Airway Epithelial Inflammation-induced Endoplasmic Reticulum Ca2+ Store Expansion Is Mediated by X-box Binding Protein-1*

Inflamed cystic fibrosis (CF) human bronchial epithelia (HBE), or normal HBE exposed to supernatant from mucopurulent material (SMM) from CF airways, exhibit endoplasmic reticulum (ER)/Ca2+ store expansion and amplified Ca2+-mediated inflammation. HBE inflammation triggers an unfolded protein response (UPR) coupled to mRNA splicing of X-box binding protein-1 (XBP-1). Because spliced XBP-1 (XBP-1s) promotes ER expansion in other cellular models, we hypothesized that XBP-1s is responsible for the ER/Ca2+ store expansion in inflamed HBE. XBP-1s was increased in freshly isolated infected/inflamed CF in comparison with normal HBE. The link between airway epithelial inflammation, XBP-1s, and ER/Ca2+ store expansion was then addressed in murine airways challenged with phosphate-buffered saline or Pseudomonas aeruginosa. P. aeruginosa-challenged mice exhibited airway epithelial ER/Ca2+ store expansion, which correlated with airway inflammation. P. aeruginosa-induced airway inflammation triggered XBP-1s in ER stress-activated indicator (ERAI) mice. To evaluate the functional role of XBP-1s in airway inflammation linked to ER/Ca2+ store expansion, control, XBP-1s, or dominant negative XBP-1 (DN-XBP-1) stably expressing 16HBE14o- cell lines were used. Studies with cells transfected with an unfolded protein response element (UPRE) luciferase reporter plasmid confirmed that the UPRE was activated or inhibited by expression of XBP-1s or DN-XBP-1, respectively. Expression of XBP-1s induced ER/Ca2+ store expansion and potentiated bradykinin-increased interleukin (IL)-8 secretion, whereas expression of DN-XBP-1 inhibited bradykinin-dependent IL-8 secretion. In addition, expression of DN-XBP-1 blunted SMM-induced ER/Ca2+ store expansion and SMM-induced IL-8 secretion. These findings suggest that, in inflamed HBE, XBP-1s is responsible for the ER/Ca2+ store expansion that confers amplification of Ca2+-dependent inflammatory responses

A noninterventional study to monitor patients with diabetic macular oedema starting treatment with ranibizumab (POLARIS)

Purpose: Antivascular endothelial growth factor agents are increasingly used in diabetic macular oedema (DME); however, there are few studies exploring their use in DME in real-world settings. Methods: POLARIS was a noninterventional, multicentre study to monitor 12-month outcomes in patients starting ranibizumab treatment in routine practices. The primary outcome was mean change in visual acuity (VA) from baseline to month 12 (last observation carried forward approach). Other outcomes included mean change in central retinal thickness (CRT) and resource utilization. Visual acuity (VA) outcomes were also stratified by country, baseline visual acuity score (VAS), sex, age and injection frequency. Results: Outcomes were analysed from all treated patients (n = 804) and from first-year completers (patients who had a visual acuity assessment at 12 months; n = 568). The mean (SD) baseline VAS was 59.4 (15.9) letters, and the mean change in visual acuity was 4.4 letters (95% confidence interval: 3.3–5.4) at month 12 (study eye; first-year completers). The mean number of injections (study eye) was 4.9, and the mean number of all visits (any eye) was 10 (58% were injection visits) over 12 months (first-year completers). The mean (SD) baseline CRT was 410.6 (128.8) μm, and the mean change in CRT was −115.2 μm at month 12 (study eye; first-year completers). Visual acuity (VA) outcomes were generally comparable across most countries and subgroups and were greatest in patients with the lowest baseline VAS (≤60 letters). Conclusion: POLARIS showed that real-world outcomes in DME patients starting treatment with ranibizumab were lower than those observed in clinical studies, in spite of extensive monitoring. © 2018 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation