Quality of life is poorly correlated to lung disease severity in school-aged children with cystic fibrosis.

BACKGROUND: There is no data exclusively on the relationship between health-related quality-of-life (HRQOL) and lung disease severity in early school-aged children with cystic fibrosis (CF). Using data from the Australian Respiratory Early Surveillance Team for Cystic Fibrosis (AREST CF) we assessed the relationships between HRQOL, lung function and structure. METHODS: 125 children aged 6.5-10 years enrolled in the AREST CF program were included from CF clinics at Royal Children's Hospital (RCH), Melbourne (n = 66) and Perth Children's Hospital (PCH), Perth (n = 59), Australia. Demographics, HRQOL measured by Cystic Fibrosis Questionnaire-Revised (CFQ-R), spirometry, multiple-breath washout (MBW) and chest CT were collected across two years. Correlation between CFQ-R scores and lung structure/function parameters and agreement between parent-proxy and child-reported HRQOL were evaluated. RESULTS: No correlation was observed between most CFQ-R domain scores and FEV1 z-scores, excepting weak-positive correlation with parent CFQ-R Physical (rho = 0.21, CI 0.02-0.37), and Weight (rho = 0.21, CI 0.03-0.38) domain and child Body domain (rho = 0.26, CI 0.00-0.48). No correlation between most CFQ-R domain scores and LCI values was noted excepting weak-negative correlation with parent Respiratory (rho = -0.23, CI -0.41--0.05), Emotional (rho = -0.24, CI -0.43--0.04), and Physical (-0.21, CI -0.39--0.02) domains. Furthermore, structural lung disease on CT data demonstrated little to no association with CFQ-R parent and child domain scores. Additionally, no agreement between child self-report and parent-proxy CFQ-R scores was observed across the majority of domains and visits. CONCLUSION: HRQOL correlated poorly with lung function and structure in early school-aged children with CF, hence clinical trials should consider these outcomes independently when determining study end-points.

A hot spot on interferon α/ß receptor subunit 1 (IFNAR1) underpins its interaction with interferon-ß and dictates signaling.

The interaction of IFN-ß with its receptor IFNAR1 (interferon α/ß receptor subunit 1) is vital for host-protective anti-viral and anti-proliferative responses, but signaling via this interaction can be detrimental if dysregulated. Whereas it is established that IFNAR1 is an essential component of the IFNAR signaling complex, the key residues underpinning the IFN-ß-IFNAR1 interaction are unknown. Guided by the crystal structure of the IFN-ß-IFNAR1 complex, we used truncation variants and site-directed mutagenesis to investigate domains and residues enabling complexation of IFN-ß to IFNAR1. We have identified an interface on IFNAR1-subdomain-3 that is differentially utilized by IFN-ß and IFN-α for signal transduction. We used surface plasmon resonance and cell-based assays to investigate this important IFN-ß binding interface that is centered on IFNAR1 residues Tyr240 and Tyr274 binding the C and N termini of the B and C helices of IFN-ß, respectively. Using IFNAR1 and IFN-ß variants, we show that this interface contributes significantly to the affinity of IFN-ß for IFNAR1, its ability to activate STAT1, the expression of interferon stimulated genes, and ultimately to the anti-viral and anti-proliferative properties of IFN-ß. These results identify a key interface created by IFNAR1 residues Tyr240 and Tyr274 interacting with IFN-ß residues Phe63, Leu64, Glu77, Thr78, Val81, and Arg82 that underlie IFN-ß-IFNAR1-mediated signaling and biological processes.

Epigenetic regulation of miRNA-124 and multiple downstream targets is associated with treatment response in myeloid malignancies.

Epigenetic regulation of microRNA (miRNA) expression has recently been implicated in the pathogenesis of myelodysplastic syndrome (MDS). Particular interest has focused on miRNA-124 expression, which is inhibited in MDS and has recently been demonstrated to be upregulated in response to epigenetic treatment (EGT). Previous studies have determined the in vitro and in vivo expression of miRNA-124 and several molecular targets, including cyclin-dependent kinase (CDK) 4, CDK6 and enhancer of zeste homolog 2 (EZH2), in order to elucidate the molecular mechanisms associated with the miRNA-124-mediated therapeutic response to EGT in MDS and identify additional potential biomarkers of early EGT treatment response in myeloid malignancies. In vitro studies in the HL60 leukemic cell line identified upregulation of miRNA-124 expression in response to single-agent EGT with either azacytidine (AZA) or the histone deacetylase inhibitor panobinostat (LBH589). Combination EGT with AZA and LBH589 resulted in significant additive induction of miRNA-124 expression. Expression of downstream targets of miRNA-124, including CDK4, CDK6 and EZH2, in response to single agent and combined EGT was determined in HL60 cells. Single and combination EGT treatment resulted in inhibition of CDK4, CDK6 and EZH2 expression with combination EGT resulting in a significant and additive inhibitory effect. In vivo studies using peripheral blood mononuclear cells from patients receiving combination EGT for high risk MDS or acute myeloid leukemia demonstrated significant induction of miRNA-124 and inhibition CDK4 and CDK6 messenger (m)RNA expression in patients that responded to combination EGT. A trend to inhibited EZH2 mRNA expression was also identified in response to combination EGT. Overall, the present observations identify a potential molecular mechanism for miRNA-124-mediated response to EGT involving regulation of CDK4, CDK6 and EZH2 expression. In addition, the present findings further qualify miRNA-124 as a possible biomarker of early response to EGT in myeloid malignancies and potentially a valid therapeutic target, together with CDK4, CDK6 and EZH2.