutrophils during infection.
Filamentous fungi are a common cause of blindness and visual impairment worldwide. Using both murine model systems and in vitro human neutrophils, we found that NADPH oxidase produced by neutrophils was essential to control the growth of Aspergillus and Fusarium fungi in the cornea. We demonstrated that neutrophil oxidant production and antifungal activity are dependent on CD18, but not on the β-glucan receptor dectin-1. We used mutant A. fumigatus strains to show that the reactive oxygen species-sensing transcription factor Yap1, superoxide dismutases, and the Yap1-regulated thioredoxin antioxidant pathway are each required for protection against neutrophil-mediated oxidation of hyphae as well as optimal survival of fungal hyphae in vivo. We also demonstrated that thioredoxin inhibition using the anticancer drug PX-12 increased the sensitivity of fungal hyphae to both H2O2- and neutrophil-mediated killing in vitro. Additionally, topical application of PX-12 significantly enhanced neutrophil-mediated fungal killing in infected mouse corneas. Cumulatively, our data reveal critical host oxidative and fungal anti-oxidative mediators that regulate hyphal survival during infection. Further, these findings also indicate that targeting fungal anti-oxidative defenses via PX-12 may represent an efficacious strategy for treating fungal infections. Topics: Animals; Antioxidants; Aspergillosis; Aspergillus flavus; Aspergillus fumigatus; CD18 Antigens; Cells, Cultured; Cornea; Enzyme Activation; Fungal Proteins; Fusariosis; Fusarium; Host-Pathogen Interactions; Humans; Keratitis; Mice; Mice, Inbred C57BL; Mice, Knockout; Microbial Viability; NADPH Oxidases; Neutrophil Infiltration; Neutrophils; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidative Stress; Peroxidase; Reactive Oxygen Species; Superoxide Dismutase; Thioredoxins; Transcription Factors | 2012 |
The delayed response of Toll-like receptors may relate to Pseudomonas aeruginosa keratitis exacerbating rapidly at the early stages of infection.
Keratitis caused by Pseudomonas aeruginosa is a potentially vision-threatening condition that requires prompt treatment to prevent vision loss. The recognition of infectious agents by the Toll-like receptor (TLR) system initiates primary innate and later adaptive immune responses. In this study, in late cases of corneal P. aeruginosa infection, the expression of TLR2, 4, 5 and 9 mRNA were all upregulated. In early infection cases, only TLR9 mRNA expression was upregulated. In late cases, the protein expression of TLR2, 4, 5, 9 and pIkappaB-alpha were elevated. In early cases, only TLR9 and pIkappaB-alpha expression were upregulated. Concentrations of IL-6 and IL-8 increased in infected corneas, especially in late cases. Myeloperoxidase (MPO) activity suggested that polymorphonuclear leukocyte (PMN) numbers were higher in late than in early stages of infection. The delayed response of TLRs may explain why P. aeruginosa infection exacerbates rapidly at the early infection stage. This finding may have important implications for the treatment of innate immunologic responses to corneal infections. Topics: Adult; Cornea; Female; Gene Expression Profiling; Humans; Interleukin-6; Interleukin-8; Keratitis; Male; Middle Aged; Neutrophils; Peroxidase; Pseudomonas aeruginosa; Pseudomonas Infections; Time Factors; Toll-Like Receptors; Up-Regulation; Young Adult | 2010 |
Selective activation of the prostaglandin E2 circuit in chronic injury-induced pathologic angiogenesis.
