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1.  Protective Role of Murine β-Defensins 3 and 4 and Cathelin-Related Antimicrobial Peptide in Fusarium solani Keratitis 
Infection and Immunity  2013;81(8):2669-2677.
Antimicrobial peptides (AMPs), such as β-defensins and cathelicidins, are essential components of innate and adaptive immunity owing to their extensive multifunctional activities. However, their role in fungal infection in vivo remains elusive. In this study, we investigated the protective effect of murine β-defensin 3 (mBD3), mBD4, and the cathelicidin cathelin-related antimicrobial peptide (CRAMP) in a murine model of Fusarium solani keratitis. C57BL/6 mice showed significant corneal disease 1 and 3 days after infection, which was accompanied by enhanced expression of β-defensins and CRAMP. Disease severity was significantly improved 7 days after infection, at which time AMP expression was returning to baseline. Mice deficient in mBD3 (genetic knockout), mBD4 (short interfering RNA knockdown), or CRAMP (genetic knockout) exhibited enhanced disease severity and progression, increased neutrophil recruitment, and delayed pathogen elimination compared to controls. Taken together, these data suggest a vital role for AMPs in defense against F. solani keratitis, a potentially blinding corneal disease.
doi:10.1128/IAI.00179-13
PMCID: PMC3719577  PMID: 23670560
2.  Expression and activation of the oxytocin receptor in airway smooth muscle cells: Regulation by TNFα and IL-13 
Respiratory Research  2010;11(1):104.
Background
During pregnancy asthma may remain stable, improve or worsen. The factors underlying the deleterious effect of pregnancy on asthma remain unknown. Oxytocin is a neurohypophyseal protein that regulates a number of central and peripheral responses such as uterine contractions and milk ejection. Additional evidence suggests that oxytocin regulates inflammatory processes in other tissues given the ubiquitous expression of the oxytocin receptor. The purpose of this study was to define the role of oxytocin in modulating human airway smooth muscle (HASMCs) function in the presence and absence of IL-13 and TNFα, cytokines known to be important in asthma.
Method
Expression of oxytocin receptor in cultured HASMCs was performed by real time PCR and flow cytomery assays. Responses to oxytocin was assessed by fluorimetry to detect calcium signals while isolated tracheal rings and precision cut lung slices (PCLS) were used to measure contractile responses. Finally, ELISA was used to compare oxytocin levels in the bronchoalveloar lavage (BAL) samples from healthy subjects and those with asthma.
Results
PCR analysis demonstrates that OXTR is expressed in HASMCs under basal conditions and that both interleukin (IL)-13 and tumor necrosis factor (TNFα) stimulate a time-dependent increase in OXTR expression at 6 and 18 hr. Additionally, oxytocin increases cytosolic calcium levels in fura-2-loaded HASMCs that were enhanced in cells treated for 24 hr with IL-13. Interestingly, TNFα had little effect on oxytocin-induced calcium response despite increasing receptor expression. Using isolated murine tracheal rings and PCLS, oxytocin also promoted force generation and airway narrowing. Further, oxytocin levels are detectable in bronchoalveolar lavage (BAL) fluid derived from healthy subjects as well as from those with asthma.
Conclusion
Taken together, we show that cytokines modulate the expression of functional oxytocin receptors in HASMCs suggesting a potential role for inflammation-induced changes in oxytocin receptor signaling in the regulation of airway hyper-responsiveness in asthma.
doi:10.1186/1465-9921-11-104
PMCID: PMC2922094  PMID: 20670427
3.  Cytokines Induce an Early Steroid Resistance in Airway Smooth Muscle Cells 
We have previously shown that long-term treatment of airway smooth muscle (ASM) cells with a combination of TNF-α and IFN-γ impaired steroid anti-inflammatory action through the up-regulation of glucocorticoid receptor beta isoform (GRβ) (Mol Pharmacol 2006;69:588–596). We here found that steroid actions could also be suppressed by short-term exposure of ASM cells to TNF-α and IFN-γ (6 h) as shown by the abrogated glucocorticoid responsive element (GRE)-dependent gene transcription; surprisingly, neither GRα nuclear translocation nor GRβ expression was affected by cytokine mixture. The earlier induction of CD38, a molecule recently involved in asthma, seen with TNF-α and IFN-γ combination but not with cytokine alone, was also completely insensitive to steroid pretreatment. Chromatin-immunoprecipitation (IP) and siRNA strategies revealed not only increased binding of interferon regulatory factor 1 (IRF-1) transcription factor to CD38 promoter, but also its implication in regulating CD38 gene transcription. Interestingly, the capacity of fluticasone to completely inhibit TNF-α–induced IRF-1 expression, IRF-1 DNA binding, and transactivation activities was completely lost in cells exposed to TNF-α and IFN-γ in combination. This early steroid dysfunction seen with cytokine combination could be reproduced by enhancing IRF-1 cellular levels using constitutively active IRF-1, which dose-dependently inhibited GRE-dependent gene transcription. Consistently, reducing IRF-1 cellular levels using siRNA approach significantly restored steroid transactivation activities. Collectively, our findings demonstrate for the first time that IRF-1 is a novel alternative GRβ-independent mechanism mediating steroid dysfunction induced by pro-asthmatic cytokines, in part via the suppression of GRα activities.
doi:10.1165/rcmb.2007-0226OC
PMCID: PMC2274949  PMID: 17947510
transcription factor; glucocorticoid; inflammation; asthma; mesenchymal cells

Results 1-3 (3)