Nitric oxide inhibition assay and the respective target identification of an aptamer designed to control atherosclerosis

Introduction: Aptamers are emerging newer therapeutics and diagnostics can be designed to bind any kind of target proteins. Vascular endothelial damage by the excess amount of nitric oxide production in systemic circulation leads to the secretion of inflammatory chemoattractant and cell adhesion, which is the prime pro-atherogenic events in the formation of plagues at atrial intimal layers due to oxidation – sensitive mechanisms. Nitric oxide inhibition assay is one of the valuable qualitative anti-atherosclerosis matrices. Methods: In this research, Nitric oxide inhibition efficiency of a ssDNA aptamer on cell lines was studied and the respective targets of that aptamer were identified by network analysis. The aptamer used here was originally designed for Selectin P Ligand Protein to control atherogenic process. 20 nM of aptamer solution in LipofectamineTM 2000 shows the highest level of 70.5 % inhibition of nitric oxide liberation on 24 hours cultured medium of Lipopolysaccharide stimulated murine macrophage RAW 264.7 cell lines. Results: Protein interaction network analysis on the nitric oxide synthesis pathway interactors and the molecular docking analysis with network resulted proteins such as AKT Serine/Threonine Kinase 1, Calmodulin, Estrogen Receptor 1, and Nitric Oxide Synthase-3 confirms that the G – quadruplex Model of 18-mer sequence effectively binds on the active sites of Estrogen Receptor 1, and Nitric Oxide Synthase-3. Conclusion : The aptamer designed for atherosclerotic target have also exert significant nitric oxide inhibition to control the atherogenic events through the proteins, AKT1, NOS3 and ESR1.