Cyclooxygenase (COX)-derived prostaglandin E(2) (PGE(2)) is a prevalent and established mediator of inflammation and pain in numerous tissues and diseases. Distribution and expression of the four PGE(2) receptors (EP1-EP4) can dictate whether PGE(2) exerts an anti-inflammatory or a proinflammatory and/or a proangiogenic effect. The role and mechanism of endogenous PGE(2) in the cornea, and the regulation of EP expression during a dynamic and complex inflammatory/reparative response remain to be clearly defined.. Chronic or acute self-resolving inflammation was induced in mice by corneal suture or epithelial abrasion, respectively. Reepithelialization was monitored by fluorescein staining and neovascularization quantified by CD31/PECAM-1 immunofluorescence. PGE(2) formation was analyzed by lipidomics and polymorphonuclear leukocyte (PMN) infiltration quantified by myeloperoxidase activity. Expression of EPs and inflammatory/angiogenic mediators was assessed by real-time PCR and immunohistochemistry. Mice eyes were treated with PGE(2) (100 ng topically, three times a day) for up to 7 days.. COX-2, EP-2, and EP-4 expression was upregulated with chronic inflammation that correlated with increased corneal PGE(2) formation and marked neovascularization. In contrast, acute abrasion injury did not alter PGE(2) or EP levels. PGE(2) treatment amplified PMN infiltration and the angiogenic response to chronic inflammation but did not affect wound healing or PMN infiltration after epithelial abrasion. Exacerbated inflammatory neovascularization with PGE(2) treatment was independent of the VEGF circuit but was associated with a significant induction of the eotaxin-CCR3 axis.. These findings place the corneal PGE(2) circuit as an endogenous mediator of inflammatory neovascularization rather than general inflammation and demonstrate that chronic inflammation selectively regulates this circuit at the level of biosynthetic enzyme and receptor expression. Topics: Animals; Cell Migration Assays, Leukocyte; Chromatography, High Pressure Liquid; Chronic Disease; Corneal Injuries; Corneal Neovascularization; Cyclooxygenase 2; Dinoprostone; Disease Models, Animal; Epithelium, Corneal; Eye Injuries; Female; Fluorescent Antibody Technique, Indirect; Keratitis; Mice; Mice, Inbred C57BL; Neutrophils; Peroxidase; Platelet Endothelial Cell Adhesion Molecule-1; Receptors, Prostaglandin E; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tandem Mass Spectrometry; Wound Healing; Wounds, Nonpenetrating | 2010 |
Moxifloxacin and cholesterol combined treatment of pneumococcal keratitis.
Compare the efficacy of treatment of pneumococcal keratitis with cholesterol, moxifloxacin, or a mixture of the two (moxifloxacin/cholesterol).. New Zealand white rabbits were injected intrastromally with 10(6) colony-forming units (CFU) of a clinical keratitis strain of Streptococcus pneumoniae. Eyes were examined before and after treatment of topical drops every 2 hr from 25 to 47 hr post-infection (PI). Corneas were harvested to quantitate bacterial CFU, and myeloperoxidase (MPO) activity was measured at 48 hr PI. Eyes were extracted for histology. Minimal inhibitory concentrations (MICs) were determined for each compound.. Eyes treated with moxifloxacin/cholesterol had a significantly lower mean slit lamp examination (SLE) score than eyes treated with phosphate-buffered saline (PBS), moxifloxacin alone, or cholesterol alone (P ≤ 0.02). A significantly lower log(10) CFU was recovered from corneas treated with moxifloxacin/cholesterol and moxifloxacin alone as compared to corneas of eyes treated with PBS or cholesterol alone (P < 0.01). At 48 hr PI, significantly lower MPO activity was quantitated from eyes treated with moxifloxacin/cholesterol as compared to eyes treated with cholesterol or moxifloxacin alone (P ≤ 0.046). Eyes treated with moxifloxacin/cholesterol had fewer immune cells and less corneal destruction than eyes from all other treatment groups. The MIC for moxifloxacin alone was 0.125 μg/mL, and cholesterol alone was unable to inhibit growth at any of the concentrations tested. The MIC for moxifloxacin when combined with 1% cholesterol was 0.0625 μg/mL.. Treatment with a mixture of moxifloxacin and cholesterol significantly lowers the severity of infection caused by pneumococcal keratitis as compared to treatment with moxifloxacin alone, cholesterol alone, or PBS. This treatment mixture eradicates the bacteria in the cornea, unlike treatment with PBS or cholesterol alone. Using cholesterol with moxifloxacin as a treatment for bacterial keratitis could help lower the clinical severity of the infection. Topics: Animals; Anti-Infective Agents; Aza Compounds; Cholesterol; Disease Models, Animal; Drug Therapy, Combination; Fluoroquinolones; Keratitis; Moxifloxacin; Peroxidase; Quinolines; Rabbits; Severity of Illness Index; Stem Cells; Streptococcus pneumoniae; Treatment Outcome | 2010 |
Exacerbated corneal inflammation and neovascularization in the HO-2 null mice is ameliorated by biliverdin.
