Expressions of ubiquitin and apotosis-related protein in diabetic rat brain / 中华老年医学杂志

ABSTRACT

Objective To explore the effect of continuous hyperglycemia on learning and memory capacity in rats, and to observe the changes of expressions of ubiquitin and apotosis-related proteins, so as to provide a relative basis for diabetic encephalopathy. Methods The male SD rats were randomly divided into normal control group and diabetes mellitus (DM) group. The DM rats was made by intraperitoneal injection of streptozocin (STZ). The capacities of learning and memory were tested by Y-maze. The structure changes in frontal lobe cortex and hippocampus were observed by Nissl's staining and immunohistochemistry. The apoptosis cell count was measured by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The expressions of Bcl-2 and P53 were assessed by Western-blot analysis. The expression of ubiquitin mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR). Results In DM rats, the learning and memory capacities were worse than in control rats (P＜0. 05), and the apoptosis cell counts in frontal lobe cortex and hippocampus were higher than in control rats, the expression of Bcl-2 gene was reduced while the expressions of ubiquitin and P53 gene were increased (P＜0. 05). Conclusions In the frontal lobe cortex and hippocampus, the expression of Bcl-2 gene is reduced while the apoptosis cell numbers and ubiquitin P53 gene expression are increased, which may contribute to neurodegeneration in DM rats.