Endogenous bone marrow stem cell mobilization in rats: Its potential role in homing and repair of damaged inner ear

Abstract

The stem cells are widely used in the last few years in different fields of medicine, either by external transplantation or endogenous mobilization, most of these studies are still experimental on animals; few were tried on humans as in the spinal cord injury or myocardial infarction. As regards its use in the inner ear, stem cell transplantation was examined in many previous studies, while the mobilization idea is a new method to be experimented in inner ear hair cell regeneration.The aim of this work was to assess the use of GCSF to induce bone marrow SC mobilization to home and repair the damaged inner ear hair cells in rats after the damage had been inflicted by Amikacin injection.First we had to develop an animal model for damaged inner ear, so we used the well known ototoxic effect of Amikacin intra-tympanic injection till we reached complete loss of hearing function. And this can be assessed by DPOAEs. Now we have an animal model of damaged inner ear hair cells and mobilization of bone marrow SCs was induced by subcutaneous injection of G-CSF for 5days.Clinical assessment was done using DPOAEs before and after G-CSF injection also histological assessment of the inner ear was done before and after G-CSF by two methods H&E staining and Scanning Electron Microscopy.The results of histological examination of the specimens showed some promising changes that may be responsible for the improvement of hearing function in some rats that was detected by OAEs.