Rheumatoid arthritis (RA) and osteoarthritis (OA) are the common joints disorder in the world. Although they have showed the analogous clinical manifestation and overlapping cellular and molecular foundation, the pathogenesis of RA and OA were different. The pathophysiologic mechanisms of arthritis in RA and OA have not been investigated thoroughly. Thus, the aim of study is to identify the potential crucial genes and pathways associated with RA and OA and further analyze the molecular mechanisms implicated in genesis. First, we compared gene expression profiles in synovial tissue between RA and OA from the

Necrosis of the femoral head (NFH), a severe orthopedic disease in adults, involves the collapse of the femoral head. The pathophysiological mechanisms underlying NFH are yet to be fully investigated. The aim of the present study was to identify potentially important genes and signaling pathways involved in NFH and investigate their molecular mechanisms. Gene expression profiles of patients with NFH and healthy controls were compared using the Gene Expression Omnibus (GEO) database repository of the National Center of Biotechnology Information. GSE74089 from the GEO database included 4 patients with NFH and 4 healthy individuals. A total of 1,191 differentially expressed genes (DEGs) were identified between the patients with NFH and controls, including 743 upregulated and 448 downregulated DEGs. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that upregulated DEGs were mainly involved in the phosphoinositide 3-kinase/protein kinase B signaling pathway, focal adhesion and extracellular matrix-receptor interactions. Additionally, protein-protein interaction (PPI) analysis identified the most central DEGs as vascular endothelial growth factor A, Jun proto-oncogene, cyclin D1, fibroblast growth factor 2, HECT domain and ankyrin repeat-containing E3 ubiquitin protein ligase 1, protein kinase Cα, bone morphogenetic protein 2 and prostaglandin-endoperoxide synthase 2. PPI analysis also identified guanine nucleotide-binding protein, γ13 as the most commonly downregulated gene based on different centrality. The results of the present study may provide novel insight into the genes and associated pathways involved in NFH, and aid the identification of novel therapeutic targets and biomarkers in the treatment of NFH.