Background: It has been suggested that cytokines, particularly TNFα, may play a role in the pathophysiology of Bipolar Disorder (BD). There is some evidence that TNFα regulates specific apoptotic cascades which can be related to the cell loss that has been detected in brains of BD patients. Here we report that another member of the TNFα family, TNFSF10, also known as TNF-related apoptosis-inducing ligand (TRAIL), may also be associated with BD.
Methods: We obtained the genes differently expressed in BD postmortem studies in the online database of twelve microarray studies from the Stanley Foundation. All data was downloaded and a relational (MySQL) database was constructed. To combine differentially expressed genes coming from different studies, we used a rank aggregation technique implemented by R statistical software. This tool allowed us to find a list of genes that were the most significantly altered in BD using information from all studies and taking into account the p value and fold from each gene in each study.
Results: From an initial pool of 8471 in the database of Stanley Foundation, we found the 50 genes mostly altered in these microarray studies and the TNFSF10 was the most significant one.
Conclusions: By means of data mining and using meta-analysis technique it was possible to find that TNFSF10 was the most significant differentially expressed gene in 12 BD microarray studies. This gene is clearly associated with apoptosis pathway, but to our knowledge this is the first report relating this specific gene with BD.