Introduction: Alzheimer's disease is the main cause of dementia among older adults. This disease was first reported by Alois Alzheimer in 1906. The most common and characteristic lesions in the patient's brain are senile neural plaques and neurofibrillary tangles. Despite the fact that science is developing rapidly, no drug or treatment for Alzheimer's disease has yet been introduced or proposed. An organism's protein-protein interaction (PPI) network serves as a skeleton for its signaling circuitry, which mediates cellular response to environmental and genetic cues. In this research, we used protein-protein interaction networks to identify and introduce important and key genes that play crucial roles in Alzheimer's disease.
Methods: In the first step, we selected the suitable access code for Alzheimer's disease through the GEO site. GEO2R (https://www.ncbi.nlm.nih.gov/geo/geo2r/) was used to screen the DEGs in Alzheimer's tumor tissues and non-tumor tissues. For analysis, p-value <0.05 and fold change (|FC|)>1 were set as the cutoff criterion to select DEGs. In the next step, using the STRING-DB.org site, the interaction network of proteins was drawn and the output file was saved in TSV format, then the output file was opened using the Cytoscape software and then, the hub genes were identified
Results: The access code selected for the study was GSE5281 with 161 samples (tumor and normal tissues). In this dataset, brain samples from three Alzheimer’s Disease Centers (ADCs) had been collected, and the expression profile was Affymetrix U133 Plus 2.0 array. The final protein interaction network that was drawn using the Cytoscape software had 188 nodes and 646 edges. among these 188 nodes, 10 main genes (CD44,NCAM1, ERBB2,PECAM1, SRC, CTLA4 ,CD28, FGF2, ,IL18,CRP) were hub genes in Alzheimer's disease
Conclusion: In this project, by the protein interaction network and Cytoscape software, 10 key genes related to Alzheimer's disease were obtained, but for further investigations, it is better that these genes are subjected to experimental tests.