Heme oxygenase (HO-1 and HO-2) represents an intrinsic cytoprotective and anti-inflammatory system based on its ability to modulate leukocyte migration and to inhibit expression of inflammatory cytokines and proteins. HO-2 deletion leads to unresolved corneal inflammation and chronic inflammatory complications including ulceration, perforation and neovascularization. We examined the consequences of HO-2 deletion on hemangiogenesis and lymphangiogenesis in the model of suture-induced inflammatory neovascularization. An 8.0 silk suture was placed at the corneal apex of wild type and HO-2 null mice. Neovascularization was assessed by vital microscopy and quantified by image analysis. Hemangiogenesis and lymphangiogenesis were determined by immunofluorescence staining using anti-CD31 and anti-LYVE-1 antibodies, respectively. Inflammation was quantified by histology and myeloperoxidase activity. The levels of HO-1 expression and inflammatory cytokines were determined by real time PCR and ELISA, respectively. Corneal sutures produced a consistent inflammatory response and a time-dependent neovascularization. The response in HO-2 null mice was associated with a greater increase compared to the wild type in the number of leukocytes (827,600+/-129,000 vs. 294,500+/-57,510; p<0.05), neovessels measured by vital microscopy (21.91+/-1.05 vs. 12.77+/-1.55 mm; p<0.001) 4 days after suture placement. Hemangiogenesis but not lymphangiogenesis was more pronounced in HO-2 null mice compared to wild type mice. Induction of HO-1 in sutured corneas was greatly attenuated in HO-2 null corneas and treatment with biliverdin diminished the exaggerated inflammatory and neovascular response in HO-2 null mice. The demonstration that the inflammatory responses, including expression of proinflammatory proteins, inflammatory cell influx and hemangiogenesis are exaggerated in HO-2 knockout mice strongly supports the notion that the HO system is critical for controlling the inflammatory and neovascular response in the cornea. Hence, pharmacological amplification of this system may constitute a novel therapeutic strategy for the treatment of corneal disorders associated with excessive inflammation and neovascularization. Topics: Animals; Biliverdine; Cornea; Corneal Neovascularization; Disease Progression; Drug Evaluation, Preclinical; Female; Heme Oxygenase (Decyclizing); Heme Oxygenase-1; Keratitis; Male; Mice; Mice, Knockout; Peroxidase | 2008 |
Heme oxygenase-1 induction attenuates corneal inflammation and accelerates wound healing after epithelial injury.
Heme oxygenase (HO) is considered a fundamental endogenous immunomodulatory, cytoprotective, and anti-inflammatory system. This protective function is primarily ascribed to the inducible HO-1. The authors examined the effect of HO-1 induction on corneal inflammation and wound healing in mice undergoing epithelial injury.. C57BL6 mice were treated with SnCl(2) the day before epithelial injury and once daily thereafter. The corneal epithelium was removed with the use of a corneal rust ring remover in anesthetized mice. Reepithelialization was measured by fluorescein staining. The inflammatory response was examined by histology and was quantified by the myeloperoxidase assay. Inflammatory lipid mediators were detected and quantified by LC/MS/MS-based lipidomic analysis. HO-1 expression was assessed by real-time PCR, and HO activity was determined by measuring HO-dependent carbon monoxide production.. Epithelial injury caused a time-dependent transient increase in HO-1 expression and HO activity that was significantly amplified by treatment with SnCl(2), resulting in a twofold to threefold increase in mRNA levels and a similar increase in corneal HO activity. Induction of HO-1 was associated with a significant acceleration of wound healing when compared with a vehicle-treated group and with attenuation of the inflammatory response, evidenced by a significant decrease in the number of infiltrating cells and by a significant reduction in the expression and production of proinflammatory lipid mediators and cytokines.. Increased expression of HO-1 provides a mechanism that modulates inflammation and promotes wound closure; pharmacologic amplification of this system may constitute a novel strategy to treat corneal inflammation while accelerating wound repair after injury. Topics: Animals; Aryl Hydrocarbon Hydroxylases; Chemokine CXCL2; Chromatography, Liquid; Enzyme Induction; Epithelium, Corneal; Heme Oxygenase-1; Interleukin-1alpha; Keratitis; Mice; Mice, Inbred C57BL; Peroxidase; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tandem Mass Spectrometry; Time Factors; Tin Compounds; Wound Healing | 2008 |
Adenovirus type 37 keratitis in the C57BL/6J mouse.
