Differential Proteome Analysis Of Temporal Lobe In Patients With Alzheimer’s Disease And Normal Older Adults Using The ITRAQ Technique

Objective： Alzheimer’s disease (Alzheimer’s Disease, AD) is the most commondementia, accounting for about55%of dementia, which is characterized by thepathological senile plaques caused by extracellular β-amyloid deposits andneurofibrillary tangles caused by hyperphosphorylated the tau protein within the cell.Their common deposition sites are such as the hippocampus, frontal and temporal lobes.Aging brain and AD has overlapping pathology and biochemical changes. Applicationof proteomics technology anlayzes the composition and expression of proteins withincells from an overall perspective, which will help filter out the molecular markers forearly diagnosis of AD, even some becoming molecular target of drug design.To make the foundation of the progressive mechanism research of the AD, westudied the differential proteins between Alzheimer’s Disease (AD) individuals andnormal older adults of temporal lobe.The main parts:12cases of human temporal lobe in autopsied individuals wereobtained through the Tissue Bank for the Institute of Geriatrics, Chinese PLA GeneralHospital and divided into two groups: normal older adults (n=6) and Alzheimer’sdisease individuals (n=6).1We chose the samples of normal older adults and samplesof AD by HE and immunohistochemistry(IHC) stain. Combing the clinical diagnosiswith the pathological diagnosis, we divided into two groups.2We carried out theisobaric tags for relative and absolute quantitation (iTRAQ) coupled withtwo-dimensional liquid chromatography-tandem mass spectrometry (2D LC-MS/MS) toidentify proteins in AD individuals versus the normal older adults in the temporal lobetissues of human. We identified the main differential proteins through the bioinformatics analysis and analyzed the influences of differential proteins in ADprogress.Results: There are3071proteins identified in the temporal cortex of normal olderadults and AD patients. Among the3071proteins identified, a total of146proteins weredifferentially expressed in AD patients versus normal older adults. Compared with thenormal older adults,62proteins were up-expressed and84proteins decreased. Wecomparatively analyzed the total146differential proteins using the bioinformaticsanalysis and identified7proteins related with AD progress （p=7.8E-3), which weremitogen activated protein kinase-1(MAPK-1)、nicotinamide adenine dinucleotide [H](NADH, subnitⅥ、subnitⅩ) and cytochrome c oxidase (COX, subnitⅠ、subnitⅡ、subnitⅢand subnitⅣ). The expression of MAPK-1in AD group was1.473times of thatin normal older adults. The iTRAQ proteomic analysis showed that protein expressionof AD group was1.57times of that in the normal older adults. The same results provedthe good reliability and accuracy of proteomes.Conclusions: Through the technique of iTRAQ, we select some differentialproteins related with AD, quickly and effectively, which may provide the basic data forthe pathophysiological mechanism of AD, effective prevention or therapeutic moleculartargets for AD. The purpose of this paper is to study the similarities and differences betweennormal aging and Alzheimer’s disease(AD) in the cerebellar structure. The20caseswere divided into three groups: middle-aged, normal aging and AD in autopsied humancerebellar tissues. Nissl staining was used to measure the changes of the number ofgranular cells and the thickness of cerebellar cortex.Immunohistochemistry(IHC) wasused to measure the number changes of glial fiber acidic protein (GFAP) immunestaining astrocytes and calbindin-D28K(CB) immune staining Purkinje cells(PCs).Results showed that significant decreases were observed in the thicknesses of themolecular, granular and total cerebellar cortex as well as in the densities of granular andPurkinje cells(PCs) in normal aging individuals compared with middle-aged individuals（p<0.05）. while the number of astrocytes was significantly increased in normal agingindividuals compared with middle-aged individuals. The comparison between AD andnormal aging individuals demonstrated significantly decreased thicknesses of themolecular and total cerebellar cortex(p<0.05) and an increase in the number ofastrocytes in the AD individuals. Our results demonstrate that processes of normal agingand AD do impact cerebellum structure. mainly manifested in the decrease of thenumber of PCs and granular cells, and the increase of the number of astrocytes.