Changes of TRIM16 expression in hippocampal neurons apoptosis of rats with cognitive dysfunction in type 2 diabetes mellitus / 中国生化药物杂志

ABSTRACT

Objective To study the relationship between the changes of TRIM16 in hippocampus of type 2 diabetic rats induced by streptozotocin (STZ) and cognitive dysfunction and apoptosis of hippocampal cells.Methods The male Sprague-Dawley (SD) rats of 8 weeks old were randomly divided into diabetic group (DM group) (n=25) and normal control group (NC group) (n=15).NC group were given normal feed, DM rats were fed with high glucose and high fat diet,followed by low dose of STZ (25 mg/kg, intraperitoneal injection), induced compensatory secretion of insulin, five days after the detection of tail vein blood glucose>16.7 mmol/L, and established the STZ.Meanwhile, citric acid buffer was injected to rats in group as control.After successful modeling, the rats in the two groups were fed with 17 weeks.Morris water maze test was used to detect the cognitive function of the two groups of rats.The protein expression of TRIM16, Bax and Bcl-2 protein in fresh hippocampus tissue of DM group and NC group rats was detected using western blotting.Rats in DM group and NC group were perfused with brain, and the hippocampal tissues were stained with immunohistochemistry.TUNEL method was used to detect the apoptosis of hippocampus cells.ResultsCompared with NC group, morris water maze test showed that the escape latency of rats in DM group is longer than NC group, staying at the original platform quadrant time in DM group is less than the NC group.TUNEL assay showed that after injection of 17 weeks, hippocampal CA1 pyramidal cells in type 2 diabetic rats appeared obvious apoptosis, positive neurons in the nuclei were brown, karyopyknosis anachromasis, while control group of neurons in the nucleus without brown coloring.Compared with the NC group, hippocampus immunohistochemistry results showed that the protein of TRIM16 in hippocampus CA1 region of type 2 diabetic rats was increased, cytoplasm brown, coarse granular.Compared with the NC group, the expression of Bcl-2 had no obvious change in hippocampus of type 2 diabetic rats at 17 weeks, while the expression of TRIM16, Bax and the ratio of Bax/Bcl-2 was significantly increased (P<0.05).Conclusion The protein expression of TRIM16 using immunohistochemical and Western blotting in hippocampus of diabetic rats induced by STZ was increased.There is apoptosis in hippocampus of diabetic rats induced by STZ, the expression of Bcl-2 was not significantly changed, the expression of Bax and the ratio of Bax/Bcl-2 were significantly increased.TRIM16 is involved in diabetic cognitive dysfunction by promoting apoptosis of diabetic rat hippocampus.