Protein-Protein Interaction Analysis of Common Top Genes in Obsessive-Compulsive disorder (OCD) and Schizophrenia: Towards New Drug Approach

Comorbidty is common among psychiatric disorders including obsessive-compulsive disorder and schizophrenia with a high rate. Many studies suggested that the disorders may have same etiological bases. In this regard, shared pathways of glutamate, dopaminergic, and serotonin are the known ones. Here, the common significant genes are examined to understand the possible molecular origin of the disorders in terms of sequence and functional features. Exploring the underling mechanisms of OCD and schizophrenia is important to achieve a better treatment options. Methods of Cytoscape software following R statistical software were applied for this purpose. Needleman-Wunsch global alignment algorithm was used to determine pair-wise similarities followed by clustering methods, AGNES and PAM in R statistical programming software. The results indicate that ten genes are significantly common for the two disorders and PPI network analysis showed the important key genes in the interaction profile. ESR1 (estrogen receptor α) as a key hub-bottleneck gene regulates many underling mechanisms of the brain. Application of global alignments indicates some of the genes with sequence similarities also elucidate similar biological terms. It seems that evaluation of gender and OCD subtype in schizophrenia patients is another important feature that may elucidate the role of ESR1 in the comoribidty.