Protective Effect of Liraglutide on Hypoxia and High Glucose-induced Oxidative Stress Injury in Cardiomyocyte / 中国药师

Objective:To explore the effects and possible mechanism of liraglutide on hypoxia and high glucose-induced oxidative stress injury in cardiomyocytes. Methods:The neonatal rat cardiomyocytes were separated and cultured in vitro. The hypoxia and high glucose-induced injury model was established in neonatal rat cardiomyocytes. The cells were divided into six groups:the normal control group, liraglutide control group, hypoxia and high glucose model group, liraglutide treatment group, GLP-1R antagonist group and hyperosmotic control group. The metabolic ability of the cells was detected by MTT assay, the activities of LDH and CK-MB were detected by colorimetric method,SOD activity and MDA content were determined by xanthine oxidase method and thiobarbituric acid method,ROS level was measured by chemiluminescence method. The mRNA and protein expression of adaptor protein p66Shc was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Results:Compared with those in the normal control group, the cells in hypoxia and high glucose model group had poorly metabolic ability,the content of LDH, CK-MB, MDA and ROS increased (P < 0.01), the activity of SOD decreased (P <0.01), and the expression of adaptor protein p66Shc greatly increased(P <0.01). After the treatment with liraglutide,the above mentioned parameters were all improved(P < 0.01). Exendin(9-39),an antagonist of GLP-1R,attenuated the protective effect of liraglutide. Conclusion:Liraglutide has a protective effect on cardiomyocytes by down-regulating adaptor protein p66Shc expression and reducing ROS formation.

Expression of Adaptin-2 in Different Stages of Mouse Cochlea / 听力学及言语疾病杂志

Objective To investigate the expression of adaptin-2(AP-2) in different stages of mouse coch‐lea and its probable role in the auditory generation and formation .Methods Mice were divided into 4 experimental groups by age (7 days old ,15 days old ,35 days old ,16 months old) ,which respectively represented the newborn mice ,developmental mice ,mature mice and old mice .Auditory brainstem response (ABR) ,laser scanning confocal microscopy (LSCM) ,immune-fluroscence histochemistry and qRT - PCR were used in this study .Results For the 15 days old ,35 days old ,16 months old groups ,ABR average threshold was 18 .67 ± 1 .21 dB nHL ,13 .83 ± 1 .47 dB nHL ,37 .83 ± 7 .68 dB nHL ,respectively ,for the 7 days old groups no responses were observed .The AP-2 im‐munoreactivity was found in all the stages of mice cochlea inner hair cell (IHC) cytoplasm ,especially in IHC basal part ,nearby the ribbon synapse .For the 7 days old ,15 days old ,35 days old ,16 months old groups ,immune-flu‐roscence histochemistry IMV(intensity mean value)were 190 .91 ± 17 .27 ,494 .06 ± 27 .63 ,838 .41 ± 38 .23 ,682 .65 ± 72 .22 ,respectively .For the 7 days old ,15 days old ,35 days old ,16 months old groups ,mRNA RQ(relative quantity)were 0 .53 ± 0 .09 ,1 .03 ± 0 .02 ,1 .00 ± 0 .09 ,1 .03 ± 0 .06 ,respectively .Developmental mice expressed significantly higher than those of the newborn in the AP -2 protein expression level which was measured by immuno -fluores‐cence histochemistry and qRT PCR(P 0 .05) ,but mature mice had significant advantages by immuno-fluorescence histochemistry .Conclusion AP-2 protein expression level may closely related to the au‐ditory formation and maintenance because its expression gradually increases with age in mice .