The Change Of NAMPT Expression In The Brain Of AD Rat

Alzheimer’s disease (AD) is also called senile dementia, the main pathologicalfeatures is extracellular clumped beta amyloid protein (Aβ) deposit formationsenile plaque and intracellular Tau protein excessive phosphorylation form neuronsfiber entanglement (NFT). AD as an important type of the Age-related diseases, is aprogressive degenerative disease of the central nervous system. At present, thecauses of AD have many statements, but till have no unified opinion. Nicotinamidephosphoric acid RNA transferase (NAMPT) is a functional protein which has manyvariety of biological activity in the vertebrate body. NAMPT decided thenicotinamide adenine dinucleotide’s(NAD’s) level in the very great degree, andaffect many physiological and biochemical process, and it depends on the level ofthe NAMPT gene expression. Study proves that NAMPT is the rate-limitingenzyme of the NAD salvage synthesis pathway in the mammals. Our experimentcheck the Nampt’s distribution changes in the brain of AD through establishing theAD model.Divide the rats into two groups,AD group and NC group, use the D-gal andAlCl3to build model for two months. The weight, food intake, open field andMorris Water Maze confirm the two groups have extremely significant differenceson the ethology(P<0.01). Silver staining,tau and Aβ’s immunohistochemistryconfirm the two groups have extremely significant differences on thehistology(P<0.01). The experimental model better simulate the behaviour andpathological characteristics of the AD.The Nampt’s immunohistochemistry shown that it mainly distributed in thecortex and the Hippocampus of the rats. In the cortex, Nampt’s immune stainingmainly distributed in the first somatosensory cortex, the positive cells areroundness or pyriform, but the cells in the AD groups are irregular form, volumereduction, the positive substances mainly located in the cell nucleus; In the NCgroups, cells’ morphology and volume are both normal, the positive substances lessand uniform distributed in the cytoplasm. In the Hippocampus,Nampt’simmunoreaction mainly distributed in the Hippocampus molecular layer andvertebral layer. In the molecular layer, AD groups’ cells are almost irregular form, volume reduction, and have cavity around, the positive substances mainly locatedin the cell nucleus, and uneven distributed; In the NC groups, cells’ morphologyand volume are both normal, are roundness or oval, and the positive substancesuniform distributed in the cytoplasm. In the vertebral layer, AD groups’s cellsarrange confusion and loose, the cell nucleus almost disappeared, and became thecavity, the positive substances almost have no expression; The NC groups’s cellsarrange orderliness and compactness, the nucleus and the nucleolus are intact, themorphology normal, the positive substances mainly located in the cytoplasm. Thestatistice shown that compare with NC groups, the Hippocampus’ cell number invertebral layer’s CA1, CA2and CA3areas are all decrease obviously(P<0.01).Nampt gene’s change of expression in the brain of AD model groups, point outthat Nampt have very close relationship with AD, Nampt may affect Sirtuinsactivity through control the cells and organism’s NAD level, than affect theproduction of ROS and the expression of antioxidant enzyme in the cells, finallyaffect the senescence’s progress and promote the formation of AD.