this explanation Interestingly the response of F

Interestingly, the response of F508del/Y1092X cells is almost double to that of F508del/G542X. While difference could be due to intrinsic responses of the F508del this explanation from each of these donors, it is also plausible that the Y1092X mutation, given its localization towards the C-terminus of the protein, does not totally abolish the production of functional CFTR protein, in contrast to G542X. Indeed, these HBE cells already exhibit levels of Ieq-sc-Fsk or I before VX-809, which are higher than those of F508del/F508del cells, suggesting that Y1092X-CFTR protein may elicit such response. Moreover, the levels of Y1092X-transcripts (Table S3) are higher than those from G542X, again indicating that Y1092X transcripts are less prone to degradation through nonsense-mediated decay. It is thus likely that Y1092X originates CFTR protein with residual function with some positive response to VX-809. In conclusion, our data suggest that CF patients bearing the A561E mutation, which is associated with a severe clinical phenotype and quite common in some countries (Mendes et al., 2003), can potentially benefit from lumacaftor treatment. Similarly, lumacaftor seems to have a positive impact on Y1092X. Our data also show that cells with only one copy of F508del-CFTR respond less to VX-809. Moreover, there is great variability in lumacaftor responses among F508del-homozygous cells from different donors. Importantly, the methodology used in this study exemplifies how ex vivo approaches may apply personalized therapies to Cystic Fibrosis and possibly other respiratory diseases. These data actually demonstrates the main topic of this study which is each patient should be tested individually for the responsiveness to the compounds.
Conflicts of Interest
Authors\' Contributions
Acknowledgments This work was supported by PEst-OE/BIA/UI4046/2011 (POCTI/FCT/PIDDAC), POCTI/PTDC/SAU-GMG/122229/2010 (FCT, Portugal) and Gilead GÉNESE Programme grant (Ref MED-2013-250) and IU are recipients of doctoral fellowships SFRH/BD/52487/2014 and SFRH/BD/69180/2010, respectively from FCT, Portugal. The authors thank Professor Bob Bridges (RFUMs, Chicago, IL, USA) and CFF (USA) for supplying compound C18 and Inh172 and are also grateful to Ines Pérez and Salvador Bejar Carbonell from Hospital la Fe (Valencia, Spain) for help with handling and shipping of patients\' materials and to Verónica Felício (FCUL, Lisboa) for help in the establishment of primary cultures.
Introduction Sickle cell anaemia (SCA) is caused by a mutation in the β globin gene. Sickle haemoglobin (HbS) polymerises when deoxygenated, resulting in red cell membrane rigidity and surface protein modifications that subsequently contribute to vaso-occlusion. SCA is seldom symptomatic in the first six months of life. One main explanation lies in the sustained level of foetal haemoglobin (HbF) and F cells during this period (Maier-Redelsperger et al., 1994) preventing HbS polymerisation (Nagel et al., 1979). However, infra clinical vaso occlusion, particularly in the spleen, occurs at a very early age (Rogers et al., 2011) and the absolute reticulocyte count is already elevated in the first semester of life, arguing for the very early onset of haemolysis despite high HbF levels (Meier et al., 2013, 2014). Furthermore, increased evidence supports that HbF elevation during hydroxycarbamide therapy is insufficient to explain the drug\'s beneficial effect (Segel et al., 2011). In fact, it is now considered that abnormal red blood cell (RBC) adhesiveness in SCA through activation, sustained or increased expression of adhesion molecules is pivotal in the genesis of vaso occlusive crisis, the hallmark of SCA (Hebbel et al., 1980). In this study, we analysed the expression pattern of 9 adhesion molecules on both reticulocytes and mature RBCs in SCA and non-SCA very young infants. These markers are known surface molecules, which allow characterisation of erythroid maturation and/or which are adhesion molecules demonstrated to play an important pathophysiological role (Cartron and Elion, 2008). Our objectives were to gain insight into very early pathophysiology by evidencing distinct profiles specifically attributable to SCA.