To develop a mouse model of adenoviral keratitis that will allow further study of viral and host pathogenic mechanisms.. Corneas of C57BL/6J mice were injected with adenovirus type 37 (Ad37) or virus-free dialysis buffer by a gas-powered microinjection system coupled to a glass micropipette needle. Mouse corneas were examined for signs of inflammation, by clinical examination, immunohistochemistry, and confocal microscopy; assayed for viral and chemokine mRNA expression by real-time PCR; titered to assess viral replication; and subjected to ELISA for chemokine and myeloperoxidase (MPO) protein expression.. C57BL/6J mice corneas injected with 10(5) TCID (tissue culture infective dose) Ad37 showed stromal opacification and inflammation beginning from 1 day after injection and continuing for several months, while buffer-injected corneas showed no signs of inflammation. Ad37-injected corneas expressed adenoviral E1A 10S and E1B 19k mRNA but not IIIa, and viral titers had fallen two logs by day 4 after injection. When compared to untouched and buffer-injected corneas, Ad37-injected corneas expressed significantly higher levels of IL-6, KC, and MCP-1 mRNA at 4 hours after injection (P < 0.05). By ELISA, KC protein was significantly elevated in Ad37-injected corneas at 8 and 16 hours, and MCP-1 protein at 16 hours after injection (P < 0.05). Ad37-injected corneas showed elevated levels of MPO (P = 0.0024) at 4 days after injection consistent with immunohistochemical evidence for a predominance of neutrophils in the corneal stroma.. Ad37 induces an acute immunopathologic response in the C57BL/6J mouse cornea, despite an absence of viral replication. This new animal model of Ad37 keratitis will facilitate studies of the molecular pathogenesis of the disorder. Topics: Adenoviridae Infections; Adenovirus E1A Proteins; Adenovirus E1B Proteins; Adenoviruses, Human; Animals; Chemokine CCL2; Chemokines; Cornea; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Eye Infections, Viral; Female; Fluorescent Antibody Technique, Indirect; Keratitis; Mice; Mice, Inbred C57BL; Microscopy, Confocal; Peroxidase; Phenotype; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Viral | 2007 |
TLR4 is required for host resistance in Pseudomonas aeruginosa keratitis.
To determine the role of Toll-like receptor 4 (TLR4) in Pseudomonas aeruginosa (P. aeruginosa) keratitis in resistant (cornea-healing) BALB/c mice.. Corneal TLR4 mRNA levels were tested by real-time PCR in BALB/c mice before and after infection. Clinical score, slit lamp, histopathology, bacterial counts, and polymorphonuclear neutrophil (PMN) quantitation were performed in the infected cornea of TLR4-deficient (TLR4(lps-d)) and wild-type BALB/c mice. mRNA for IL-1beta, MIP-2, IFN-gamma, IL-18, inducible nitric oxide synthase (iNOS), and beta-defensin-2 levels were measured by real-time PCR. Protein levels for IL-1beta, MIP-2, and IFN-gamma were tested by ELISA.. In resistant BALB/c mice, TLR4 mRNA expression was significantly upregulated in the cornea after P. aeruginosa infection. In contrast, TLR4-deficient mice were susceptible to infection with P. aeruginosa and showed increased corneal opacity, PMN infiltration, bacterial counts, and perforated infected corneas. After infection, TLR4-deficient mice also showed increased mRNA expression of proinflammatory cytokines (IL-1beta and MIP-2) and type-1-associated cytokines (IFN-gamma and IL-18) when compared with wild-type BALB/c mice. ELISA analyses showed that IL-1beta, MIP-2, and IFN-gamma protein levels also were significantly upregulated in the cornea of TLR4-deficient versus wild-type mice. In contrast, levels of iNOs and beta-defensin-2 were significantly decreased in TLR4-deficient compared with wild-type mice.. TLR4 is critical in host resistance to P. aeruginosa, as its deficiency results in increased PMN infiltration and proinflammatory cytokine production, decreased iNOs and beta-defensin-2 production, impaired bacterial killing, and a susceptible phenotype. Topics: Animals; beta-Defensins; Colony Count, Microbial; Cytokines; Enzyme-Linked Immunosorbent Assay; Eye Infections, Bacterial; Female; Immunity, Innate; Keratitis; Mice; Mice, Inbred BALB C; Mice, Knockout; Neutrophils; Nitric Oxide Synthase Type II; Peroxidase; Pseudomonas Infections; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Toll-Like Receptor 4; Up-Regulation | 2006 |
A protective role for IL-6 in staphylococcal microbial keratitis.
To determine whether interleukin-6 (IL-6) plays a protective role in Staphylococcus aureus keratitis in a gene knockout (gko) mouse model and to determine whether IL-6 may be used as a therapy to modulate host responses and control bacterial infection, thereby reducing scarring.. The eyes of IL-6 gko mice and wild-type mice were challenged topically with S. aureus and examined at 24 hours after infection. Keratitis was examined clinically and histologically. Bacterial and polymorphonuclear leukocytes (PMNs) were enumerated, and cytokine and chemokine levels were determined by ELISA. Exogenous IL-6 was administered to both IL-6 gko and wild-type mice, and clinical parameters were determined.. IL-6 gko mice showed more severe disease, with increased bacterial counts and PMNs, than did wild-type mice. Changes in levels of chemokines and cytokines were also observed. Administration of exogenous IL-6 resulted in an improved outcome in IL-6 gko mice, with a threefold reduction in bacterial load.. The data suggest an important regulatory role for IL-6 in modulating excessive inflammatory responses and in controlling bacterial proliferation. IL-6 may play a role in the priming and activation of neutrophils. It could represent a broad-spectrum therapy to improve outcomes in patients who have these potentially blinding infections. Topics: Animals; Chemokines; Colony Count, Microbial; Cytokines; Enzyme-Linked Immunosorbent Assay; Eye Infections, Bacterial; Interleukin-6; Keratitis; Mice; Mice, Inbred C57BL; Mice, Knockout; Neutrophils; Peroxidase; Recombinant Proteins; Staphylococcal Infections; Staphylococcus aureus | 2006 |
Lumican regulates corneal inflammatory responses by modulating Fas-Fas ligand signaling.
