Proliferating Cells And Their Differentiated Cells In Neonatal Mouse Cochlear Culture And Gene Expression

PARTâ… Gene expression in different stages of mouse inner ear developmentObjectives:With the help of many molecular biological techniques like Knock-out and Gene Targeting,there have been proved that around 40 genes participate in the regulation of morphogenesis of the vertebrate inner ear and the differentiation of their sensory epithilia.These genes work temporally and spatially all together for the development of inner ear.We selected some of those previously proved genes to investigate their gene expression patterns during different developing stages for the better understanding of inner ear development and hair cell regeneration.Methods:21 genes including transcription factors and secretion factors known to take part in the regulation of vertebrate inner ear development were selected.First we use RT-PCR to screen out those positive expressed genes from fresh cochlear tissues of embryonic day 18th' s mice;then we separately select mice from embryonic day 10th, 14th,18th,postnatal day 0 and 14th,use the previously method of RT-PCR to observe those gene expression patterns during different development stages of mouse inner ear.Results:Upon using RT-PCR,we got those early developing markers of mouse inner ear as Otx2,BMP4,BMP7 and Islet1,hair cell markers as Math1,myosinâ…¦a and espin,supporting cell markers as Jagged1.It shows that these early developing markers as Otx2,BMP4,BMP7 and Islet1 are down-regulated throughout different stages of inner ear development while hair cell markers as Math1,myosinâ…¦a and espin,supporting cell markers as Jagged1 are all up-regulated.Conclusions:Genes related to development like Otx2,BMP4,BMP7,Islet1,Math1, myosinâ…¦A,espin and Jagged1 can be expressed during mouse inner ear development. Those early inner ear developing markers as Otx2,BMP4,BMP7 and Islet1 showed down-regulation throughout the whole developing period,while the hair cell markers as Math1,myosinâ…¦A and espin,the supporting cell markers as Jagged1 showed upregulation. PARTâ…¡Cultivation and Gene Expression of Highly Proliferative Cells and differentiated cells from the Cochlea of Newborn MiceObjectives:To investigate if there exist highly proliferative cells in the cochlea of the newborn mice and in which way can these proliferative cells be differentiated to different cell types.To study the different gene expression patterns in these proliferative cells and further differentiated cells.Methods:After carefully dissection of the cochlear basilar membranes from C57 newborn mice,these BM tissues went on further digestion,trituration and finally came to be single cell suspension which was cultured in DMEM/F12 media containing B27 and N2 supplements.Cell spheres formed in suspension after 7 days' cultivation,then they were plated onto slides precoated for further differentiation for another fortnight. We collected those cell spheres and the differentiated cells of the 7^thand 14^thday. isolated the total RNA from these cells and went on RT-PCRs to investigate the expression patterns of those genes involed in inner ear development.Results:We found there to be existed some kind of highly proliferative cells in the cochlea of the newborn mice.These proliferative cells can be cultivated in vitro to form cell spheres and sorts of differentiated cells.The highly proliferative cell spheres can express those early inner ear developing markers as Otx2,BMP4,BMP7 and islet1 while the down-regulation can be seen in these markers throughout the cell differentiation.Also we found that the differentiated cells can express the hair cell markers as Math1,myosinâ…¦A and espin,the supporting cell marker as Jagged1 while the up-regulation can be detected in all these markers mentioned during cell differentiation.Conclusion:There exist some highly proliferative cells in the cochlea of newborn mice,and these cells can form cell spheres under in vitro cultivation and go on further differentiation to form hair cell-like cells and supporting cell-like cells. Objectives:The aim of our study was to investigate the short-term efficacy and safety of transtympanic pressure treatment using Meniett device in Meniere's disease.Methods:Eight patients with unilateral Meniere's disease according to the criteria of the Chinese Medical Association(1996)were assessed for the outcome and severity of symptoms,also for the changes of pure tone average thresholds before and after the treatment with the Meniett device.The follow-up time was 1-6 months.Results:Six out of eight patients showed improvement in hearing and reduced vertigo, out of which four patients demonstrated a significant audiometric gain of more than 10dB.Two patients who had no improvements had undergone previous surgery of endolymphatic sac decompression.There were no complications during the treatment with the Meniett device.Conclusions:According to this study,the Meniett device seems to be a minimally invasive and non-destructive treatment tool which can be used in the transtympanic pressure treatment for Meniere's disease to reduce vertigo and to improve hearing. Previous surgical vestibular intervention procedures may adversely influence the effect of the Meniett device.