FOXA1 is a transcriptional activator of Odf2/Cenexin and regulates primary ciliation

Primary cilia are sensory organelles essential for embryonic and postnatal development, and tissue homeostasis in adulthood. They are generated in a cell cycle-dependent manner and found on most cells of the body. Although cilia formation is intensively investigated virtually nothing is known about the transcriptional regulation of primary ciliation. We used here Odf2/Cenexin, encoding a protein of the mother centriole and the basal body that is mandatory for primary cilia formation, as the target gene for the identification of transcriptional activators. We identified a consensus binding site for Fox transcription factors (TFs) in its promoter region and focused here on the Fox family. We found transcriptional activation of Odf2 neither by FOXO TFs nor by the core TF for multiciliation, FOXJ1. However, we identified FOXA1 as a transcriptional activator of Odf2 by reporter gene assays and qRT-PCR, and showed by qWB that Foxa1 knockdown caused a decrease in ODF2 and CP110 proteins. We verified the binding sequence of FOXA1 in the Odf2 promoter by ChIP. Finally, we demonstrated that knockdown of FOXA1 affected primary cilia formation. We, thus, showed for the first time, that FOXA1 regulates primary ciliation by transcriptional activation of ciliary genes.

Fixation of the electrode array with bone paté in cochlear implant surgery

The aims of this study are to report on our experiences using a bone paté (a mixture of bone dust and fibrin glue) fixation technique of the Combi 40/Combi 40+ electrode array during cochlear implant surgery. A retrospective study involving 57 patients implanted with Combi 40/Combi 40+ cochlear implants over 31 months fixated with bone paté was performed, utilizing our electrical fitting data as well as re-operation and X-ray findings. We found no signs of electrode retraction in any of the 57 patients. Electrical fitting data showed no reduction in the number of active channels between the first and last times patients were evaluated (a period of 4-31 months). Furthermore, a comparison of X-rays performed within the first week following cochlear implant surgery and again 7-27 months later showed no signs of electrode retraction in 10 patients. Three patients who required re-operations after implantation allowed us the opportunity to examine the effectiveness of the bone paté fixation and revealed new bone growth with the electrode fixed in place. Histological examinations of the newly built bone showed laminar and compact bone structures. The use of bone paté was thus found to be a suitable method of electrode fixation in cochlear implant surgery. Compared with other fixation methods, it is inexpensive and uses no foreign materials.