OBJECTIVETo detect the expression of signal transducer and activator of transcription 3 (STAT3) and P-STAT3 in the brain of the APPswe/PS δE9 double transgenic mouse model of Alzhaimer's disease (AD) and investigate their possible role in AD.

METHODSAPPswe/PS δE9 double transgenic mice and control mice were examined for cerebral STAT3 and P-STAT3 expressions using immunothistochemistry.

RESULTSSTAT3 and P-STAT3 were expressed in the different regions of mouse brain. In the transgenic mice and the control mice, the positivity rates of STAT3 were 93.75% and 87.50% in the cerebral cortex, 87.50% and 43.75% in the basal forebrain, 81.25% and 37.50% in the hippocampus, and 62.50% and 0.00% in the cerebellum, respectively, showing significant differences between the mice in the STAT3 expressions in the basal forebrain, hippocampus and cerebellum (P<0.05). The positivity rates of P-STAT3 in the two groups were 0.00% and 0.00% in the cerebral cortex, 68.75% and 0.00% in the basal forebrain, 62.50% and 12.50% in the hippocampus, and 43.75% and 0.00% in the cerebellum, respectively, showing also significant differences in the basal forebrain, hippocampus and cerebellum (P<0.05). The expression of STAT3 was positively correlated with that of P-STAT3 in transgenic AD mice (P<0.05).

CONCLUSIONSTAT3 and P-STAT3 are highly expressed in the basal forebrain, hippocampus and cerebellum in transgenic AD mice and may participate in the pathological process of AD.