[Different doses transplanted microglia effect on β-amyloid protein in rat Alzheimer's models].
OBJECTIVE
To explore the effects of different doses of transplanted microglia (MG) on β-amyloid protein (Aβ) in rat brain model of Alzheimer's disease (AD).


METHODS
A total of 60 SD rats were randomly divided into experimental group and control group. The experimental group was injected with Aβ-42 and the control group saline in hippocampus. At Day 3, different doses of continuously expressed enhanced green fluorescent protein (EGFP) microglial cells cultured in vitro were injected into the rats via carotid artery. At Day 3 post-injection, Aβ was labeled by immunofluorescent method. And the expressions of EGFP microglia and Aβ were detected in hippocampus by fluorescence. The relative brain expression of β-amyloid precursor protein (APP) mRNA was analyzed by RT-PCR (reverse transcription-polymerase chain reaction).


RESULTS
The mean fluorescent intensity of EGFP was significantly higher in each experimental group (5.62 ± 0.61, 8.85 ± 0.33, 10.24 ± 0.45, 11.26 ± 0.37, 12.75 ± 0.65) than the control group (2.22 ± 0.32, all P < 0.05); Fluorescent immunohistochemistry showed that the mean fluorescent intensity of Aβ in the 4×10(6) dose group (9.53 ± 0.23) and the 12×10(6) dose group (8.32 ± 0.46) were significantly higher than that in the 8×10(6) dose group (4.56 ± 0.13, both P < 0.05); The fluorescent regions had partial consistence of EGFP and Aβ; RT-PCR (reverse transcription-polymerase chain reaction) results showed that the relative expressions of APP mRNA in the 4×10(6) dose group (1.83 ± 0.22) and the 12×10(6) dose group (1.94 ± 0.28) were significantly higher than that in the 8×10(6) dose group (0.43 ± 0.12, both P < 0.05).


CONCLUSIONS
Aβ has the chemotactic role of MG. MG may swallow Aβ protein partially. But a high dose of MG also accelerates the formation of Aβ.
Department of Neurology, Henan Provincial People's Hospital, Zhengzhou 450003, China. Email: hy139378@126.com.
Yue
Y
Huang
Xiu-Hua
XH
Ren
Shan-Feng
SF
Zhang
Jie-Wen
JW
Zhang
D000544:Alzheimer Disease / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D017628:Microglia / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor