| ObjectiveSensorineural hearing loss (SNHL) is one of the most common disabilities. Hearing depends largely on hair cells (HCs) and their associated spiral ganglion neurons (SGNs), and defects in these cells produce permanent deafness. In mammalian, the cochlear HCs and SGNs do not regenerate or repair naturally following severe injury. Recently, several mammalian stem cell lines have suc-cessfully via the scala tympani, scala media and the scala vestibuli compartments transplanted into the perilymph (extracellular-like fluid, high Na+ low K+) and endolymph (intracellular-like fluid, high K+ low Na+), arrived at different posi-tions of inner ear, survived and differentiated into a variety of cell types. How-ever, It was reported that the survival rate of the cell grafts was comparatively low, the majority of transplanted stem cells may appotosis or die after trans-planted into new enviroment, it is hard to find the engrafted cells integrate into the cochlea epithelium and differentiate into new hair cell via inner ear fluids, indicating that inner fluids microenviroment especially the endolymph might be an challenging factor of transplanted cells survival. Moreover, until recently, the effect of inner ear fluids especially endolymph on the engrafted cells is still un-clear. In our experiment, we observated the inner ear lymphatic simulation envi-roment how affects the fates of NSCs in vitro culture experimental study and ex-plore high K+ how affect the survival and apoptosis feature of NSCs.Methods:1.Isolation and identification of neural stem cells derived from the olfactory bulb.We obtained the neural stem cells from the olfactory bulb of E12.5-14.5 SD rats embryos, observed the survival and passage ability, and then identified of neural stem cells derived from the olfactory bulb2. This study was designed to firstly investigate the effect of artificial endo-lymph and perilymph on neural precursor cells(NPCs) from the aspect of survival and apoptosis features.We had obtained and culture NSCs from olfactory bulb at the embryonic day 12.5–14.5 and prepare artifical PL, artifical EL. Then NSCs were exposed to artifical PL and artifical EL medium 24h and observed the changes.3. This study was designed to investigate the effect of artificial endolymph with altering potassium concentration medium on neural stem cells(NSCs) from the aspect of survival and apoptosis features.5mM, 30 mM, 50 mM, 70 mM, 150 mM potassium concentration of artifi-cial endolymph like solution cultured NSCs 24h consecutively. Cell viability, apoptosis rate and morphology changes were observed.Results:1.NSCs can obtained from olfactory bulb neural stem cells of SD rats em-bryos, the cell spheres in vitro culture, survived well and were stained nestin positive. 2. The cell viability and survival rate of NSCs of artificial EL medium was lower than artificial PL solutions medium. Also, most of cells were late apoptotic and necrotic cells in artificial EL medium .3. The results indicated that under the condition of 150mM and 70 mM po-tassium concentration solutions medium, the cell viability and survival rate of NPCs was lower than 5 mM and 30 mM potassium concentration solutions. Also, most of cells were late apoptotic and necrotic cells.Conclusion:1. These indicated that those cells were stained with neural stem cells marker. They hold the self-renewal ability and could generate daughter cells through asymmetric cell divisions.2. The endolymph is a challengeing environment for engraft stem cells.3. The high potassium concentration of endolymph might play an unex-pected role in the aspect of survival and apoptosis of transplanted stem cells and neural progenitor cells into inner ear. |
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