The authors have previously shown that apoptosis of stromal cells is downregulated in the lumican-null mouse and that this may be due to disruption of Fas-Fas ligand (FasL) signaling. The present study was undertaken to investigate the role of lumican in regulating Fas and its impact on inflammation and healing of corneal injuries.. Apoptosis was determined by measuring caspase-3/7 activity in corneal extracts. Protein and RNA levels of Fas were estimated by immunoblot analysis and RT-PCR, respectively. Circular and incisional stromal wounds were exposed to Pseudomonas aeruginosa LPS, and healing was assessed by (1) observing wound closure with fluorescence and bright-field microscopy, (2) histology to quantify inflammatory infiltrates by immunostaining for macrophages (F4/80) and neutrophils (NIMP-R14), (3) measuring myeloperoxidase (MPO) levels by ELISA to quantify neutrophils, and (4) measuring proinflammatory cytokines by ELISA.. Lum-/- -injured corneas showed significantly lower caspase-3/7 activity (apoptosis). Lum-/- -wounded corneas showed delayed healing, reduced recruitment of macrophages and neutrophils, lower MPO levels, and no induction of the proinflammatory cytokines TNFalpha and IL1beta. The Fas protein level, before and after wounding, was dramatically lower in Lum-/- - compared with Lum+/+-injured cornea. However, Fas mRNA levels were comparable in both genotypes, suggesting regulation of Fas at the protein level. Moreover, a solid-state binding assay and coimmunoprecipitation of FasL and lumican suggested binding of FasL to lumican.. The data suggest that lumican binds FasL and facilitates induction of Fas. Poor signaling through Fas-FasL in lumican deficiency leads to impaired induction of inflammatory cytokines and corneal healing. Topics: Animals; Apoptosis; Caspase 3; Caspase 7; Caspases; Cell Culture Techniques; Chondroitin Sulfate Proteoglycans; Corneal Stroma; Enzyme-Linked Immunosorbent Assay; Fas Ligand Protein; fas Receptor; Fluorescent Antibody Technique, Indirect; Keratan Sulfate; Keratitis; Lumican; Macrophages; Membrane Glycoproteins; Mice; Mice, Knockout; Neutrophils; Peroxidase; Receptors, Tumor Necrosis Factor; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Signal Transduction; Transfection; Wound Healing | 2005 |
Effects of toxin production in a murine model of Staphylococcus aureus keratitis.
To investigate the corneal virulence of toxin-deficient mutants of Staphylococcus aureus in young and aged mice in a topical inoculation model of keratitis.. Corneas of young and aged A/J mice were scarified and topically inoculated with a log phase S. aureus parent strain (8325-4), an alpha-toxin-deficient mutant (DU1090), or an Agr-defective mutant (ISP546) deficient in production of multiple toxins or with purified alpha-toxin. Slit lamp examination (SLE) and histopathology were performed, and bacterial colony-forming units (CFU) and myeloperoxidase (MPO) activity were determined.. The infection of young mice with the mutant strains demonstrated significantly lower SLE scores (P < or = 0.0001) and reduced histopathologic changes compared with infections with the parent bacterial strain. Either mutant strain of S. aureus produced SLE scores in aged mice through 9 days after infection (PI) that were significantly lower than those of aged mice similarly infected with the toxin-producing parent strain (P < or = 0.0001). Despite use of identical inocula, the CFU per eye were greater for the parent than the mutant strains from 1 to 5 days PI in the young mice (P < or = 0.0372) and from 1 to 3 days PI in the aged mice (P < or = 0.0018). MPO activities were at the maximum at day 1 PI and were similar overall for all infections. Administration of purified alpha-toxin caused greater gross and histopathologic changes in eyes of aged mice than in those of young mice.. Bacterial toxins, and especially alpha-toxin, can mediate corneal disease in mice. Differences in severity of S. aureus keratitis in aged versus young mice correlates with their susceptibility to alpha-toxin. Topics: Aging; Animals; Bacterial Toxins; Colony Count, Microbial; Cornea; Disease Models, Animal; Eye Infections, Bacterial; Hemolysin Proteins; Keratitis; Male; Mice; Mice, Inbred A; Peroxidase; Staphylococcal Infections; Staphylococcus aureus; Virulence | 2005 |
Interleukin-4 is not critical to pathogenesis in a mouse model of Pseudomonas aeruginosa corneal infection.
