Induction of p73, Δ133p53, Δ160p53, pAKT lead to neuroprotection via DNA repair by 5-LOX inhibition.

The inflammatory process plays a key role in neurodegenerative disorder. The inflammatory molecule, 5-lipooxygenase (5-LOX), protein is involved in the pathologic phenotype of AD which includes Aβ amyloid deposition and tau hyperphosphorylation. This study aims to identify the mechanistic role in neuroprotection by 5-LOX inhibitor in neurotoxic SH-SY5Y cell line model by evaluating different cell survival pathway. The neurotoxic SH-SY5Y cells were developed by the treatment of Aβ25-35. The cells were then treated with 5-LOX peptide inhibitor, YWCS to prevent neurotoxicity reported earlier from our lab. The effect of 5-LOX inhibition on cell survival pathways were determined by western blot experiment with different doses of peptide by using polyclonal anti body of p53, anti-Akt and anti-phosphorylated Akt. Immunoprecipitation and mass spectroscopic studies were done to identify the altered proteins appeared on the blot. Over expression of phosphorylated Akt and 3 bands on p53 lane blot other than p53 were observed. Three bands were identified as isoforms of p53 which correspond to p73, Δ133p53 and Δ160p53 in the cells treated only with 80 µM of YWCS compare to untreated cells. However, no alteration of total p53 and Akt were observed in treated cells. The results exposed the novel mechanistic pathway of neuroprotection by 5-LOX inhibition is likely to be mediated by DNA DSB repair through p53 isoforms and PI3K/Akt pathway. Our finding has opened a new window in the therapeutic approach for the prevention of AD.