Research reportInterfering effect and mechanism of neuregulin on experimental dementia model in rats

Objective: To investigate the effect of neuregulin 1β (NRG1β) on the neuronal apoptosis and the expressions of Bcl-2 and Bax proteins in experimental dementia model rats. Methods: Thirty adult healthy male Wistar rats were randomly divided into control group, model group and treated group consisting of 10 rats, respectively. The experimental dementia models were established by injecting beta-amyloid protein 1-40 (Aβ1-40) stereotactically into the left lateral ventricle, and treated by injecting NRG1β into right lateral ventricle. The cognitive capacity of rats was evaluated with Y-electric maze. The neuronal apoptosis was counted by TUNEL assay. The expressions of Bcl-2 and Bax were determined with immunohistochemistry assay and double immunofluorescence labeling. Results: The cognitive ability in model group rats decreased, along with the number of neuronal apoptosis and the expressions of Bcl-2 and Bax increased significantly than those in control group (P < 0.05). After treatment with NRG1β, the cognitive ability of rats improved, the number of neuronal apoptosis reduced and the expression of Bcl-2 increased while Bax decreased significantly than those in model group (P < 0.05). Conclusion: NRG1β could inhibit neuronal apoptosis by regulating the expressions of Bcl-2/Bax to improve the capacity of learning and memory in experimental dementia rats.

The expression of Bcl-2 (4A) and Bax (4B) proteins are shown in the same cell (4C) in treated group with double immunofluorescence (FITC and CY3) staining × 400, scale bar is 25 μm.241