ABSTRACT
Objective:To explore the effect of duck Tembusu virus infection on secretion of exosomes in BHK-21 cells and the pathogenesis of the Tembusu virus.Methods:The exosomes were collected and purified from the culture supernatant of BHK-21 cells infected with duck Tembusu virus AH-F10 strain and the control BHK-21 cells by PEG precipitation method respectively.The purified exosomes were identified by electron microscopy,Western blot assay and mass spectrometry.Results: The classical exosome particle morphology was observed with hyperchromic cup-shaped vesicles and average particle size of 30-160 nm in diameter under transmission electron microscopy.The mean size of the exosome from the infected cells were bigger than the mean size of the exosome from the unin-fected.Western blot assay demonstrated that CD9 and CD63 were detected in purified exosomes as exosome marker molecula.A total of 106 proteins were identified by mass spectrometry assay,84 proteins of infected BHK-21 cells exosome,49 proteins of the uninfected, and the infected and the uninfected BHK-21 share 27 common proteins on exosomes.Conclusion:Duck Tembusu virus infection affect the exosome secretion of cells in connection to the particle size and protein molecular composition.This experiment can lay the foundation for further research of Tembusu virus infection and pathogenesis.
ABSTRACT
The aim of the present study was to assess the ototoxicity of kanamycin sulfate (KM) in adult rats and its underlying mechanism. Forty male Sprague-Dawley rats (6-7 weeks old) were randomly divided into the experimental group and the control group. The animals in the experimental group were injected subcutaneously with KM (500 mg/kg per day) for two weeks, and the control group received equal volume of normal saline. To assess the ototoxicity of KM, the auditory brainstem response (ABR) was recorded to monitor the changes in hearing thresholds, and the density of spiral ganglion cells (SGCs) and morphology of cochlea were observed using surface preparations and frozen sections of cochlea. The results showed that the hearing threshold of rats in the experimental group was elevated by more than 60 dB across all the frequencies two weeks after the first administration of KM. And in the experimental group, the density of SGCs became lower, and organ of Corti suffered loss of hair cells. The loss of outer hair cells (OHCs) was more severe than that of inner hair cells (IHCs), correlated with the density decrease of SGCs. We conclude that the ototoxicity of KM in the adult rats was apparent and the underlying mechanism is associated with the loss of SGCs and hair cells.