The Changes Of NIX And Mitophagy On The Hippocampus With AD Transgenic Mice

Alzheimer’s disease (Alzheimer’s disease, AD) is a kind of neurodegenerative diseases that old people easy suffered from and its main character is progressive dementia. The major clinical manifestations are cognitive impairment and memory function progressive decrease. The main pathological changes including the accumulation of senile plaque outside the cell, the (Neurons fiber tangles, NFT) inside the cell and loss of neurons in the hippocampus. Autophagy is a main metabolic pathway which mammalian cells maintain cell steady-state through degradation the long life protein and organelle in cytoplasmic and removing the damaged contents of the cytoplasm. It plays a very important role in the process of keep cells healthy, and is also important to survival in starvation. Autophagy has a positive effect to prevent some diseases such as neural degenerative disease. NIX located in the outer membrane of mitochondria, NIX can cause the increase of mitochondrial permeability, eventually lead to mitochondrial happen autophagy be cleared.LC3is a kind of phosphorus protein, the amount of LC3II can reflect whether autophagy is occurring. Mitochondrial’damage will produce excessive ROS, and in decouple united state can consume ATP, eventually lead to cell’s disorders, and even death. Mitophagy may constitute a "quality checkpoints "to maintain the mitochondria’bioenergetics and prevent age related disorders and aging, it is an important regulatory mechanism of cells to clear abnormal mitochondria, keep their normal function, genome stability and maintain their own steady state. If autophagy is insufficient,mitochondrial’motive power damaged can lead to the accumulation of damaged organelles and aging, especially the way damaged which in responsible for clearing and degradation of mitochondria; Excessive of autophagy may cause normal cells’death, so how to control this "degree" also needs to be studied. Through the regulation of cell’s autophagy level, make full use of autophagy’beneficial aspects and eliminate its disadvantages, targeted therapy mitochondria, to control the neurodegenerative diseases is expected such as the development of the AD, delay caducity and improve the quality of life. Objective Research the changes of NIX-Mito, mitophagy on the hippocampus with AD Transgenic mice, as so to discuss the mitophagy’possible role in the AD.Methods Study the wild-type and the mutant of the AD Transgenic mice:observe the change of memory by the Morris water maze, detect the change of the structure of the hippocampus via the congo red,silver staining, study the change of apoptosis protein NIX and the LC3by immunohistochemistry, stereology measurement analysis the Bielschowsky silver dyeing, Congo red stain positive matter respectively to the grid of every small division1.5cm×1.5cm,0.5cm×0.5cm, detect the change of LC3-Mito, NIX-Mito’fluorescence intensity and the numble of mitochondria in which NIX is located, mitophagy on the hippocampus via the confocal laser scanning microscopy.Results (1)The median of escape latency of the wild-type and the mutant are29.00s and38.00s, statistically significant indifferences,P>0.05; The search strategy compared between the wild-type and the mutant showed a decreased use of strategies, statistically significant differences, P<0.05;(2)The median of NIXTOD of the wild-type and the mutant are103.83and128.85, statistically significant differences, P<0.05; Wild-type’cells in the hippocampus are closely aligned, uniform distribution, structure are clear, the mutant’are arranged disorder, sparse, appear immune response positive things which present lots of claybank particles;(3)The median of LC3of the wild-type and the mutant are3.00and9.00, statistically significant differences, P<0.05; wild-type’cytoplasm and neurite in the hippocampus structure are immune response positive things which present claybank homogeneous shape, the mutant’are claybank granular and lots of claybank positive things gather together in blocks extracellular;(4)The average fluorescence intensity of the apoptosis proteins NIX of the wild-type and the mutant are92.18±7.81and103.07±14.94, statistically significant differences, P<0.05; The average fluorescence intensity of the Mito-Tracker Green of the wild-type and the mutant are90.10±10.17and86.87±20.51, the difference was statistically significant, P>0.05; The average number of mitochondria which NIX and mitochondria are colocalization of the wild-type and the mutant are240.94±169.47and544.18±336.44, statistically significant differences,P<0.05; Wild-type’ cells in the hippocampus are closely aligned, uniform distribution, structure are clear, appear a few red and green fluorescence coincidence present yellow particles in the cytoplasm and neurite, the mutant’are arranged disorder, sparse, appear lots of red and green fluorescence coincidence present yellow particles in the cytoplasm and neurite;(5)The fluorescence intensity of the LC3increases, the average fluorescence intensity of the wild-type and the mutant are91.69±14.69and130.89±28.90, statistically significant differences,P<0.05; The average fluorescence intensity of the Mito-Tracker Green of the wild-type and the mutant are70.29±29.72and65.05±29.06, the difference was statistically significant, P>0.05; The average number of mitophagy of the wild-type and the mutant are229.67±79.54and312.26±101.55, statistically significant differences, P<0.05; Wild-type’cytoplasm and neurite in the hippocampus structure are immune response positive things which present red homogeneous shape and a few granular, the mutant’are lots of red granular, appear lots of red and green fluorescence coincidence present yellow particles in the cytoplasm and neurite which are mitochondria happened autophagy.Conclusions (1) AD transgenic mice appear behavior and typical pathological changes,so they can be reliable model.(2) The total amount of LC3on the hippocampus with AD transgenic mice enhance, autophagy increase.(3) The number of mitochondria which LC3and mitochondria colocalization on the hippocampus with AD transgenic mice increase, mitophagy increase.(4) NIX may regulate the mitophagy.