Further, a significant enrichment of regulated genes involved in transcription regulator activity and response to hypoxia was observed. The regulation of genes involved in these processes is suggested to lead to adaptive changes, which allow the cell to gain more energy and lead to the delivery of oxygen. Interestingly, we could not identify an accumulation of hypoxia-regulated genes involved in inflammation, although hypoxia in adipose tissue is suggested to lead to a chronic inflammatory state. Of note, white adipose tissue consists of different cell types, such as preadipocytes, macrophages, endothelial cells, fibroblasts and leukocytes, which all contribute to the production and release of cytokines. It is also suggested, that the response to hypoxia differs depending on the cell type and the tissue environment. Therefore, the contribution of adipocytes to the total amount of secreted factors from adipose tissue in vivo which lead to a chronic inflammation is not fully understood. From the large number of hypoxia-regulated transcripts, nine genes were found to be differentially expressed after all time periods of hypoxia investigated in our microarray study. Our findings in SGBS adipocytes are consistent with Niraparib previous reports observed in other cell types. As the SGBS cells, used for this study have been proven in several human adipocyte biology studies to have characteristics very similar to adipocytes we consider our findings also relevant for adipocytes in general. VEGF is essential for the development of the vascular system and promotes angiogenesis and also ADM has been shown to induce angiogenesis. Both, the growth of adipose tissue and hypoxic conditions require the development of the vascular network. Concentrations of serum VEGF have been described to positively correlate with body mass index and body weight reduction led to a decrease in VEGF circulating levels. This angiogenic factor has also been suggested to be involved in the development of the comorbidities associated with obesity. Furthermore, plasma concentration of the antiadipogenic factor ADM increases with obesity, the incidence of type 2 diabetes, cardiovascular diseases and inflammation. The expression of ADM and DDIT4 in adipocytes, which is induced in response to different situations of cellular stress is in addition to hypoxia also regulated by insulin and in terms of DDIT4, whose overexpression may participate to the development of insulin resistance, depends on the transcription factor HIF-1. Further, also KDM3A has been described as a regulator of genes involved in energy expenditure and fat storage. Therefore, these identified genes may play a crucial role in the regulation of obesity and the metabolic syndrome. The remaining hypoxia-regulated genes that were identified are involved in different cellular functions: protein-protein interaction and signalling, glycolysis, glucogen accumulation which is suggested as metabolic longterm adaption to hypoxia, and regulation of transcription. The function of WD-repeat proteins differs from signal transduction, regulation of transcription, and apoptosis, but the function of WDR73 still remains unknown.