To determine the contribution of interleukin-4 (IL-4) to the initial host response during corneal infection with Pseudomonas aeruginosa in a mouse model.. Corneas of 6- to 8-week-old IL-4(-/-) and wild-type mice were topically challenged with P. aeruginosa. Ocular tissue was collected 24 hr and 7 days postchallenge. Viable bacterial counts, myeloperoxidase assays, cytokine levels, and clinical and histological examinations were performed.. During challenge with P. aeruginosa, no differences were observed clinically, histologically, or in bacterial load between IL-4(-/-) and wild-type mice at either time point. However, differences in cytokine levels of IL-6, KC, and IL-10 were observed.. The data presented indicate that IL-4, a central Th2 cytokine, may not be critical to the pathogenesis or bacterial clearance in this model of P. aeruginosa bacterial keratitis during the early stages of the infectious process. Topics: Animals; Chemokines; Colony Count, Microbial; Cytokines; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Eye Infections, Bacterial; Interleukin-4; Keratitis; Leukocyte Count; Mice; Mice, Inbred C57BL; Mice, Knockout; Neutrophils; Peroxidase; Pseudomonas aeruginosa; Pseudomonas Infections; Reverse Transcriptase Polymerase Chain Reaction | 2005 |
Phospholipase A2 activity in normal and Staphylococcus aureus-infected rabbit eyes.
To quantify phospholipase A(2) (PLA(2)) activity in normal rabbit eyes and in eyes with Staphylococcus aureus keratitis.. PLA(2) was assayed by the killing of S. aureus at 33 degrees C or by the release of arachidonic acid from S. aureus labeled with radioactive oleic acid. Rabbit corneas were intrastromally injected with 100 log phase colony-forming units (CFU) of S. aureus 8325-4. The activity of myeloperoxidase (MPO) and PLA(2) were quantified in ocular tissues.. The PLA(2)-mediated killing of S. aureus by normal rabbit tears decreased by more than 70% as the rabbits aged from 10 to 28 weeks and by nearly 50% from early morning to afternoon. In rabbits with S. aureus keratitis, the activity of PLA(2) and MPO increased proportionally with time from 5 to 25 hours postinfection (PI), as measured in ocular tissues. PLA(2) activity increased fivefold in tears from infected eyes collected at 25 hours PI compared with normal tears (P < or = 0.0001), whereas a ninefold increase was found in aqueous humor of infected eyes at 25 hours PI (P < or = 0.0001). Infected eyes demonstrated a significant increase in MPO activity compared with uninfected eyes beginning at 10 hours PI for the aqueous humor (P = 0.03), at 16 hours PI for the tear film (P = 0.0024) and at 22 hours PI for the corneal homogenate (P = 0.0007).. The decrease in PLA(2) activity in the rabbit eye with age or after sleep and its increase during sleep or with the progression of infection are consistent with its role as an innate host defense factor. Topics: Aging; Animals; Aqueous Humor; Cornea; Eye Infections, Bacterial; Keratitis; Peroxidase; Phospholipases A; Phospholipases A2; Rabbits; Staphylococcal Infections; Staphylococcus aureus; Tears; Time Factors | 2003 |
A new topical model of Staphylococcus corneal infection in the mouse.
To establish, in the scarified mouse eye, a new model of Staphylococcus aureus keratitis suitable for studies of pathogenesis and host defense mechanisms.. Corneas of three strains of mice (BALB/c, A/J, and C57BL/6) were scarified and inoculated with S. aureus strain 8325-4. Mice underwent slit lamp examination (SLE) at 1, 3, 5, 7, and 9 days after infection and were killed. Histopathologic analyses, determination of bacterial colony-forming units (CFU), and myeloperoxidase (MPO) activity assays were performed at each time point.. S. aureus keratitis developed in both BALB/c and A/J strains of mice, but not in C57BL/6. The BALB/c and A/J strains demonstrated greater susceptibility to infection, as evidenced by significantly higher SLE scores and more viable bacteria per infected eye than in C57BL/6 mice at 5, 7, and 9 days after infection (P Topics: Animals; Aqueous Humor; Colony Count, Microbial; Cornea; Disease Models, Animal; Eye Infections, Bacterial; Keratitis; Male; Mice; Mice, Inbred A; Mice, Inbred BALB C; Mice, Inbred C57BL; Neutrophils; Peroxidase; Staphylococcal Infections; Staphylococcus aureus | 2003 |
Peripheral nonulcerative keratitis as a presenting sign of microscopic polyangiitis.
