ETS-Domain Transcription Factor Elk1 is Critical for Embryo Implantation via Regulatory Control on Superoxide Dismutase 1 (SOD1) .

Mitogen Activated Protein Kinase (MAPK) signaling is one of the decisive pathways in regulating embryo-uterine interactions. Ras-MAP Kinase activation is effected by ETS family proteins; ELK1, being the first member of the Ternary Complex Factor (TCF) family, is rapidly activated by ERK. Based on the significance of ETS family member in the process of embryo implantation and presence of ELK1 during embryogenesis, we hypothesized that ELK1 would also discharge its role in embryo implantation. We intend to analyze the importance of ELK1 during embryo implantation for which we have used a mouse pregnancy model system. Our results clearly document the expression of ELK1 during different days of pregnancy. ELK1 is highly activated during peri-implantation period as its expression in the nucleus is increased compared to pre-implantation stages. Elk-1 knock down leads to pregnancy failure which is attributed to changes in perforin, c-fos, Mcl-1 and Sod1. Elk-1 also decreases SOD activity which is the crucial factor controlling superoxide during embryo implantation. These results suggest that Elk-1 affects the process of embryo attachment to uterus either directly or by way of molecules that are obligatory for the process of embryo implantation.