The Distribution Of FoxO3α In The Brain Of Alzheimer’s Rats

Alzheimer’s disease (AD) commonly knowns as Presenile dementia，which ischaracterized by the accumulation of senile plaques (SP), which are predominatelycomposed of the short amyloid-peptide (A β),and neurofibirllary tangles(NFT),which are composed largely of hyperphosphorylated tau protein. AD as animportant type of the Age-related diseases, is a progressive degenerative disease ofthe central nervous system(CNS).Currently,there are several hypotheses regardingthe etiology of AD, but none has been confirmed.Fox transcription factors are a class of protein molecules that regulate genesexpression, which control the development, differentiation, metabolism of the bodyby regulating the expression of target genes. FoxO3a is a presence of the mammalwhich regulates target genes upon biological functions such as anti-oxidative stress,regulate apoptosis. FoxO3a is very likely to have an impact on AD.Ourexperiments checked the FoxO3a’s distribution in the brain of AD rat.We divided the rats into two groups,AD group and NC group,and used D-gal andAlCl3to build model for two months.The weight,food intake,open field and MorrisWater Maze confirmed that the two groups had extremely significant differences onthe ethology(P<0.01).silver staining,tau and Aβ’s immunohistochemistry confirmedthe two groups had marked distinctions on the histology(P<0.01).The FoxO3a immunoreactive reaction was distributed in the cortex,hippocampus, hypothalamus lateral nucleus, parafascicular nucleus and septalnucleus.In the cortex,immunoreactive reaction was mainly distributed in externalpyramidal layer and internal pyramidal layer, and positive cells of AD group wereround or pear-shaped with the positive substances positioning cytoplasmic, darkercoloring; while in the control group, the cells were cone-shaped or triangular,withfew positive material in the nucleus,lighter coloring. In the thalamus andhypothalamus nuclei, the AD group positive cells were in larger quantities, roundor triangular, and positive material was evenly distributed in the cytoplasm; while small number of positive cells were in the control group, positive material locatedin the nucleus, lighter color. In the hippocampus,FoxO3a immunoreactive reactionwas mainly distributed in the CA1and CA2pyramidal layers. AD group positivecells were tapered with positive material in the cytosol.Furthermore, many cavitiesin those areas suggested that lots of cells dead in the region. While the controlgroup was significantly weaker coloring, with normal cell morphology and sizeround and triangular, a small amount of positive material distribution in the nucleus.The optical density statistics showed that FoxO3a expression of the AD group inthe cortex (P<0.05), CA1area (P<0.01) and CA2area (P <0.05) was significantlyenhanced in compared with the control group.FoxO3a gene’s changes of expression in the brain of AD groups, suggest thatFoxO3a has very close relationship with AD. FoxO3a may protect cells fromoxidative stress and affect the regulation of apoptosis by regulating the expressionof target genes, thereby affecting the aging process and the formation of AD.