Research on changes in cognitive function, β-amyloid peptide and neurotrophic factor in stroke patients.

OBJECTIVE: To investigate the changes as well as the related mechanism in cognitive function and levels of serum β-amyloid peptide (Aβ) and brain-derived neurotrophic factor (BDNF) in stroke patients.

PATIENTS AND METHODS: A total of 30 patients with acute stroke treated in our hospital from June 2015 to September 2016 were selected as stroke group, while 30 volunteers during the same period were enrolled as control group. Changes in cognitive function of patients were evaluated using the Montreal Cognitive Assessment (MoCA) and mini-mental state examination (MMSE) before and after the treatment. At the same time, the concentrations of serum Aβ1-40 and BDNF were detected, and their correlations with the MMSE score were analyzed. Finally, levels of serum cyclic adenosine monophosphate (cAMP) and phosphorylated-cAMP-response element binding protein (p-CREB), and the phosphorylation level of Tau protein were detected by Western blotting.

RESULTS: MoCA and MMSE scores of patients in stroke group were significantly lower than those in control group (p < 0.01), and the scores were significantly higher in stroke patients after treatment than those before treatment (p < 0.01). Compared with those in control group, the serum Aβ1-40 concentration in patients in stroke group was significantly increased (p < 0.01), but the BDNF level was significantly decreased (p < 0.01). Compared with those before treatment, the serum Aβ1-40 concentration in patients was significantly decreased after treatment (p < 0.01), but the BDNF concentration was significantly increased (p < 0.01). Correlation analysis showed that the MMSE score was negatively correlated with the concentration of Aβ1-40 (r2 = 0.764, p < 0.01), but positively related to the level of BDNF (r2 = 0.827, p < 0.01). Compared with those in control group, the content of serum cAMP and p-CREB in stroke patients was significantly decreased (p < 0.01), but the expression of p-Tau was statistically increased (p < 0.01).

CONCLUSIONS: The cognitive function in stroke patients is impaired, with the rising content of serum Aβ1-40 and reduction of BDNF, the mechanism of which is related to the decrease of cAMP and p-CREB and the increase of p-Tau. This provides a theoretical basis for searching the new therapeutic targets and new drugs for stroke.