To report a 16-year-old woman who had peripheral keratitis as a presenting sign of microscopic polyangiitis (MPA), which rapidly progressed to acute renal failure.. Case report.. The patient's vasculitis was diagnosed by renal biopsy, which was evaluated with histologic, immunofluorescence, and electron microscopy. The diagnosis was confirmed by laboratory study, which showed a positive antimyeloperoxidase antibody.. MPA may rarely present with ocular findings and should be considered in the differential diagnosis when a patient has peripheral keratitis. Topics: Acute Kidney Injury; Adolescent; Autoantibodies; Diagnosis, Differential; Female; Humans; Keratitis; Peroxidase; Vasculitis | 2001 |
Acute inflammation of the eyelid and cornea in Staphylococcus keratitis in the rabbit.
The inflammatory response during Staphylococcus keratitis was analyzed biochemically and histologically to determine the source of the neutrophils infiltrating the tear film and cornea.. Rabbit eyes were swabbed and then examined by slit-lamp microscopy at 0, 5, 10, 15, 20, and 25 hours after intracorneal inoculation with Staphylococcus aureus. Bacterial colony-forming units were quantified in the cornea, eyelid, and acute inflammatory exudate. Myeloperoxidase activity of ocular swabs of acute inflammatory exudate, corneal homogenates, and eyelid homogenates was determined. Gross and microscopic examinations of corneas and eyelids were performed.. The colony-forming units per cornea exceeded 10(7) after 10 hours, whereas no bacteria were cultured from the eyelid until 15 hours postinfection. Slit-lamp examination revealed progressive pathology, and the myeloperoxidase activities of ocular swabs, corneas, and eyelids increased markedly by 15 hours postinfection. Corneas showed a wave of neutrophils moving from the tear film toward bacteria in the central corneal stroma and early neutrophil migration from the limbus into the stroma. In the eyelid, neutrophils migrated from the stromal vessels to the tear film.. Staphylococcus keratitis in the rabbit causes acute inflammation in the overlying eyelid. Neutrophils of the acute inflammatory exudate interact with the infected cornea, whereas neutrophils migrating through the cornea from the limbus remained distant from the site of infection. Topics: Acute Disease; Animals; Blepharitis; Chemotaxis, Leukocyte; Colony Count, Microbial; Cornea; Eye Infections, Bacterial; Eyelids; Keratitis; Neutrophils; Peroxidase; Rabbits; Staphylococcal Infections; Staphylococcus aureus | 1999 |
Specific roles of alpha-toxin and beta-toxin during Staphylococcus aureus corneal infection.
Staphylococcus aureus corneal infection results in extensive inflammation and tissue damage. Our previous studies of bacterial mutants have demonstrated a role for alpha-toxin in corneal virulence. This study analyzes, by genetic rescue experiments, the virulence of mutants affecting alpha-toxin and beta-toxin activity and demonstrates the ocular toxicity of these purified staphylococcal proteins. Three types of isogenic mutants were analyzed: (i) mutants specifically deficient in alpha-toxin (Hla) or beta-toxin (Hlb), (ii) a mutant deficient in both Hla and Hlb, and (iii) a regulatory mutant, deficient in the accessory gene regulator (agr), that produces reduced quantities of multiple exoproteins, including alpha- and beta-toxins. Plasmids coding for Hla and Hlb (pDU1212 and pCU1hlb, respectively) were used to restore toxin activity to mutants specifically deficient in each of these toxins. Either corneas were injected intrastromally with logarithmic-phase S. aureus or purified alpha- or beta-toxins were administered to normal eyes. Ocular pathology was evaluated by slit lamp examination and myeloperoxidase activity of infiltrating polymorphonuclear leukocytes. Corneal homogenates were cultured to determine the CFU per cornea. Eyes infected with the wild-type strain developed significantly greater corneal damage than eyes infected with Agr-, Hlb-, or Hla- strains. Epithelial erosions produced by parent strains were not produced by Agr- or Hla- strains. Hlb+ strains, unlike Hlb- strains, caused scleral edema. Plasmid pDU1212 restored corneal virulence to strain DU1090 (Hla-), and plasmid pCU1hlb restored corneal virulence to strain DU5719 (Hlb-). Application of purified alpha-toxin produced corneal epithelial erosions and iritis, while application of beta-toxin caused scleral inflammation. These studies confirm the role of alpha-toxin as a major virulence factor during S. aureus keratitis and implicate beta-toxin, a mediator of edema, as a lesser contributor to ocular damage. Topics: Animals; Bacterial Proteins; Bacterial Toxins; Colony Count, Microbial; Edema; Epithelium; Eye; Genetic Complementation Test; Iritis; Keratitis; Neutrophils; Peroxidase; Plasmids; Rabbits; Recombination, Genetic; Sclera; Scleritis; Staphylococcal Infections; Staphylococcus aureus; Trans-Activators; Transcription Factors; Virulence | 1997 |
Proinflammatory cytokine deficiency and pathogenesis of Pseudomonas aeruginosa keratitis in aged mice.
