Search

While IκB-kinase-ε (IKKε) induces immunomodulatory genes following viral stimuli, its upregulation by inflammatory cytokines remains under-explored. Since airway epithelial cells respond to airborne insults and potentiate inflammation, IKKε expression was characterized in pulmonary epithelial cell lines (A549, BEAS-2B) and primary human bronchial epithelial cells grown as submersion or differentiated air-liquid interface cultures. IKKε expression was up-regulated by the pro-inflammatory cytokines, interleukin-1β (IL-1β) and tumour necrosis factor-α (TNFα). Thus, mechanistic interrogations in A549 cells were used to demonstrate the NF-κB dependence of cytokine-induced IKKε. Furthermore, chromatin immunoprecipitation in A549 and BEAS-2B cells revealed robust recruitment of the NF-κB subunit, p65, to one 50 and two intronic regions within the IKKε locus (IKBKE). In addition, IL-1β and TNFα induced strong RNA polymerase 2 recruitment to the 50 region, the first intron, and the transcription start site. Stable transfection of the p65- binding regions into A549 cells revealed IL-1β- and TNFα-inducible reporter activity that required NF-κB, but was not repressed by glucocorticoid. While critical NF-κB motifs were identified in the 50 and downstream intronic regions, the first intronic region did not contain functional NF-κB motifs. Thus, IL-1β- and TNFα-induced IKKε expression involves three NF-κB-binding regions, containing multiple functional NF-κB motifs, and potentially other mechanisms of p65 binding through non-classical NF-κB binding motifs. By enhancing IKKε expression, IL-1β may prime, or potentiate, responses to alternative stimuli, as modelled by IKKε phosphorylation induced by phorbol 12-myristate 13- acetate. However, since IKKε expression was only partially repressed by glucocorticoid, IKKε-dependent responses could contribute to glucocorticoid-resistant disease. [ABSTRACT FROM AUTHOR]

Roles for the baculoviral inhibitor of apoptosis repeat-containing (BIRC) genes, BIRC2 and BIRC3, may include signaling to the inflammatory transcription factor, nuclear factor-κB (NF-κB) and protection from cell death. However, distinct functions for each BIRC are not well-delineated. Given roles for the epithelium in barrier function and host defence, BIRC2 and BIRC3 expression was characterized in pulmonary epithelial cell lines and primary human bronchial epithelial cells (pHBECs) grown as undifferentiated cells in submersion culture (SC) or as highly differentiated cells at air-liquid interface (ALI). In A549 cells, interleukin-1β (IL1B) and tumor necrosis factor α (TNF) induced BIRC3 mRNA (~20-50-fold), with maximal protein expression from 6–24 h. Similar effects occurred in BEAS-2B and Calu-3 cells, as well as SC and ALI pHBECs. BIRC2 protein was readily detected in unstimulated cells, but was not markedly modulated by IL1B or TNF. Glucocorticoids (dexamethasone, budesonide) modestly increased BIRC3 mRNA and protein, but showed little effect on BIRC2 expression. In A549 cells, BIRC3 mRNA induced by IL1B was unchanged by glucocorticoids and showed supra-additivity with TNF-plus-glucocorticoid. Supra-additivity was also evident for IL1B-plus-budesonide induced-BIRC3 in SC and ALI pHBECs. Using A549 cells, IL1B- and TNF-induced BIRC3 expression, and to a lesser extent, BIRC2, was prevented by NF-κB inhibition. Glucocorticoid-induced BIRC3 expression was prevented by silencing and antagonism of the glucocorticoid receptor. Whereas TNF, but not IL1B, induced degradation of basal BIRC2 and BIRC3 protein, IL1B- and TNF-induced BIRC3 protein remained stable. Differential regulation by cytokines and glucocorticoids shows BIRC2 protein expression to be consistent with roles in rapid signaling events, whereas cytokine-induced BIRC3 may be more important in later effects. While TNF-induced degradation of both BIRCs may restrict their activity, cytokine-enhanced BIRC3 expression could prime for its function. Finally, shielding from glucocorticoid repression, or further enhancement by glucocorticoid, may indicate a key protective role for BIRC3. [ABSTRACT FROM AUTHOR]

Purpose: Orbital decompression for thyroid eye disease (TED) has been noted to improve lower lid retraction by 0.5-1 mm. We hypothesize that orbital decompression via transconjunctival approach may lead to increased reduction in marginal reflex distance 2 (MRD2) as it involves division of the lower lid retractors. The purpose of this study is to evaluate relative changes in lower lid position for patients undergoing lateral and transconjunctival orbital decompression, respectively. Methods: In this cross-sectional study, all TED patients managed with lateral or transconjunctival orbital decompression for a 3-year period were screened for inclusion. Photographs taken in the primary position preoperatively and three months postoperatively were utilized to evaluate the MRD2 from each patient. Measurements were made utilizing NIH ImageJ software standardized to a corneal diameter. Hertel measurements of proptosis were obtained pre and postoperatively. The primary outcome measure was MRD2 in operative eyes. Results: A total of 131 (86 patients) operative eyes were included in the sample. Mean change MRD2 was not significantly different between the surgical groups (p = 0.07). In multivariate modeling, mean change in MRD2 was significantly associated with change in exophthalmometry, independent of surgical approach. Conclusions: The association between decrease in Hertel measurement and decrease in MRD2 is consistent with the existing literature on the topic. It appears that transconjunctival division of the lower eyelid retractors provides no additional benefit in reducing lower lid retraction relative to change in proptosis. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to determine if ocular dominance plays a role in predicting compensatory eyebrow elevation in cases of ptosis. Methods: This retrospective observational cohort study screened all individuals presenting to two tertiary oculoplastics practices with complaints of ptosis for entry. Primary position photographs were obtained. Ocular dominance was assessed via a modified Porta test. Ptosis was defined in bilateral cases as marginal reflex distance of <2.5 mm in both eyes and in unilateral cases as either an MRD1 < 2.5 mm or MRD1 of >1 mm lower on one side. Asymmetry in brow height was defined as a difference of >1 mm. Chi square and t-tests were performed. Results: Sixty-eight patients from the both tertiary practices met inclusion criteria (37 male, 31 female). Concordance between the higher brow and the dominant side was 50.0% (n = 22, p > 0.05). Mean brow height on the dominant side (15.5 mm) was not statistically different than brow height on the non-dominant side (15.3 mm, p > 0.05). The concordance between the higher brow and the lower MRD1 eyelid was not significant (45.5%, n = 20, p > 0.05). The difference in mean brow height between the lower and higher MRD1 eyes was not significantly different (−0.11 mm; p > 0.05). This also held true when restricted to unilateral cases (0.28; p > 0.05). Conclusions: Although asymmetric brow elevation can be noted in patients with ptosis, ocular dominance does not appear to be concordant with this asymmetry. Additionally, brow height does not appear to be concordant with MRD1 in cases of ptosis. [ABSTRACT FROM AUTHOR]