Identification of HIF-1α/VEGFA signaling pathway and transcription factors in Kashin-Beck disease by integrated bioinformatics analysis.

Kashin-Beck disease (KBD) is a chronic and endemic osteoarthropathy. The pathogenesis of KBD has yet to be fully elucidated, although previous studies have shown that its etiology may be associated with low selenium abundance and high exposure to mycotoxins, such as T-2 toxin. In the present study, the Comparative Toxicogenomics Database was used to identify key genes associated with KBD, T-2 toxin and selenium. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used to identify the biological processes and pathways that key genes may be associated with. By searching the Search Tool for the Retrieval of Interacting Genes database and the Molecular Complex Detection plug-in with Cytoscape, it was possible to construct a KBD-associated protein-protein interaction (PPI) network, and screen the core modules and genes. Western blot analysis was subsequently used to verify the expression levels of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor A (VEGFA), two components that are associated with the HIF-1 signaling pathway in KBD disease. Via this approach, a total of 301 key genes were identified that were associated with KBD, T-2 toxin and selenium. The results of the GO and KEGG enrichment analyses demonstrated that these key genes were mainly involved in the process of apoptosis. Previous studies have demonstrated that excessive apoptosis of chondrocytes plays a crucial role in the pathophysiology of KBD, and that HIF-1α has an important role in chondrocyte apoptosis; therefore, the present study was focused on the expression level of HIF-1α in KBD. By analyzing the PPI network constructed from the key genes, a total of 10 core genes were obtained that may be associated with KBD. The results of western blotting experiments revealed that, after treating chondrocytes with different concentrations of T-2 toxin, the expression levels of HIF-1α and VEGFA were markedly downregulated. The iRegulon plug-in for Cytoscape was used to predict the transcription factors that may regulate HIF-1α and VEGFA in the HIF-1 signaling pathway. Using this approach, 10 core genes and 15 transcription factors were obtained. These results may help to clarify the pathogenesis of KBD, thereby providing further avenues for the therapeutic treatment of KBD.