Corneal clarity in young adult Swiss (HSD:ICR) mice is restored after Pseudomonas aeruginosa infection. Previous data showed that this response involves a rapid up-regulation of constitutive intercellular cell adhesion molecule-1 (ICAM-1) and migration of inflammatory cells into the cornea. In contrast, in aged mice, there is no up-regulation of corneal ICAM-1, inflammatory cell infiltration into the cornea is delayed, and the cornea perforates. Therefore, the aim of this study was to test whether specific cytokines which up-regulate ICAM-1 expression differ in young and aged mice. Corneas of young (6- to 8-week-old) and aged (1- to 2-year-old) mice were scarified and inoculated with P. aeruginosa. The eyes were graded for pathologic changes (score 0 to +4); at 6, 12, 24, and 48 h postinfection (p.i.), six mice from each age group were sacrificed. Three corneas from each respective group were excised for quantitation of interleukin-1beta (IL-1beta), tumor necrosis factor alpha, and gamma interferon (IFN-gamma) by enzyme-linked immunosorbent assay. The remaining three corneas from each age group were harvested for quantitation of viable bacteria by direct plate count determination and for infiltrating polymorphonuclear leukocytes (PMNs) by a myeloperoxidase (MPO) assay. Compared to those of young mice, the corneas of infected aged mice had less IL-1beta at 6 h p.i. (P < or = 0.04) and less IFN-gamma at 12 to 48 h p.i. (P < or = 0.05). Also, compared to those of young mice, corneas of aged mice had fewer PMNs (P < or = 0.008) by the MPO assay at 6 h p.i. and more viable bacteria (P < or = 0.01) per cornea by plate count determination at 24 h p.i. These data suggest that the lack of up-regulation of ocular ICAM-1 in aged mice may reflect a reduction in both IL-1beta and IFN-gamma levels in the infected cornea. Consequently, a sufficient number of PMNs and other inflammatory cells fail to rapidly migrate into the infected corneas of aged mice, the bacterial load is initially greater than that in young mice, and the cornea perforates. Topics: Aging; Animals; Cornea; Female; In Vitro Techniques; Intercellular Adhesion Molecule-1; Interferon-gamma; Interleukin-1; Keratitis; Mice; Mice, Inbred ICR; Neutrophils; Peroxidase; Pseudomonas Infections; Tumor Necrosis Factor-alpha; Up-Regulation | 1997 |
Characterization of arachidonic acid metabolism and the polymorphonuclear leukocyte response in mice infected intracorneally with Pseudomonas aeruginosa.
To examine the activity of myeloperoxidase (MPO) and the concentrations of the proinflammatory metabolites of arachidonic acid (AA) in ocular tissue of mice that are either capable or incapable of restoring corneal clarity during an intraocular Pseudomonas aeruginosa infection.. For a period of 11 days after infection, whole eyes were enucleated and homogenized in buffer from mice given only an initial infection as well as from mice given a subsequent infection in the previously uninfected eye either 4 or 8 weeks after the initial infection. Tissue-free supernatants from the ocular homogenates were used for the determination of MPO activity by quantitating the conversion of specific substrate by spectrophotometric methods and for the quantitation of AA metabolites by ELISA:. Overall, animals reinfected at 4 and 8 weeks had a lower inflammatory response when compared to the mice given only the initial infection. The lowest levels of LTB4 and MPO activity, indicators of PMN involvement, were observed in the the 8-week reinfected mice, which restored corneal clarity in an enhanced manner.. These results suggest that induced ocular PMN responses may play a role, in part, in the inflammatory response leading to the tissue destruction observed during ocular P. aeruginosa infection. Topics: Animals; Arachidonic Acid; Cornea; Dinoprostone; Enzyme-Linked Immunosorbent Assay; Eye Infections, Bacterial; Female; Keratitis; Leukocyte Count; Leukotriene B4; Mice; Mice, Inbred C57BL; Neutrophils; Peroxidase; Pseudomonas Infections; Thromboxane B2 | 1995 |